#Article 1: April (527 words)


April is the fourth month of the year, and comes between March and May. It is one of four months to have 30 days.

April always begins on the same day of week as July, and additionally, January in leap years. April always ends on the same day of the week as December.

April's flowers are the Sweet Pea and Daisy. Its birthstone is the diamond. The meaning of the diamond is innocence.

April comes between March and May, making it the fourth month of the year. It also comes first in the year out of the four months that have 30 days, as June, September and November are later in the year.

April begins on the same day of the week as July every year and on the same day of the week as January in leap years. April ends on the same day of the week as December every year, as each other's last days are exactly 35 weeks (245 days) apart.

In common years, April starts on the same day of the week as October of the previous year, and in leap years, May of the previous year. In common years, April finishes on the same day of the week as July of the previous year, and in leap years, February and October of the previous year. In common years immediately after other common years, April starts on the same day of the week as January of the previous year, and in leap years and years immediately after that, April finishes on the same day of the week as January of the previous year.

In years immediately before common years, April starts on the same day of the week as September and December of the following year, and in years immediately before leap years, June of the following year. In years immediately before common years, April finishes on the same day of the week as September of the following year, and in years immediately before leap years, March and June of the following year.

April is a spring month in the Northern Hemisphere and an autumn/fall month in the Southern Hemisphere. In each hemisphere, it is the seasonal equivalent of October in the other.

It is unclear as to where April got its name. A common theory is that it comes from the Latin word aperire, meaning to open, referring to flowers opening in spring. Another theory is that the name could come from Aphrodite, the Greek goddess of love. It was originally the second month in the old Roman Calendar, before the start of the new year was put to January 1.

Quite a few festivals are held in this month. In many Southeast Asian cultures, new year is celebrated in this month (including Songkran). In Western Christianity, Easter can be celebrated on a Sunday between March 22 and April 25. In Orthodox Christianity, it can fall between April 4 and May 8. At the end of the month, Central and Northern European cultures celebrate Walpurgis Night on April 30, marking the transition from winter into summer.

Poets use April to mean the end of winter. For example: April showers bring May flowers.




#Article 2: August (448 words)


August (Aug.) is the eighth month of the year in the Gregorian calendar, coming between July and September. It has 31 days. It is named after the Roman emperor Augustus Caesar.

August doesn't begin on the same day of the week as any other month in common years, but begins on the same day of the week as February in leap years. August always ends on the same day of the week as November.

This month was first called Sextilis in Latin, because it was the sixth month in the old Roman calendar. The Roman calendar began in March about 735 BC with Romulus. October was the eighth month. August was the eighth month when January or February were added to the start of the year by King Numa Pompilius about 700 BC. Or, when those two months were moved from the end to the beginning of the year by the decemvirs about 450 BC (Roman writers disagree). In 153 BC January 1 was determined as the beginning of the year.

August is named for Augustus Caesar who became Roman consul in this month. The month has 31 days because Julius Caesar added two days when he created the Julian calendar in 45 BC. August is after July and before September.

August, in either hemisphere, is the seasonal equivalent of February in the other. In the Northern hemisphere it is a summer month and it is a winter month in the Southern hemisphere.

August does not begin on the same day of the week as any other month in common years, but begins on the same day of the week as February in leap years. August ends on the same day of the week as November every year, as each other's last days are 13 weeks (91 days) apart.

In common years, August starts on the same day of the week as March and November of the previous year, and in leap years, June of the previous year. In common years, August finishes on the same day of the week as March and June of the previous year, and in leap years, September of the previous year. In common years immediately after other common years, August starts on the same day of the week as February of the previous year.

In years immediately before common years, August starts on the same day of the week as May of the following year, and in years immediately before leap years, October of the following year. In years immediately before common years, August finishes on the same day of the week as May of the following year, and in years immediately before leap years, February and October of the following year.




#Article 3: Art (664 words)


Art is a creative activity that expresses imaginative or technical skill. It produces a product, an object. Art is a diverse range of human activities in creating visual, performing artifacts, and expressing the author's imaginative mind. The product of art is called a work of art, for others to experience. 

Some art is useful in a practical sense, such as a sculptured clay bowl that can be used. That kind of art is sometimes called a craft.

Those who make art are called artists. They hope to affect the emotions of people who experience it. Some people find art relaxing, exciting or informative. Some say people are driven to make art due to their inner creativity.

Art is divided into the plastic arts, where something is made, and the performing arts, where something is done by humans in action. The other division is between pure arts, done for themselves, and practical arts, done for a practical purpose, but with artistic content.

Some people say that art is a product or item that is made with the intention of stimulating the human senses as well as the human mind, spirit and soul.  An artwork is normally judged by how much impact it has on people, the number of people who can relate to it, and how much they appreciate it. Some people also get inspired.

The first and broadest sense of art means arrangement or to arrange. In this sense, art is created when someone arranges things found in the world into a new or different design or form; or when someone arranges colors next to each other in a painting to make an image or just to make a pretty or interesting design.

Art may express emotion.  Artists may feel a certain emotion and wish to express it by creating something that means something to them.  Most of the art created in this case is made for the artist rather than an audience.  However, if an audience is able to connect with the emotion as well, then the art work may become publicly successful.

There are sculptures, cave painting and rock art dating from the Upper Paleolithic era.

All of the great ancient civilizations, such as Ancient Egypt, India, China, Greece, Rome and Persia had works and styles of art. In the Middle Ages, most of the art in Europe showed people from the Bible in paintings, stained glass windows, and mosaic tile floors and walls.

Islamic art includes geometric patterns, Islamic calligraphy, and architecture. In India and Tibet, painted sculptures, dance, and religious painting were done. In China, arts included jade carving, bronze, pottery, poetry, calligraphy, music, painting, drama, and fiction. There are many Chinese artistic styles, which are usually named after the ruling dynasty.

In Europe, after the Middle Ages, there was a Renaissance which means rebirth. People rediscovered science and artists were allowed to paint subjects other than religious subjects. People like Michelangelo and Leonardo da Vinci still painted religious pictures, but they also now could paint mythological pictures too. These artists also invented perspective where things in the distance look smaller in the picture. This was new because in the Middle Ages people would paint all the figures close up and just overlapping each other.

In the late 1800s, artists in Europe, responding to Modernity created many new painting styles such as Classicism, Romanticism, Realism, and Impressionism. The history of twentieth century art includes Expressionism, Fauvism, Cubism, Dadaism, Surrealism, and Minimalism.

In some societies, people think that art belongs to the person who made it. They think that the artist put his or her talent and industry into the art. In this view, the art is the property of the artist, protected by copyright.

In other societies, people think that art belongs to no one. They think that society has put its social capital into the artist and the artist's work. In this view, society is a collective that has made the art, through the artist.

The  of art include:




#Article 4: A (263 words)


A or a is the first letter of the English alphabet. The small letter, a or α, is used as a lower case vowel. 

When it is spoken,  ā is said as a long a, a diphthong of ĕ and y. A is similar to  alpha of the Greek alphabet. That is not surprising, because it stands for the same sound. 

A is the letter that was used to represent a team in an old TV show, The A-Team. A capital a is written A. Use a capital a at the start of a sentence if writing.

The letter 'A' was in the Phoenician alphabet's aleph. This symbol came from a simple picture of an ox head. 

This Phoenician letter helped make the basic blocks of later types of the letter. The Greeks later modified this letter and used it as their letter alpha. The Greek alphabet was used by the Etruscans in northern Italy, and the Romans later modified the Etruscan alphabet for their own language.

The letter A has six different sounds. It can sound like æ, in the International Phonetic Alphabet, such as the word pad. Other sounds of this letter are in the words father, which developed into another sound, such as in the word ace.

In algebra, the letter A along with other letters at the beginning of the alphabet is used to represent known quantities.

In geometry, capital A, B, C etc. are used to label line segments, lines, etc. Also, A is typically used as one of the letters to label an angle in a triangle.




#Article 5: Air (333 words)


Air refers to the Earth's atmosphere. Air is a mixture of many gases and tiny dust particles. It is the clear gas in which living things live and breathe. It has an indefinite shape and volume. It has mass and weight, because it is matter. The weight of air creates atmospheric  pressure. There is no air in outer space. 

Air is a mixture of about 78% of nitrogen, 21% of oxygen, 0.9% of argon, 0.04% of carbon dioxide, and very small amounts of other gases.  There is an average of about 1% water vapour.

Animals live and need to breathe the oxygen in the air. In breathing, the lungs put oxygen into the blood, and send back carbon dioxide to the air. Plants need the carbon dioxide in the air to live. They give off the oxygen that we breathe. Without it we die of asphyxia.  

Wind is moving air, this is refreshing. This causes weather. 

Air can be polluted by some gases (such as carbon monoxide, hydrocarbons, and nitrogen oxides), smoke, and ash. This air pollution causes various problems including smog, acid rain and global warming. It can damage people's health and the environment. 

Since early times, air has been used to create technology. Ships moved with sails and windmills used the mechanical motion of air. Aircraft use propellers to move air over a wing, which allows them to fly. Pneumatics use air pressure to move things. Since the late 1900s, air power is also used to generate electricity. 

Air is invisible: it cannot be seen by the eye, though a shimmering in hot air can be seen.

File:Sauerstoffgehalt-1000mj2.png|thumb|Oxygen content of the atmosphere over the last billion years

The constant re-arrangement of continents by plate tectonics influences the long-term evolution of the atmosphere. Carbon dioxide was transferred to and from large continental carbonate stores. Free oxygen did not exist in the atmosphere until about 2.4 billion years ago. The Great Oxygenation Event is shown by the end of the banded iron formations. 




#Article 6: Autonomous communities of Spain (167 words)


Spain is divided in 17 parts called autonomous communities. Autonomous means that each of these autonomous communities has its own executive, legislative judicial powers. These are similar to, but not the same as, states in the United States of America, for example.

Spain has fifty smaller parts called provinces. In 1978 these parts came together, making the autonomous communities. 
Before then, some of these provinces were together but were broken. The groups that were together once before are called historic communities: Catalonia, Basque Country, Galicia and Andalusia.

The Spanish language is the sole official language in every autonomous community but six, where Spanish is co-official with other languages, as follows:

List of the autonomous communities, with their Capital city (the place where the government has its offices):

Spain also has two cities on the north coast of Africa: Ceuta and Melilla. They are called autonomous cities and have simultaneously the majority of the power of an autonomous community and also power of provinces and power of municipalities.




#Article 7: Alan Turing (773 words)


Alan Mathison Turing OBE FRS (London, 23 June 1912 – Wilmslow, Cheshire, 7 June 1954) was an English mathematician and computer scientist. He was born in Maida Vale, London.

Alan Turing was born in Maida Vale, London on 23 June 1912. His father was part of a family of merchants from Scotland. His mother, Ethel Sara, was the daughter of an engineer.

Turing went to St. Michael's, a school at 20 Charles Road, St Leonards-on-sea, when he was five years old.

The Stoney family were once prominent landlords, here in North Tipperary. His mother Ethel Sara Stoney (1881–1976) was daughter of Edward Waller Stoney (Borrisokane, North Tipperary) and Sarah Crawford (Cartron Abbey, Co. Longford); Protestant Anglo-Irish gentry.

Educated in Dublin at Alexandra School and College; on October 1st 1907 she married Julius Mathison Turing, latter son of Reverend John Robert Turing and Fanny Boyd, in Dublin. Born on June 23rd 1912, Alan Turing would go on to be regarded as one of the greatest figures of the twentieth century.

A brilliant mathematician and cryptographer Alan was to become the founder of modern-day computer science and artificial intelligence; designing a machine at Bletchley Park to break secret Enigma encrypted messages used by the Nazi German war machine to protect sensitive commercial, diplomatic and military communications during World War 2. Thus, Turing made the single biggest contribution to the Allied victory in the war against Nazi Germany, possibly saving the lives of an estimated 2 million people, through his effort in shortening World War II.

In 2013, almost 60 years later, Turing received a posthumous Royal Pardon from Queen Elizabeth II. Today, the “Turing law” grants an automatic pardon to men who died before the law came into force, making it possible for living convicted gay men to seek pardons for offences now no longer on the statute book.

Alas, Turing accidentally or otherwise lost his life in 1954, having been subjected by a British court to chemical castration, thus avoiding a custodial sentence. He is known to have ended his life at the age of 41 years, by eating an apple laced with cyanide

Turing was one of the people who worked on the first computers. He created the theoretical  Turing machine in 1936. The machine was imaginary, but it included the idea of a computer program.

Turing was interested in artificial intelligence. He proposed the Turing test, to say when a machine could be called intelligent. A computer could be said to think if a human talking with it could not tell it was a machine.

During World War II, Turing worked with others to break German ciphers (secret messages). He  worked for the Government Code and Cypher School (GCCS) at Bletchley Park, Britain's codebreaking centre that produced Ultra intelligence.
Using cryptanalysis, he helped to break the codes of the Enigma machine. After that, he worked on other German codes.

From 1945 to 1947, Turing worked on the design of the ACE (Automatic Computing Engine) at the National Physical Laboratory. He presented a paper on 19 February 1946. That paper was the first detailed design of a stored-program computer. Although it was possible to build ACE, there were delays in starting the project. In late 1947 he returned to Cambridge for a sabbatical year. While he was at Cambridge, the Pilot ACE was built without him. It ran its first program on 10 May 1950.

Turing was a homosexual man. In 1952, he admitted having had sex with a man in England. At that time, homosexual acts were illegal. Turing was convicted. He had to choose between going to jail and taking hormones to lower his sex drive. He decided to take the hormones. After his punishment, he became impotent. He also grew breasts.

In May 2012, a private member's bill was put before the House of Lords to grant Turing a statutory pardon. In July 2013, the government supported it. A royal pardon was granted on 24 December 2013.

In 1954, Turing died from cyanide poisoning. The cyanide came from either an apple which was poisoned with cyanide, or from water that had cyanide in it. The reason for the confusion is that the police never tested the apple for cyanide. It is also suspected that he committed suicide.

The treatment forced on him is now believed to be very wrong. It is against medical ethics and international laws of human rights. In August 2009, a petition asking the British Government to apologise to Turing for punishing him for being a homosexual was started. The petition received thousands of signatures. Prime Minister Gordon Brown acknowledged the petition. He called Turing's treatment appalling.




#Article 8: Alanis Morissette (311 words)


Alanis Nadine Morissette (born 1 June 1974) is a Grammy Award-winning Canadian-American singer and songwriter. She was born in Ottawa, Canada. She began singing in Canada as a teenager in 1990. In 1995, she became popular all over the world.

As a young child in Canada, Morissette began to act on television, including 5 episodes of the long-running series, You Can't Do That on Television. Her first album was released only in Canada in 1990.

Her first international album was Jagged Little Pill, released in 1995. It was a rock-influenced album. Jagged has sold more than 33 million units globally. It became the best-selling debut album in music history. Her next album, Supposed Former Infatuation Junkie, was released in 1998. It was a success as well. Morissette took up producing duties for her next albums, which include Under Rug Swept, So-Called Chaos and Flavors of Entanglement. Morissette has sold more than 60 million albums worldwide.

She also acted in several movies, including Kevin Smith's Dogma, where she played God.

Alanis Morissette was born in Riverside Hospital of Ottawa in Ottawa, Ontario. Her father is French-Canadian. Her mother is from Hungary. She has an older brother, Chad, and a twin brother, Wade, who is 12 minutes younger than she is. Her parents had worked as teachers at a military base in Lahr, Germany.

Morissette became an American citizen in 2005. She is still Canadian citizen.

On May 22, 2010, Morissette married rapper Mario “MC Souleye” Treadway.

Morissette has had many albums. Her 1995 album Jagged Little Pill became a very popular album. It has sold over 30 million copies worldwide. The album caused Morissette to win four Grammy Awards. The album Jagged Little Pill touched many people.

On the album, Morissette sang songs about many different things. These things include:

Morissette has written many songs. Some of her most famous songs are:




#Article 9: Farming (682 words)


Farming is growing crops or keeping animals by people for food and raw materials. Farming is a part of agriculture. 

Agriculture started thousands of years ago, but no one knows for sure how old it is. The development of farming gave rise to the Neolithic Revolution whereby people gave up nomadic hunting and became settlers in what became cities.

Agriculture and domestication probably started in the Fertile Crescent (the Nile Valley, The Levant and Mesopotamia). The area called Fertile Crescent is now in the countries of Iraq, Syria, Turkey, Jordan, Lebanon, Israel, and Egypt. Wheat and barley are some of the first crops people grew. People probably started agriculture slowly by planting a few crops, but still gathered many foods from the wild. People may have started farming because the weather and soil began to change. Farming can feed many more people than hunter-gatherers can feed on the same amount of land.

Arable farming means growing crops. This would include wheat or vegetables like brussels sprouts. Growing fruit means having orchards devoted to fruit. They cannot be switched easily with growing  field crops. Therefore they are not classed as arable land in the statistics.

Agriculture is not only growing food for people and animals, but also growing other things like flowers and nursery plants, manure or dung, animal hides (skins or furs), leather, animals, fungi, fibers (cotton, wool, hemp, and flax), biofuel , and drugs (biopharmaceuticals, marijuana, opium).

Many people still live by subsistence agriculture, on a small farm. They can only grow enough food to feed the farmer, his family, and his animals. The yield is the amount of food grown on a given amount of land, and it is often low. This is because subsistence farmers are generally less educated, and they have less money to buy equipment. Drought and other problems sometimes cause famines. Where yields are low, deforestation can provide new land to grow more food. This provides more nutrition for the farmer's family, but can be bad for the country and the surrounding environment over many years.

In some countries, farms are often fewer and larger. During the 20th century they have become more productive because farmers are able to grow better varieties of plants, use more fertilizer, use more water, and more easily control weeds and pests. Many farms also use machines, so fewer people can farm more land. There are fewer farmers in rich countries, but the farmers are able to grow more.

This kind of intensive agriculture comes with its own set of problems. Farmers use a lot of chemical fertilizers, pesticides (chemicals that kill bugs), and herbicides (chemicals that kill weeds). These chemicals can pollute the soil or the water. They can also create bugs and weeds that are more resistant to the chemicals, causing outbreaks of these pests. The soil can be damaged by erosion (blowing or washing away), salt buildup, or loss of structure. Irrigation (adding water from rivers) can pollute water and lower the water table. These problems have all got solutions, and modern young farmers usually have a good technical education.

Farmers select plants with better yield, taste, and nutritional value. They also choose plants that can survive plant disease and drought, and are easier to harvest. Centuries of artificial selection and breeding have changed crop plants. The crops produce better yield. Fertilizers, chemical pest control, and irrigation all help.

Some plants are improved with  genetic engineering. One example is modifying the plant to resist herbicides.

It is important for there to be enough food for everyone. The food must also be safe and good. People say it is not always safe, because it contains some chemicals. Other people say intensive agriculture is damaging the environment. For this reason, there are several types of agriculture.

Agricultural policy focuses on the goals and methods of agricultural production. Common goals of policy include the quality, amount, and safety of food.

There are some serious problems that people face trying to grow food today.
These include:

The major crops produced in the world in 2002, are maize (corn), wheat, rice, and cotton.




#Article 10: Arithmetic (155 words)


In mathematics, arithmetic is the basic study of numbers. The four basic arithmetic operations are addition, subtraction, multiplication, and division, although other operations such as exponentiation and extraction of roots are also studied in arithmetic.

Other arithmetic topics includes working with signed numbers, fractions,  decimals and percentages.

Most people learn arithmetic in primary school, but some people do not learn arithmetic and others forget the arithmetic they learned. Many jobs require a knowledge of arithmetic, and many employers complain that it is hard to find people who know enough arithmetic. A few of the many jobs that require arithmetic include carpenters, plumbers, auto mechanics, accountants, architects, doctors, and nurses. Arithmetic is needed in all areas of mathematics, science, and engineering.

Some arithmetic can be carried out mentally. A calculator can also be used to perform arithmetic. Computers can do it more quickly, which is one reason Global Positioning System receivers have a small computer inside.




#Article 11: Addition (480 words)


In mathematics, addition, represented by the symbol , is an operation which combines two mathematical objects together into another mathematical object of the same type, called the sum. Addition can occur with simple objects such as numbers, and more complex objects such as vectors and matrices.

In arithmetic, addition is finding the total of two or more numbers. The sign for addition is +, and the name for the sign + is plus. Another name for the total is the sum.

For example, there are  in two groups. The objects are small circles: o. One group has five of these objects. The other group has three of these objects. To find the total number of objects in both groups, the objects can be counted. Another way to find the number of objects in both groups is to add the numbers in each group.  

Another method is to add the numbers of objects in group A and group B, since they are already counted. In symbols:

There are rules for adding numbers that people learn. There are also rules for adding numbers that are built into machines (binary adder). The rule says that:

In another counting example, Sally and Bill have 2 children. Sally and Bill get 3 more children. Sally and Bill have added three children to their two children, and now have five children.

Vertical Addition

The animation above demonstrates the addition of seven hundred and eighty six and four hundred and sixty seven, the problems digits have been separated into units, tens and hundreds (place value). 

First, the units 6 and 7 are added together to make 13, so 1 ten and 3 units, with the 3 written below and the 1 ten carried to the tens column. Next, in the tens column, the 1, 8 and 6 are added together to make 15 tens, so 1 hundred and 5 tens, with the 5 written below and the 1 hundred carried to the hundreds column. Finally, in the hundreds column, 1, 7 and 4 are added together to make 12 hundreds, so 1 thousand and 2 hundreds, with the 2 written below and the 1 thousand carried to the thousand column. The final answer is thus one thousand two hundred and fifty three.

Tom wants to know the distance between his house and Sally's house. Bob's house is 300 meters east of Tom's house. Sally's house is 120 meters east of Bob's house:

The distance from Tom's house to Sally's house can be found by adding the distances already measured. The distance from Tom's house to Bob's house, added to the distance from Bob's house to Sally's house, is the same as the distance from Tom's house to Sally's house. That is, three hundred (300) meters plus 120 meters.

Hence Sally's house is 420 meters to the east of Tom's house.

Addition can also mean to make bigger.




#Article 12: Australia (3827 words)


Australia, formally the Commonwealth of Australia, is a country and sovereign state in the southern hemisphere, located in Oceania. Its capital city is Canberra, and its largest city is Sydney.

Australia is the sixth biggest country in the world by land area, and is part of the Oceanic and Australasian regions. Australia, New Zealand, New Guinea and other islands on the Australian tectonic plate are together called Australasia, which is one of the world's great ecozones. When other Pacific islands are included with Australasia, it is called Oceania.

Australia is known for its mining (coal, iron, gold, diamonds and crystals), its production of wool, and as the world's largest producer of bauxite. Its emblem is a flower called the Golden Wattle.

Australia's landmass of 7,617,930 square kilometers is on the Indo-Australian plate. The continent of Australia, including the island of Tasmania, was separated from the other continents of the world many millions of years ago. Because of this, many animals and plants live in Australia that do not live anywhere else. These include animals like the kangaroo, the koala, the emu, the kookaburra, and the platypus.

People first arrived in Australia more than 50,000 years ago. These native Australians are called the Australian Aborigines. For the history of Australia, see History of Australia.

Most of the Australian colonies, having been settled from Britain, became mostly independent democratic states in the 1850s and all six combined as a federation on 1 January 1901. The first Prime Minister of Australia was Edmund Barton in 1901. Australia is a member of the United Nations and the Commonwealth of Nations. It is a parliamentary democracy and a constitutional monarchy with Elizabeth II as Queen of Australia and Head of State and a Governor-General who is chosen by the Prime Minister to carry out all the duties of the Queen in Australia.

Australia has six states, two major mainland territories, and other minor territories. The states are New South Wales, Queensland, South Australia, Tasmania, Victoria, and Western Australia. The two major mainland territories are the Northern Territory and the Australian Capital Territory (ACT).

In 2013 according to world bank Australia had just over 23.13 million people. Most Australians live in cities along the coast, such as Sydney, Melbourne, Brisbane, Perth, Darwin, Hobart and Adelaide. The largest inland city is Canberra, which is also the nation's capital. The largest city is Sydney.

Australia is a very big country, but much of the land is very dry, and the middle of the continent is mostly desert. Only the areas around the east, west and south coast have enough rain and a suitable climate (not too hot) for many farms and cities.

The Australian Aboriginal people arrived in Australia about 50,000 years ago or even earlier. Until the arrival of British settlers in 1788, the Aboriginal people lived by hunting and gathering food from the land. They lived in all sorts of climates and managed the land in different ways. An example of Aboriginal land management was the Cumberland Plain where Sydney is now. Every few years the Aboriginal people would burn the grass and small trees. This meant that a lot of grass grew back, but not many big trees. Kangaroos like to live on grassy plains, but not in forests. The kangaroos that lived on the plain were a good food supply for the Aboriginal people. Sometimes, Aborigines would name a person after an animal, and they could not eat that animal to help level out the food population.

Aboriginal people did not usually build houses, except huts of grass, leaves and bark. They did not usually build walls or fences, and there were no horses, cows or sheep in Australia that needed to be kept in pens. The only Aboriginal buildings that are known are fish-traps made from stones piled up in the river, and the remains of a few stone huts in Victoria and Tasmania. The Aboriginal people did not use metal or make pottery or use bows and arrows or weave cloth. In some parts of Australia the people used sharp flaked-stone spearheads, but most Aboriginal spears were made of sharply pointed wood. Australia has a lot of trees that have very hard wood that was good for spear making. The boomerang was used in some areas for sport and for hunting.

The Aboriginal people did not think that the land belonged to them. They believed that they had grown from the land, so it was like their mother, and they belonged to the land.

In the 1600s, Dutch merchants traded with the islands of Batavia (now Indonesia), to the north of Australia and several different Dutch ships touched on the coast of Australia. The Dutch governor, van Diemen, sent Abel Tasman on a voyage of discovery and he found Tasmania, which he named Van Diemen's Land. Its name was later changed to honour the man who discovered it.

The British Government was sure that there must be a very large land in the south, that had not been explored. They sent Captain James Cook to the Pacific Ocean. His ship, HMS Endeavour, carried the famous scientists, Sir Joseph Banks and Dr Solander who were going to Tahiti where they would watch the planet Venus pass in front of the Sun. Captain Cook's secret mission was to find Terra Australis (the Land of the South).

The voyage of discovery was very successful, because they found New Zealand and sailed right around it. Then they sailed westward. At last, a boy, William Hicks, who was up the mast spotted land on the horizon. Captain Cook named that bit of land Point Hicks. They sailed up the coast and Captain Cook named the land that he saw New South Wales. At last they sailed into a large open bay which was full of fish and stingrays which the sailors speared for food. Joseph Banks and Dr. Solander went ashore and were astonished to find that they did not know what any of the plants or birds or animals that they saw were. They collected hundreds of plants to take back to England.

Captain Cook saw the Aboriginal people with their simple way of life. He saw them fishing and hunting and collecting grass seeds and fruit. But there were no houses and no fences. In most parts of the world, people put up a house and a fence or some marker to show that they own the land. But the Aboriginal people did not own the land in that way. They belonged to the land, like a baby belongs to its mother. Captain Cook went home to England and told the government that no-one owned the land. This would later cause a terrible problem for the Aboriginal people.

In the 1700s, in England, laws were tough, many people were poor and gaols (jails) were full. A person could be sentenced to death for stealing a loaf of bread. Many people were hung for small crimes. But usually they were just thrown in gaol. Often they were sent away to the British colonies in America. But by the 1770s, the colonies in America became the United States. They were free from British rule and would not take England's convicts any more, so England needed to find a new and less populated place.

By the 1780s the gaols of England were so full that convicts were often chained up in rotting old ships. The government decided to make a settlement in New South Wales and send some of the convicts there. In 1788 the First Fleet of eleven ships set sail from Portsmouth carrying convicts, sailors, marines, a few free settlers and enough food to last for two years. Their leader was Captain Arthur Phillip. They were to make a new colony at the place that Captain Cook had discovered, named Botany Bay because of all the unknown plants found there by the two scientists.

Captain Phillip found that Botany Bay was flat and windy. There was not much fresh water. He went with two ships up the coast and sailed into a great harbor which he said was the finest harbor in the world! There were many small bays on the harbor so he decided on one which had a good stream of fresh water and some flat shore to land on. On 26 January 1788, the flag was raised and New South Wales was claimed in the name of King George III of England, and the new settlement was called Sydney.

For the first few years of the settlement, things were very difficult. No-one in the British Government had thought very hard about what sort of convicts should be sent to make a new colony. Nobody had chosen them carefully. There was only one man who was a farmer. There was no-one among the convicts who was a builder, a brick-maker or a blacksmith. No-one knew how to fix the tools when they broke. All of the cattle escaped. There were no cooking pots. All the plants were different so no-one knew which ones could be eaten. It was probable that everyone in the new colony would die of starvation.

Somehow, the little group of tents with a hut for the Governor, Arthur Phillip, and another hut for the supply of food, grew into a small town with streets, a bridge over the stream, a windmill for grinding grain and wharves for ships. By the 1820s there was a fine brick house for the Governor. There was also a hospital and a convict barracks and a beautiful church which are still standing today. Settlements had spread out from Sydney, firstly to Norfolk Island and to Van Diemen's Land (Tasmania), and also up the coast to Newcastle, where coal was discovered, and inland where the missing cattle were found to have grown to a large herd. Spanish Merino sheep had been brought to Sydney, and by 1820, farmers were raising fat lambs for meat and also sending fine wool back to the factories of England.

While the settlement was growing in New South Wales, it was also growing in Tasmania. The climate in Tasmania was more like that in England, and farmers found it easy to grow crops there.

Because Australia is such a very large land, it was easy to think that it might be able to hold a very large number of people. In the early days of the colony, a great number of explorers went out, searching for good land to settle on.
When the settlers looked west from Sydney, they saw a range of mountains which they called the Blue Mountains. They were not very high and did not look very rugged but for many years no-one could find their way through them. In 1813 Gregory Blaxland, William Lawson and a 17-year-old called William Charles Wentworth crossed the Blue Mountains and found land on the other side which was good for farming. A road was built and the governor, Lachlan Macquarie founded the town of Bathurst on the other side, 100 miles from Sydney.

Some people, like Captain Charles Sturt were sure that there must be a sea in the middle of Australia and set out to find it. Many of the explorers did not prepare very well, or else they went out to explore at the hottest time of year. Some died like Burke and Wills. Ludwig Leichhardt got lost twice. The second time, he was never seen again. Major Thomas Mitchell was one of the most successful explorers. He mapped the country as he went, and his maps remained in use for more than 100 years. He travelled all the way to what is now western Victoria, and to his surprise and annoyance found that he was not the first white person there. The Henty brothers had come from Tasmania, had built themselves a house, had a successful farm and fed the Major and his men on roast lamb and wine.

The gold rushes of New South Wales and Victoria started in 1851 leading to large numbers of people arriving to search for gold. The population grew across south east Australia and made great wealth and industry. By 1853 the gold rushes had made some poor people, very rich.

The transportation of convicts to Australia ended in the 1840s and 1850s and more changes came. The people in Australia wanted to run their own country, and not be told what to do from London. The first governments in the colonies were run by governors chosen by London. Soon the settlers wanted local government and more democracy. William Wentworth started the Australian Patriotic Association (Australia's first political party) in 1835 to demand democratic government. In 1840, the city councils started and some people could vote. New South Wales Legislative Council had its first elections in 1843, again with some limits on who could vote. In 1855, limited self-government was given by London to New South Wales, Victoria, South Australia and Tasmania. In 1855, the right to vote was given to all men over 21 in South Australia. The other colonies soon followed. Women were given the vote in the Parliament of South Australia in 1895 and they became the first women in the world allowed to stand in elections.

Australians had started parliamentary democracies all across the continent. But voices were getting louder for all of them to come together as one country with a national parliament.

File:Australian PR COB 2006.PNG|right|300px|thumb|Countries of birth of Australian estimated resident population, 2006.Source:Australian Bureau of Statistics

Until 1901, Australia was not a nation, it was six separate colonies governed by Britain. They voted to join together to form one new country, called the Commonwealth of Australia, in 1901. Australia was still part of the British Empire, and at first wanted only British or Europeans to come to Australia. But soon it had its own money, and its own Army and Navy.

In Australia at this time, the trade unions were very strong, and they started a political party, the Australian Labor Party. Australia passed many laws to help the workers.

In 1914, the First World War started in Europe. Australia joined in on the side of Britain against Germany, Austria-Hungary and the Ottoman Empire. Australian soldiers were sent to Gallipoli, in the Ottoman Empire. They fought bravely, but were beaten by the Turks. Today Australia remembers this battle every year on ANZAC Day. They also fought on the Western Front. More than 60,000 Australians were killed.

Australia had a really hard time in the Great Depression of the 1930s and joined Britain in a war against Nazi Germany when Hitler invaded Poland in 1939. But in 1941 lots of Australian soldiers were captured in the Fall of Singapore by Japan. Then Japan started attacking Australia and people worried about invasion. But with help from the United States Navy, the Japanese were stopped. After the war, Australia became a close friend of the United States.

When the war ended, Australia felt that it needed many more people to fill the country up and to work. So the government said it would take in people from Europe who had lost their homes in the war. It did things like building the Snowy Mountains Scheme. Over the next 25 years, millions of people came to Australia. They came especially from Italy and Greece, other countries in Europe. Later they also came from countries like Turkey and Lebanon. An important new party, the Liberal Party of Australia was made by Robert Menzies in 1944 and it won lots of elections from 1949 until in 1972, then Gough Whitlam won for the Labor Party. Whitlam made changes, but he made the Senate unhappy and the Governor-General sacked him and forced an election in 1975. Then Malcolm Fraser won a few elections for the Liberal Party.

In the 1960s many people began coming to Australia from China, Vietnam, Malaysia and other countries in Asia. Australia became more multicultural. In the 1950s and 1960s Australia became one of the richest countries in the world, helped by mining and wool. Australia started trading more with America, than Japan. Australia supported the United States in wars against dictatorships in Korea and Vietnam and later Iraq. Australian soldiers also helped the United Nations in countries like East Timor in 1999.

In 1973, the famous Sydney Opera House opened. In the 1970s, 80s and 90s lots of Australian movies, actors and singers became famous around the world. In the year 2000, Sydney had the Summer Olympics.

In the 1980s and 90s, the Labor Party under Bob Hawke and Paul Keating, then the Liberal Party under John Howard made lots of changes to the economy. Australia had a bad recession in 1991, but when other Western countries had trouble with their economies in 2008, Australia stayed strong.

Today Australia is a rich, peaceful and democratic country. But it still has problems. Around 4-5% of Australians could not get a job in 2010. A lot of land in Australia (like Uluru) has been returned to Aboriginal people, but lots of Aborigines are still poorer than everybody else. Every year the government chooses a big number of new people from all around the world to come as immigrants to live in  Australia. These people may come because they want to do business, or to live in a democracy, to join their family, or because they are refugees. Australia took 6.5 million immigrants in the 60 years after World War Two, including around 660,000 refugees.

Julia Gillard became the first woman Prime Minister of Australia in 2010 when she replaced her colleague Kevin Rudd of the Labor Party.

Australia is made up of six states, and two mainland . Each state and territory has its own Parliament and makes its own local laws. The Parliament of Australia sits in Canberra and makes laws for the whole country, also known as the Commonwealth or Federation.

The Federal government is led by the Prime Minister of Australia, who is the member of Parliament chosen as leader. The current Prime Minister is Scott Morrison.

The leader of Australia is the Prime Minister, although the Governor-General represents the Queen of Australia, who is also the Queen of Great Britain, as head of state. The Governor-General, currently His Excellency David Hurley, is chosen by the Prime Minister.

Australia was colonised by people from Britain, but today people from all over the world live there. English is the main spoken language, and Christianity is the main religion, though all religions are accepted and not everybody has a religion. Australia is multicultural, which means that all its people are encouraged to keep their different languages, religions and ways of life, while also learning English and joining in with other Australians.

Famous Australian writers include the bush balladeers Banjo Paterson and Henry Lawson who wrote about life in the Australian bush. More modern famous writers include Peter Carey, Thomas Keneally and Colleen McCullough. In 1973, Patrick White won the Nobel Prize in Literature, the only Australian to have achieved this; he is seen as one of the great English-language writers of the twentieth century.

Australian music has had lots of world-wide stars, for example the opera singers Nellie Melba and Joan Sutherland, the rock and roll bands Bee Gees, AC/DC and INXS, the folk-rocker Paul Kelly (musician), the pop singer Kylie Minogue and Australian country music stars Slim Dusty and John Williamson. Australian Aboriginal music is very special and very ancient: it has the famous digeridoo woodwind instrument. 

Australian TV has produced many successful programs for home and overseas - including Skippy the Bush Kangaroo, Home and Away and Neighbours - and produced such well known TV stars as Barry Humphries (Dame Edna Everage), Steve Irwin (The Crocodile Hunter) and The Wiggles. Major Australian subgroups such as the Bogan have been shown on Australian TV in shows such as Bogan Hunters and Kath  Kim.

Australia has two public broadcasters (the ABC and the multi-cultural SBS), three commercial television networks, three pay-TV services, and numerous public, non-profit television and radio stations. Each major city has its daily newspapers, and there are two national daily newspapers, The Australian and The Australian Financial Review.

Australian movies have a very long history. The world's first feature movie was the Australian movie The Story of the Kelly Gang of 1906.  In 1933, In the Wake of the Bounty, directed by Charles Chauvel, had Errol Flynn as the main actor. Flynn went on to a celebrated career in Hollywood. The first Australian Oscar was won by 1942's Kokoda Front Line!, directed by Ken G. Hall. In the 1970s and 1980s lots of big Australian movies and movie stars became world famous with movies like Picnic at Hanging Rock, Gallipoli (with Mel Gibson), The Man From Snowy River and Crocodile Dundee. Russell Crowe, Cate Blanchett and Heath Ledger became global stars during the 1990s and Australia starring Nicole Kidman and Hugh Jackman made a lot of money in 2008.

Australia is also a popular destination for business conferences and research, with Sydney named as one of the top 20 meeting destinations in the world.

Sport is an important part of Australian culture because the climate is good for outdoor activities. 23.5% Australians over the age of 15 regularly take part in organised sporting activities. In international sports, Australia has very strong teams in cricket, hockey, netball, rugby league and rugby union, and performs well in cycling, rowing and swimming. Local popular sports include Australian Rules Football, horse racing, soccer and motor racing. Australia has participated in every summer Olympic Games since 1896, and every Commonwealth Games. Australia has hosted the 1956 and 2000 Summer Olympics, and has ranked in the top five medal-winners since 2000. Australia has also hosted the 1938, 1962, 1982 and 2006 Commonwealth Games and are to host the 2018 Commonwealth Games. Other major international events held regularly in Australia include the Australian Open, one of the four Grand Slam tennis tournaments, annual international cricket matches and the Formula One Australian Grand Prix. Corporate and government sponsorship of many sports and elite athletes is common in Australia. Televised sport is popular; some of the highest-rated television programs include the Summer Olympic Games and the grand finals of local and international football competitions.

The main sporting leagues for males are the Australian Football League, National Rugby League, A-League and NBL.
For women, they are ANZ Netball Championships, W-League and WNBL.

Famous Australian sports players include the cricketer Sir Donald Bradman, the swimmer Ian Thorpe and the athlete Cathy Freeman.

Just 60 years ago, Australia had only one big art festival. Now Australia has hundreds of smaller community-based festivals, and national and regional festivals that focus on specific art forms.

Australia is home to many animals that can be found nowhere else on Earth, which include: the Koalas,the Kangaroos, the Wombat, the Numbat, the Emu, among many others. Most of the marsupials in the world are found only on the continent.




#Article 13: American English (392 words)


American English or United States English is the dialect of the English language spoken in the United States of America.  It is different in some ways from other types of English, such as British English.  Many types of American English came from local dialects in England.

Many people today know about American English even if they live in a country where another sort of English is spoken. This may be because people hear and read American English through the media, for example movies, television, and the Internet, where the most common form of English is American English.

Because people all over the world use the English language, it gets many new words.  English has been changing in this way for hundreds of years.  For example, the many millions who speak Indian English frequently add American English words to go along with its British English base and many other words from the various Indian languages. 

Sometimes people learn American English as it is spoken in America. For example, in telephone call centers in India and other places, people often learn American English to sound more like their customers who call from America. These people often keep using American English in everyday life.

The meaning of many words are different in American English. Most changes in a language start with small things. For example, Italian, Spanish, and French all came from Latin.

There are many words that sound the same in both American English and British English, but are spelled differently.  For example:

Words that come from French that end in -re in British English (metre, centre) end in -er in American English. In these cases Canadian English usage is to keep the British (and French) spelling.

Books show that many of these differences come from the writings of English-lover Noah Webster, who made the American dictionary following the American War of Independence.

Some more differences in American English:

There are also some words in American English that are a bit different from British English, e.g.:

General American English is the kind most spoken in mass media. It more vigorously pronounces the letter R than some other kinds do. R-dropping is frequent in certain places where r sound is not pronounced after a vowel. For example as in the words car and card sounding like cah and cahd. This occurs in the Boston area.




#Article 14: Aquaculture (162 words)


Aquaculture is the farming of fish, shrimp, abalones, algae, and other seafood.  Aquaculture supplies fish, such as catfish, salmon, and trout.  It was developed a few thousand years ago in China.  Aquaculture supplies over 20% of all the seafood harvested. 

Fish farming has been practiced, in some parts of the world, for thousands of years. Goldfish originated about a thousand years ago in carp farms in China, and the Roman Empire farmed oysters and other seafood.  Today, half of the seafood eaten in the U.S. is farmed.  To help meet the growing global demand for seafood, aquaculture is growing fast.

The environmental impact of fish farming varies widely, depending on the species being farmed, the methods used and where the farm is located. When good practices are used, it's possible to farm seafood in a way that has very little impact to the environment. Such operations limit habitat damage, disease, escapes of farmed fish and the use of wild fish as feed.




#Article 15: Abbreviation (204 words)


An abbreviation is a shorter way to write a word or phrase. People use abbreviations for words that they write a lot. The English language occasionally uses the apostrophe mark ' to show that a word is written in a shorter way, but some abbreviations do not use this mark. More often, they use periods, especially the ones that come from the Latin language. Common Latin abbreviations include i.e. [id est] that is, e.g. [exempli gratia] for example, and et al. [et alia] and others.

Some new abbreviations have been created by scientists, by workers in companies and governments, and by people using the Internet.

People often think words are abbreviations when in fact they are acronyms.

Here are examples of common acronyms: The word radar is an acronym for Radio Detection and Ranging. The name of the large computer company IBM comes from the words International Business Machines. The name of the part of the United States government that sends rockets into outer space is NASA, from the words National Aeronautics and Space Administration. When people using the Internet think that something is very funny, they sometimes write LOL to mean Laughing Out Loud. People sometimes write ASAP for As Soon As Possible.




#Article 16: Angel (414 words)


In many mythologies and religions, an angel is a good spirit. The word angel comes from the Greek word angelos which means messenger. Angels appear frequently in the Old Testament, the New Testament, Qur'an and Aqdas.

Angels are powerful, smart spirits that obey God's commands and praise him with singing and they have male (masculine)gender, but without any sex. They sometimes appear to humans in human form. They can deliver messages to people in person or in dreams. Angels that are named in the Bible are Michael (called a chief prince), Gabriel (known for telling Mary that she would be the mother of Jesus), and Raphael (in the Apocryphal Book of Tobit).  The Ethiopian Book of Enoch also lists four Archangels which watch over the four quadrants of heaven; Michael, Raphael, Gabriel and Uriel. Lucifer is also known as an angel in the Bible.

Ezekiel 28:13-14

It describes the sound of their wings, like the roar of rushing waters.

Ezekiel 10:5-7 ; Ezekiel 10:8 reveals that they have hands like a man under their wings .

Ezekiel 1:7 KJV reveals that they look like man but are different because they have straight feet and four wings and four faces.

Ezekiel ch 1, and 10 describe the cherubim creatures ascending and descending from the earth with wheels. Ezekiel 1:14-20 ; Ezekiel 10:16

Ezekiel 10:9-13 describes what the wheels appeared to look like, and how they moved around, how they moved or flew through the sky quickly but turned not as they went; and how the inside workings of the wheels appeared to be a wheel in the midst of a wheel and that the color of the wheels was the color of Amber Stone. There are four separate wheels in both accounts, one for each single cherub which is there.

They are often shown in art as having wings and a halo. The wings represent their speed, and the halo represents their holiness.

The cherubim in art always appear as baby faced angels with very small non useful wings.

The cherubim statue or bronze casting of cherubim in the Temple of Solomon depicted them as two four winged creatures whose wings touched at the peak of the ark that they were making.

The same cherubim creatures were said to be cast in gold on top of the Ark of the Covenant. Casting metal is one of the oldest forms of artwork, and was attempted by Leonardo da Vinci.

The study of Angels is called Angelology.




#Article 17: Ad hominem (246 words)


Ad hominem is a Latin word for a type of argument. It is a word often used in rhetoric. Rhetoric is the science of speaking well, and convincing other people of your ideas.

Translated to English, ad hominem means against the person. In other words, when someone makes an ad hominem, they are attacking the person they are arguing against, instead of what they are saying.

The term comes from the Latin word homo, which means human. Hominem is a gender neutral version of the word homo. In ancient Rome it referred to all free men, or in other words, all free human beings.

Ad hominem can be a way to use reputation, rumors and hearsay to change the minds of other people listening. When a social network has already excluded or exiled one person, or applied a negative label to them, this can work more often.

It is most of the time considered to be a weak and poor argument. In courts and in diplomacy ad hominems are not appreciated.

Ad hominems are not wrong every time. For example, when people think that someone can't be trusted, things that they have said previously can be doubted.

In logic, a  is something that starts with premises, and goes through a few logical arguments, to reach a conclusion.

In this example it can be seen that the (completely unrelated) fact that person A is uneducated and poor is used to prove that abortion should not be illegal.




#Article 18: Native American (515 words)


Native Americans (also called Aboriginal Americans, American Indians, Amerindians or indigenous peoples of America) are the people and their descendants, who were in the Americas when Europeans arrived.  There are many different tribes of Native American people, with many different languages.  There are more than three million Native Americans in Canada and the U.S. combined.  About 51 million Native Americans live in Latin America.

Sometimes these people are called Indians, but this may be confusing, because it is the same word used for people from India. When Christopher Columbus explored, he did not know about the Americas. He was in the Caribbean but thought he was in the East Indies, so he called the people Indians. 

Many Native Americans died after the Europeans came to the Americas. There were diseases that came with the Europeans but were new to the Native Americans. There were battles with the Europeans. Many native people were hurt, killed, or forced to leave their homes by settlers who took their lands.

Some Native Americans kept jaguars as pets.

Native Americans introduced vanilla and chocolate to the world. 

The ancestors of Native Americans came to the Americas from Asia. Some of them may have come to America 15,000 years ago when Alaska was connected to Siberia by the Bering land bridge.

The earliest peoples in the Americas came from Siberia when there was an ice bridge across the Bering Strait. The cold but mainly grassy plain which connected Siberia with Canada is called Beringia.  It is reckoned that a few thousand people arrived in  Beringia from eastern Siberia during the Last Glacial Maximum before moving into the Americas sometime after 16,500 years before the present (BP). This would have occurred as the American glaciers blocking the way southward melted, but before the bridge was covered by the sea about 11,000 years BP. 

Before European colonization, Beringia was inhabited by the Yupik peoples on both sides of the straits. This culture remains in the region today, with others. In 2012, the governments of Russia and the United States announced a plan to formally establish a transboundary area of shared Beringian heritage. Among other things this agreement would establish close ties between the Bering Land Bridge National Preserve and the Cape Krusenstern National Monument in the United States and Beringia National Park in Russia.

Native Americans are divided into many small nations, called First Nations in Canada and tribes elsewhere.

According to the 2010 United States census, 0.9% of Americans say they are Native American, 2.9 million people, and 1.7% of Americans say they are both Native American and something else.  They are not evenly spread out through the United States.  About a third of the people in Alaska are Native Alaskan and about a sixth of the people in Oklahoma are Native American.

In the United States, most Native Americans live in cities.  About 28% of Native Americans live on reservations.  Many Native Americans are poor, and 24% are extremely poor.  The history of violence against Native Americans persists today in higher rates of violence against Native American people than white people.




#Article 19: Apple (1180 words)


The apple tree (Malus domestica) is a tree that grows apples. It is best known for this juicy, tasty fruit. The tree is grown worldwide. Its fruit is low-cost, and is harvested all over the world. 

The tree came from Central Asia. Apples have been grown for thousands of years in Asia and Europe. They were brought to North America by European settlers. Apples have religious and mythological significance in many cultures.

Apples are generally propagated by grafting, although wild apples grow readily from seed. Apple trees are large if grown from seed, but small if grafted onto roots (rootstock). There are more than 7,500 known cultivars of apples, with a range of desired characteristics. Different cultivars are bred for various tastes and uses: cooking, eating raw and cider production are the most common uses. 

Trees and fruit are attacked by fungi, bacteria and pests. In 2010, the fruit's genome was sequenced as part of research on disease control and selective breeding in apple production.

Worldwide production of apples in 2013 was 90.8 million tonnes. China grew 49% of the total.

The apple has a small, leaf-shedding tree that grows up to  tall. The apple tree has a broad crown with thick twigs.
The leaves are alternately arranged simple ovals. They are 5 to 12 centimetres long and 3–6centimetres (1.2–2.4in) wide. It has a sharp top with a soft underside. Blossoms come out in spring at the same time that the leaves begin to bud. The flowers are white. They also have a slightly pink color. They are five petaled, and 2.5 to 3.5 centimetres (0.98 to 1.4 in) in . The fruit  in autumn. It is usually 5 to 9 centimetres (2.0 to 3.5 in) in diameter. There are five carpels arranged in a star in the middle of the fruit. Every carpel has one to three seeds.

The wild ancestor of apple trees is Malus sieversii. They grow wild in the mountains of Central Asia in the north of Kazakhstan, Kyrgyzstan, Tajikistan, and Xinjiang, China, and possibly also Malus sylvestris. Unlike  apples, their leaves become red in autumn. They are being used recently to develop Malus domestica to grow in colder .

The apple tree was possibly the earliest tree to be cultivated. Its fruits have become better over thousands of years. It is said that Alexander the Great discovered  apples in Asia Minor in 300 BC. Asia and Europe have used winter apples as an important food for thousands of years. From when Europeans arrived, Argentina and the United States have used apples as food as well. Apples were brought to North America in the 1600s. The first apple orchard on the North American continent was said to be near Boston in 1625. In the 1900s, costly fruit industries, where the apple was a very important species, began developing.

In Norse mythology, the goddess Iðunn gives apples to the gods in Prose Edda (written in the 13th century by Snorri Sturluson) that makes them young forever. English  H. R. Ellis Davidson suggests that apples were related to religious practices in Germanic paganism. It was from there, she claims, that Norse paganism developed. She points out that buckets of apples were discovered in the place of burial for the Oseberg ship in Norway. She also remarks that fruit and nuts (Iðunn having been described as changing into a nut in Skáldskaparmál) have been discovered in the early graves of the Germanic peoples in England. They have also been discovered somewhere else on the continent of Europe. She suggests that this may have had a symbolic meaning. Nuts are still a symbol of fertility in Southwest England.

Sometimes apples are eaten after they are cooked. Often apples are eaten uncooked. Apples can also be made into drinks. Apple juice and apple cider are apple drinks. 

The flesh of the fruit is firm with a taste anywhere from sour to sweet. Apples used for cooking are sour, and need to be cooked with sugar, while other apples are sweet, and do not need cooking. There are some seeds at the core, that can be removed with a tool that removes the core, or by carefully using a knife.

The scientific name of the apple tree genus in the Latin language is Malus. Most apples that people grow are of the Malus domestica species.

Most apples are good to eat raw (not cooked), and are also used in many kinds of baked foods, such as apple pie. Apples are cooked until they are  to make apple sauce.

Apples are also made into the drinks apple juice and cider. Usually, cider contains a little alcohol, about as much as beer. The regions of Brittany in France and Cornwall in England are known for their apple ciders.

If one wants to grow a certain type of apple it is not possible to do this by planting a seed from the wanted type. The seed will have DNA from the apple that the seeds came from, but it will also  have DNA from the apple flower that pollinated the seeds, which may well be a different type. This means that the tree which would grow from planting would be a mixture of two. In order to grow a certain type of apple, a small twig, or 'scion', is cut from the tree that grows the type of apple desired, and then added on to a specially grown stump called a rootstock. The tree that grows will only create apples of the type needed.

There are more than 7,500 known cultivars (varieties) of apples. Different cultivars are available for temperate and subtropical climates. One large collection of over 2,100 apple cultivars is at the National Fruit Collection in England. Most of these cultivars are grown for eating fresh (dessert apples). However, some are grown simply for cooking or making cider. Cider apples are usually too  to eat immediately. However, they give cider a rich flavor that dessert apples cannot.

Most popular apple cultivars are soft but . Colorful skin, easy shipping, disease resistance, 'Red Delicious' apple shape, and popular flavor are also needed. Modern apples are usually sweeter than older cultivars. This is because popular tastes in apples have become different. Most North Americans and Europeans enjoy sweet apples. Extremely sweet apples with hardly any acid taste are popular in Asia and India.

In the United Kingdom there are about 3000 different types of apples. The most common apple type grown in England is the 'Bramley seedling', which is a popular cooking apple.

Apple orchards are not as common as they were in the early 1900s, when apples were rarely brought in from other countries. Organizations such as  teach people about the importance of rare and local varieties of fruit.

Many apples are grown in temperate parts of the United States and Canada. In many areas where apple growing is important, people have huge celebrations:

There are many different varieties of apples, including:

Apples are in the group Maloideae. This is a subfamily of the family Rosaceae. They are in the same subfamily as pears.




#Article 20: Abrahamic religion (132 words)


An Abrahamic religion is a religion whose followers believe in the prophet Abraham. They believe Abraham and his sons/grandsons hold an important role in human spiritual development. The best known Abrahamic religions are Judaism, Christianity and Islam. Smaller religious traditions sometimes included as Abrahamic religions are Samaritanism, Druze, Rastafari, Yazidi, Babism and Bahá'í Faith. Mandaeism (a religion that holds many Abrahamic beliefs) is not called Abrahamic because its followers think Abraham was a false prophet

True Abrahamic religions are monotheistic (the belief that there is only one God). They also all believe that people should pray to God and worship God often. Among monotheistic religions, the Abrahamic religions have the world's largest number of followers. They are also all ethical monotheistic religions. This means they have rules that they have to follow.




#Article 21: Algebra (1666 words)


Algebra (from Arabic: الجبر‎, transliterated al-jabr, meaning reunion of broken parts) is a part of mathematics (often called math in the United States and maths or numeracy in the United Kingdom ). It uses variables to represent a value that is not yet known.  When an equals sign (=) is used, this is called an equation.  A very simple equation using a variable is: 2 + 3 = x. In this example, x = 5, or it could also be said that x equals five.  This is called solving for x.  

Besides equations, there are inequalities (less than and greater than). A special type of equation is called the function.  This is often used in making graphs because it always turns one input into one output.

Algebra can be used to solve real problems because the rules of algebra work in real life and numbers can be used to represent the values of real things.  Physics, engineering and computer programming are areas that use algebra all the time.  It is also useful to know in surveying, construction and business, especially accounting.

People who do algebra use the rules of numbers and mathematic operations used on numbers.  The simplest are adding, subtracting, multiplying, and dividing.  More advanced operations involve exponents, starting with squares and square roots.  

Algebra was first used to solve equations and inequalities. Two examples are linear equations (the equation of a straight line, y=mx+b or y=mx+c) and quadratic equations, which has variables that are squared (multiplied by itself, for example: 2*2, 3*3, or x*x).  

Early forms of algebra were developed by the Babylonians and the Greek geometers such as Hero of Alexandria. However the word algebra is a Latin form of the Arabic word Al-Jabr (casting) and comes from a mathematics book Al-Maqala fi Hisab-al Jabr wa-al-Muqabilah, (Essay on the Computation of Casting and Equation) written in the 9th century by a Persian mathematician, Muhammad ibn Mūsā al-Khwārizmī, who was a Muslim born in Khwarizm in Uzbekistan. He flourished under Al-Ma'moun in Baghdad, Iraq through 813-833 AD, and died around 840 AD. The book was brought into Europe and translated into Latin in the 12th century. The book was then given the name 'Algebra'. (The ending of the mathematician's name, al-Khwarizmi, was changed into a word easier to say in Latin, and became the English word algorithm).

Here is a simple example of an algebra problem:

These are the steps you can use to solve the problem:

With practice, algebra can be used when faced with a problem that is too hard to solve any other way. Problems such as building a freeway, designing a cell phone, or finding the cure for a disease all require algebra.

As in most parts of mathematics, adding z to y (or y plus z) is written as y + z.

Subtracting z from y (or y minus z) is written as y − z.

Dividing y by z (or y over z: ) is written as y ÷ z or y/z. y/z is more commonly used.

In algebra, multiplying y by z (or y times z) can be written in 4 ways: y × z, y * z, y·z, or just yz. The multiplication symbol × is usually not used, because it looks too much like the letter x, which is often used as a variable.  Also, when multiplying a larger expression, parentheses can be used: y (z+1).

When we multiply a number and a letter in algebra, we write the number in front of the letter: 5 × y = 5y. When the number is 1, then the 1 is not written because 1 times any number is that number (1 × y = y) and so it is not needed.

As a side note, you do not have to use the letters x or y in algebra. Variables are just symbols that mean some unknown number or value, so you can use any variable. x and y are the most common, though.

An important part of algebra is the study of functions, since functions often appear in equations that we are trying to solve. A function is like a machine you can put a number (or numbers) into and get a certain number (or numbers) out. When using functions, graphs can be powerful tools in helping us to study the solutions to equations. 

A graph is a picture that shows all the values of the variables that make the equation or inequality true. Usually this is easy to make when there are only one or two variables. The graph is often a line, and if the line does not bend or go straight up-and-down it can be described by the basic formula y = mx + b. The variable b is the y-intercept of the graph (where the line crosses the vertical axis) and m is the slope or steepness of the line. This formula applies to the coordinates of a graph, where each point on the line is written (x, y).  

In some math problems like the equation for a line, there can be more than one variable (x and y in this case).  To find points on the line, one variable is changed. The variable that is changed is called the independent variable.  Then the math is done to make a number. The number that is made is called the dependent variable. Most of the time the independent variable is written as x and the dependent variable is written as y, for example, in y = 3x + 1.  This is often put on a graph, using an x axis (going left and right) and a y axis (going up and down).  It can also be written in function form: f(x) = 3x + 1.  So in this example, we could put in 5 for x and get y = 16.  Put in 2 for x would get y=7.  And 0 for x would get y=1.  So there would be a line going thru the points (5,16), (2,7), and (0,1) as seen in the graph to the right.

If x has a power of 1, it is a straight line.  If it is squared or some other power, it will be curved.  If it uses an inequality (), then usually part of the graph is shaded, either above or below the line.

In algebra, there are a few rules that can be used for further understanding of equations. These are called the rules of algebra. While these rules may seem senseless or obvious, it is wise to understand that these properties do not hold throughout all branches of mathematics. Therefore, it will be useful to know how these axiomatic rules are declared, before taking them for granted. Before going on to the rules, reflect on two definitions that will be given.

'Commutative' means that a function has the same result if the numbers are swapped around. In other words, the order of the terms in an equation do not matter. When the operator of two terms is an addition, the 'commutative property of addition' is applicable. In algebraic terms, this gives .

Note that this does not apply for subtraction! (i.e. )

When the operator of two terms is an multiplication, the 'commutative property of multiplication' is applicable. In algebraic terms, this gives .

Note that this does not apply for division! (i.e. , when )

'Associative' refers to the grouping of numbers. The associative property of addition implies that, when adding three or more terms, it doesn't matter how these terms are grouped. Algebraically, this gives . Note that this does not hold for subtraction, e.g.  (see the distributive property).

The associative property of multiplication implies that, when multiplying three or more terms, it doesn't matter how these terms are grouped. Algebraically, this gives . Note that this does not hold for division, e.g. .

The distributive property states that the multiplication of a number by another term can be distributed. For instance: . (Do not confuse this with the associative properties! For instance, .)

'Identity' refers to the property of a number that it is equal to itself. In other words, there exists an operation of two numbers so that it equals the variable of the sum. The additive identity property states that the sum of any number and 0 is that number: . This also holds for subtraction: .

The multiplicative identity property states that the product of any number and 1 is that number: . This also holds for division: .

The additive inverse property is somewhat like the opposite of the additive identity property. When an operation is the sum of a number and its opposite, and it equals 0, that operation is a valid algebraic operation. Algebraically, it states the following: . Additive inverse of 1 is (-1).

The multiplicative inverse property entails that when an operation is the product of a number and its reciprocal, and it equals 1, that operation is a valid algebraic operation. Algebraically, it states the following: . Multiplicative inverse of 2 is 1/2.

In addition to elementary algebra, or basic algebra, there are advanced forms of algebra, taught in colleges and universities, such as abstract algebra, linear algebra, and universal algebra. 
This includes how to use a matrix to solve many linear equations at once. Abstract algebra is the study of things that are found in equations, going beyond numbers to the more abstract with groups of numbers.

Many math problems are about physics and engineering. In many of these physics problems time is a variable. Time uses the letter t. Using the basic ideas in algebra can help reduce a math problem to its simplest form making it easier to solve difficult problems. Energy is e, force is f, mass is m, acceleration is a and speed of light is sometimes c.  This is used in some famous equations, like f = ma and e=mc^2 (although more complex math beyond algebra was needed to come up with that last equation).




#Article 22: Atom (2322 words)


Atoms are very small pieces of matter. There are many different types of atoms, each with its own name, mass and size.  These different types of atoms are called chemical elements.  The chemical elements are organized on the periodic table.  Examples of elements are hydrogen and gold.

Atoms are very small, but their exact size depends on the element.  Atoms range from 0.1 to 0.5 nanometers in width. One nanometer is about 100,000 times smaller than the width of a human hair. This makes atoms impossible to see without special tools. Scientists discover how they work and interact with other atoms through experiments.

Atoms can join together to make molecules: for example, two hydrogen atoms and one oxygen atom combine to make a water molecule. When atoms join together it is called a chemical reaction.

Atoms are made up of three kinds of smaller particles, called protons, neutrons and electrons. The protons and neutrons are heavier, and stay in the middle of the atom, which is called the nucleus. The nucleus is surrounded by a cloud of light-weight electrons, these are attracted to the protons in the nucleus by the electromagnetic force because they have opposite electric charges.

The number of protons an atom has defines what chemical element it is, this number is sometimes called its atomic number. For example, hydrogen has one proton and sulfur has 16 protons. Because the mass of neutrons and protons is very similar, and the mass of electrons is very small, we can call the amount of protons and neutrons in an atom its atomic mass.

Atoms move faster when they are in their gas form (because they are free to move) than they do in liquid form and solid matter. In solid materials, the atoms are tightly packed next to each other so they vibrate, but are not able to move (there is no room) as atoms in liquids do.

The word atom comes from the Greek (ἀτόμος) atomos, , from (ἀ)-, not, and τόμος, a cut. The first historical mention of the word atom came from works by the Greek philosopher Democritus, around 400 BC. Atomic theory stayed as a mostly philosophical subject, with not much actual scientific investigation or study, until the development of chemistry in the 1650s.

In 1777 French chemist Antoine Lavoisier defined the term element for the first time. He said that an element was any basic substance that could not be broken down into other substances by the methods of chemistry. Any substance that could be broken down was a compound.

In 1803, English philosopher John Dalton suggested that elements were tiny, solid balls made of atoms. Dalton believed that all atoms of the same element have the same mass. He said that compounds are formed when atoms of more than one element combine. According to Dalton, in a certain compound, the atoms of the compound's elements always combine the same way.

In 1827, British scientist Robert Brown looked at pollen grains in water under his microscope. The pollen grains appeared to be jiggling. Brown used Dalton's atomic theory to describe patterns in the way they moved. This was called brownian motion. In 1905 Albert Einstein used mathematics to prove that the seemingly random movements were caused by the reactions of atoms, and by doing this he conclusively proved the existence of the atom.
In 1869, Russian scientist Dmitri Mendeleev published the first version of the periodic table. The periodic table groups elements by their atomic number (how many protons they have. This is usually the same as the number of electrons).
Elements in the same column, or period, usually have similar properties. For example, helium, neon, argon, krypton and xenon are all in the same column and have very similar properties. All these elements are gases that have no colour and no smell. Also, they are unable to combine with other atoms to form compounds. Together they are known as the noble gases.

The physicist J.J. Thomson was the first person to discover electrons. This happened while he was working with cathode rays in 1897. He realized they had a negative charge, unlike protons (positive) and neutrons (no charge). Thomson created the plum pudding model, which stated that an atom was like plum pudding: the dried fruit (electrons) were stuck in a mass of pudding (protons). In 1909, a scientist named Ernest Rutherford used the Geiger–Marsden experiment to prove that most of an atom is in a very small space called the atomic nucleus. Rutherford took a photo plate and covered it with gold foil, and then shot alpha particles (made of two protons and two neutrons stuck together) at it.   Many of the particles went through the gold foil, which proved that atoms are mostly empty space. Electrons are so small they make up only 1% of an atom's mass.

In 1913, Niels Bohr introduced the Bohr model. This model showed that electrons travel around the nucleus in fixed circular orbits. This was more accurate than the Rutherford model. However, it was still not completely right. Improvements to the Bohr model have been made since it was first introduced.

In 1925, chemist Frederick Soddy found that some elements in the periodic table had more than one kind of atom.
For example, any atom with 2 protons should be a helium atom. Usually, a helium nucleus also contains two neutrons. However, some helium atoms have only one neutron. This means they truly are helium, because an element is defined by the number of protons, but they are not normal helium, either. Soddy called an atom like this, with a different number of neutrons, an isotope. To get the name of the isotope we look at how many protons and neutrons it has in its nucleus and add this to the name of the element. So a helium atom with two protons and one neutron is called helium-3, and a carbon atom with six protons and six neutrons is called carbon-12. However, when he developed his theory Soddy could not be certain neutrons actually existed. To prove they were real, physicist James Chadwick and a team of others created the mass spectrometer. The mass spectrometer actually measures the mass and weight of individual atoms. By doing this Chadwick proved that to account for all the weight of the atom, neutrons must exist.

In 1937, German chemist Otto Hahn became the first person to create nuclear fission in a laboratory. He discovered this by chance when he was shooting neutrons at a uranium atom, hoping to create a new isotope. However, he noticed that instead of a new isotope the uranium simply changed into a barium atom, a smaller atom than uranium. Apparently, Hahn had broken the uranium atom. This was the world's first recorded nuclear fission reaction. This discovery eventually led to the creation of the atomic bomb.

Further into the 20th century, physicists went deeper into the mysteries of the atom. Using particle accelerators they discovered that protons and neutrons were actually made of other particles, called quarks.

The most accurate model so far comes from the Schrödinger equation. Schrödinger realized that the electrons exist in a cloud around the nucleus, called the electron cloud. In the electron cloud, it is impossible to know exactly where electrons are. The Schrödinger equation is used to find out where an electron is likely to be. This area is called the electron's orbital.

The complex atom is made up of three main particles; the proton, the neutron and the electron. The isotope of Hydrogen Hydrogen-1 has no neutrons, just the one proton and one electron. Protons have a positive electric charge and electrons have a negative charge.  A positive hydrogen ion has no electrons, just the one proton.  These two examples are the only known exceptions to the rule that all other atoms have at least one proton, one neutron and one electron each.

Electrons are by far the smallest of the three atomic particles, their mass and size is too small to be measured using current technology. They have a negative charge. Protons and neutrons are of similar size and weight to each other, protons are positively charged and neutrons have no charge.
Most atoms have a neutral charge; because the number of protons (positive) and electrons (negative) are the same, the charges balance out to zero. However, in ions (different number of electrons) this is not always the case, and they can have a positive or a negative charge. Protons and neutrons are made out of quarks, of two types; up quarks and down quarks. A proton is made of two up quarks and one down quark and a neutron is made of two down quarks and one up quark.

The nucleus is in the middle of an atom. It is made up of protons and neutrons. Usually in nature, two things with the same charge repel or shoot away from each other. So for a long time it was a mystery to scientists how the positively charged protons in the nucleus stayed together. They solved this by finding a particle called a gluon. Its name comes from the word glue as gluons act like atomic glue, sticking the protons together using the strong nuclear force. It is this force which also holds the quarks together that make up the protons and neutrons.

The number of neutrons in relation to protons defines whether the nucleus is stable or goes through radioactive decay. When there are too many neutrons or protons, the atom tries to make the numbers the same by getting rid of the extra particles. It does this by emitting radiation in the form of alpha, beta or gamma decay. Nuclei can change through other means too. Nuclear fission is when the nucleus splits into two smaller nuclei, releasing a lot of stored energy. This release of energy is what makes nuclear fission useful for making bombs and electricity, in the form of nuclear power.
The other way nuclei can change is through nuclear fusion, when two nuclei join together, or fuse, to make a heavier nucleus. This process requires extreme amounts of energy in order to overcome the electrostatic repulsion between the protons, as they have the same charge. Such high energies are most common in stars like our Sun, which fuses hydrogen for fuel.

Electrons orbit, or travel around, the nucleus. They are called the atom's electron cloud. They are attracted towards the nucleus because of the electromagnetic force. Electrons have a negative charge and the nucleus always has a positive charge, so they attract each other.
Around the nucleus, some electrons are further out than others, in different layers. These are called electron shells. In most atoms the first shell has two electrons, and all after that have eight. Exceptions are rare, but they do happen and are difficult to predict. The further away the electron is from the nucleus, the weaker the pull of the nucleus on it. This is why bigger atoms, with more electrons, react more easily with other atoms.
The electromagnetism of the nucleus is not strong enough to hold onto their electrons and atoms lose electrons to the strong attraction of smaller atoms.

Some elements, and many isotopes, have what is called an unstable nucleus. This means the nucleus is either too big to hold itself together or has too many protons or neutrons. When this happens the nucleus has to get rid of the excess mass or particles. It does this through radiation. An atom that does this can be called radioactive. Unstable atoms continue to be radioactive until they lose enough mass/particles that they become stable. All atoms above atomic number 82 (82 protons, lead) are radioactive.

There are three main types of radioactive decay; alpha, beta and gamma.

Every radioactive element or isotope has what is named a half-life. This is how long it takes half of any sample of atoms of that type to decay until they become a different stable isotope or element. Large atoms, or isotopes with a big difference between the number of protons and neutrons will therefore have a long half life, because they must lose more neutrons to become stable.

Marie Curie discovered the first form of radiation. She found the element and named it radium. She was also the first female recipient of the Nobel Prize.

Frederick Soddy conducted an experiment to observe what happens as radium decays. He placed a sample in a light bulb and waited for it to decay. Suddenly, helium (containing 2 protons and 2 neutrons) appeared in the bulb, and from this experiment he discovered this type of radiation has a positive charge.

James Chadwick discovered the neutron, by observing decay products of different types of radioactive isotopes. Chadwick noticed that the atomic number of the elements was lower than the total atomic mass of the atom. He concluded that electrons could not be the cause of the extra mass because they barely have mass.

Enrico Fermi, used the neutrons to shoot them at uranium. He discovered that uranium decayed a lot faster than usual and produced a lot of alpha and beta particles. He also believed that uranium got changed into a new element he named hesperium.

Otto Hahn and Fritz Strassmann repeated Fermi's experiment to see if the new element hesperium was actually created. They discovered two new things Fermi did not observe. By using a lot of neutrons the nucleus of the atom would split, producing a lot of heat energy. Also the fission products of uranium were already discovered: thorium, palladium, radium, radon and lead.

Fermi then noticed that the fission of one uranium atom shot off more neutrons, which then split other atoms, creating chain reactions. He realised that this process is called nuclear fission and could create huge amounts of heat energy.

That very discovery of Fermi's led to the development of the first nuclear bomb code-named 'Trinity'.




#Article 23: Astronomy (1949 words)


Astronomy (from the Greek astron (ἄστρον) meaning star and nomos (nόμος) meaning law) is the scientific study of celestial bodies such as stars, planets, comets, and galaxies

The objects studied include stars, galaxies, planets, moons, asteroids, comets and nebulae. Phenomena outside the Earth's atmosphere are also studied. That includes supernovae explosions, gamma ray bursts, and cosmic microwave background radiation. Astronomy concerns the development, physics, chemistry, meteorology and movement of celestial bodies, as well as the structure and development of the Universe.

Astronomy is one of the oldest sciences. Ancient people used the positions of the stars to navigate, and to find when was the best time to plant crops. Astronomy is very similar to astrophysics. A related subject, cosmology, is concerned with studying the Universe as a whole, and the way the universe changed over time. Astronomy is not the same as astrology, the belief that motion of the stars and the planets may affect human lives.

Since the 20th century there have been two main types of astronomy, observational and theoretical astronomy. Observational astronomy uses telescopes and cameras to  or look at stars, galaxies and other astronomical objects. Theoretical astronomy uses maths and computer models to explain the observations and predict what might happen.  Working together, theories predict what should happen and observations show whether the predictions work.  The main work of astronomy is to explain puzzling features of the universe.  For thousands of years the most important issue was the motions of planets; now many other topics are studied.

Early astronomers used only their eyes to look at the stars. They made maps of the constellations and stars for religious reasons and calendars to work out the time of year. Early civilisations such as the Maya people and the Ancient Egyptians built simple observatories and drew maps of the stars positions. They also began to think about the place of Earth in the universe. For a long time people thought Earth was the center of the universe, and that the planets, the stars and the sun went around it.  This is known as geocentrism.

Ancient Greeks tried to explain the motions of the sun and stars by taking measurements. A mathematician named Eratosthenes was the first who measured the size of the Earth and proved that the Earth is a sphere. A theory by another mathematician named Aristarchus was, that the sun is in the center and the Earth is moving around it. This is known as heliocentrism. Only a few people thought it was right. The rest continued to believe in the geocentric model. Most of the names of constellations and stars come from Greeks of that time.

Arabic astronomers made many advancements during the Middle Ages including improved star maps and ways to estimate the size of the Earth.  They also learned from the ancients by translating Greek books into Arabic.

During the renaissance a priest named Nicolaus Copernicus thought, from looking at the way the planets moved, that the Earth was not the center of everything. Based on previous works, he said that the Earth was a planet and all the planets moved around the sun. This brought back the old idea of heliocentrism. A physicist called Galileo Galilei built his own telescopes, and used them to look more closely at the stars and planets for the first time. He agreed with Copernicus. The Catholic Church decided that Galileo was wrong. He had to spend the rest of his life under house arrest. Heliocentric ideas were soon improved by Johannes Kepler and Isaac Newton who invented the theory of gravity.

After Galileo, people made better telescopes and used them to see farther objects such as the planets Uranus and Neptune. They also saw how stars were similar to our Sun, but in a range of colours and sizes. They also saw thousands of other faraway objects such as galaxies and nebulae.

The 20th century after 1920 saw important changes in astronomy.

In the early 1920s it began to be accepted that the galaxy in which we live, the Milky Way, is not the only galaxy. The existence of other galaxies was settled by Edwin Hubble, who identified the Andromeda nebula as a different galaxy. It was also Hubble who proved that the universe was expanding. There were many other galaxies at large distances and they are receding, moving away from our galaxy. That was completely unexpected.

In 1931, Karl Jansky discovered radio emission from outside the Earth when trying to isolate a source of noise in radio communications, marking the birth of radio astronomy and the first attempts at using another part of the electromagnetic spectrum to observe the sky. Those parts of the electromagnetic spectrum that the atmosphere did not block were now opened up to astronomy, allowing more discoveries to be made.

The opening of this new window on the Universe saw the discovery of entirely new things, for example pulsars, which sent regular pulses of radio waves out into space. The waves were first thought to be alien in origin because the pulses were so regular that it implied an artificial source.

The period after World War 2 saw more observatories where large and accurate telescopes are built and operated at good observing sites, normally by governments. For example, Bernard Lovell began radio astronomy at Jodrell Bank using leftover military radar equipment. By 1957, the site had the largest steerable radio telescope in the world. Similarly, the end of the 1960s saw the start of the building of dedicated observatories at Mauna Kea in Hawaii, a good site for visible and infra-red telescopes thanks to its high altitude and clear skies.

The next great revolution in astronomy was thanks to the birth of rocketry.  This allowed telescopes to be placed in space on satellites.

Space telescopes gave access, for the first time in history, to the entire electromagnetic spectrum including rays that had been blocked by the atmosphere.  The X-rays, gamma rays, ultraviolet light and parts of the infra-red spectrum were all opened to astronomy as observing telescopes were launched.  As with other parts of the spectrum, new discoveries were made.

From 1970s satellites were launched to be replaced with more accurate and better satellites, causing the sky to be mapped in nearly all parts of the electromagnetic spectrum.

Discoveries broadly come in two types:  bodies and phenomena.  Bodies are things in the Universe, whether it is a planet like our Earth or a galaxy like our Milky Way.  Phenomena are events and happenings in the Universe.

For convenience, this section has been divided by where these astronomical bodies may be found: those found around stars are solar bodies, those inside galaxies are galactic bodies and everything else larger are cosmic bodies.

Diffuse Objects:

Compact Stars:

Burst events are those where there is a sudden change in the heavens that disappears quickly.  These are called bursts because they are normally associated with large explosions producing a burst of energy.  They include: 

Periodic events are those that happen regularly in a repetitive way.  The name periodic comes from period, which is the length of time required for a wave to complete one cycle.  Periodic phenomena include: 

Noise phenomena tend to relate to things that happened a long time ago.  The signal from these events bounce around the Universe until it seems to come from everywhere and varies little in intensity.  In this way, it resembles noise, the background signal that pervades every instrument used for astronomy.  The most common example of noise is static seen on analogue televisions.  The principal astronomical example is: Cosmic background radiation.

There are way  astronomers can get better pictures of the heavens.  Light from a distant source reaches a sensor and gets measured, normally by a human eye or a camera.  For very dim sources, there may not be enough light particles coming from the source for it to be seen.  One technique that astronomers have for making it visible is using integration (which is like longer exposures in photography).

Astronomical sources do not move much: only the rotation and movement of the Earth causes them to move across the heavens. As light particles reach the camera over time, they hit the same place making it brighter and more visible than the background, until it can be seen.

Telescopes at most observatories (and satellite instruments) can normally track a source as it moves across the heavens, making the star appear still to the telescope and allowing longer exposures.  Also, images can be taken on different nights so exposures span hours, days or even months. In the digital era, digitised pictures of the sky can be added together by computer, which overlays the images after correcting for movement.

Adaptive optics means changing the shape of the mirror or lens while looking at something, to see it better.

Data analysis is the process of getting more information out of an astronomical observation than by simply looking at it. The observation is first stored as data.  This data will then have various techniques used to analyse it.

Fourier analysis in mathematics can show if an observation (over a length of time) is changing periodically (changes like a wave).  If so, it can extract the frequencies and the type of wave pattern, and find many things including new planets.

A good example of a fields comes from pulsars which pulse regularly in radio waves.  These turned out to be similar to some (but not all) of a type of bright source in X-rays called a Low-mass X-ray binary.  It turned out that all pulsars and some LMXBs are neutron stars and that the differences were due to the environment in which the neutron star was found. Those LMXBs that were not neutron stars turned out to be black holes.

This section attempts to provide an overview of the important fields of astronomy, their period of importance and the terms used to describe them. It should be noted that astronomy in the Modern Era has been divided mainly by electromagnetic spectrum, although there is some evidence this is changing.

Solar astronomy is the study of the Sun. The Sun is the closest star to Earth at around 92 million (92,000,000) miles away. It is the easiest to observe in detail. Observing the Sun can help us understand how other stars work and are formed. Changes in the Sun can affect the weather and climate on Earth. A stream of charged particles called the Solar wind is constantly sent off from the Sun. The Solar Wind hitting the Earth's magnetic field causes the northern lights. Studying the Sun helped people understand how nuclear fusion works.

Planetary Astronomy is the study of planets, moons, dwarf planets, comets and asteroids as well as other small objects that orbit stars. The planets of our own Solar System have been studied in depth by many visiting spacecraft such as Cassini-Huygens (Saturn) and the Voyager 1 and 2.

Galactic Astronomy is the study of distant galaxies.  Studying distant galaxies is the best way of learning about our own galaxy, as the gases and stars in our own galaxy make it difficult to observe.  Galactic Astronomers attempt to understand the structure of galaxies and how they are formed through the use of different types of telescopes and computer simulations.

Gravitational wave astronomy is the study of the Universe in the gravitational wave spectrum.  So far, all astronomy that has been done has used the electromagnetic spectrum.  Gravitational Waves are ripples in spacetime emitted by very dense objects changing shape, which include white dwarves, neutron stars and black holes.  Because no one has been able to detect gravitational waves directly, the impact of Gravitational Wave Astronomy has been very limited.




#Article 24: Architecture (754 words)


Architecture is designing the structures of buildings. It uses both art and engineering. Examples include houses, churches, hotels, office buildings, roads, viaducts, tunnels and bridges. 

Architecture is the profession of an architect. Usually, a person must  at an institution of higher education (university) to become an architect. There were architects long before there was higher education. They learnt by being an apprentice to an established architect. 

Architecture can do small designs, such as for a garage, or large designs, such as for a whole city. The capital cities of Brasília, and Canberra were designed. Architecture often overlaps with structural engineering, and architects and engineers often work together.

In the past, people built s and wood houses to protect themselves from the weather. For safety, they were often close together. Great civilizations like the Ancient Egyptians built large temples and structures, like the Great Pyramids of Giza. The Ancient Greeks and Romans made what we now call Classical Architecture. The Romans, working over 2000 years ago, copied the arch from the Etruscans, who copied it from the Mesopotamians. 

Classical architecture was formal, and it always obeyed laws. It used symmetry, which really means , and it used proportion between shapes. The Golden Mean was a rule which said, (to put it simply) if you are making a room, or any other thing, it will work best if you always make the long side 1.6 times as long as the short side. There are many 'laws' in classical architecture, like how high the middle of an arched bridge needs to be (which depends on how wide the bridge needs to be). These laws were learned from thousands of years of experience and they are often used today. However, today more notice is taken of specific facts, such as what wind speeds occur once or twice in a century. Several bridges have blown down because that was not properly taken into consideration.

In some parts of the world, like India, the architecture is famous for carving the stone on temples and palaces. Different architectural styles occur in China, Japan, Southeast Asia, Africa, Mexico, and Central and South America.

Architects in Western Europe in the Middle Ages made Romanesque architecture, then Gothic architecture. Gothic buildings have tall, pointed windows and arches. Many churches have Gothic architecture. Castles were also built at this time. In Eastern Europe, churches usually had domes. People added their own ideas and decoration to the Classical Architecture of the past. The Renaissance brought a return to classical ideas. 

In the late 18th century with the Industrial Revolution, people began to invent machines to make things quickly and cheaply. Many factories and mills were built during, or after this revolution. Decades later, in the Victorian era, architects like George Fowler Jones and Decimus Burton still followed the Gothic style to build new churches. Up to this point, buildings were limited in size and style by the strength of the wood and masonry used to construct them. Gothic cathedrals were among the largest buildings because the gothic arch when combined with buttresses allowed stone buildings to be built taller. For example, the cathedral in Ulm, Germany is over 500 feet tall. However, building with stone has its limits, and building too tall could result in collapse. This happened to the Beauvais Cathedral, which was never completed. 

Towards the end of the 19th Century with a second Industrial Revolution, steel became much cheaper. Architects began to use inventions like metal girders and reinforced concrete to build. An example is the Eiffel Tower in Paris. Buildings can now be built taller than ever before. We call them skyscrapers. This new technology has made us free from traditional limitations, and because of the new possibilities presented by these materials, many traditional methods of construction and ideas about style were reevaluated, replaced, or abandoned. Cheap, strong glass soon brought transparent exterior walls, especially for office buildings.

Modernism is the name for the architectural style which developed because of these new building technologies, and its beginnings can been seen as early as 1890. Modernism can also refer to a specific group of architects and buildings from the early to late 20th century, and so may not be the proper term to use for many building built since then, which are sometimes called post-modern.

Many of the world's greatest structures were built by modern-day architects such as Frank Lloyd Wright; Sir Hugh Casson; Norman Foster; I. M. Pei; Adrian Smith; Edward Durell Stone; Frank Gehry; Fazlur Khan; Gottfried Böhm; and Bruce Graham.




#Article 25: Anatomy (207 words)


Anatomy is the study of the bodies of people and other animals. Anatomy is the study of the inside of the body and outside the body. Anatomy notes the position and structure of organs such as muscles, glands and bones. A person who studies anatomy is an anatomist. 

The history of anatomy dates back to 1600 BC when Egyptians began studying human anatomy. They discovered the functions of many organs like the liver, spleen, kidneys, heart etc. and were the first to discover the structure and functions of the lymphatic system.

For long periods the dissection of deceased people was forbidden, and correct ideas about human anatomy was a long time coming.

Academic human anatomists are usually employed by universities, medical schools and teaching hospitals. They are often involved in teaching, and research. Gross anatomy studies parts of the body that are big enough to see. Micro-anatomy studies smaller parts.

There are different organ systems, such as the cardiovascular system, also known as the circulatory system (the system that gets blood around the body), the muscular system (the system that contains muscles), the nervous system (the system that controls the nerves,and the brain) and the skeleton (the bones).

Anatomy, physiology and biochemistry are similar basic medical sciences.




#Article 26: Asteroid (306 words)


An asteroid is a space rock. It is a small object in the Solar System that travels around the Sun. It is like a planet but smaller. They range from very small (smaller than a car) to 600 miles (1000 km) across. A few asteroids have asteroid moon.

The name asteroid means like a star in the ancient Greek language. Asteroids may look like small stars in the sky, but they really do move around the Sun, while stars only seem to move because the Earth spins. Like planets, asteroids do not make their own light. Because of this, some people think asteroids is not a good name, and think that the name planetoid (like a planet) would be a better name.

Giuseppe Piazzi found the first asteroid, in 1801. He called it Ceres, and it is the biggest object in the asteroid belt. Others, like Juno, Pallas, and Vesta were found later. In the 1850s so many had been found, that they were numbered by a Minor planet designation starting with 1 Ceres. Today, astronomers using computerized telescopes find thousands of asteroids every month. Asteroid impact prediction is one of the purposes.  

Asteroids are the leftover rock and other material from the formation of the Solar System. These rocks were too small to come together to make a planet. Some are made of carbon or metal. Depending on what's on the surface, they are classified into various asteroid spectral types including Type M (metal), Type S (stone), and Type C (carbon).

Most asteroids in our Solar System are in the asteroid belt between Mars and Jupiter. Many are not in the main asteroid belt. The ones that come close to Earth are called Near-Earth asteroids. Many scientists think asteroids striking the Earth killed off all the dinosaurs and caused some of the other extinction events.




#Article 27: Afghanistan (2253 words)


Afghanistan (, also pronounced //; Pashto/Dari: , Pashto:  , Dari:  ), officially the Islamic Republic of Afghanistan, is a country located in Central Asia and South Asia. It has borders with Pakistan in the south and east, Iran in the west, Turkmenistan, Uzbekistan and Tajikistan in the north, and China in the far northeast.

In early times people passed through it with animals and other goods as it connected China and India with Central Asia and the Middle East. More recently, Afghanistan has been damaged by many years of war. This has resulted in there not being enough jobs.

The country is around  in size or area. There are 30 million people in Afghanistan. There are about 3 million Afghan refugees (people who had to leave the country) who are in Pakistan and Iran for some time. In 2011, its capital, Kabul, had about 3,691,400 people living in it.

Afghanistan has a continental climate with hot summers and cold winters. Having no water sometimes causes problems for farmers. Sandstorms happen a lot in the desert.

Southern Afghanistan has not many plants because it is dry. There are more plants where there is more water. Mountains have forests of pine and fir, cedar, oak, walnut, alder, and ash trees.

Afghanistan's wild animals live in the mountains. There are wolves, foxes, jackals, bears, and wild goats, gazelles, wild dogs, camels, and wild cats such as the snow leopard in the country. The birds are falcons, eagles and vultures. The Rhesus Macaque and the red flying squirrel are also in Afghanistan.

Many years of war, hunting, and years of no water have killed animals in Afghanistan. There used to be tigers in Afghanistan, but now there aren't any. Bears and wolves are almost gone.

Many people have moved through or invaded the land of Afghanistan. Today's people of Afghanistan are known as Afghans. They have many traits passed down from these previous peoples.

The largest group of people are the Pashtuns. These make up about half the population. Tajiks are the second-largest ethnic group, making up about one-fifth of the population. Before the 20th century, Tajiks were called Sarts and some come from the Iranian peoples. Most Pashtuns are also related to the Iranian peoples. Some Pashtuns and Tajiks marry each other but at the same time they are rivals. The third-largest group are the Hazaras. They are native to the Hazaristan area in central Afghanistan. The country's other groups include the Uzbek, Aimaq, Turkmen, Nuristani, Baloch, Pashayi and a few others.

Dari-Persian and Pashto are the official languages of Afghanistan. Many people speak both languages. Both are Indo-European languages from the Iranian languages sub-family. They are usually written with the Arabic alphabet. Uzbek and Turkmen are widely spoken in the north and Nuristani and Pashai are spoken in the east. Almost all Afghans follow the religion of Islam.

Afghanistan is a largely rural country. This means there are only a few major cities. About one fifth of the population live in cities. Kabul, the capital, is the largest city. It is  south of the Hindu Kush range and alongside the Kabul River. Other cities in Afghanistan include Kandahar, Herat, Mazar-e Sharif, and Jalalabad. The rural population is made up of farmers and nomads. The farmers live mainly in small villages along the rivers. The nomads live in tents while moving from place to place with their animals and belongings. Some people live in the high central mountains. Some live in the deserts in the south and southwest. Millions of people left Afghanistan to get away from the wars that happened in the late 20th and early 21st centuries. Most of them lived in neighboring Pakistan and Iran.

Afghanistan is in the path of important trade routes that connect southern and eastern Asia to Europe and the Middle East. Because of this, many empire builders have decided to rule over the area. Signs that these emperors were near Afghanistan still exist in many parts of the country.

Archaeologists digging a cave in what is now northeastern Afghanistan (in Badakhshan), discovered that people lived in the country as early as 100,000 years ago. They found the skull of a Neanderthal, or early human, as well as tools from about 30,000 years ago. In other parts of Afghanistan, archaeologists uncovered pottery and tools that are 4,000 to 11,000 years old—evidence that Afghans were among the first people in the world to grow crops and raise animals. 

Farmers and herders settled in the plains surrounding the Hindu Kush as early as 7000 B.C. These people may have grown rich off the lapis lazuli they found along riverbeds, which they traded to early city sites to the west, across the Iranian plateau and Mesopotamia. As farms and villages grew and thrived in Afghanistan, these ancient people eventually invented irrigation (digging ditches for water so it flows to crops) that allowed them to grow crops on the northern Afghanistan desert plains. This civilization (advanced state of organization) is today called BMAC (Bactria–Margiana Archaeological Complex), or the Oxus civilization.

The Oxus civilization expanded as far east as western edge of the Indus Valley during the period between 2200 and 1800 B.C. These people, who were the ancestors of the Indo-Aryans, used the term Aryan to identify their ethnicity, culture, and religion. Scholars know this when they read the ancient texts of these people; the Avesta of Iranian people and the Vedas of Indo-Aryans.

Before the middle of the sixth century BCE, the land was held by the Medes.
Then the Achaemenids took over control of the land and made it part of the Persian empire. Alexander the great defeated and conquered the Persian Empire in 330 BCE. He founded some cities in the area. The people used Greek culture and language. After Alexander, Greco-Bactrians, Scythians, Kushans, Parthians and Sassanians ruled the area.

Kushans spread Buddhism from India in the 1st century BCE, and Buddhism remained an important religion in the area until the Islamic conquest in the 7th century CE.

In the 10th century, the local Ghaznavids turned Ghazni into their capital and firmly established Islam throughout all areas of Afghanistan, except the Kafiristan region in the northeast. Mahmud of Ghazni, a great Ghaznavid sultan, conquered the Multan and Punjab region, and carried raids into the heart of India. Mohammed bin Abdul Jabbar Utbi (Al-Utbi), a historian from the 10th century, wrote that thousands of Afghans were in the Ghaznavid army. The Ghaznavid dynasty was replaced by the Ghorids of Ghor in the late 12th century, who reconquered Ghaznavid territory in the name of Islam and ruled it until 1206. The Ghorid army also included ethnic Afghans.

Afghanistan was recognized as Khorasan, meaning land of the rising sun, which was a prosperous and independent geographic region reaching as far as the Indus River.

All the major cities of modern Afghanistan were centers of science and culture in the past. The New Persian literature arose and flourished in the area. The early Persian poets such as Rudaki were from what is now Afghanistan. Moreover, Ferdowsi, the author of Shahnameh, the national epic of Iran, and Rumi, the famous Sufi poet, were also from modern-day Afghanistan. It has produced scientists such as Avicenna, Al-Farabi, Al-Biruni, Omar Khayyám, Al-Khwarizmi, and many others who are widely known for their important contributions in areas such as mathematics, astronomy, medicine, physics, geography, and geology. It remained the cultural capital of Persia until the devastating Mongol invasion in the 13th century.  

Timur, the Turkic conqueror, took over in the end of the 14th century and began to rebuild cities in this region. Timur's successors, the Timurids (1405–1507), were great patrons of learning and the arts who enriched their capital city of Herat with fine buildings. Under their rule Afghanistan enjoyed peace and prosperity.

Between south of the Hindu Kush and the Indus River (today's Pakistan) was the native land of the Afghan tribes. They called this land Afghanistan (meaning land of the Afghans). The Afghans ruled the rich northern Indian subcontinent with their capital at Delhi. From the 16th to the early 18th century, Afghanistan was disputed between the Safavids of Isfahan and the Mughals of Agra who had replaced the Lodi and Suri Afghan rulers in India. The Safavids and Mughals occasionally oppressed the native Afghans but at the same time the Afghans used each empire to punish the other. In 1709, the Hotaki Afghans rose to power and completely defeated the Persian Empire. Then they marched towards the Mughals of India and nominally defeated them with the help of the Afsharid forces under Nader Shah Afshar.

In 1747, after Nader Shah of Persia was killed, a great leader named Ahmad Shah Durrani united all the different Muslim tribes and established the Afghan Empire (Durrani Empire). He is considered the founding father of the modern state of Afghanistan while Mirwais Hotak is the grandfather of the nation.

During the 1800s, Afghanistan became a buffer zone between two powerful empires, British India and Russia. As British India advanced into Afghanistan, Russia felt threatened and expanded southward across Central Asia. To stop the Russian advance, Britain tried to make Afghanistan part of its empire but the Afghans fought wars with British-led Indians from 1839 to 1842 and from 1878 to 1880. After the third war in 1919, Afghanistan under King Amanullah gained respect and recognition as a completely independent state.

The Kingdom of Afghanistan was a constitutional monarchy established in 1926. It was the successor state to the Emirate of Afghanistan. On 27 September 1934, during the reign of Zahir Shah, the Kingdom of Afghanistan joined the League of Nations.  During World War II, Afghanistan remained neutral. It pursued a diplomatic policy of non-alignment.

The creation of Pakistan in 1947 as its eastern neighbor created problems. In 1973, political crises led to the overthrow of the king. The country's new leader ended the monarchy and made Afghanistan a republic. In 1978, a Communist political party supported by the Soviet Union seized control of Afghanistan's government. This move sparked rebellions throughout the country. The government asked the Soviet Union for military assistance. The Soviets took advantage of the situation and invaded Afghanistan in December 1979.

Most people in Afghanistan opposed the sudden Soviet presence in their country. For nearly a decade, anti-Communist Islamic forces known as Mujahideen were trained inside neighboring Pakistan to fight the Soviets and the Afghan government. The United States and other anti-Soviet countries supported the Mujahideen. In the long war, over one million Afghan civilians were killed. The Soviet Army also lost more than 15,000 soldiers in that war. Millions of Afghans left their country to stay safe in neighboring Pakistan and Iran. In 1989 the Soviet Army withdrew the last of its troops.

After the Soviets left, different Afghan warlords began fighting for control of the country. The warlords received support from other countries, including neighboring Pakistan and Iran. A very conservative Islamic group known as the Taliban emerged in an attempt to end the civil war. By the late 1990s the Taliban had gained control over 95% of Afghanistan. A group known as the Northern Alliance, based in northern Afghanistan near the border with Tajikistan, continued to fight against the Taliban.

The Taliban ruled Afghanistan according to their strict version of Islamic law. People whom the Taliban believed violated these laws were given cruel punishments. In addition, the Taliban completely restricted the rights of women. Because of such policies, most countries refused to recognize the Taliban government. Only Pakistan, Saudi Arabia and the United Arab Emirates (UAE) accepted them as the official government.

The Taliban also angered other countries by allowing suspected terrorists to live freely in Afghanistan. Among them were Osama bin Laden and members of the al-Qaeda terrorist network. In September 2001, the United States blamed bin Laden for the terrorist attacks on the World Trade Center in New York City and the Pentagon outside Washington, D.C. The Taliban refused to hand him over to the United States. In response, the United States and its allies launched a bombing campaign against al-Qaeda in October 2001. Within months the Taliban abandoned Kabul, and a new government led by Hamid Karzai came to power, but fighting between the Taliban and US-led armies continued.  Taliban fighters have gone into Afghanistan from neighboring Pakistan.  Afghans accuse Pakistan's military of being behind the Taliban militants but Pakistan has rejected this and stated that a stable Afghanistan is in Pakistan's own interest.

In December 2004, Hamid Karzai became the first democratically elected president of Afghanistan. NATO began rebuilding Afghanistan, including its military and government institutions.  Many schools and colleges were built.  Freedom for women has improved. Women can study, work, drive, and run for office.  Many Afghan women work as politicians, some are ministers while at least one is a mayor.  Others have opened businesses, or joined the military or police. Afghanistan's economy has also improved dramatically, and NATO agreed in 2012 to help the country for at least another 10 years after 2014.  In the meantime, Afghanistan improved diplomatic ties with many countries in the world and continues.

Afghanistan is a newly formed democracy. Under the new constitution, the president and two vice presidents are elected every five years. The International Security Force Assistance (ISAF) helps the government maintain peace and rebuild the country.

The government still faces problems with the Taliban, internal security, and public services.

As of 2004, there are thirty-four provinces.  Each province is divided into districts. (For cities see List of cities in Afghanistan.)




#Article 28: Angola (236 words)


Angola, (), officially the Republic of Angola, is a country in southern Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city.

Angola is a member state of the African Union, the Community of Portuguese Language Countries, the Latin Union, South Atlantic Peace and Cooperation Zone and the Southern African Development Community.

Portugal built up its power in Angola from the late 15th to the middle 20th century.

After independence there was a civil war from 1975 to 2002. Cuba and the Soviet Bloc supported the ruling People's Movement for the Liberation of Angola (MPLA). South Africa supported the insurgent anti-communist National Union for the Total Independence of Angola (UNITA). The war ended after the rebel leader was killed.

Angola is the world's twenty-third largest country. Angola is bordered by Namibia to the south, Zambia to the east, the Democratic Republic of the Congo to the north-east, and the South Atlantic Ocean to the west.

Angola's average temperature on the coast is  in the winter and  in the summer. It has two seasons; dry (May to October) and hot rainy (November to April).

Angola had a population of 25,789,024 in 2014.

Angola is divided into eighteen provinces.

See List of settlements in Angola for the cities and towns in the country.




#Article 29: Argentina (960 words)


Argentina (officially the Argentine Republic)  is a country in South America. Argentina is the second-largest country in South America and the eighth-largest country in the world.

Spanish is the most spoken language, and the official language, but many other languages are spoken. There are minorities speaking Italian, German, English, Quechua and even Welsh in Patagonia.

In eastern Argentina is Buenos Aires, the capital of Argentina, it is also one of the largest cities in the world. In order by number of people, the largest cities in Argentina are Buenos Aires, Córdoba, Rosario, Mendoza, La Plata, Tucumán, Mar del Plata,  Salta, Santa Fe, and Bahía Blanca.

Argentina is between the Andes mountain range in the west and the southern Atlantic Ocean in the east and south. It is bordered by Paraguay and Bolivia in the north, Brazil and Uruguay in the northeast, and Chile in the west and south. It also claims the Falkland Islands (Spanish: Islas Malvinas) and South Georgia and the South Sandwich Islands.  Most citizens of the Argentine Republic are descendants of immigrants from Europe.  They are united by citizenship and not necessarily by ethnicity. Most Argentinians embrace both their ethnic origins and Argentinian nationality.

The name Argentina comes from the Latin argentum (silver) as the Spanish conquistadors believed the area had silver. In the Americas (South and North), Canada, US, Brazil and Argentina are the largest countries (in that order).

The oldest signs of people in Argentina are in the Patagonia (Piedra Museo, Santa Cruz), and are more than 13,000 years old. In 1480 the Inca Empire conquered northwestern Argentina, making it part of the empire. In the northeastern area, the Guaraní developed a culture based on yuca and sweet potato however typical dishes all around Argentina are pasta, red wines (Italian influence) and beef.

Other languages spoken are Italian, English and German. Lunfardo is Argentinean slang and is a mix of Spanish and Italian. Argentinians are said to speak Spanish with an Italian accent.

Argentina declared independent from Spain in 1816, and achieved it in a War led by José de San Martín in 1818. Many immigrants from Europe came to the country. By the 1920s it was the 7th wealthiest country in the world, but it began a decline after this. In the 1940s, following the infamous decade where the country's politics were not stable, Juan Peron came to power. Peron was one of the most important people in the country's history and many politicians today call themselves Peronist. Peron was forced out of power in 1955. After spending years in exile he returned to power in the 1970s.

In 1976, the country was falling into chaos, and the military took power. This was not the first time the military had done this. Leading the new government was Jorge Rafael Videla. Videla was one of history's most brutal dictators. Thousands of people disappeared or were killed during his time as president. Videla retired in 1980.

One of his successors was another general turned dictator, Leopoldo Galtieri. By the time Galtieri was in office in 1981 the dictatorship became unpopular. To stir up support, Galtieri ordered an invasion of the Falkland Islands, starting the Falklands War.  Argentina lost the war, and soon the country fell into chaos again. Galtieri was removed from power and eventually democracy was restored. Galtieri and Videla would be charged with crimes against humanity because of the mass murder and other crimes that they ordered as president.

In the early 21st century Argentina is one of the most important countries in Latin America, though it still has many problems. It has a large economy and is influential in the southern cone of South America and a member of the G20 developing nations.

Argentina is a federal republic. The people of Argentina vote for a President to rule them and Senators and Deputies to speak for them and make laws for them. The President is Alberto Fernández since December 2019.

Argentina is divided into 23 provinces (provincias; singular: provincia), and 1 city (commonly known as capital federal):

Argentina is almost 3,700 km long from north to south, and 1,400 km from east to west (maximum values). It can be divided into three parts: the Pampas in the central part of the country, Patagonia in the southern part down to Tierra del Fuego; and the Andes mountain range along the western border with Chile, with the highest point in the province of Mendoza. Cerro Aconcagua, at 6,960 metres (22,834 ft), is the Americas' highest mountain.

The most important rivers include the River Plate, Paraguay, Bermejo, Colorado, Uruguay and the largest river, the Paraná. River Plate was incorrectly translated though, and should have been translated to English as River of (the) Silver. River Plate is also a famous Buenos Aires soccer team.

See List of cities in Argentina for the many places people live in Argentina.

The majority of the Argentineans are descendants of Europeans mainly from Spain, Italy, Germany, Ireland, France, other Europeans countries and Mestizo representing more than 90% of the total population of the country. More than 300,000 Roma gypsies live in Argentina. Since the 1990s, Romanian, Brazilian and Colombian gypsies arrived in Argentina.

Football or soccer is the most popular sport, although the national sport of the country is Pato. Argentina has a number of highly ranked Polo players. Field hockey (for women) rugby and golf are also favorites.

Argentina is a Christian country. Most of Argentina's people (80 percent) are Roman Catholic. Argentina also has the largest population of Jewish community after Israel and US. Middle Eastern immigrants who were Muslims converted to Catholicism, but there are still Muslims as well.

Medicine is socialized and so is education, making Argentina's literacy rate about 98%. State University is free as well.




#Article 30: Austria (580 words)


Austria (; officially called Republic of Austria), is a country in Central Europe. Around Austria there are the countries of Germany, Czech Republic, Slovakia, Hungary, Slovenia, Italy, Switzerland, and Liechtenstein. Currently, the chancellor is Sebastian Kurz. The previous chancellor was Brigitte Bierlein (2019). Austria has been a member-state of the United Nations since 1955 the European Union since 1995 and OPEC since 2019.

The people in Austria speak German, a few also speak Hungarian, Slovenian and Croatian. The capital of Austria is Vienna (Wien).

Austria is more than a thousand years old. Its history can be followed to the ninth century. At that time the first people moved to the land now known as Austria. The name Ostarrichi is first written in an official document from 996. Since then this word has developed into the Modern German word Österreich, which literally means East Empire.

Austria is a democratic republic. It is a neutral state, that means it does not take part in wars with other countries. It has been in the United Nations since 1955 and in the European Union since 1995.

Austria is also a federal state and divided into nine states (): 

More information: States of Austria.

There has been human settlement in the area that is now Austria for a long time. The first settlers go back to the Paleolithic age. That was the time of the Neanderthals. They left works of art such as the Venus of Willendorf. In the Neolithic age people were living there to dig for mineral resources, especially copper. Ötzi, a mummy found in a glacier between Austria and Italy, is from that time. In the Bronze Age people built bigger settlements and fortresses, especially where there were mineral resources. Salt mining began near Hallstatt. At that time, Celts began to form the first states.

The Romans came 15 B.C. to Austria and made the Celtic Regnum Noricum to a province. Modern Austria was part of three provinces, Raetia, Noricum and Pannonia. The border in the north was the Danube.

Austria was the Austrian Empire from about 800 to 1867 and was ruled by The House of Habsburg for most of that period. Between 1867 and 1918 it was a part of Austria-Hungary. Then it became a republic. The First Republic was from 1918 to 1938. From 1938 to 1945 Austria was part of Nazi Germany. The Second Republic was started in 1945.

Austria is a largely mountainous country since it is partially in the Alps. The high mountainous Alps in the west of Austria flatten somewhat into low lands and plains in the east of the country where the Danube flows.

Many famous composers were Austrians or born in Austria. There are Wolfgang Amadeus Mozart, Joseph Haydn, Franz Schubert, Anton Bruckner, Johann Strauss, Sr., Johann Strauss, Jr. and Gustav Mahler. In modern times there were Arnold Schoenberg, Anton Webern and Alban Berg, who belonged to the Second Viennese School.

Austria has many artists, there are Gustav Klimt, Oskar Kokoschka, Egon Schiele or Friedensreich Hundertwasser, Inge Morath or Otto Wagner and scienc.

Famous Austrian dishes are Wiener Schnitzel, Apfelstrudel, Schweinsbraten, Kaiserschmarren, Knödel, Sachertorte and Tafelspitz. But you can also find a lot of local dishes like Kärntner Reindling (a kind of cake), Kärntner Nudeln (also called Kärntner Kasnudeln, you may write it ...nudln too), Tiroler Knödl (may be written ...knödel; ), Tiroler Schlipfkrapfen (another kind of Kärntner Nudeln), Salzburger Nockerl (also may be written ...Nockerln), Steirisches Wurzelfleisch (...Wurzlfleisch) or Sterz (Steirischer Sterz).




#Article 31: Armenia (454 words)


Armenia  is officially the Republic of Armenia. It is a country in the South Caucasus region of Eurasia. It is in Eastern Europe on the Armenian Highlands,

Armenia is bordered by Turkey to the west and Georgia to the north. The de facto independent Republic of Artsakh and Azerbaijan is to the east, and Iran and Azerbaijan's exclave of Nakhchivan to the south.

Armenia is a multi-party, democratic nation-state.

It has an ancient cultural heritage. Urartu was established in 860 BC and by the 6th century BC it was replaced by the Satrapy of Armenia. The Kingdom of Armenia reached its height under Tigranes the Great in the 1st century BC and became the first state in the world to adopt Christianity as its official religion in the late 3rd or early 4th century AD. The official date of state adoption of Christianity is 301.

Between the 16th century and 19th century, the traditional Armenian homeland composed of Eastern Armenia and Western Armenia came under the rule of the Ottoman and Iranian empires, repeatedly ruled by either of the two over the centuries. By the 19th century, Eastern Armenia had been conquered by the Russian Empire, while most of the western parts of the traditional Armenian homeland remained under Ottoman rule.

During World War I, Armenians living in their ancestral lands in the Ottoman Empire were systematically exterminated in the Armenian Genocide. In 1918, following the Russian Revolution, all non-Russian countries declared their independence after the Russian Empire ceased to exist, leading to the establishment of the First Republic of Armenia. By 1920, the state was incorporated into the Transcaucasian Socialist Federative Soviet Republic, and in 1922 became a founding member of the Soviet Union. In 1936, the Transcaucasian state was dissolved, transforming its constituent states, including the Armenian Soviet Socialist Republic, into full Union republics. The modern Republic of Armenia became independent in 1991 during the dissolution of the Soviet Union.

Armenia is divided into ten provinces, with the city of Yerevan having special administrative status as the country's capital. The chief executive in each of the ten provinces is the marzpet (marz governor), appointed by the government of Armenia. In Yerevan, the chief executive is the mayor, appointed by the president.

, Armenia includes 915 communities, of which 49 are considered urban and 866 are considered rural.

The Republic of Armenia recognises the Armenian Apostolic Church, the world's oldest national church, as the country's primary religious establishment. The unique Armenian alphabet was invented by Mesrop Mashtots in 405 AD.

Armenia is a member of the Eurasian Economic Union, the Council of Europe and the Collective Security Treaty Organization. Armenia supports the de facto independent Republic of Artsakh, which was proclaimed in 1991.




#Article 32: Archaeology (669 words)


Archaeology, or archeology, is the study of the human past. It looks at remains and objects left by the people who lived long ago. These remains may include old coins, tools, buildings, and inscriptions. Archaeologists, the people who study archaeology, use these remains to understand how people lived.

When archaeologists do fieldwork, they look for remains, often by digging in the ground. As settlements (places where people lived in groups) change and grow, old buildings get buried. Usually, this is a natural process. A typical student project is to leave an object in a place where there is nothing going on. It will get covered rather quickly, because wind, water and plants will bury it. Sometimes buildings are deliberately buried to make way for new buildings. Ancient Rome, for example, is now up to 40 feet (12 metres) below the present city. This process of natural or man-made burial is why archaeological fieldwork involves digging, and is expensive and takes a long time.

When things are found, or even when nothing is found, the results of the fieldwork are taken back to a base. Short term, the base is often on or near the site. Longer term, the results will usually go to a university or museum. Everything is written down on paper or entered into a computer. Gradually, they build up a picture of what happened long ago. Archaeologists publish their research so others can understand what they learned.

Archaeologists do not all study the same topics. They have specialties. Some fields of interest include Ancient Egypt (these specialists are called Egyptologists), Ancient China, or the Vikings. Archaeologists study every civilization that is known, especially the ones where there is no written history. They can study any time period. For example, one might study the beginning of human life in Africa, or study World War II. Marine archaeologists study things that are now underwater. They search for sunken ships or cities that have been lost under the sea.

There are many different ways of doing archaeology. these depend on the methods used, the things studied, and the environment. Some of these subdisciplines overlap with each other.

Archaeology relating to oceans, seas and lakes is usually done underwater. It includes the study of sunken ships and submerged coastlines. Maritime archaeology is a part of this subdivision. It refers to the archaeological investigation of past ships and seafaring. A famous example of maritime archaeology is the recovery and restoration of the ship burial at Sutton Hoo.

When a glacier melts, objects that were captured in it are revealed. The recovery and study of these objects is called ice-patch archaeology. A famous example is Ötzi the Iceman.

Historical archaeology deals with places, things, and issues from the past or present at or related to sites with written records or oral traditions. Or it can be defined as the archaeological investigation of any past culture that has developed a literate tradition. A prominent example of historical archaeology is the work done at Colonial Williamsburg.

This relatively new branch of archaeology consists of the systematic study of structures and artefacts as a means of enlarging our understanding of the industrial past.

Archaeozoology, or zooarchaeology, is the study of the relationships between humans and animals in the archaeological record. This includes the study of bones, feathers, teeth and other body parts as well as their interpretation.

This field involves attempts at replicating the actions and conditions of ancient cultures. Good examples are Butser Ancient Farm and Overton Down.

In many countries, governments and other groups of people protect important archaeological sites so they will not be destroyed and so that visitors can always come and see them.

Sometimes archaeological sites are found when foundations are dug for new buildings. Archaeologists have to work quickly when this happens, because people who are building often don't have a lot of time. As soon as the archaeologists are done with their work, the remains that they have found will be covered over, unless they are very important.




#Article 33: Animal (401 words)


Animals are eukaryotic organisms with many cells. They do not use light to get energy as plants do. Animals use different ways to get energy from other living things. They may eat other living things, though some are parasites or have photosynthetic protists as symbionts.

Most animals are mobile, meaning they can move around. Animals take in oxygen, and give out carbon dioxide. This cellular respiration is part of their metabolism (chemical working). In both these ways they are different from plants. Also, the cells of animals have different cell membranes to other eukaryotes like plants and fungi. The study of animals is called zoology.

Plants are also multicellular eukaryotic organisms, but live by using light, water and basic elements to make their tissues.

There are many different types of animals. The common animals most people know are only about 3% of the animal kingdom. When biologists look at animals, they find things that certain animals have in common. They use this to group the animals in a biological classification. They think several million species exist but they have only identified about one million.

Animals can mainly be divided into two main groups: the invertebrates and the vertebrates. Vertebrates have a backbone, or spine; invertebrates do not.

Vertebrates are:

Some invertebrates are:

In scientific usage, humans are considered animals, in everyday nonscientific usage, humans are often not considered to be animals.

The animal mode of nutrition is called heterotrophic because they get their food from other living organisms. Some animals eat only plants; they are called herbivores. Other animals eat only meat and are called carnivores. Animals that eat both plants and meat are called omnivores.

The environments animals live in vary greatly. By the process of evolution, animals adapt to the habitats they live in. A fish is adapted to its life in water and a spider is adapted to a life catching and eating insects. A mammal living on the savannahs of East Africa lives quite a different life from a dolphin or porpoise catching fish in the sea.

The fossil record of animals goes back about 600 million years to the Ediacaran period, or somewhat earlier. During the whole of this long time, animals have been constantly evolving, so that the animals alive on Earth today are very different from those on the edges of the sea-floor in the Ediacaran. The study of ancient life is called palaeontology.




#Article 34: Black pudding (175 words)


Black pudding is an English name for zwarte pudding.  It is food made by cooking down the blood of any mammal (usually pigs or cattle) with meat, fat or filler until it is thick enough to congeal (become firm or solid) when cooled.

In Great Britain, blood sausage is called  black pudding. The ingredients include pig's blood, suet, bread, barley and oatmeal. The most common kind of German blutwurst is made from fatty pork meat, beef blood and filler such as barley. Though already cooked and ready to eat it is usually served warm.

Other kinds of blood sausage include boudin noir (France), boudin rouge (Creole and Cajun) and morcilla (Spain).

A legend says that blood sausage was invented in a bet between two Bavarian butchers drunk on the alcoholic drink absinthe during the 14th century. Homer's Odyssey from Ancient Greece says that As when a man besides a great fire has filled a sausage with fat and blood and turns it this way and that and is very eager to get it quickly roasted....




#Article 35: Boot device (246 words)


A boot device is used to start a computer.  It is named after a boot which fits on the foot.  The word bootstrap is also closely related, and means, to use something simpler to get something more complex to make itself work better. It comes from the English phrase pull yourself up by your own bootstraps.

Before a computer can operate normally, it must have operating system instructions that tell it how to perform basic functions.  A boot device loads the operating system into the memory of the computer. 

Devices that can boot a computer are usually boot disks or boot drives (normally a hard drive, but can be a floppy disk or a CD). Some network computers use boot chips that get the operating system over a network. Web phones also use such chips to identify the user to the mobile phone network.  Boot card standards may let many users boot kiosk computers with full privacy and access to all application software they own. There are also boot boards or boot add-in cards that are more permanent than boot cards.

Some people refer to the boot device as just a boot and non-boot devices as data devices, although it is not the computer but the operating system that cares about the difference between these.

The boot in boot device is the same as booting (or starting up). This is short for bootstrapping, or to start with simple stuff and make complex stuff out of it.

 




#Article 36: Bankruptcy (929 words)


Bankruptcy is a legal process which happens when a person or an organisation does not have enough money to pay all of its debts.  Legally they are insolvent.

Where it is a person who cannot pay their debts, the person's creditors may ask the court to appoint a trustee in bankruptcy.   This is a professional accountant who is appointed by the court, to take control of the bankrupt person's assets.  Some assets are protected by law, but the trustee in bankruptcy will sell off all of the other assets and use the money to pay as much of that person's debts as possible.  After the process is complete the person is discharged from bankruptcy, and the person is free from any further liability to pay those claims, but normally that person will be limited in their ability to borrow money again because their credit rating will be damaged.

Where it is an organisation which cannot pay its debts, the creditors may ask the court to appoint a liquidator.  The liquidator does a very similar job to the trustee in bankruptcy except that there are no assets which are protected so the liquidator can sell everything.  Once all of the assets of the organisation have been sold, the organisation is then dissolved and no longer exists.  Organisations do not get discharged from bankruptcy in the same way that a living person does.

People often confuse the terms bankruptcy and insolvency, and sometimes they use one word when they really mean the other.  Insolvency usually just means that a someone does not have enough money to pay their debts or (sometimes) that the total amount of their debts is worth more than the total amount of their assets.  Bankruptcy is a formal legal process in front of the courts.  Although the two terms are connected, just because a person is insolvent does not necessarily mean that they will go into bankruptcy.

Many countries have alternatives to bankruptcy to try and allow people and businesses to try and avoid the bankruptcy process.

In various countries, individual people can try and reach individual voluntary arrangements (or IVAs) with their creditors.  This means that the creditors agree to take less money to discharge their debts.  There are similar processes for companies and other organisations, and they go by various different names in different countries, but in many countries they are called schemes of arrangement.

In many countries a company or business can ask the courts for bankruptcy protection to try and protect the business so that the creditors cannot destroy all of the physical capital and goodwill by breaking it apart and moving it away. The aim of this is provide is more time for the business to reorganise itself and to work out a new deal between the owners and the people the business owes money.  In many countries this is called going into administration.

However, not all countries have bankruptcy protection laws for businesses.

Often a creditor threatens a debtor with debt slavery in many parts of the world. In some cases the debtor does not know that they have a right to go bankrupt. This is a human rights problem in some countries. Also, some creditors continue to harass a debtor even though bankruptcy laws say they should not, hoping that the debtor will pay them money that they do not deserve.

Bankruptcy in the United States falls mostly under federal law, Title 11 of the United States Code (Bankruptcy Code). The types of bankruptcy available in the United States are named after the primary divisions, or chapters, of that law. The person or business that files a bankruptcy case is known as the debtor.

When a bankruptcy case is filed, a trustee is chosen by the court. The trustee has authority over the property of the bankrupt person or business and may use some of the debtor's assets to pay the creditors. After a bankruptcy is filed, creditors are notified that they are to stop trying to collect money directly from the debtor and are to make claims for payment to the bankruptcy court.

The most common form of bankruptcy is the Chapter 7 Bankruptcy, which can be filed by businesses or individuals. It is also called liquidation bankruptcy because some of a debtor's property may be sold (liquidated) to satisfy creditors.  When a business is in debt which it cannot pay, it may ask or be forced to file bankruptcy in court under Chapter 7.  This usually makes a company stop doing business.  Employees often lose their jobs when company files for chapter 7.

Chapter 11 bankruptcy is a complicated type of bankruptcy that reorganizes the debtor's finances, usually reducing the amount of debt owed and changing debt repayment terms. A Chapter 11 bankruptcy case allows a business to keep running while it finds ways to reduce and arrange payment of its debts.

Almost all Chapter 11 bankruptcies are filed by businesses. Ordinary people do not usually file Chapter 11 bankruptcy, because a Chapter 13 bankruptcy will almost always be cheaper and easier for them.

Chapter 13 is the most popular form of bankruptcy in the United States for ordinary people. In a Chapter 13 bankruptcy some of your debts may be forgiven (discharged), but you will have to pay back a portion of your debt. The debt repayment plan is supervised by the bankruptcy court and usually lasts for three to five years. Businesses cannot file for Chapter 13 bankruptcy.

Less common forms of bankruptcy may be filed under Chapter 9 and Chapter 12 of the bankruptcy code.




#Article 37: Breakfast sausage (202 words)


Breakfast sausage is a type of fresh pork sausage made from seasoned ground meat mixed with bread crumbs. Breakfast sausage has a blander flavor than many other types of sausage, such as British or Italian-style sausages.

Breakfast sausages are not cured or smoked like other types of sausages, which means that they have to be cooked soon after they are purchased (unless they are frozen).  Uncooked sausages should be stored in the refrigerator or the freezer. Individuals handling them should wash their hands in hot soapy water, because uncooked pork is unhealthy for humans. Pork sausages have to be heated until all of the meat inside is cooked. 

They are usually fried or grilled in a pan until they are browned and served at breakfast, often with cooked eggs, pancakes, and toasted bread. Breakfast sausages are also used in other dishes, such as toad in the hole a cooked batter dish.

Different types made from pork and beef mixtures as well as poultry can now be found. There are also vegetarian types that use textured vegetable protein in place of meat. Breakfast sausages are available in patties or slices from a large roll, or in weiner-like links of different lengths and thickness.




#Article 38: Beekeeping (145 words)


Beekeeping or apiculture is the farming of honeybees.

The keeping of bees is usually, and has been in the past, for honey. That is becoming less true. Instead, it is more used for crop pollination and other products. These are  and propolis.

There is only one queen bee in each hive and she is bigger than the rest. She lays all the eggs, which makes all the other bees in the hive her daughters and sons. However, they do not control the hive.

The largest beekeeping operations are agricultural businesses that are operated for profit. Some people also have small beekeeping operations that they do as a hobby. Urban beekeeping is a growing trend, and some have found that city bees are actually healthier than rural bees because there are fewer pesticides and greater biodiversity.

Colony Collapse Disorder is a growing problem, along with mites.




#Article 39: British English (400 words)


British English is the kind of English language which is used in the United Kingdom and in most countries which previously were in the British Empire.

In the United Kingdom, many different people say words in different ways. For example, a man from a place near London may not pronounce his rs the same as a man from Scotland or a man from Northern Ireland. Across the country, the accent is different. For instance, in Liverpool, people may speak with a scouse accent, in Birmingham with a brummie accent, and in London with a cockney accent. Different variations on all of British English exist from the manner in which words are pronounced to the manner in which they are spelt. One place people speak English in a different way is Cornwall, where the Cornish dialect is spoken.

Britain, like other countries, has languages other than English. In Wales many speak Welsh; in Scotland some people speak Gaelic, and in Ireland a few people speak Irish. However, that is not the subject of this particular article.

British English often keeps more traditional ways of spelling words than American English.

In British English, dock refers to the water in the space between two piers or wharfs. In American English, the pier or wharf could be called a dock, and the water between would be a slip.

Some common differences:

British – American

American English is only an official language in the United States. In Canada, the accent sounds extremely similar to American English but with few exceptions (see Canadian English). The American spelling in Canada is sometimes used, but traditionally, the British Spelling (with the exceptions of some words like programme, -isation/-ise/-isable, chilli, etc.) is used. Although Commonwealth English is the most spoken, American English is seen more often on the internet. American English vocabulary dominates the visual media: movies (British: films) and television.

All Commonwealth nations and Africa learn Commonwealth English, while American English is often learnt in the Americas and China. Z pronounced 'Zee' is only seen in the U.S.A and less commonly in Canada, while Z pronounced 'Zed' is spoken almost everywhere else. The United Kingdom and Ireland use British layout keyboards, while Australia, South Africa, Canada, New Zealand and the U.S.A use American layout keyboards. In continental Europe English as a second language is nowadays sometimes even taught in American English, except perhaps in Scandinavia and the Netherlands.




#Article 40: Beijing (571 words)


Beijing is the capital of the People's Republic of China. The city used to be known as Peking.  It is in the northern and eastern parts of the country. It is the world's most populous capital city.

The city of Beijing has played a very important role in the development of China. Many people from different cities and countries come to Beijing to look for better chances to find work. Nearly 15 million people live there. In 2008 Beijing hosted the Summer Olympic Games, and will host the 2022 Winter Olympic Games. It will be the only city to host both.

Beijing is well known for its ancient history.  Since the Jin Dynasty, Beijing has been the capital of several dynasties (especially the later ones), including the Yuan, Ming, and Qing. There are many places of historic interest in Beijing.

The Mandarin Chinese name of the city is Běijīng, which means The Northern Capital. It got this name when the Yongle Emperor of the Ming family of rulers moved most of his government from Nanjing (The Southern Capital) in the early 1400s.  In Chinese, Beijing's name is written  Today, people spell it Beijing because they use the pinyin way of spelling, which shows what the name should sound like in Mandarin. People used to spell it Peking because that was the spelling used by some of the first people from Europe to visit the Ming and write home about it; the Jesuits' work was made popular by their French brother Du Halde. It then became the official Chinese Postal Map spelling around 1900 and continued to be used until pinyin became more popular.

Beijing was also known as Beiping (City of Northern Peace) between 1928 and 1949, when the Nationalists moved the Chinese capital to Nanjing and Chongqing.

The center of Beijing was settled in the 1st millennium BC. In those days, the Kingdom of Yan (燕, Yān) set up their capital where Beijing is today. They called it Ji (蓟, Jì). After the Kingdom of Yan was destroyed, the city became smaller, although it was still an important place.

Beijing became more important again in the 10th century, when the Jin dynasty set its capital there. This city was destroyed by Mongol forces in 1215.  Then in 1267, Mongols built a new city on the north side of the Jin capital, and called it Great Capital (大都, Dàdū), which was the beginning of modern Beijing. When Kublai Khan the Mongolian monarch, set up the Yuan dynasty, this city became his capital.

The Yuan Dynasty, Ming Dynasty and Qing dynasty all made Beijing their capital. When the Qing dynasty lost power and the Republic of China was set up, the new Republic moved its capital from Beijing to Nanjing. When the People's Republic of China seized power, Beijing became the capital of China again.

In 1989, there were protests in Tian'anmen Square because some people wanted democracy.

Important places in Beijing include:

Beijing is the education center of People's Republic of China. More than 500 famous universities of China are in Beijing.  They also include 5 of the top universities: Peking University, Tsinghua University, China People University, Beijing Normal University, and Beihang University. Beijing is also education center of China for teaching Chinese as a foreign language. The standard Chinese pronunciation is based on Beijing dialect, so over 70% foreigners who want to study Chinese go to Beijing for their studies.




#Article 41: Berry (228 words)


The word berry is used for many different kinds of small fruits that have many seeds and can be used as food. Some examples are raspberry, strawberry, lingonberry and blueberry.

When botanists talk about berries, they mean a simple fruit produced from a single ovary. They sometimes call this true berry, to distinguish it from false berries. By that statement of how words are used, grapes or tomatoes are true berries.

The berry is the most common type of soft fruit in which the entire ovary wall gets to the right stage of development of the pericarp which can be taken as food. The flowers of these plants have an upper ovary with one or more carpels. The seeds are inside the soft body of the ovary.

Berries are small, sweet, bright colored fruits. Due to this, they are able to bring more animals towards them and spread their seeds.

Some fruits that are called berries in English are not true berries by the use of words above. These include raspberries, strawberry, blackberries, cranberries, and boysenberries. Some true berries do not have berry in their name. These include tomatoes, bananas, eggplants, guavas, pomegranates and chillies. Pumpkins, cucumbers, melons, oranges and lemons are also berries that have slightly different structure and may be called by different names (pepo for pumpkins, cucumbers, and melons, or hesperidium for oranges and lemons).




#Article 42: Beard (114 words)


A beard is the hair growing on the lower part of a man's face.

The hair that grows on the upper lip of some men is a mustache.  When a man has hair only below the lower lip and above the chin, it is called a soul patch.  Some men have a lot of hair and a big beard, and some have very little. In the modern world, many men shave part or all of their beards, or cut their beard so it does not get very long. Women can also have beards, but it is less common. 

Some animals also have hair like this, and people sometimes also call this hair a beard. 




#Article 43: Black (261 words)


In light, black is lack of all color.  In painting, however, the black pigment is the combination of all colors. In heraldry, black is called sable. It is the opposite of white.

The word black comes from Old English blæc (black, dark, also, ink), from Proto-Germanic *blakkaz (burned), and from Proto-Indo-European *bhleg-. Black is the darkest color/tone on a scale.

In science, an object that is black absorbs the light that hits it. Because these objects do not reflect any light, the human eye can't see any color coming from that object. The brain then sees these objects as black. 

A way to create black objects is to mix pigments. A pigment works by reflecting only the color of the pigment. For example, a blue pigment absorbs all colors except blue. By mixing pigments in the right quantities, black can be made.

In sunlight, black objects become quickly warm because they absorb much light.

Black is associated with power, elegance, formality, safety, birth, male, and mystery. Black is a dark color, the darkest color there is. Black, along with gray and white, is a neutral color. This means that it is not a hot color or a cool color.

Black is a color seen with fear and the unknown (black holes). It can have a bad meaning (blackbird, black bunny) or a good meaning ('in the black', 'black is beautiful'). Black can stand for strength and power. It can be a formal, elegant, and high-class color (black tie, black Mercedes, black man). Black clothing is dark in emo and goth subculture.




#Article 44: Bubonic plague (566 words)


Bubonic plague is the best-known form of the disease plague, which is caused by the bacterium Yersinia pestis. The name bubonic plague is specific for this form of the disease, which enters through the skin, and travels through the lymphatic system.

If the disease is left untreated, it kills about half its victims, in between three and seven days. The bubonic plague was the disease that caused the Black Death, which killed tens of millions of people in Europe, in the Middle Ages.

Symptoms of this disease include coughing, fever, and black spots on the skin.

There are different kinds of Bubonic plague. The most common form of the disease is spread by a certain kind of flea, that lives on rats. Then there is an incubation period which can last from a few hours to about seven days.

Sepsis happens when the bacterium enters the blood and makes it form tiny clots.

This happens when the bacterium can enter the lungs. About 95% of all people with this form will die. Incubation period is only one to two days.

This is the most harmless form. It will result in a little fever. After that, there are antibodies that protect against all forms for a long time.

The first recorded epidemic was in the Eastern Roman Empire (Byzantine Empire), It was called the Plague of Justinian after emperor Justinian I, who was infected but survived through extensive treatment. The pandemic resulted in the deaths of an estimated 25 million (6th century outbreak) to 50 million people (two centuries of recurrence).

During the 1300s, this epidemic struck parts of Asia, North Africa, and Europe. Almost a third of the people in Europe died of it. Unlike  that pull communities together, this epidemic was so terrifying that it broke people's trust in one another. Giovanni Boccaccio, an Italian writer of the time, described it: This  had implanted so great a terror in the hearts of men and women that brothers  brothers, uncles their nephews, sisters their brothers, and in many cases wives deserted their husbands. But even worse,... fathers and mothers refused to nurse and assist their own children.

Local outbreaks of the plague are grouped into three plague pandemics, whereby the respective start and end dates and the assignment of some outbreaks to either pandemic are still subject to discussion. The pandemics were:

Globally about 600 cases of plague are reported a year. In 2017 the countries with the most cases include the Democratic Republic of the Congo, Madagascar, and Peru.

The transmission of Y. pestis by fleas is well known. Fleas are the vector. The flea gets the bacteria as they feed  on an infected animal, usually a rodent. Several proteins then work to keep the bacteria in the flea digestive tract. This is important for the survival of Y. pestis in fleas.

In the 20th century, some countries did research on the bacteria that causes bubonic plague. They did research to use it for biological warfare.

Samples of this bacteria are carefully controlled. There is much paranoia (fear) about it. Dr. Thomas C. Butler, a US expert in this organism was charged in October 2003 by the FBI with various crimes. This happened after he said he lost samples of Yersinia pestis. This is the bacteria that causes bubonic plague. The FBI did not find the samples. They do not know what happened to them.




#Article 45: Biology (186 words)


Biology is the science that studies life, and living things, and the evolution of life. Living things include animals, plants, fungi (such as mushrooms), and microorganisms such as bacteria and archaea.

The term 'biology' is relatively modern. It was introduced in 1799 by a physician, Thomas Beddoes.

People who study biology are called biologists. Biology looks at how animals and other living things behave and work, and what they are like. Biology also studies how organisms react with each other and the environment. It has existed as a science for about 200 years, and was preceded by natural history. Biology has many research fields and branches. Like all sciences, biology uses the scientific method. This means that biologists must be able to show evidence for their ideas and that other biologists must be able to test the ideas for themselves.

Biology attempts to answer questions such as:

Modern biology is influenced by evolution, which answers the question: How has the living world come to be as it is?

The word biology comes from the Greek word βίος (bios), life, and the suffix -λογία (logia), study of.




#Article 46: Belgium (1655 words)


Belgium, officially the Kingdom of Belgium, is a federal state in Western Europe. Belgium has an area of . Around 11 million people live in Belgium. It is a founding member of the European Union and is home to its headquarters. The capital city of Belgium is Brussels, where the European Union, NATO and other famous organisations are based.

There are three regions in Belgium:

The population is about 60% Dutch-speaking, 39% French-speaking, and 1% German-speaking (the so-called Deutschbelgier). To look after all these groups, Belgium has a complicated system of government.

The name 'Belgium' comes from Gallia Belgica. This was a Roman province in the northernmost part of Gaul. Before Roman invasion in 100 BC, the Belgae, a mix of Celtic and Germanic peoples, lived there. The Germanic Frankish tribes during the 5th century brought the area under the rule of the Merovingian kings. A slow shift of power during the 8th century led the kingdom of the Franks to change into the Carolingian Empire. The Treaty of Verdun in 843 divided the region into Middle and West Francia. They were vassals either of the King of France or of the Holy Roman Emperor.
Many of these fiefdoms were united in the Burgundian Netherlands of the 14th and 15th centuries.

The Eighty Years' War (1568–1648) divided the Low Countries into the northern United Provinces and the Southern Netherlands. Southern Netherlands were ruled by the Spanish and the Austrian Habsburgs. This made up most of modern Belgium.

After the , the Low Countries were added into the French First Republic. This ended Austrian rule in the area. Adding back the Low Countries formed the United Kingdom of the Netherlands. This happened at the end of the First French Empire in 1815.

The Belgian Revolution was in 1830. Leopold I became king on  1831. This is now celebrated as Belgium's National Day.

The Berlin Conference of 1885 gave control of the Congo Free State to King Leopold II. This was for him personally and not for the country of Belgium. Millions of Congolese people were hurt or killed, mostly to make rubber, and Leopold became very wealthy. In 1908 the Belgian state took control of the colony after there was a scandal about the deaths. It was then called the Belgian Congo, but the indigenous peoples continued to be killed and face violence from the colonial government.

Germany invaded Belgium in 1914. This was part of World War I. The opening months of the war were very bad in Belgium. During the war Belgium took over the of Ruanda-Urundi (modern-day Rwanda and Burundi). After the First World War, the Prussian districts of Eupen and Malmedy were added into Belgium in 1925. The country was again invaded by Germany in 1940 and under German control until 1944. After World War II, the people made king Leopold III leave his throne in 1951. This is because they thought he helped the Germans.

In 1960 the Belgian Congo stopped being under Belgian rule. Two years later Ruanda-Urundi also became free. Belgium joined NATO as a founding member.

Since 1993, Belgium is a federal state, divided into three regions and three communities.

It has a system of government known as a constitutional monarchy, meaning that it has a monarch, but that the monarch does not rule the country, and that a government is elected democratically.

Belgium has had its own monarchy since 1831. King Albert II left the throne on July 21, 2013 and the current king is Philippe.

In Belgium, the government is elected. Between mid-2010 and late 2011, after no clear result in the election, Belgium had no official government, until Elio Di Rupo became Prime Minister. Flanders and Wallonia both also have their own regional governments, and there is a notable independence movement in Flanders. Charles Michel is currently the Prime Minister.

Belgium is next to France, Germany, Luxembourg and the Netherlands. Its total area is 33,990 square kilometers. The land area alone is 30,528 km². Belgium has three main geographical regions. The coastal plain is in the north-west. The central plateau are part of the Anglo-Belgian Basin. The Ardennes uplands are in the south-east. The Paris Basin reaches a small fourth area at Belgium's southernmost tip, Belgian Lorraine.

The coastal plain is mostly sand dunes and polders. Further inland is a smooth, slowly rising landscape. There are fertile valleys. The hills have many forests. The plateaus of the Ardennes are more rough and rocky. They have caves and small, narrow valleys. Signal de Botrange is the country's highest point at 694 metres (2,277 ft).

Belgium is divided into three Regions.  Flanders and Wallonia are divided into provinces. The third Region, Brussels is not part of any province.

The Belgian Armed Forces have about 46,000 active troops. In 2009 the yearly defence budget was $6 billion. There are four parts: Belgian Land Component, or the Army; Belgian Air Component, or the Air Force; Belgian Naval Component, or the Navy; Belgian Medical Component.

Adding to science and technology has happened throughout the country's history. cartographer Gerardus Mercator, anatomist Andreas Vesalius, herbalist Rembert Dodoens and mathematician Simon Stevin are among the most influential scientists.

Chemist Ernest Solvay and engineer Zenobe Gramme gave their names to the Solvay process and the Gramme dynamo in the 1860s. Bakelite was formed in 1907–1909 by Leo Baekeland. A major addition to science was also due to a Belgian, Georges Lemaître. He is the one who made the Big Bang theory of the start of the universe in 1927.

Three Nobel Prizes in Physiology or Medicine were awarded to Belgians: Jules Bordet in 1919, Corneille Heymans in 1938 and Albert Claude together with Christian De Duve in 1974.  Ilya Prigogine was awarded the Nobel Prize in Chemistry in 1977. Two Belgian mathematicians have been awarded the Fields Medal: Pierre Deligne in 1978 and Jean Bourgain in 1994.

In February 2014, Belgium became the first country in the world to legalize euthanasia without any age limits.

There have been many additions to painting and architecture. Several examples of major architectural places in Belgium belong to UNESCO's World Heritage List. In the 15th century the religious paintings of Jan van Eyck and Rogier van der Weyden were important. The 16th century had more styles such as Peter Breughel's landscape paintings and Lambert Lombard's showing of the antique. The style of Peter Paul Rubens and Anthony van Dyck was strong in the early 17th century in the Southern Netherlands.

During the 19th and 20th centuries many original romantic, expressionist and surrealist Belgian painters started. These include James Ensor and other artists in the Les XX group, Constant Permeke, Paul Delvaux and René Magritte. The sculptor Panamarenko is still a remarkable figure in contemporary art. The artist Jan Fabre and the painter Luc Tuymans are other internationally known figures in contemporary art.

Belgian contributions to architecture were also in the 19th and 20th centuries. Victor Horta and Henry van de Velde were major starters of the Art Nouveau style.

In the 19th and 20th centuries, there were major violinists, such as Henri Vieuxtemps, Eugène Ysaÿe and Arthur Grumiaux. Adolphe Sax invented the saxophone in 1846. The composer César Franck was born in Liège in 1822. Newer music in Belgium is also famous. Jazz musician Toots Thielemans and singer Jacques Brel have made global fame. In rock/pop music, Telex, Front 242, K's Choice, Hooverphonic, Zap Mama, Soulwax and dEUS are well known. In the heavy metal scene, bands like Machiavel, Channel Zero and Enthroned have a worldwide fan-base.

Belgium has several well-known authors, including the poet Emile Verhaeren and novelists Hendrik Conscience, Georges Simenon, Suzanne Lilar and Amélie Nothomb. The poet and playwright Maurice Maeterlinck won the Nobel Prize in literature in 1911. The Adventures of Tintin by Hergé is the best known of Franco-Belgian comics. Many other major authors, including Peyo, André Franquin, Edgar P. Jacobs and Willy Vandersteen brought the Belgian cartoon strip industry a worldwide fame.

Belgian cinema has brought a number of mainly Flemish novels to life on-screen. Belgian directors include André Delvaux, Stijn Coninx, Luc and Jean-Pierre Dardenne. Well-known actors include Jan Decleir and Marie Gillain. Successful films include Man Bites Dog and The Alzheimer Affair.

Belgium is famous for beer, chocolate, waffles and french fries. French fries were first made in Belgium. The national dishes are steak and fries with salad, and mussels with fries.
Other local fast food dishes include a Mitraillette. Brands of Belgian chocolate and pralines, like Côte d'Or, Guylian, Neuhaus, Leonidas, Corné and Galler are famous. Belgium makes over 1100 varieties of beer. The Trappist beer of the Abbey of Westvleteren has repeatedly been rated the world's best beer. The biggest brewer in the world by volume is Anheuser-Busch InBev, based in Leuven.

Since the 1970s, sports clubs are organised separately by each language community. Association football is one of the most popular sports in both parts of Belgium, together with cycling, tennis, swimming and judo. With five victories in the Tour de France and many other cycling records, Belgian Eddy Merckx is said to be one of the greatest cyclists of all time. Jean-Marie Pfaff, a former Belgian goalkeeper, is said to be one of the greatest in the history of football (soccer). Belgium and The Netherlands hosted the UEFA European Football Championship in 2000. Belgium hosted the 1972 European Football Championships.

Kim Clijsters and Justine Henin both were Player of the Year in the Women's Tennis Association. The Spa-Francorchamps motor-racing circuit hosts the Formula One World Championship Belgian Grand Prix. The Belgian driver, Jacky Ickx, won eight Grands Prix and six 24 Hours of Le Mans. Belgium also has a strong reputation in motocross. Sporting events held each year in Belgium include the Memorial Van Damme athletics competition, the Belgian Grand Prix Formula One, and a number of classic cycle races such as the Tour of Flanders and Liège–Bastogne–Liège. The 1920 Summer Olympics were held in Antwerp.




#Article 47: Brazil (799 words)


Brazil (officially called Federative Republic of Brazil; how to say: ) is a country in South America. It is the world's fifth largest country. The country has about 209 million people. The capital of Brazil is Brasília. Brazil was named after brazilwood, which is a tree that once grew very well along the Brazilian coast.

The first people to come to Brazil came around 9,000 B.C. That group of indigenous people is often called the South American Indians and probably came from North America. They practiced hunting, foraging, and farming. Over thousands of years, many different indigenous peoples were living there.

Pedro Álvares Cabral was the first European to see Brazil. He saw it in 1500. He was from Portugal and the Portuguese kingdom claimed Brazil. Soon, Portugal colonized Brazil and created colonies all along the coastline. They began to import black slaves from Africa and force them to work. Because of the violence of the slave masters, many of these slaves would run away into the forest and create their own communities called quilombos.

In the late 1500s and early 1600s, the Dutch and the French tried to take land in Brazil. Dutch, French, and Portuguese started moving inland further than the Treaty of Tordesillas said they could. This caused some fights with the Spaniards (people from Spain) and indigenous peoples in the area.

In 1822, Brazil claimed to be its own country and not a part of Portugal anymore. Soon there was civil war. Meanwhile, the quilombos survived and Brazil was bringing in more slaves than any other country in the Americas, even though many countries were beginning to legally abolish slavery. This led to an increase in slave revolts, especially in the 1860s and 1880s, which forced the government to change the system in order to keep the country stable. Slavery was legally abolished in 1888.

In 1889, there was a military coup, and Pedro II had to leave the country. In 1889, Brazil became a republic. The only people who could vote were people who owned land. There were some uprisings in the 1920s because some people thought the government was unfairly helping coffee growers. Brazil joined the Allies during World War II.

During the 1960s, the military leader Castelo Branco overthrew the government and created a dictatorship that was supported by the United States. It was very anti-communist and they imprisoned, tortured, or killed many people on the left. Since then, the country has become more democratic, but some people feel that there are still big problems in health, education, crime, poverty and social inequality.

In August 2016, then-president Dilma Rousseff was removed from office because of impeachment.

Most people in Brazil speak Portuguese. Brazil is the only country in South America that speaks Portuguese.

Some people in Brazil speak German dialects. That came from German immigrants. 2% of Brazilians speak German as their first language. Yiddish is spoken by the elders of the Jewish community.

Other people in Brazil speak their ancestors' languages like Italian, Japanese, Polish, Ukrainian, French, Russian, Lithuanian, Chinese, Dutch and Korean. Spanish or Portunhol, a mix of Portuguese and Castilian (Spanish) is spoken at some of the borders. Indigenous languages as Guarani and Aymará are the first languages of a small number of Brazilians.

Brazil has the world's largest rainforest, the Amazon Rainforest. It makes up 40% of the country's land area. Brazil also has other types of land, including a type of savanna called cerrado, and a dry plant region named caatinga.

The most important cities are Brasília (the capital), Belém, Belo Horizonte, Curitiba, Florianópolis, Fortaleza, Goiânia, Manaus, Porto Alegre,  Recife, Rio de Janeiro, Salvador, São Paulo (the biggest city) and Vitória.  Other cities are at List of largest cities in Brazil.

Brazil is divided into 26 states plus the Federal District in five regions (north, south, northeast, southeast and centre-west):

The country is the fifth largest in the world by area. It is known for its many rainforests and jungles. It is next to every country in South America except Chile and Ecuador.
The name Brazil comes from a tree named brazilwood.

Brazil is the largest country in South America and fifth largest in the world. Its people are called Brazilians or Brasileiros (In Portuguese). The people include citizens of Portuguese or other European descent who mainly live in the South and Southeast, Africans, Native Americans, Arabs, Gypsies and people of Mixed ancestry. Brazil also has the largest Japanese community outside Japan. Other East Asians follow the Japanese group.The Amazon River flows through Brazil, it is the 2nd longest river in the world (after the Nile).The current President of Brazil is Jair Messias Bolsonaro. Two major sporting events were held in Brazil recently: the 2014 FIFA World Cup and the 2016 Summer Olympics in Rio de Janeiro.




#Article 48: Chemistry (1062 words)


Chemistry is a branch of  science that deals with chemical elements and compounds, and how these things work together and change.

Before 1600, people studied substances to figure out how to do things such as turn lead into gold, but no one managed to do that. This was called alchemy. After 1600, using the scientific method alchemists became chemists. Chemists separated the air into many parts and isolated the noble gases from it. They also processed special minerals from a mine in Sweden to get rare earth metals. Radioactivity was also discovered. Today chemists have discovered 118 different elements. Some are very common, like oxygen. Many are very rare and expensive, like platinum. Some cannot be found on earth and can only be made in labs, like rutherfordium.

Since the 1920s, the increased understanding of physics has changed chemists' theories about chemical reactions.  With smaller and faster computers, chemists have built better tools for analyzing substances. These tools have been sent to study chemicals on Mars.  Police also use those tools to study evidence from crime s.

There are several types of chemistry. Analytical chemistry looks at which  chemicals are in things. For example, looking at how much arsenic is in food. Organic chemistry looks at things that have carbon in them. For example, making acetylene. Inorganic chemistry looks at things that do not have carbon in them. One example is making an integrated circuit. Theoretical chemistry tries to explain chemical data with mathematics and computers.

A large area of chemistry is polymer chemistry. This looks at plastics. One example is making nylon. Because plastics are made of carbon, polymer chemistry is part of organic chemistry. Another area is biochemistry. This looks at the chemistry of living things. An example would be seeing how arsenic poisons people. Biochemistry is also part of organic chemistry. There are many other small branches of chemistry.

The basic unit of an element is called an atom. An atom is the smallest building block that you can cut an element into without the element breaking down (turning into a lighter element, for example through nuclear fission or radioactive decay). A chemical compound is a substance made up of two or more elements. In a compound, two or more atoms are joined together to form a molecule. The tiniest speck of dust or drop of liquid, that one can see is made up of many millions or billions of these molecules. Mixtures are substances where chemicals are mixed but not reacted. An example would be mixing sand and salt. This can be undone again to produce salt and sand separately. Chemical compounds are changed by a chemical reaction. An example would be heating sodium bicarbonate, common baking soda. It will make water, carbon dioxide, and sodium carbonate. This reaction cannot be undone.

One very important concept in chemistry is that different atoms interact with one another in very specific proportions.  For example, two hydrogen atoms interacting with one oxygen atom lead to the water molecule, H2O.  This relationship is known as the Law of constant proportions and leads to the idea of stoichiometry, a term that refers to the ratios of different atoms in chemical compounds.  For example, in water, there are always exactly 2 hydrogen atoms to 1 oxygen atom.  In carbon dioxide, there are exactly 2 oxygen atoms for 1 carbon atom.  These relationships are described using chemical formulas such as H2O  (two hydrogen atoms and one oxygen atom) and CO2 (one carbon atom and two oxygen atoms).

Because atoms of different elements react with one another in very specific proportions but atoms of different elements have different weights, chemists often describe the amount of different elements and compounds in terms of the number of moles.  A mole of any element contains the same number of atoms:  602,214,150,000,000,000,000,000 atoms. The atomic mass of an element can be used to see how much of the element makes a mole. For example, the atomic mass of copper is about 63.55. That means about 63.55 grams of copper metal has a mole of atoms. The atomic mass of chlorine is about 35.45. That means 35.45 grams of chlorine has a mole of atoms in it.

Moles can be used to see how many molecules are in chemical compounds, too. Copper(II) chloride is an example. CuCl2 is its chemical formula. There is one copper atom (63.55) and two chlorine atoms (35.45 · 2 = 70.90). Add all the molar masses of the elements together to get the molar mass of the chemical compound (63.55 + 70.90 = 134.45). That means in 134.45 grams of copper(II) chloride, there is one mole of copper(II) chloride molecules. This concept is used to calculate how much chemicals are needed in a chemical reaction if no reactants (chemicals that are reacted) should be left. If too much reactant is used, there will be some reactants left in the chemical reaction.

Acids and bases are common chemicals. Acids release H+ ions when in water, and bases release OH− ions when in water. Acids can react with bases. The H+ ion is taken from the acid by the base. This makes water, H2O. A salt is also made when an acid and a base react together. An example would be reacting hydrochloric acid (HCl) and sodium hydroxide (NaOH). Hydrochloric acid releases H+ and Cl- ions in water. The base releases Na+ and OH- ions. The H+ and the OH- react to make water. There is a solution of sodium chloride (NaCl) left. Sodium chloride is a salt.

Chemistry is very useful in everyday life and makes up the foundation of many branches of science. Most objects are made by chemists (people who do chemistry). Chemists are constantly working to find new and useful substances. Chemists make new drugs and materials like paints that we use every day.

Many chemicals are harmless, but there are some chemicals that are dangerous. For example, mercury(II) chloride is very . Chromates can cause cancer. Tin(II) chloride pollutes water easily. Hydrochloric acid can cause bad burns. Some chemicals like hydrogen can explode or catch fire. To stay safe, chemists experiment with chemicals in a chemical lab. They use special equipment and clothing to do reactions and keep the chemicals contained. The chemicals used in drugs and in things like bleach have been tested to make sure they are safe if used correctly.




#Article 49: Computer science (470 words)


 Computer science deals with the theoretical foundations of computation and practical techniques for their application.

Computer science is the study of manipulating, managing, transforming and encoding information.

There are many different areas in computer science. Some areas consider problems in an abstract manner, while some need special machines, called computers.

A person who works with computers will often need mathematics, science, and logic in order to design and work with computers.

This is so people can find new and easier ways to do things, and the way to approach problems with this information.

While computers can do some things easily (like simple math, or sorting out a list of names from A-to-Z), computers cannot answer questions when there is not enough information, or when there is no real answer. Also, computers may take too much time to finish long . For example, it may take too long to find the shortest way through all of the towns in the USA - so instead a computer will try to make a close guess. A computer will answer these simpler questions much faster.

Algorithms are a specific set of instructions or steps on how to complete a task. For example, a computer scientist wants to sort playing cards. There are many ways to sort them - by suits (diamonds, clubs, hearts, and spades) or by numbers (2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Queen, King, and Ace).  By deciding on a set of steps to sort the cards, the scientist has created an algorithm. The scientist then needs to test whether this algorithm works. This shows how well and how fast the algorithm sorts cards.

A simple but slow algorithm is: pick up two cards and check whether they are sorted correctly. If they are not, reverse them. Then do it again with another two, and repeat them all until they are all sorted. This bubble sort method will work, but it will take a very long time.
 
A better algorithm is: find the first card with the smallest suit and smallest number (2 of diamonds), and place it at the start. After this, look for the second card, and so on. This algorithm is much faster, and does not need much space. This algorithm is a selection sort.

Ada Lovelace wrote the first computer algorithm in 1843, for a computer that was never finished. Computers began during World War II. Computer science separated from the other sciences during the 1960s and 1970s. Now, computer science has its own methods, and has its own technical terms. It is related to electrical engineering, mathematics, and language science.

Computer science looks at the theoretical parts of computers. Computer engineering looks at the physical parts of computers (hardware). Software engineering looks at the use of computer programs and how to make them.




#Article 50: Computer (2835 words)


A computer is a machine that accepts data as input, processes that data using programs, and outputs the processed data as information. Many computers can store and retrieve information using hard drives. Computers can be connected together to form networks, allowing connected computers to communicate with each other.

The two principal characteristics of a computer are: It responds to a specific instruction set in a well-defined manner and it can execute a prerecorded list of instructions call a program. There are four main processing steps in a computer: inputting, storage, outputting and processing.

Modern computers can do billions of calculations in a second. Being able to calculate many times per second allows modern computers to multi-task, which means they can do many different tasks at the same time. Computers do many different jobs where automation is useful. Some examples are controlling traffic lights, vehicle , security systems, washing machines and digital televisions.

Computers can be designed to do almost anything with information. Computers are used to control large and small machines which in the past were controlled by humans. Most people have used a personal computer in their home or at work. They are used for things such as calculation, listening to music, reading an article, writing etc.

Modern computers are electronic computer hardware. They do mathematical arithmetic very quickly but computers do not really think. They only follow the instructions in their software programs. The software uses the hardware when the user gives it instructions, and gives useful output.

Humans control computers with user interfaces. Input devices include keyboards, computer mice, buttons, and touch screens. Some computers can also be controlled with voice commands, hand gestures or even brain signals through electrodes implanted in the brain or along nerves.

Computer programs are designed or written by computer programmers. A few programmers write programs in the computer's own language called machine code. Most programs are written using a programming language like C, C++, Java. These programming languages are more like the language with which one talks and writes every day. The compiler translates the user's instructions into binary code (machine code) that the computer will understand and do what is needed.

Most humans have a problem with math. To show this, try doing 584 × 3,220 in your head. It is hard to remember all the steps! People made tools to help them remember where they were in a math problem. The other problem people have is that they have to do the same problem over and over and over again. A cashier had to make change every day in her head or with a piece of paper. That took a lot of time and made mistakes. So, people made calculators that did those same things over and over. This part of computer history is called the history of automated calculation, which is a fancy phrase for the history of machines that make it easy for me to do this same math problem over and over without making mistakes.

The abacus, the slide rule,  the astrolabe and the Antikythera mechanism (which dates from about 150-100 BC) are examples of automated calculation machines.

People do not want a machine that would do the same thing over and over again. For example, a music box is a machine that plays the same music over and over again. Some people wanted to be able to tell their machine to do different things. For example, they wanted to tell the music box to play different music every time. They wanted to be able to program the music box- to order the music box to play different music. This part of computer history is called the history of programmable machines which is a fancy phrase for The history of machines that I can order to do different things if I know how to speak their language.

One of the first examples of this was built by Hero of Alexandria (c. 10–70 AD). He built a mechanical theater which performed a play lasting 10 minutes and was operated by a complex system of ropes and drums. These ropes and drums were the language of the machine- they told what the machine did and when. Some people argue that this is the first programmable machine.

Historians disagree on which early machines are computers. Many say the castle clock, an astronomical clock invented by Al-Jazari in 1206, is the first known programmable analog computer.  The length of day and night could be adjusted every day in order to account for the changing lengths of day and night throughout the year. Some count this daily adjustment as computer programming.

Others say the first computer was made by Charles Babbage.  Ada Lovelace is considered to be the first programmer.

At the end of the Middle Ages, people started thinking math and engineering were more important. In 1623, Wilhelm Schickard made a mechanical calculator. Other Europeans made more calculators after him. They were not modern computers because they could only add, subtract, and multiply- you could not change what they did to make them do something like play Tetris. Because of this, we say they were not programmable. Now engineers use computers to design and plan.

In 1801, Joseph Marie Jacquard used punched paper cards to tell his textile loom what kind of pattern to weave. He could use punch cards to tell the loom what to do, and he could change the punch cards, which means he could program the loom to weave the pattern he wanted. This means the loom was programmable. At the end of the 1800s Herman Hollerith invented the recording of data on a medium that could then be read by a machine, developing punched card data processing technology for the 1890 U.S. census. His tabulating machines read and summarized data stored on punched cards and they began use for government and commercial data processing.

Charles Babbage wanted to make a similar machine that could calculate. He called it The Analytical Engine. Because Babbage did not have enough money and always changed his design when he had a better idea, he never built his Analytical Engine.

As time went on, computers were used more. People get bored easily doing the same thing over and over. Imagine spending your life writing things down on index cards, storing them, and then having to go find them again. The U.S. Census Bureau in 1890 had hundreds of people doing just that. It was expensive, and reports took a long time. Then an engineer worked out how to make machines do a lot of the work. Herman Hollerith invented a tabulating machine that would automatically add up information that the Census bureau collected. The Computing Tabulating Recording Corporation (which later became IBM) made his machines. They leased the machines instead of selling them. Makers of machines had long helped their users understand and repair them, and CTR's tech support was especially good.

Because of machines like this, new ways of talking to these machines were invented, and new types of machines were invented, and eventually the computer as we know it was born.

In the first half of the 20th century, scientists started using computers, mostly because scientists had a lot of math to figure out and wanted to spend more of their time thinking about science questions instead of spending hours adding numbers together. For example, if they had to launch a rocket ship, they needed to do a lot of math to make sure the rocket worked right. So they put together computers. These analog computers used analog circuits, which made them very hard to program. In the 1930s, they invented digital computers, and soon made them easier to program. However this is not the case as many consecutive attempts have been made to bring arithmetic logic to l3.Analog computers are mechanical or electronic devices which solve problems.Some are used to control machines as well.

Scientists figured out how to make and use digital computers in the 1930s to 1940s. Scientists made a lot of digital computers, and as they did, they figured out how to ask them the right sorts of questions to get the most out of them. Here are a few of the computers they built:

Several developers of ENIAC saw its problems. They invented a way to for a computer to remember what they had told it, and a way to change what it remembered. This is known as stored program architecture or von Neumann architecture. John von Neumann talked about this design in the paper First Draft of a Report on the EDVAC, distributed in 1945. A number of projects to develop computers based on the stored-program architecture started around this time. The first of these was completed in Great Britain. The first to be demonstrated working was the Manchester Small-Scale Experimental Machine (SSEM or Baby), while the EDSAC, completed a year after SSEM, was the first really useful computer that used the stored program design. Shortly afterwards, the machine originally described by von Neumann's paper—EDVAC—was completed but was not ready for two years.

Nearly all modern computers use the stored-program architecture. It has become the main concept which defines a modern computer. The technologies used to build computers have changed since the 1940s, but many current computers still use the von-Neumann architecture.

In the 1950s computers were built out of mostly vacuum tubes. Transistors replaced vacuum tubes in the 1960s because they were smaller and cheaper. They also need less power and do not break down as much as vacuum tubes. In the 1970s, technologies were based on integrated circuits. Microprocessors, such as the Intel 4004 made computers smaller, cheaper, faster and more reliable. By the 1980s, microcontrollers became small and cheap enough to replace mechanical controls in things like washing machines. The 1980s also saw home computers and personal computers. With the evolution of the Internet, personal computers are becoming as common as the television and the telephone in the household.

In 2005 Nokia started to call some of its mobile phones (the N-series) multimedia computers and after the launch of the Apple iPhone in 2007, many are now starting to add the smartphone category among real computers. In 2008, if smartphones are included in the numbers of computers in the world, the biggest computer maker by units sold, was no longer Hewlett-Packard, but rather Nokia.

There are many types of computers. Some include:

A desktop computer is a small machine that has a screen (which is not part of the computer). Most people keep them on top of a desk, which is why they are called desktop computers. Laptop computers are computers small enough to fit on your lap. This makes them easy to carry around. Both laptops and desktops are called personal computers, because one person at a time uses them for things like playing music, surfing the web, or playing video games.

There are bigger computers that many people at a time can use. These are called Mainframes, and these computers do all the things that make things like the internet work. You can think of a personal computer like this:  the personal computer is like your skin: you can see it, other people can see it, and through your skin you feel wind, water, air, and the rest of the world. A mainframe is more like your internal organs: you never see them, and you barely even think about them, but if they suddenly went missing, you would have some very big problems.

An embedded computer, also called embedded system is a computer that does one thing and one thing only, and usually does it very well. For example, an alarm clock is an embedded computer: it tells the time. Unlike your personal computer, you cannot use your clock to play Tetris. Because of this, we say that embedded computers cannot be programmed, because you cannot install more programs on your clock. Some mobile phones, automatic teller machines, microwave ovens, CD players and cars are operated by embedded computers.

All-in-one computers are desktop computers that have all of the computer's inner mechanisms in the same case as the monitor. Apple has made several popular examples of all-in-one computers, such as the original Macintosh of the mid-1980s and the iMac of the late 1990s and 2000s.

Computers store data and the instructions as numbers, because computers can do things with numbers very quickly. These data are stored as binary symbols (1s and 0s). A 1 or a 0 symbol stored by a computer is called a bit, which comes from the words binary digit. Computers can use many bits together to represent instructions and the data that these instructions use. A list of instructions is called a program and is stored on the computer's hard disk. Computers work through the program by using a central processing unit, and they use fast memory called RAM also known as (Random Access Memory) as a space to store the instructions and data while they are doing this. When the computer wants to store the results of the program for later, it uses the hard disk because things stored on a hard disk can still be remembered after the computer is turned off.

An operating system tells the computer how to understand what jobs it has to do, how to do these jobs, and how to tell people the results. Millions of computers may be using the same operating system, while each computer can have its own application programs to do what its user needs. Using the same operating systems makes it easy to learn how to use computers for new things. A user who needs to use a computer for something different, can learn how to use a new application program. Some operating systems can have simple command lines or a fully user-friendly GUI.

One of the most important jobs that computers do for people is helping with communication. Communication is how people share information. Computers have helped people move forward in science, medicine, business, and learning, because they let experts from anywhere in the world work with each other and share information. They also let other  communicate with each other, do their jobs almost anywhere, learn about almost anything, or share their opinions with each other. The Internet is the thing that lets people communicate between their computers.

A computer is now almost always an electronic device. It usually contains materials that will become electronic waste when discarded. When a new computer is bought in some places, laws require that the cost of its waste management must also be paid for. This is called product stewardship.

Computers can become  quickly, depending on what programs the user runs. Very often, they are thrown away within two or three years, because some newer programs require a more powerful computer. This makes the problem worse, so computer recycling happens a lot. Many projects try to send working computers to developing nations so they can be re-used and will not become waste as quickly, as most people do not need to run new programs. Some computer parts, such as hard drives, can break easily. When these parts end up in the landfill, they can put poisonous chemicals like lead into the ground-water. Hard drives can also contain secret information like credit card numbers. If the hard drive is not erased before being thrown away, an identity thief can get the information from the hard drive, even if the drive doesn't work, and use it to steal money from the previous owner's bank account.

Computers come in different forms, but most of them have a common design.

A computer has several main parts. When comparing a computer to a human body, the CPU is like a brain. It does most of the thinking and tells the rest of the computer how to work. The CPU is on the Motherboard, which is like the skeleton. It provides the basis for where the other parts go, and carries the nerves that connect them to each other and the CPU. The motherboard is connected to a power supply, which provides electricity to the entire computer. The various drives (CD drive, floppy drive, and on many newer computers, USB flash drive) act like eyes, ears, and fingers, and allow the computer to read different types of storage, in the same way that a human can read different types of books. The hard drive is like a human's memory, and keeps track of all the data stored on the computer. Most computers have a sound card or another method of making sound, which is like vocal cords, or a voice box. Connected to the sound card are speakers, which are like a mouth, and are where the sound comes out. Computers might also have a graphics card, which helps the computer to create visual effects, such as 3D environments, or more realistic colors, and more powerful graphics cards can make more realistic or more advanced images, in the same way a well trained artist can.




#Article 51: Continent (435 words)


A continent is a large area of the land on Earth that is joined together. In general it is agreed there are seven continents in the world: Africa, Antarctica, Asia, Europe, North America, Australia or Oceania, and South America. 

\The most populous continent by population is Asia followed by Africa. The third most populous continent is the Americas. The fourth most populous is Europe and then Oceania. In sub-Saharan Africa, the largest age group are denarians (in their teens). In north Africa the largest age group are vicenarian (in their twenties). In Europe, most people are tricenarian (in their thirties) or quadragenarian (in their forties).

Some sources say that Australia is one of the seven continents. Others say that Australia is part of Oceania.   Oceania is a region which includes Australia, New Zealand and the Pacific Islands. The third alternative is the term Australasia, which includes at least all countries on the Australian continental plate. This includes the islands of New Guinea, Tasmania, New Zealand and a number of smaller islands. It is on the south-eastern side of the Wallace Line, with distinct differences in its biology from the Asian side of the line.

North America and South America are often described as the Americas. This has the advantage of including Central America and the Caribbean islands. Otherwise, Central America is counted as part of North America.

Eurasia is not really an alternative, it is a recognition that the landmass of Europe and Asia are continuous, and some of its largest countries are in both continents. Russia extends from eastern Europe to the far east of Asia without a break. The Ural Mountains, which run roughly north/south, are the traditional dividing-line between Europe and Asia. For many purposes it is convenient to consider the great landmass as a single continent, Eurasia.

When British people talk about the Continent (or Continental things) they mean the European mainland. This meaning is not used as much as it used to be, but is still seen in phrases like Continental breakfast (rolls with cheese, jam etc. as distinct from an English breakfast which is a cooked breakfast).

Continents not only move but also sometimes move against each other. The Indian subcontinent has been colliding with the Eurasian continent for a while now. As these continents push against each other, they buckle and bend. Because of this, the Himalaya Mountains, where Mount Everest is, are still being made today.

Zealandia is an almost entirely submerged land mass, and 93% of it still remains under water. Zealandia may have broken off the Australian plate between 85 and 130 million years ago.




#Article 52: China (1850 words)


China ( Pinyin: Zhōngguó) is a cultural region, an ancient civilization, and a nation in East Asia. The official name is People's Republic of China.

The last Chinese Civil War (19271949) resulted in two different political powers today:

China is one of the world's oldest civilizations: it has the oldest continuous civilization. There is archaeological evidence over 5,000 years old. China also has one of the world's oldest writing systems (and the oldest in use today). China has been the source of many major inventions. Geographically, China’s longest river is the Yangtze River which runs through mega cities and is home to many species. It is the worlds third longest river.

The first recorded use of the word China is dated 1555. It is derived from chīnī, a Persian adjective meaning 'Chinese' which was popularized in Europe by Marco Polo.

Ancient China was one of the first civilizations and was active since the 2nd millennium BC as a feudal society. Chinese civilization was also one of the few to invent writing, with the others being Mesopotamia, the Indus Valley civilization, the Maya civilization, the Minoan civilization of ancient Greece, and Ancient Egypt. It reached its golden age during the Tang Dynasty (c. A.D. 10th century).  Home of  Confucianism and Daoism, it had great influence on nearby countries including Japan, Korea, and Vietnam in the areas of political system, philosophy, religion, art, writing and literature. China is home to some of the oldest artwork in the world. Statues and pottery, as well as decorations made of jade, are some classic examples.

Before the Qin Dynasty united China, there were hundreds of small states that fought each other for hundreds of years in a war to control China. This is known as the Warring States Period. Although the continuing wars made people suffer, it was at this time when many great philosophies were born, including Confucianism and Daoism. Confucianism and Daoism alone have been the foundation of many social values seen in modern eastern-Asian cultures today.

Its geography mostly looked like that of modern China, except with northern and western edges that varied. It was often attacked by northern nomadic people such as the Turkic peoples and the Mongols led by Genghis Khan and Kublai Khan. During the history of ancient China, the northern nomadic people and the Chinese people had been fighting each other and taking turns to rule the land and the people of China. However, when the northern people beat the Chinese people and came to rule the kingdom, they also Incorporated the Chinese way of living and became like the Chinese. Many of the strongest dynasties of China were ruled by the northern people, including the Qin, Tang, Yuan (Mongolian), and Qing. Each time, they also brought new elements into the Chinese culture.

While China achieved many things in the First millennium and early 2nd millennium, it became an isolationist country in the 15th century C.E. This was because Spain found enormous silver in the new continent, which was the main currency (money) in China and Europe at the time, and China did not want to be bought by the foreigners.

By the time of the Renaissance, European powers started to take over other countries in Asia. While China was never actually taken over, many European countries, such as Britain and France built spheres of influence in China. Since China had cut itself off from the world over the previous few centuries, by the Qing Dynasty, it had fallen behind other countries in technology, and was helpless to stop this from happening. This had become clear when it lost the Opium Wars to Britain in the 19th century.

Still influenced by Western sources, China faced internal strife. The Taiping Rebellion or Taiping War occurred in China from 1851 through 1864. The Taiping Rebellion was led by Hong Xiuquan from Guangdon. Hong Xiuquan was influenced by Christian missionaries and declared himself the brother of Jesus. Hong made his mission to bring down the Qing Dynasty. Gaining influence on the southern Chinese population, the Taiping Rebellion attracted tens of thousands of supporters. The Taiping regime successfully created a state within the Qing Empire with the capital at Nanjing. Hong called his new state the Taiping Tianguo or The Heavenly State of Great Peace. Local armies eventually suppressed the rebellion at the final battle of Nanjing. 

In 1911, the Republic of China was founded by Sun Yat-sen, but its government was very weak. Warlords controlled many areas. Chiang Kai-shek led wars against them, and he became President and dictator.

In 1931, Japan invaded Manchuria, a place in the northeastern part of China. On July 7, 1937, the Japanese attacked the rest of the country, starting what was called the Second Sino-Japanese War. The war later became part of World War II. The war was fought for eight years and millions of Chinese people were killed.

However, the Chinese Civil War later started between the Kuomintang (Nationalists) of the Republic of China (ROC) and the Communists of the People's Republic of China (PRC). The Communists wanted to make China like the Soviet Union, whereas the other side wanted to keep China in its current state at the time. The Communists were led by Mao Zedong, Liu Shaoqi ,Zhou Enlai and others. The Communists eventually won the war by uniting all the people from different positions. The Nationalists (led by Chiang Kai-shek) fled to the island of Taiwan and set up their new capital city in Taipei. After the Chinese Civil War, the Communist leader Mao Zedong declared a new country, the People's Republic of China (PRC), in Beijing on October 1, 1949.

Under Mao the country stayed poor while Taiwan became richer. His attempt at industrialization and collectivization with the Great Leap Forward led to the deaths of many people from famine. The Cultural Revolution caused great social upheaval. After 1976, China underwent market economy reforms under Deng Xiaoping, and experienced rapid economic growth, which made the former progress made by Taiwan became overshadowed.  China is now one of the largest economies in the world, relying mainly on exports.

In recent history, China has had problems with protests, blocking of information on the Internet, and censorship of news. 1989 was notable for the controversial Tian An Men Event. But also known for its social stability and low crime rate. Since the 2008 Olympics, China has hosted many major international events, and the 2022 Winter Olympics will be held in Beijing, China.

China's landscape is vast and diverse. It ranges from the Gobi and Taklamakan Deserts in the north to subtropical forests in the south. The Himalaya, Karakoram, Pamir and Tian Shan mountain ranges separate China from much of South and Central Asia. The Yangtze and Yellow Rivers run from the Tibetan Plateau to the densely populated eastern coast. The Yangtze River is the third-longest river in the world while the Yellow River is the sixth-longest. China's coastline along the Pacific Ocean is 14,500 kilometers (9,000 mi) long. It is bounded by the Bohai, Yellow, East China and South China seas. China connects through the Kazakh border to the Eurasian Steppe. The Eurasian Steppe has been an artery of communication between East and West since the Neolithic through the Steppe route. The Steppe Route is the ancestor of the terrestrial Silk Road(s).

China's constitution states that The People's Republic of China is a socialist state under the people's democratic dictatorship led by the working class and based on the alliance of workers and peasants. It also states the state organs apply the principle of democratic centralism. The PRC is one of the world's only socialist states openly being communist.

With 2.3 million active troops, the People's Liberation Army (PLA) is the largest standing military force in the world. The PLA is commanded by the Central Military Commission (CMC). China has the second-biggest military reserve force, only behind North Korea. The PLA consists of the Ground Force (PLAGF), the Navy (PLAN), the Air Force (PLAAF), and the People's Liberation Army Rocket Force (PLARF). According to the Chinese government, China's military budget for 2017 was US$151,5 billion. China has the world's second-largest military budget.

China was once a world leader in science and technology up until the Ming dynasty. There are many Ancient Chinese discoveries and inventions. For example, papermaking, printing, the compass, and gunpowder  are known as the Four Great Inventions. They became widespread across East Asia, the Middle East and later to Europe. Chinese mathematicians were the first to use negative numbers. By the 17th century, Europe and the Western world became better than China in science and technology.

The national census of 2010 recorded the population of the People's Republic of China to be about 1,370,536,875. About 16.60% of the population were 14 years old or younger, 70.14% were between 15 and 59 years old, and 13.26% were over 60 years old. The population growth rate for 2013 is estimated to be 0.46%.

China is the origin of Eastern martial arts, called Kung Fu or its first name Wushu. China is also the home of the well-respected Spa Monastery and Wudang Mountains. Martial art started more for the purpose of survival, defense, and warfare than art. Over time some art forms have branched off, while others have retained their distinct Chinese flavor.

China has had renowned artists including Wong Fei Hung (Huang Fei Hung or Hwang Fei Hung) and many others. Art has also co-existed with a variety of paints including the more standard 18 colors. Legendary and controversial moves like Big Mak are also praised and talked about within the culture.

China has many traditional festivals, such as Spring Festival, Dragon Boat Festival, Mid-autumn Festival and so on. The most important is Chinese New Year. People in China will have holidays to celebrate these festivals.

Spring Festival is the Chinese New Year.

Dragon Boat Festival is celebrated to commemorate the death of Qu Yuan, a patriotic poet of the State of Chu during the Warring States period. He persuaded his emperor not to accept Qin's diplomats' offers several times but his emperor did not listen to him. He was very sad and ended up jumping into the river to end his life. The people loved him so much that they did not want the fish to eat his corpse. They made and threw rice dumplings into the river. They hope the fish eat these dumplings instead of the poet's corpse. They also rowed dragon boats in the river to get rid of the fish. Such practices, eating rice dumplings and holding dragon boat races, become what Chinese do in this festival nowadays.

Held on the fifteenth day of the eighth lunar month, Mid-Autumn Festival is a festival for families. Now when the festival sets in, people would sit together to eat moon cakes, appreciate the bright full moon cakes, appreciate the bright full moon, celebrate the bumper harvest and enjoy the family love and happiness. To the Chinese people, the full moon symbolizes family reunion, as does the moon cakes. Hence the Mid-Autumn Festival is also called the Family Reunion Festival.




#Article 53: Country (536 words)


As defined by Montevideo Convention, a country is a territory with distinct political boundaries that claims sovereignty over a specific geographic area with a permanent population, controlled by its own government that enters relations with other states. There is no universally accepted answer as to how many countries in the world there actually are, however the minimum answer is 193 for the 193 United Nations members.

This number can become bigger in other ways. For example, there are two United Nations observer states. The Vatican City State and the State of Palestine. This would add two to the list of United Nations member states, there for the number of countries the would be 195. 

Taiwan is also sometimes classified as a country. However, there is an ongoing disputes over Taiwan's sovereignty with the People's Republic of China.

This can be developed on even further by adding the constituent countries of the United Kingdom, The Kingdom of the Netherlands and the Kingdom of Denmark which could add anywhere from three to eleven countries to the prior number. 

There are a number of disputed areas that have declared independence from their parent state and receive limited recognition. For example, Kosovo, South Ossetia, Transnistria and Abkhazia. These are just some of the many examples of terrirories with limited to no recognition that are sometimes classed as countries.

There is a lot of controversy surrounding the above examples and quite often any one of these territories may be counted as countries purely based on opinion. If all of the above were added the list of U.N members there could be anything up to 211 countries based on the previous examples given. 

There are however many more territories with unique political circumstances that could also be counted. 

Depending on how loosely the dictionary definition for the word country is used there could be anything from 193 countries in the world or more. The matter is purely subjective depending on varying opinions and there has never been any consideration as to what the maximum number of countries in the world could be. 

There are multiple organisations that have their own lists of countries, one example being the Travellers Century Club which recognises 327 countries as of 01/01/18. 

Constituent country is a term sometimes used, usually by official institutions, in contexts in which a number of countries compose a long entity or grouping. The Organisation for Economic Co-operation and Development (OECD) has used the term referring to the former Yugoslavia, and the European institutions like the Council of Europe often use it in reference to the European Union.

A disputed territory is that territory whose sovereignty is jealously desired by two or more countries. Usually the administration of the territory is carried out by one of the countries that claims sovereignty, while the other country does not recognize the sovereignty over the territory of the other country. This does not usually happen in land or sea areas on which none possesses effective control, such as Antarctica, or only partially. It can also be considered as a disputed territory to those areas that are given by two different governments, and therefore are divided. One example is the Turkish Republic of Northern Cyprus and Cyprus.




#Article 54: Colchester (207 words)


Colchester is a town in the northern part of the English county of Essex. It has a population of 104,000 people. People believe that Colchester is the oldest Roman town in England.

Before Roman times, Colchester was Camulodunon. This is a Celtic name that came from Camulos. Camulos was the Celtic god of war. The Romans called Colchester Camulodunum (written CAMVLODVNVM) and made it the capital of Roman Britain. Colchester was attacked and burnt by Boudicca in 61 AD.  The Romans moved their capital of Britannia to Londinium (now London), but Camulodunum remained an important city until the fifth century, when the Saxons conquered the region. 

The Roman town of Camulodunum, officially known as Colonia Victricensis, reached its peak in the Second and Third centuries AD.  It may have reached a population of 30,000 in those centuries, but when the Romans withdrew from Britannia in 410 AD it probably had fewer than 5,000 inhabitants. 

The church at the Benedictine abbey of Saint John the Baptist was destroyed in 1539.  This action was part of the dissolution of the monasteries by King Henry VIII.  Only a gate remains, that people still go to visit.

King Cunobelinus (or Cunobelin) was from Colchester.

Colchester is twinned with the following cities:




#Article 55: Cartography (156 words)


Cartography is making maps. It is part of geography. How people make maps is always changing. In the past, maps were drawn by hand, but today most printed maps are made using computers and people usually see maps on computer screens. Someone who makes maps is called a cartographer.

Making a map can be as simple as drawing a direction on a napkin, or as complicated as showing a whole country or world. Anyone can make a map, but cartographers spend their lives learning how to make better maps.

For many centuries maps were usually carefully drawn onto paper or parchment. Now they are made on a computer which makes them look neater with accurate images.

Maps are of two main types: 

General maps are produced in a series. Governments produce them in larger-scale and smaller-scale maps of great detail.

Thematic maps are now very common. They are necessary to show spatial, cultural and social data.




#Article 56: Creator (125 words)


A creator is a person who creates something.

In some religions (Judaism, Christianity, Islam) God (or Allah meaning the God in Arabic) is the most important and original creator of the whole universe - including Man who is made in his image (see Genesis) to observe it and control it like God. The idea that anything that a person is creating, like an idea, can be owned as property comes from the ethical traditions and legal codes that came from these religions.

In other traditions (Buddhism, Native American mythology) anyone has this potential for creating, and can become part of the greater creating of the universe. Stewardship of home, land and all of Earth is a test for participating in this, or just good sense.




#Article 57: Chorizo (113 words)


Chorizo is a pork (pig-meat) sausage which people first made in the Iberian Peninsula. It is made with large pieces of fatty pork, chili pepper and paprika. The special taste of this sausage comes from the mild Spanish paprika in it. 

In the western hemisphere, the Mexican and Caribbean types are better known. These types of chorizo are made with smaller pieces of pork and different seasonings and peppers are used.

Cured smoked chorizo is edible and can be eaten without cooking. Fresh chorizo must be cooked before eating. It can be eaten by its self, or as part of meal. It can also be used in place of ground beef or pork.




#Article 58: Creativity (389 words)


Creativity is the ability of a person or group to make something new and useful or valuable, or the process of making something new and useful or valuable. It happens in all areas of life - science, art, literature and music. As a personal ability it is very difficult to measure. The reason is that we don't understand the mental processes that help some people be more creative than others. Judging what is creative is also controversial. Some people say only things which are historically new are creative, while other people say that if it is new for the creator and the people around them, then it is also creativity.

Some think that creativity is an important thing that makes humans different from apes. Others recognize that even apes, other primates, other mammals and some birds adapt to survive by being creative (for example - primates using tools). Liane Gabora believes that all culture comes from creativity, not imitation. Therefore, these people say, human science should focus on it (pay special attention to it): Ethics for example would focus on finding creative solutions to ethical dilemmas. Politics would focus on the political virtues that need some creativity. Imitation would not be the focus of education. Linguistics might be more interested in how new words are created by culture, rather than in how existing ones are used in grammar.

Intellectual interests (recognized as intellectual rights or intellectual property in the law) are a way to reward creativity in law, but they do not always work very well. A good example is copyright which is supposed to pay authors and artists, but may only pay lawyers to make (imitative) arguments in court.

Creativity is a central question in economics, where it is known as ingenuity (the ability to come up with new ideas) or individual capital - capacities that individuals have, that do not arise from simple imitation of what is known already. This is separate from the instructional capital that might try to capture some of that in a patent or training system that helps others do what the individual leader or  of the system can do. In urban economics there are various ways to measure creativity - the Bohemian Index and Gay Index are two attempts to do this  and predict the economic growth of cities based on creativity.




#Article 59: Catharism (929 words)


The Cathar  was a version of Christianity. They were usually considered Gnostics. The word 'Cathar' comes the Greek word katharos meaning 'unpolluted' (from Tobias Churton, The Gnostics) or  the pure ones.

The Cathars believed that the world had been made by a bad god.  They believed that this bad god had taken them from the good god and put them in the world, but inside their bodies there was a spirit, and that spirit needed to return to the good god.  They were famous for a belief in a form of reincarnation and believed that when someone died the bad god would put that person's spirit in a new body. They believed this cycle of coming back to life could be escaped by a ritual cleansing.  They were opposed to the doctrine of sin.  

Women were prominent in the faith.  They were pacifists.  They didn't eat anything that was made from other animals, including meat and cows milk. The only  to this was fish. Fish was OK to eat because they believed fishes were not alive but just things that were sometimes produced from dirt and water.

They preached tolerance of other faiths.  They rejected the usual Christian rules of marriage and only believed in the New Testament.  An earlier 10th-century Bulgarian heresy, Bogomilism and also Manichaeism started some of these trends.  

They used a bible in the language people spoke. Many other Christians used a Bible in Latin. Latin was spoken only by the priests.

In 1145, open challenge to Catholic dominance began.  In about 1165, the first Cathars said that the Church was full of ravening (starving) wolves and hypocrites and worshipping the wrong God, right in front of the most powerful Catholics. In 1166, the Council of Oxford in England wiped out the English Cathars.  It was also suppressed in Northern France.  In 1167, Cathar bishops met to discuss organizing a counter Church - in the South of France, the Languedoc nobles protected it, and many noble women became Perfects.  Parish clergy had low morale, or confidence.

The Catholic Church was against Catharism, seeing it as a heresy.

In the South of France there was tremendous religious fervor, and an economy that was starting to grow, and a social class of  merchants and  peasants was starting to grow.  Peasants owned their own land.  Meanwhile, in other parts of Europe, peasants were forced to give up their land to nobles and become serfs or slaves - the system of feudalism.  There was a strong central absolute monarchy that did not exist in the South of France.  The burghers and bankers had more power in this looser system.  R. I. Moore is a historian who believes that it was desire to crush this system and take over the land that drove the attack.

However, there was real cultural and religious difference to cause problems:  Troubadors, who combined some of the traditions of the Bards of the Celts, and Jews, were both part of the multicultural society in the South of France.  Their influences were not appreciated by local or Roman Church figures.  The 12th century Roman Catholic Monks were founding their monasteries outside the towns, drawing the best people there.

The Cathars thus had little competition.  The Cathar Perfects, the so-called Good Men or Good Women, lived restrained lives and spread their faith in towns - where the Catholics in general did not have their best agents.  Also, Cathars preached that only these Good leaders had to follow the regimens their whole lives - lay people could repent only on their deathbeds.  Many 20th century Christian sects have similar beliefs.

The Pope ordered a crusade against the Cathars in southern France. He said any crusader who answered the call would be given the same rewards as a crusader who went to the Holy Land. This was an absolution of all sin.

In the Launguedoc, on the 22nd of July 1209, a force of about 30,000 Crusaders arrived at the walls of Beziers bearing the cross pattee to mislead and create ease among the Cathars, thinking they were friend, not foe, and  demanded that about 200 Cathars be surrendered.  The people of the town who were mostly Catholic, said that rather than turn over their friends and family, we would rather be flayed alive.  

A mistake by the defenders of Beziers let thousands of attackers in. Arnauld Amaury made the famous quote Kill them all, god knows his own  on being asked how to tell who were Cathars during the assault. Everyone in the town was killed, some while taking refuge in the church.  It is guessed that 20,000 were killed, many of whom were Catholics and not Cathars at all.  The crusade became known as the Albigensian crusade after the town of Albi.  It was to wipe out the Cathars almost entirely over forty or so years.  The Crusaders wanted to go home, but were ordered by the Pope to continue until the whole South of France was controlled and all Cathars were dead. In 1210, they attacked the fortress at Minerv and built the first great bonfire of heretics - beginning the practice of burning at the stake that would continue in the Inquisition of the Counter-Reformation. It is interesting to note that at the siege of Montsegur when the fires were lit the Cathars ran down the hill and threw themselves on, as their beliefs were very strong.

Catharism disappeared from the northern Italian cities after the 1260s, pressured by the Inquisition. The last known Cathar perfectus in the Languedoc, Guillaume Bélibaste, was killed in 1321.




#Article 60: Cosmology (417 words)


Cosmology is the branch of astronomy that deals with the origin, structure, evolution and space-time relationships of the universe. NASA defines cosmology as The study of the structure and changes in the present universe. Another definition of cosmology is the study of the universe, and humanity's place in it.

Modern cosmology is dominated by the Big Bang theory, which brings together observational astronomy and particle physics. 

Though the word cosmology is recent (first used in 1730 in Christian Wolff's Cosmologia Generalis), the study of the universe has a long history.

Until recently, people thought that the universe was only the Milky Way galaxy. They thought this because they could only see the planets up to Saturn and stars. With the invention of the telescope, we could see more of the universe. Even in the 20th century, people thought that the Milky Way was the entire universe. With the Hubble Space Telescope, people could see things far away.

Modern cosmology is considered to have started in 1917 with the final paper of Albert Einstein's theory of general relativity. This paper was known as Cosmological Considerations of the General Theory of Relativity which made physicists start to change the assumption that the Universe never changed. When a scientific discipline begins to change an idea that is believed by many people, it is known as a paradigm shift. During this paradigm shift, the Great Debate took place. Many scientists debated if there were other galaxies. The debate ended when Edwin Hubble found Cepheid Variables in the Andromeda Galaxy in 1926.

The Big Bang model was then created by Belgian priest, Georges Lemaître in 1927. This was supported by Edwin Hubble's discovery of the redshift in 1929 and later by the discovery of cosmic microwave background radiation. This was found by Arzo Penzias and Robert Woodrow Wilson in 1964. 

All of these discoveries have been further supported throughout the 20th century. Some more observations of the cosmic microwave background radiation were found by the COBE, WMAP, and Planck satellites. Some more observations of the redshift were found by the 2dfGRS and SDSS. These are known as redshift surveys. Survey is this context refers to an astronomical survey. An astronomical survey is a place in space. A redshift survey is a survey that looks for redshifts.

On 1 December 2014, at the Planck 2014 meeting in Ferrara, Italy, astronomers reported that the universe is 13.8 billion years old and is composed of 4.9% regular matter, 26.6% dark matter and 68.5% dark energy.




#Article 61: Church (building) (937 words)


A church is a building that was constructed to allow people to meet to worship together. These people are usually Christians, or influenced by Christianity. Some other religious groups also call their religious buildings churches.

Depending on the number of people that are in a community, the churches come in different sizes. Small churches are called chapels. The churches in a particular geographical area form a group called the diocese.  Each diocese has a cathedral.  In most cases, the cathedral is a very big church. Cathedrals are the seat of bishops.

 

In the early days of Christianity people had to worship in secret. Christian worship was not allowed in the Roman empire, so Christians had to meet in a secret place. Sometimes they met in people’s houses or barns, sometimes they met underground. The first places that were built for Christian worship were small chapels that were cut into a rock where people could worship without being discovered.

After the death of the Roman emperor Constantine in 337 A.D. Christians were allowed to have buildings to worship in. These first churches were built on a similar plan to Roman basilicas. This plan was later used for the fine Gothic cathedrals and churches that were built at the end of the Middle Ages.

There are several parts in the architecture of a church. Not all churches will have all these parts:

In Roman Catholic churches there is always a stoup (bowl) of holy water near the entrance of the church. This tradition comes from the fact that Roman basilicas had a fountain for washing in front of the entrance. The font is a bowl where people (often babies) are baptized. This is also near the entrance of the church. This is a symbol of the fact that it is welcoming the people into the Christian church.

Traditionally the nave has long benches for the congregation to sit on. These are called pews. Some churches may now have replaced their pews with chairs so that they can be moved about for different occasions. At the front of the nave is the pulpit where the priest preaches (these talks are called “sermons”). There is also a lectern (like a large music stand) from where the lessons (the Bible readings) are read.

If there are aisles along the side of the nave there will be pillars which hold up the roof. In large churches or cathedrals there may be a row of little arches along the top of these pillars. This is called the triforium. Over the triforium is the clerestory which is a row of windows high up in the church wall.

The chancel is the most holy part of the church, and this is why it is often separated from the nave by a screen which can be made of wood or stone, or occasionally iron. The congregation can see through the screen. On the top of the screen there may be a cross. This is called a rood (pronounce like “rude”) screen. Priests used to climb up a staircase to the top of the rood screen to read the epistle and the gospel. Sometimes people sang from there.

Inside the chancel are the benches where the choir sit. These are called choir stalls. They are on both sides. The two sides of the choir sit facing one another. The choir members who sit on the left (north side) are called “cantoris” (the side where the “cantor” sits) and those on the right (south side) are called “decani” (the side where the deacon sits). In some large churches or cathedrals the seats for the priests tip up. The top of these seats, when they are tipped up, are called misericords (from the Latin word for “mercy”). This is because the priests or monks were able to lean against them when they got tired if they had to stand up for a long time.

Sometimes there are holes in the walls of the screen so that the congregation can see through. These are called squints. If there is a recess in the wall it is called an aumbry. It is a cupboard for communion wine and bread that have been consecrated by a priest.

The altar may be right at the east end of the church, but in larger churches or cathedrals it is often much farther forward. In that case the very east end is called an apse. Sometimes it is a separate chapel called the “Lady Chapel”.

The design of churches changed a lot during the course of history. Often churches were made bigger. When this happened there may be a mixture of architectural styles. These styles vary a lot in different countries.

In English churches there were several different periods of architecture:

In the 1600s, churches were built in a variety of styles. Often they copied some of the older styles. After the Great Fire of London many new churches were built by the architect Sir Christopher Wren. They were built in the classical style. Churches continued to be built in later centuries like this, but also the Gothic style continued to be used.

Modern churches often do not have the traditional cross-shape. It is difficult for the congregation to see and hear what is happening in the chancel. Modern churches bring the congregation, choir and priests in closer touch. An example is the round design for the Church of Christ the Cornerstone in Milton Keynes. Modern churches are often simpler but with a warmer character than the Gothic churches. Many have beautiful mosaic glass windows. Coventry Cathedral is a famous example of a modern church building.




#Article 62: City (1000 words)


	
A city is a populous community that may include structures, buildings and landmarks. Examples of cities in the United States include Dallas, Phoenix, Omaha, Kansas City, St. Louis, San Francisco, Boston, Atlanta, New York City, Jersey City, Providence, New Orleans, Las Vegas, Chicago, Los Angeles, Indianapolis, Detroit, Milwaukee and more.  

A city has many buildings and streets. It has houses or apartments for many people to live, shops where they may buy things, places for people to work and a government organisation to run the city, and to keep law and  in the city. People live in cities because it is easy for them to find and do the things they want there. A city usually has a city centre where government and business take place, and places called suburbs where people live around the outside of the centre.

Cities in the US are usually very-left leaning. The best examples of these would be New York, New York, and Washington. In the state of Louisiana, for example, the only Democratic delegate in US Congress who is a Democrat was elected from a district comprising in New Orleans. Below is a list of states, and the major city/cities that provide much of the liberal support in them:

If you know any others, add to this list!

There is no rule that is used all over the world to decide why some places are called city and other places are called town. 

Some things that make a city are: 

 
In American English, people often call all places where many people live cities. (See below: Size of cities)

 

The sizes of cities can be very different. This depends on the type of city that it is. Cities that were built hundreds of years ago and which have not changed much, are very much smaller than modern cities. There are two main reasons. One reason is that old cities often have a city wall, and most of the city is inside it. Another important reason is that the streets in old cities are often narrow. If the city got too big, it was hard for a cart carrying food to get to the market place. People in cities need food, and the food always has to come from outside the city. Cities that were on a river like London could grow much bigger than cities that were on a mountain like Sienna in Italy, because the river made a transport route for carrying food and other goods, as well as for transporting people. London has been changing continually for hundreds of years, while Siena, which was a very important city in the 1300s has changed very little in 700 years. Modern cities with modern transport systems can grow very large, because the streets are wide enough for cars, buses and trucks, and there are often railway lines as well.

In the US, the word city is often used for towns that are not very big. When the first European people went to America, they gave the name city to new places. They hoped the places would be great cities in the future. For example, Salt Lake City was the name given to a village of 148 people. When they started building the town they made street plans and called it Great Salt Lake City (for the nearby Great Salt Lake). Now, 150 years later, it really is a big city. 

In modern times many cities have grown bigger and bigger. The whole area is often called a metropolis and can sometimes includes several small ancient towns and villages. The metropolis of London includes the City of London, the City of Westminster and many old villages such as Notting Hill, Southwark, Richmond, Greenwich and etc. The part that is officially known as the City of London only takes up one square mile. The rest is known as Greater London. Many other cities have grown in the same way. 

These giant cities can be exciting places to live, and many people can find good jobs there, but modern cities also have many problems. Many people cannot find jobs in the cities and have to get money by begging or by crime. Cars, factories, and waste create a lot of pollution that makes people sick. the smallest city is Urban history 

Urban History is history of civilization. The first cities were made in ancient times, as soon as people began to create civilization. Famous ancient cities which fell to ruins included Babylon, Troy, Mycenae and Mohenjo Daro.

Benares in northern India is one among the ancient cities which has a history of more 3000 years. Other cities that have existed since ancient times are Athens in Greece, Rome and Volterra in Italy, Alexandria in Egypt and York in England.

In Europe, in the Middle Ages, being a city was a special , granted by nobility. Cities that fall into this category, usually had (or still have) city walls. The people who lived in the city were privileged over those who did not. Medieval cities that still have walls include Carcassonne in France, Tehran in Iran, Toledo in Spain and Canterbury in England. 

In the United Kingdom, a city is a town which people have always called a city, or which has got the name city status by royal charter (a special paper from the king or queen). Cities usually get this because they have a special number of people or are important. In the past, cities got that name if they had a cathedral or a university. Some cathedral cities, for example St David's, are small, and people do not normally think of them as cities. Cities that became cities because of their university generally grow because more people move there to be educated at the university colleges. The university cities of Oxford and Cambridge are famous throughout the world. The largest city is Shanghai, while the fastest growing is Dubai. The smallest city in the UK is Wells.

 
 

These cities have more than 10 million people:




#Article 63: Cooking (281 words)


Cooking is a process to make food ready to eat by heating it. Cooking can kill bacteria that may be in the food.

Raw food is food that is not cooked. Some foods are good to eat raw.  Other foods are not good for the body when they are raw, so they must be cooked. Some foods are good to eat either raw or cooked.

Cooking is often done in a kitchen using a stove or an oven. It can also be done over a fire (for example, over a campfire or on a barbecue).

The heat for cooking can be made in different ways. It can be from an open fire that burns wood or charcoal. It can be on a stove or in an oven that uses propane, natural gas, or electricity.

There are several different ways to cook food. Boiling cooks food in hot water. Frying (deep or shallow) cooks food in hot butter, fat or oil.  Baking and roasting cook food by surrounding it with hot air. Grilling means cooking food on a metal grill that has heat under it.

People often cook meat by boiling, roasting, frying, or grilling it. Some foods such as bread or pastries are usually baked.

Usually food is cooked in some kind of pot or pan.  Sometimes people cook food by putting it directly into the fire, or by wrapping the food in leaves before they put it into the fire.

A person whose job it is to cook food may be called a cook or a chef.  The word cooker means a machine or tool that a cook might use to cook food. Rice cookers and pressure cookers are examples.




#Article 64: Crime (665 words)


A crime (or misdemeanor or felony) is an act done by a person which is against the laws of a country or region. A person who does this is called a criminal.

The basic idea of what things are called crimes is that they are thought to be things that might cause a problem for another person. Things like killing another person, injuring another person, or stealing from another person are crimes in most countries. Also, it can be a crime to have or sell contraband such as guns or illegal drugs.

When some criminals make money from crime, they try to stop the police finding out where the money came from by money laundering.  Men and boys commit many more crimes than women and girls.

The word crime is derived from the Latin root cernō, meaning I decide, I give judgment. Originally the Latin word crīmen meant charge or cry of distress. The Ancient Greek word κρίμα, krima, from which the Latin cognate derives, typically referred to an intellectual mistake or an offense against the community, rather than a private or moral wrong.

In 13th century English crime meant sinfulness, according to the Online Etymology Dictionary. It was probably brought to England as Old French crimne (12th century form of Modern French crime), from Latin crimen (in the genitive case: criminis). In Latin, crimen could have signified any one of the following: charge, indictment, accusation; crime, fault, offense.

Whether a given act or omission constitutes a crime does not depend on the nature of that act or omission; it depends on the nature of the legal consequences that may follow it. An act or omission is a crime if it is capable of being followed by what are called criminal proceedings.

For the purpose of section 243 of the Trade Union and Labour Relations (Consolidation) Act 1992, a crime means an offence punishable on indictment, or an offence punishable on summary conviction, and for the commission of which the offender is liable under the statute making the offence punishable to be imprisoned either absolutely or at the discretion of the court as an alternative for some other punishment.

A normative definition views crime as deviant behavior that violates prevailing norms – cultural standards prescribing how humans ought to behave normally. 

There are various levels of crimes. In some jurisdictions they are:

Different countries have different ideas of what things are crimes, and which ones are the worst.  Some things that are crimes in one country are not crimes in other countries.  Many countries get their ideas of what things are crimes from religions or controversial events which cause a law to be quickly created.  For example, a religious Taboo might say eating a particular food is a crime.   When automobiles became numerous, they killed or hurt many people in road accidents, so new laws were made for them.

In many countries, if people say they made or wrote a book, movie, song, or Web page that they did not really make or write, it is a crime against copyright laws. In many countries, helping to grow, make, move, or sell illegal drugs is a crime.

In most countries, police try to stop crimes and to find criminals. When the police find someone who they think might be a criminal, they usually hold the person in a jail. Then, usually, a court or a judge decides if the person really did a crime. If the court or judge decides that the person really did it, then he or she might have to pay a fine or go to prison. Sometimes the judge might decide that the criminal should be executed (killed). This is called Capital punishment (or the Death Penalty). There are countries in the world that execute criminals, and others that do not.

In many countries, two conditions must exist for an act to be thought of as a crime:

Both must be present for the act to be thought of as a crime.




#Article 65: Time Cube (215 words)


Time Cube was a personal website created on 1997 by Otis Eugene Ray. On that website, Ray explained his theory of everything, known as Time Cube. It described the planet Earth as having a cubic symmetry, and time as rotating four corners. He also said that all of modern physics is wrong. Scientists reject these ideas, saying that they make no sense and cannot be tested.

The Time Cube website was written in an angry and hateful voice. On his site, Ray said that not believing in Time Cube would be stupid and evil. Some of the comments were racist and discriminatory, especially against black people and Jews. There were also many comments against gay people. Many people found the site to be difficult to understand. 

Ray spoke about Time Cube at the Massachusetts Institute of Technology in January 2002. At MIT, a professor tried to cancel the lecture before it took place. Ray believed this is proof of a conspiracy to keep information about Time Cube hidden. Ray also spoke about Time Cube at the Georgia Institute of Technology in April 2005.

Otis Eugene Ray died on March 18, 2015. He was 87 years old. The website went down on August 2015. It was last archived by the Wayback Machine on January 12, 2016.




#Article 66: Maize (269 words)


Maize or Indian corn (called corn in some countries) is Zea mays, a member of the grass family Poaceae. It is a cereal grain which was first grown by people in ancient Central America. Approximately 1 billion tonnes are harvested every year. However, little of this maize is eaten directly by humans. Most is used to make corn ethanol, animal feed and other maize products, such as corn starch and corn syrup.

Maize is a leafy stalk whose kernels have seeds inside. It is an angiosperm, which means that its seeds are enclosed inside a fruit or shell. It is has long been a staple food by many people in Mexico, Central and South America and parts of Africa. In Europe and the rest of North America, maize is grown mostly for use as animal feed. In Canada and the United States, maize is commonly referred to as corn.  

Centuries of cross breeding have produced larger plants, and specialized varieties. Corn has become an important ingredient in American foods through the use of corn starch. People have long eaten sweet corn and popcorn with little processing, and other kinds after processing into flour for making cornbread, tortillas, and other artificial foods.

Maize has been a fruitful model organism for research in genetics for many years: see Barbara McClintock. Research has shown that artificial selection developed maize from a Mexican plant called Teosinte.

There are five species and many subspecies in the genus. They are all plants similar to the cultivated maize, with less developed cobs. The wild ones are sometimes called teosintes, and they are all native to Mesoamerica.




#Article 67: Calculus (1500 words)


Calculus is a branch of mathematics that helps us understand changes between values that are related by a function. For example, given a formula indicating how much money one gets every day, calculus would help one understand related formulas, such as how much money one has in total, and whether one is getting more or less money than before. Many of these formulas are functions of time, and one way to think of calculus is to see it as a study of functions of time.

There are two different types of calculus. Differential calculus divides things into small (different) pieces, and tells us how they change from one moment to the next, while integral calculus joins (integrates) the small pieces together, and tells us how much of something is made, overall, by a series of changes. Calculus is used in many different areas such as physics, astronomy, biology, engineering, economics, medicine and sociology.

In the 1670s and 1680s, Sir Isaac Newton in England and Gottfried Leibniz in Germany figured out calculus at the same time, working separately from each other. Newton wanted to have a new way to predict where to see planets in the sky, because astronomy had always been a popular and useful form of science, and knowing more about the motions of the objects in the night sky was important for navigation of ships. Leibniz wanted to measure the space (area) under a curve (a line that is not straight). Many years later, the two men argued over who discovered it first. Scientists from England supported Newton, but scientists from the rest of Europe supported Leibniz. Most mathematicians today agree that both men share the credit equally. Some parts of modern calculus come from Newton, such as its uses in physics. Other parts come from Leibniz, such as the symbols used to write it.

They were not the first people to use mathematics to describe the physical world — Aristotle and Pythagoras came earlier, and so did Galileo Galilei, who said that mathematics was the language of science. But both Newton and Leibniz were the first to design a system that describes how things change over time, and can predict how they will change in the future.

The name calculus was the Latin word for a small stone the ancient Romans used in counting and gambling. The English word calculate comes from the same Latin word.

Differential calculus is used to find the rate of change of a variable—compared to another variable. 

In the real world, it can be used to find the speed of a moving object, or to understand how electricity and magnetism work. It is very important for understanding physics—and many other areas of science.

Differential calculus is also useful for graphing. It can be used to find the slope of a curve, and the highest and lowest points of a curve (these are called the maximum and minimum, respectively).

Variables can change their value. This is different from numbers because numbers are always the same. For example, the number 1 is always equal to 1, and the number 200 is always equal to 200. One often write variables as letters such as the letter x: x can be equal to 1 at one point and 200 at another. 

Some examples of variables are distance and time, because they can change. The speed of an object is how far it travels in a particular time. So if a town is 80 kilometres (50 miles) away and a person in a car gets there in one hour, they have traveled at an average speed of 80 kilometres (50 miles) per hour. But this is only an average: maybe they travelled faster at some times (say on a highway), and slower at other times (say at a traffic light or on a small street where people live). Certainly it is more difficult for a driver to figure out a car's speed using only its odometer (distance meter) and clock—without a speedometer.

Until calculus was invented, the only way to work this out was to cut the time into smaller and smaller pieces, so the average speed over the smaller time would get closer and closer to the actual speed at a point in time. This was a very long and hard process, and had to be done each time people wanted to work something out.

A very similar problem is to find the  (how steep it is) at any point on a curve. The slope of a straight line is easy to work out — it is simply how much it goes up or down (y or ) divided by how much it goes across (x or ). On a curve, however, the slope is a variable (has different values at different points) because the line bends. But if the curve was to be cut into very, very small pieces, the curve at the point would look almost like a very short straight line. So to work out its slope, a straight line can be drawn through the point with the same slope as the curve at that point. If this is done exactly right, the straight line will have the same slope as the curve, and is called a tangent. But there is no way to know (without complex mathematics) whether the tangent is exactly right, and our eyes are not accurate enough to be certain whether it is exact or simply very close.

What Newton and Leibniz found was a way to work out the slope (or the speed in the distance example) exactly, using simple and logical rules. They divided the curve into an infinite number of very small pieces. They then chose points on either side of the range they were interested in and worked out tangents at each. As the points moved closer together towards the point they were interested in, the slope approached a particular value as the tangents approached the real slope of the curve. The particular value it approached was the actual slope.

Given a function . f is short for function, so this equation means y is a function of x. This tells us that how high y is on the vertical axis depends on what x (the horizontal axis) is at that time. For example, with the equation , we know that if  is 1, then  will be 1; if  is 3, then  will be 9; if  is 20, then  will be 400. The slope of the tangent line produced using this method here is , or 2 multiplied by . So we know without having to draw any tangent line at any point on the curve  that the derivative, often written as  (marked with the prime symbol), will be  at any point. This process of working out a slope using limits is called differentiation, or finding the derivative.

The way to write the derivative in mathematics is

Leibniz came to the same result, but called h , which means with respect to x. He called the resulting change in  , which means a tiny amount of y. Leibniz's notation is used by more books, because it is easy to understand when the equations become more complicated. In Leibniz notation:
.

Mathematicians have grown this basic theory to make simple algebra rules—which can be used to find the derivative of almost any function.

Integral calculus is the process of calculating the area underneath a graph of a function. An example is calculating the distance a car travels: if one knows the speed of the car at different points in time and draw a graph of this speed, then the distance the car travels will be the area under the graph.

The way to do this is to divide the graph into many very small pieces, and then draw very thin rectangles under each piece. As the rectangles become thinner and thinner, the rectangles cover the area underneath the graph better and better. The area of a rectangle is easy to calculate, so we can calculate the total area of all the rectangles. For thinner rectangles, this total area value approaches the area underneath the graph. The final value of the area is called the integral of the function.

In mathematics, the integral of the function f(x) from a  to b, is written as
.

The main idea in calculus is called the fundamental theorem of calculus. This main idea says that the two calculus processes, differentiation and integration, are inverses of each other. That is, a person can use differentiation to undo an integration process. Also, a person can use integration to undo a differentiation. This is just like using division to undo multiplication, or addition to undo subtraction.

In a single sentence, the fundamental theorem runs something like this: The derivative of the integral of a function f is the function itself.

Calculus is used to describe things that , like things in nature. It can be used for showing and learning all of these:




#Article 68: Coin (284 words)


A coin is normally a round piece of metal that is used as currency, or money. Coins have been made for about 2600 years; the first place to make coins was Lydia (modern Turkey).[citation needed] These coins were made of Precious metals and allowed people to trade with a standard amount of metal.

Most people use coins as currency. They usually have lower value than banknotes. Most are made in government mints.

Many coins have unique or complicated decorations; one side often has the picture of a famous or important person's head on it. 

The different decorations on each side of a coin might be used to decide things randomly. This is called tossing a coin.  A person can throw the coin into the air and catch it.  You then look at which side is facing up. If the head is facing up it is called heads, if the other side is facing up it is called tails. Before tossing the coin someone has to decide what each side means. Tossing a coin can be a type of gambling, which is illegal (against the law) in some countries.

Some people see coins as a sign of greed, such as some Communists and Puritans, who sometimes condemn over-hoarding of coins, and ascetics, who often keep little in the ways of money (coins), leading a poor-lifestyle.

Because coins have been made for a very long time, some people collect old coins. They can be much cheaper than other old things, especially if they are made of cheap metals like copper. Older coins normally cost more than newer ones, but rarity matters more-some coins from the 1920s cost vast sums, while some Roman coins cost very little.




#Article 69: Conceptual metaphor (101 words)


A conceptual metaphor or cognitive metaphor is a metaphor which refers to one domain (group of ideas) in terms of another. For example, treating quantity in terms of direction:

The idea of a conceptual metaphor came from a book by George Lakoff and Mark Johnson in 1980: Metaphors we live by.

A convention is to write conceptual metaphors in small capital letters, e.g. , with the target domain (idea being referred to) first, here money, and the source domain (terms used to refer to it) second.

There are many more, enough to prove the importance of the metaphor in our lives.




#Article 70: Comedy (674 words)


Comedy (from ), in modern times, is entertainment with generally funny content. It is able to make people laugh. This definition was used for theatre plays, and was first used in Ancient Greece. Aristotle defined this as “Comedy is, as an imitation of characters of a lower type- not, however, in the full sense of the word bad, the ludicrous being merely a subdivision of the ugly. It consists in some defect or ugliness which is not painful or destructive. To take an obvious example, the comic mask is ugly and distorted, but does not imply pain.” To him, the lampooners became writers of Comedy and the truly artistic ones became writers of Tragedy.

Comedy is also a media genre that is for television shows or movies that are either funny or silly. People who are known for acting in comedies are termed as comedians or comedic actors.

The ancient Greeks had comedies, which were presented in competitions at the festival of Dionysia. 

One of the best-known comedy authors of the time was Aristophanes (about 446386 BC). One of his works, The Clouds was performed 425 BC. The work did not survive completely, but a later version did survive. It is a satire against Socrates, and pictures the great philosopher as a swaggering con artist. Some of the accusations were re-used at Socrates' trial, twenty years later.  

Typical for satire are that the author criticizes society, and living people. 

Another type of Ancient Greek theatre was the satyr play. This was mock drunkenness, brazen sexuality (including phallic props), pranks, sight gags, and general merriment. The modern equivalent would be knock-about comedy.

Humour, or 'New Comedy' is not about criticizing people or ideas, but rather about showing characters in funny situations. The most important Greek playwright of this type was probably Menander. The best known Roman comedy writer was Plautus. He often used Greek comedies for his plays.

Many comedy plays were written in the 1500s by the British writer William Shakespeare.
Shakespeare's comedy plays include: All’s Well That Ends Well, The Comedy of Errors, A Midsummer Nights Dream, and Twelfth Night. In Shakespeare's day a comedy did not mean a play that would make people laugh or that had a lot of jokes. Instead it was a play in which all the problems work out all right in the end. This was unlike a tragedy, where the problems do not work out, usually resulting in someone's death.
The two masks, one was smiling, the other crying, often associated with theatre represent comedy and tragedy.

There are different types of comedy. One type of comedy is called slap stick comedy. In slap stick comedy, people do silly things such as tripping, falling over or embarrassing themselves just to make people laugh. Slap stick comedy can be used in comedy movies or comedy television shows.

Slap stick comedy was used a lot in silent (no sound) movies from the 1920s. A comedian who acted in the silent movies who used a lot of slapstick comedy was Charlie Chaplin. In the 1950s and 1960s, comedian Jerry Lewis also used silly slap stick comedy in his comedy movies.

A comedy is a very popular type of movie. Some comedy movies have slapstick comedy, in which people just do silly things such as tripping, falling over or embarrassing themselves just to make people laugh. Other comedy movies show funny stories or situations in which people are behaving in a silly manner. Some comedies make the audience laugh by showing strange or unusual images or situations that do not make sense.

A parody or spoof movie imitates or exaggerates another person or movie to make them seem silly, dumb, or just plain out of it. 

Some types of comedy movies mix comedy with other types of movies. 

Comedy shows are very popular on television. Comedy shows on television are often called sitcoms. The word sitcom is a shortened way of saying situational comedy. Television situational comedies usually show characters who do silly or funny things which make the audience laugh.




#Article 71: Comet (521 words)


A comet is a ball of mostly ice that moves around in outer space. Comets are often described as dirty snowballs. They are very different from asteroids.  The orbital inclinations of comets are usually high and not near the ecliptic where most solar system objects are found. Most of them are long-period comets and come from the Kuiper belt. That is very far away from the Sun, but some of them also come near enough to Earth for us to see at .  

They have long tails, because the Sun melts the ice. A comet's tail does not trail behind it, but points directly away from the Sun, because it is blown by the solar wind.
The hard centre of the comet is the nucleus. It is one of the blackest things (lowest albedo) in the solar system. When light shone on the nucleus of Halley's Comet, the comet reflected only 4% of the light back to us.

Periodic comets visit again and again. Non-periodic or single-apparition comets visit only once.

Comets sometimes break up, as Comet Biela did in the 19th century.  Comet Shoemaker-Levy 9 broke up, and the pieces hit Jupiter in 1994. Some comets orbit (go around) together in groups. Astronomers think these comets are broken pieces that used to be one object.

For thousands of years, people feared comets. They did not know what they were, or where they came from. Some thought that they were fireballs sent from demons or gods to destroy the earth. They said that each time a comet appeared, it would bring bad luck with it. Whenever a comet appeared, a king would die. For example, the Bayeux Tapestry shows the return of Halley's Comet and the death of a king. Comets were also known to end wars and thought to bring famine. During the Renaissance, astronomers started to look at comets with less superstition and to base their science on observations. Tycho Brahe reasoned that comets did not come from the earth, and his measurements and calculations showed that comets must be six times farther than the earth is from the moon.

Edmond Halley reasoned that some comets are periodic, that is, they appear again after a certain number of years, and again and again. This led to the first prediction of a comet's return, Halley's Comet, named after him.

Isaac Newton also studied comets. He realised that comets make U-turns around the sun. He asked his friend Edmond Halley to publish this in his book Philosophiae Naturalis Principia Mathematica. Before Newton said this, people believed that comets go in to the sun, then another comes out from behind the sun. 

In later years some astronomers thought comets were spit out by planets, especially Jupiter.

All this new information and research gave people confidence, but some still thought that comets were messengers from the gods. One 18th century vision said that comets were the places that hell was, where souls would ride, being burned up by the heat of the sun and frozen by the cold of space.

In modern times space probes have visited comets to learn more about them.




#Article 72: Christian (396 words)


A Christian () is a person who believes in Christianity, a monotheistic religion. Christianity is mostly about the life and teachings of Jesus Christ, in the New Testament and interpreted of prophesied in the Hebrew Bible/Old Testament.  Christianity is the world's largest religion, with 2.1 billion followers around the world. 

Christians consider the Holy Bible to be a sacred book, inspired by God.  The Holy Bible is a combination of the Hebrew Bible, or Torah, and a collection of writings called the New Testament.  Views on the importance of these writings vary.  Some Christian groups prefer to favor the New Testament, while others believe the entire Bible is equally important.  Also, while many Christians prefer to consider the Bible as fully true, not all Christian groups believe that it is completely accurate. 

The question of who is a Christian? can be very difficult.  Christians often disagree over this due to their differences in opinion on spiritual matters. In countries where most persons were baptized in the state church or the majority Christian church, the term Christian is a default label for citizenship or for people like us.
In this context, religious or ethnic minorities can use Christians or you Christians as a term for majority members of society who do not belong to their group - even in a very secular (though formerly Christian) society.

Persons who are more devoted the their Christian faith prefer not to use the word so broadly, but only use it to refer to those who are active in their Christian religion and really believe the teachings of Jesus and their church.  In some Christian movements (especially Fundamentalism and Evangelicalism), to be a born-again Christian is to undergo a  spiritual rebirth by believing in the Bible's teachings about Jesus and choosing to follow him.

Many Christians choose to go to church. Most Christians believe this to be a sign of their religious devotion to God and an act of worship.  However, some Christian groups think that one can be a Christian without ever going to a church.  Though there are many different viewpoints on the issue, most Protestants believe all Christians are part of the spiritual church of Christ, whether or not those Christians go to an actual church each week.  On the other hand, Catholics in the past have believed that the Holy Catholic Church is the only true church. 




#Article 73: Cheese (275 words)


Cheese is a type of  that comes from milk. There are many types of cheese, such as cheddar, Swiss, and provolone. 

Many things affect the form, texture, colour and flavour of a cheese. These include the milk (cow or goat), if the milk has been pasteurized, the amount of butterfat, bacteria and mold in the cheese, how the cheese is made, how much fat is in the cheese, and how old the cheese is. Example for cheese used in a sentence: Todd the dog likes cheese.

People have been making cheese since before history was written down. It is not known when cheese was first made. It is known that cheese was eaten by the Sumerians in about 4000 BC.

Cheese is made using milk. The milk of cows, goats, and sheep are most popular. Buffalo, camel, donkey and even hippopotamus milk can also be used. Cheese makers usually cook the milk in large pots. 
Most cheeses are  by bacteria. This bacteria turns milk sugars into lactic acid. 

Salt is added, and a substance from the stomach of young cows called rennet. This curdles the cheese and makes it solid. Some makers do not add rennet, but curdle the cheese in other ways. Vegetarian alternatives to rennet are made by fermentation of a fungus called Mucor miehei. Other alternatives use species of the Cynara thistle family.

Other ingredients are added and the cheese is usually aged for a varied length of time.

There are many different ways to classify cheeses. Some ways include:

There are also man-made foods that some people use instead of cheese. These are called Cheese analogues.

Different types of cheese include:




#Article 74: Constitution (347 words)


The constitution of a country (or a state) is a special type of law document that tells how its government is supposed to work. It tells how the country's leaders are to be chosen and how long they get to stay in office, how new laws are made and old laws are to be changed or removed based on law, what kind of people are allowed to vote and what other rights they are guaranteed, and how the constitution can be changed.

Limits are put on the Government in how much power they have within the Constitution (see Rule of Law ). On the other hand, countries with repressive or corrupt governments frequently do not stick to their constitutions, or have bad constitutions without giving freedom to citizens and others. This can be known as dictatorship or simply bending the rules. A Constitution is often a way of uniting within a Federation.

The UK's constitution is not written in one single  like many other countries' are. In fact, the UK's constitution is not completely written down at all. Some of it can be found in writing, starting with the Magna Carta of 1215 and the Bill of Rights Act 1689 and including more modern Acts of Parliament. Other parts of it are considered common law and are made up of the decisions of judges over many hundreds of years in a system called legal or judicial precedence. Because of this, some people say that the United Kingdom has a de facto or unwritten constitution.
 
The United States in 1787 began a trend in the writing of constitutions. The United States Constitution is also the shortest that people are still using, and it has been changed (amended) many times over the years. It was made after the colonists won their independence from Britain. At first they had the Articles of Confederation but the Articles were replaced with today's Constitution.

The Indian constitution of 1950 is the longest ever written constitution in the world. It  has 448 Articles and 12 Schedules in it, with 5 appendices and 98 amendments.




#Article 75: Circle (432 words)


A circle is a round, two-dimensional shape.  All points on the edge of the circle are at the same distance from the center. 

The radius of a circle is a line from the centre of the circle to a point on the side.  Mathematicians use the letter r for the length of a circle's radius.  The  of a circle is the point in the very middle. It is sometimes written as .

The diameter (meaning all the way across) of a circle is a straight line that goes from one side to the opposite and right through the centre of the circle.  Mathematicians use the letter d for the length of this line.  The diameter of a circle is equal to twice its radius (d equals 2 times r):

The circumference (meaning all the way around) of a circle is the line that goes around the centre of the circle.  Mathematicians use the letter C for the length of this line.

The number π (written as the Greek letter pi) is a very useful number. It is the length of the circumference divided by the length of the diameter (π equals C divided by d). As a fraction the number π is equal to about   or 335/113 (which is closer) and as a number it is about 3.1415926535.

The area, A, inside a circle is equal to the radius multiplied by itself, then multiplied by π (A equals π times r times r).

π can be measured by drawing a large circle, then measuring its diameter (d) and circumference (C). This is because the circumference of a circle is always π times its diameter.

π can also be calculated by only using mathematical methods.  Most methods used for calculating the value of π have desirable mathematical properties. However, they are hard to understand without knowing trigonometry and calculus.  However, some methods are quite simple, such as this form of the Gregory-Leibniz series:

While that series is easy to write and calculate, it is not easy to see why it equals π.  A much easier way to approach is to draw an imaginary circle of radius r centered at the origin.  Then any point (x,y) whose distance d from the origin is less than r, calculated by the Pythagorean theorem, will be inside the circle:

Finding a set of points inside the circle allows the circle's area A to be estimated, for example, by using integer coordinates for a big r. Since the area A of a circle is π times the radius squared, π can be approximated by using the following formula:




#Article 76: Cuba (1912 words)


Cuba is an island country in the Caribbean Sea. The country is made up of the big island of Cuba, the Isla de la Juventud island (Isle of Youth), and many smaller islands. Havana is the capital of Cuba. It is the largest city. The second largest city is Santiago de Cuba. In Spanish, the capital is called La Habana. Cuba is near the United States, Mexico, Haiti, Jamaica and the Bahamas. People from Cuba are called Cubans (cubanos in Spanish). The official language is Spanish. Cuba is warm all year.

In 1492, Christopher Columbus landed on the island of Cuba. He claimed it for the Kingdom of Spain. Cuba became a Spanish colony until the Spanish–American War of 1898. After the war, it was part of the United States. It gained independence in 1902.

In 1959, guerrilla fighters led by Fidel Castro and Che Guevara overthrew Cuba's dictator, Fulgencio Batista, in what became the Cuban Revolution. Castro began making relations with the Soviet Union and tried to close a lot of American businesses in Cuba; the United States did not like this. In 1961 Castro officially announced that his government was socialist. The US attempted to invade Cuba to regain control of it and overthrow it's communist led government but failed. The Communist Party of Cuba was created in 1965 and has ruled the island ever since. Today, Cuba is the only communist state outside of Asia, in the Caribbean, and in the western hemisphere.

Cuba is famous for many types of music, especially dance music such as the Salsa and Mambo. Because Cubans have ancestors from Spain, Africa, South America and North America, Cuban music is special and different.

Reading is very popular in Cuba. Many people especially enjoy reading books or things that come from outside the country, even though the government does not approve of this. They also love music and sports. Cuban music is very lively. This is because a lot of it comes from African and Spanish rhythms. Baseball, basketball, and athletics events are loved by many Cuban people. The Cheifs football-team took at one Football-World-Cup part. In 1938, they reached the quarter-final and lost against Sweden 0:8.

Before Cuba was conquered by the Spaniards, three tribes lived on the island. They were the Taínos, the Ciboneys, and the Guanajatabeyes. The Taínos were the largest and most common of the three tribes. They farmed crops such as beans, corn, squash, and yams. The Taínos also slept in hammocks which the Spaniards would introduce to the rest of the world. Then, in 1492, Christopher Columbus arrived in Cuba on his first trip to the Americas. Three years later he claimed the islands for the Spanish. The Spanish began to rule Cuba afterwards. The Spanish brought thousands of slaves from Africa to Cuba to work for them. Most of the native Cubans died because of the new diseases brought by the Spanish and Africans. The Spanish also treated the native Cubans very cruelly and massacred many of them.

The Spanish ruled for many years. Cuba became the most important producer of sugar. In the early 1800s, Cubans rebelled against the Spanish rulers, but failed until 1898, when the United States went to war with the Spanish and defeated them. Cuba became American for four years afterwards, before it became an independent republic in 1902. Even though Cuba was independent, the Americans still controlled the island by a law called the Platt Amendment. In 1933 the Cubans stopped the Platt Amendment, but the Americans still had a big say in Cuban politics. Americans owned most of Cuba’s businesses. The Americans supported the leader Fulgencio Batista, who was seen by many Cubans as corrupt.

In addition to political control, the United States also exercised significant control over the Cuban economy. At the time, Cuba was a monoculture economy. While they produced coffee, tobacco, and rice, they relied primarily on sugar. Thus, they were known by other countries as the sugar bowl of the world. The United States bought sugar from the Republic of Cuba at a price higher than the global standard. In exchange, Cuba was to give preference to the United States, and its industries. Cuba depended on the United States and their investments. Cuba was not industrialized and needed the revenue for goods and oil. They also needed the US investment for gas, electricity, communications, railways, and banks. While Cuban workers had better conditions than other countries in the continent, they still faced inequality, lack of infrastructure, high illiteracy rates, and a lack of full-time work (the sugar industry was seasonal).

In 1959, Fidel Castro led a revolution against Fulgencio Batista. Castro took power in Cuba with Che Guevara from Argentina, his brother Raul, and others who fought against Batista. Castro made many changes to Cuba. He ended American ownership of Cuban businesses. This made Castro unpopular in America and the United States banned all contact with Cuba. Many Cubans went to America because of this. In 1961, the Americans helped some of these Cubans to attack Cuba and try to remove Castro, but they failed. Castro then asked the Soviet Union to help defend them from the Americans, which they did. The Soviet Union put nuclear weapons in Cuba and aimed them at the United States. American President Kennedy demanded that they be removed or a new war would begin. This was known as the Cuban Missile Crisis. The Soviet Union removed the missiles when the United States agreed to not continue attacking Cuba and to remove missiles from Turkey.

Cuba became a communist-led country like the Soviet Union after this. The Soviet Union bought most of Cuba’s sugar for expensive prices. Cuba spent this money on health, education and the army. This made Cuba’s schools and hospitals some of the best in the world. The army fought in Africa to support black Africans against the white South African army. Cuba also supported groups in South America fighting against the dictators of those countries.

However, the Cuban government began to control most of life in Cuba under the communist system. Disagreeing with the Cuban government and Fidel Castro in public was not allowed. Some Cubans did not like this and tried to leave Cuba. Most Cubans who left went to the United States. Some Cubans who did not like the government and stayed were put in jail. Many groups from around the world protested against Cuba because of this, and demanded that Fidel Castro give up power.

In 1991, the Soviet Union collapsed. This meant that Cuba, which had sold most of its products to the Soviet Union, had no money coming into the country. The Americans made the restrictions against contact with Cuba tighter. America said the restrictions on contact would continue unless Fidel Castro gave up power. Cuba became very poor in the 1990s. This became known in Cuba as “The Special Period”. Because of the disaster, Cuba changed to allow less control by the government, more discussion amongst the people, and private shops and businesses. Cuba also tried to get tourists to visit the island.

In the 2000s, tourism to Cuba began to make money for the island again. Though Fidel Castro had remained in power, he had passed all duties to his brother Raul after an illness. Fidel Castro was one of the longest-serving heads of state. In 2018, Miguel Díaz-Canel became the official President of Cuba.

In April 2015, historic talks took place with US President Obama and Cuban General Secretary Raúl Castro in improving relations between the two nations.

The trade embargo issued by President Kennedy in the 1960s has been considerably loosened under Obama's administration. US citizens can now travel directly to Cuba at certain times of the year. Before, Americans had to go via Mexico if they wanted to go to Cuba. Americans are still not allowed to purchase or smoke Cuban cigars. The cigars are smuggled over the US-Canadian border since they are legal in Canada.

For military service, men from the age of 17 to 28 years old must go into the army for two years. It is optional for women.

The country is divided into 15 provinces and one special municipality (Isla de la Juventud). The provinces are divided into municipalities.

The population of Cuba is close to 13 million. The people of Cuba come from three different groups. The largest group is the descendants of the Spanish settlers who came to Cuba. The smallest group is the descendants of the black African slaves who were brought in to do the work and birth children (in the barracoon) as New World slaves who could be legally sold into life time bondage in the United States. The middle-sized group is a mix of African and Spanish. The government succeeded in seeing that the three different groups were treated the same. According to a DNA Caribbean Studies Institute, the racial-makeup of the population of Cuba is:

Cuba is a developing country, and is often depicted as a very poor country. In some aspects, however, like education, health care and life expectancy it ranks much better than most countries in Latin America. Its infant death rate is lower than some developed countries. The average life expectancy is 78 years.

All the children are required to go to school from six to twelve years old, and nearly everybody is able to read and write at least. There is free education at every level. Because of this, Cuba has a 99.8% literacy rate.

In 2006, the World Food Programme certified Cuba to be the only country in this region without undernourished children. In the same year, the United Nations said that Cuba was the only nation in the world that met the World Wide Fund for Nature's definition of sustainable development.

Cuba is the largest island in the West Indies. It has many resources. Only about one-fourth of the land is mountains or hills. Much of the land is gentle hills or plains which are good for farming or raising cattle. Cuba has fertile soil and a mostly warm and humidodity  climate that makes it a great place for growing crops.

Sugar is the most important crop of Cuba, and they may get it from the sugar cane. Sugar cane is the largest cash crop grown in Cuba, and it brings in most of the money. After that, the second is tobacco. Tobacco is made into cigars by hand. A hand-made cigar is considered by many people to be the finest in the world. Other important crops are rice, coffee, and fruit. Cuba also has many minerals. Cobalt, nickel, iron, copper, and manganese are all on the island. Salt, petroleum, and natural gas are there too. The coast of Cuba has many bays and a few good harbors. Havana, which is the capital, is also a port. Other harbors have port cities. Nuevitas is a port city on the north coast. Cienfuegos, Guantánamo, and Santiago de Cubaare some of the port cities on the south coast.

Cuba has a semi-tropical climate. That means that the cool ocean winds keep it becoming hot, despite its being in the tropiocal zone. Cuba has a wet season and a dry season. The dry season is from November to April, and the wet season is from May to October. August to October is also the hurricane season in the Atlantic Ocean. Because of this, most of Cuba's port cities can be flooded along the coast.




#Article 77: Cube (162 words)


A cube is a block with all right angles and whose height, width and depth are all the  same. 

A cube is one of the simplest mathematical shapes in space. Something that is shaped like a cube is sometimes referred to as cubic.
Surface area of cube=6l^2
Lateral Surface area of cube=4l^2
Volume of cube=l^3

The basic difference between a cube and a square is, a cube is a 3D figure (having 3 dimensions) i.e. length, breadth and height while a square has only 2 dimensions i.e. length and breadth.
The 2-dimensional (2D) shape (like a circle, square, triangle, etc.) that a cube is made of is squares. The sides (faces) of a cube are squares. The edges are straight lines. The corners (vertices) are at right angles.  A cube has 8 corners, 12 edges and 6 faces, as in the most usual kind of dice.  A tesseract carries this idea into the fourth dimension (4D) and is made of 8 cubes.




#Article 78: December (591 words)


December (Dec.) is the twelfth and last month of the year in the Gregorian calendar, with 31 days, coming between November (of the same year) and January (of the following year). With the name of the month coming from the Latin decem for ten, it was the tenth month of the year before January and February were added to the Roman calendar.

December always begins on the same day of the week as September, and ends on the same day of the week as April.

December's flower is the Narcissus. Its birthstone is the turquoise. The meaning of the turquoise is prosperity.

Some of the holidays  in December are Christmas, New Year's Eve, Kwanzaa, and Hanukkah.

December is the 12th and last month of every calendar year in the Gregorian calendar, and is one of seven months of the year to have 31 days. December 31 is followed by January 1 of the following year.

December begins on the same day of the week as September every year, as each other's first days are exactly 13 weeks (91 days) apart. December ends on the same day of the week as April every year, as each other's last days are exactly 35 weeks (245 days) apart.

In common years, December starts on the same day of the week as April and July of the previous year, and in leap years, October of the previous year. In common years, December finishes on the same day of the week as July of the previous year, and in leap years, February and October of the previous year. In leap years and years immediately after that, December both starts and finishes on the same day of the week as January of the previous year.

In years immediately before common years, December starts on the same day of the week as June of the following year, and in years immediately before leap years, March and November of the following year. In years immediately before common years, December finishes on the same day of the week as September of the following year, and in years immediately before leap years, March and June of the following year.

December is one of two months to have a solstice (the other is June, its seasonal equivalent in both hemispheres), and in this month the Tropic of Capricorn in the Southern Hemisphere is turned towards the Sun, meaning that December 21 or December 22 is the Northern Winter Solstice and the Southern Summer Solstice. This means that this date would have the least daylight of any day in the Northern Hemisphere, and the most in the Southern Hemisphere. There are 24 hours of darkness at the North Pole and 24 hours of daylight at the South Pole.

In mainly Christian countries, December is dominated by Christmas, which is celebrated on December 25 in most of those countries, though Eastern Orthodox Christians celebrate it on January 7. It marks the birth of Jesus Christ. Epiphany, January 6, is also important in relation to Christmas. Advent starts on the Sunday on, or closest to, November 30, and some countries have their own related celebration before the 25th. Sinterklaas is celebrated on December 5 in the Netherlands and Belgium, and St. Nicholas Day on December 6 is also celebrated in some countries. The Scandinavian countries, mainly Sweden, celebrate St. Lucia Day on December 13, while Iceland celebrates Thorlaksmessa on December 23. The week after Christmas is spent preparing for New Year.

Judaism's festival of light, Hanukkah, is also celebrated over eight days in this month.




#Article 79: Dublin (122 words)


Dublin () is the capital of the Republic of Ireland, and the biggest city on the island of Ireland. In 2011 there were over 1.1 million people living in the Greater Dublin Area.

Dublin was built by the Vikings upon the river Liffey. The river divides the city into two parts, North Dublin and South Dublin.

Many famous writers lived in Dublin. Oscar Wilde and George Bernard Shaw were born in Dublin. James Joyce is probably Dublin's best known and most international writer.

Dublin is home to Ireland's largest stadium for all sports, Croke Park. It can hold up to 85,000 people. Croke Park is the usual venue for all Ireland hurling and football finals. The Aviva Stadium hosts rugby and soccer.




#Article 80: Dance (733 words)


Dance is a performing art. It is described in many ways. It is when people move to a musical rhythm. They may be alone, or in a group. The dance may be an informal play, a part of a ritual, or a part of a professional performance. There are many kinds of dances, and every human society has its own dances.

As with other performing arts, some people dance to express their feelings and emotions, or to feel better. Dance can be used to tell a story. In some societies, dance goes with song as well as music. Dancing is sometimes done as sport, and has similar athletic aspects. People who want to learn to dance can go to dance schools. It may take years of practice to become an experienced and capable dancer.

To plan a dance is called choreography, done by a choreographer. Often this goes with music, and fits into a certain style. Dances may be planned in detail, or they may be whatever dancers feel like doing. However, most dancing does follow some general style or pattern. One style is the couple dance, where (usually) a man and a woman dance together. Other dances need an ensemble, a group of people together to make it work.

People have always danced. Every society has its own dances. There are pictures, on pottery and stone, which show dances from several thousand years ago, in Egypt and Greece.

Sachs divides early dances into 'Imageless dances' and 'Image dances'. By 'imageless dances' he meant dances which have no set form, but aim at getting the dancers into a state of ecstasy. In this state the dancer(s) seem changed, in a trance, and are often thought of (by their society) as being 'possessed by spirits'. These dances are done on certain occasions: marriage, war, famine, illness or death, and so on. They are found in all early ('primitive') societies.p49; 62

The 'image dances', according to Sachs, are to do with the world outside the dancer. By imitating an animal or object, the dancer believes he can capture a power and make it useful. To dance in imitation of the animal which is going to be hunted is to become one with them. To imitate the act of sex is to achieve fertility. This is the kind of thinking behind an image dance. Sachs points out that societies of this kind do not really understand the connection between cause and effect. They really believe the image dances work. The dance type which is used in image dances is mime.p49; 77

The two styles of dance may be joined together. Fertility dances may involve both ecstatic states and mime. The great dancer Nijinsky used some of these ideas in his choreography for the ballet Le Sacre du Printemps (The Rite of Spring), a ballet about the sacrifice of a girl during a primitive celebration of Spring.

In more recent times, the first dance school we know about was opened in 1661 in Paris. Only men were accepted until 1681. After 1681, women were accepted too. Ballroom dances are forms of modern dance. Ballroom dances such as the waltz are done by couples.

Until the 20th century, most ballroom dances were sequence dances. The way people moved was planned in set formation. These formations were usually lines or squares. Everyone moved at the same time, and finished at the same time. The music played for a set time, and then stopped. After the invention of the waltz, around 1800, another style of dancing developed. In the waltz, and later dances, people danced in couples, but they did so separately. They did not dance in formation, but moved round the room as they pleased (but anti-clockwise). Often, new dance styles arrive. Some dance as individuals, separately, as they please. Street dance is like that. All these types of dance have music.

At the same time, round the world there are many traditional dances. Some of them have been going for hundreds of years. We call them folkloric dances.

The coming of popular music videos and DVDs led to a kind of dancer previously seen in some stage shows. A backup dancer (or background dancer) is a performer who dances with or behind the lead performers in a live musical act or in a music video.

There are many different styles of dance, which fall into these general types:




#Article 81: Deadline (193 words)


A deadline is a time by which some  must be d.

Very often, it means a time limit that is set in place by an authority - for example, a teacher tells students that they must turn in their  in by a certain time. This is so the teacher is able to report fairly to his or her principal that every student had the same chance to do the work.

Deadlines may also be set by a time horizon that comes from something that is not a human authority, but part of nature.  For example, by sunset one must do those tasks requiring daylight.  However, a human must watch the sun and decide what light is strong enough to still be daylight, so time limits will still be involved even if one observes a horizon and sets a deadline oneself.

A way to remember this is that a time horizon is like the physical horizon where sunset happens and a time limit is a thing people set up to deal with this. A deadline is a thing powerful people set up to ensure less powerful people comply with their way of doing things.




#Article 82: Dutton's Speedwords (254 words)


Dutton Speedwords is a  made-up language written by Reginald John Garfield Dutton. The idea of Dutton Speedwords is to make frequent words short, and very frequent words very short. Dutton Speedwords can be used as a second language for international communications. Dutton Speedwords is also a shorthand writing system – this means you can use it to write quickly. 

The method was made up by Reginald John Garfield Dutton (1886-1970) in 1922. It was first published in 1935. It was called International Symbolic Script. A year later, it was called Speedwords. It was changed in 1946 and 1951.

It has two uses; to be a language and to be used for writing quickly. Dutton hoped that this would mean more people would learn it because they could use it for two reasons.

The books that Dutton wrote about Speedwords are not printed anymore. But Speedwords is now being used by more people because they find it is good for working online. For example, it makes it faster to type an email.

Another way of writing quickly is Pitman's shorthand. This uses special symbols instead of letters. Speedwords uses Roman letters. This makes it easier to learn. It also means it can be typed using a normal keyboard. Each word means only one thing. This means you do not need to use different forms of the same word.

The words used in Speedwords are the same as the words used in many other languages. The words are like short versions of the writer's own language.




#Article 83: Devil (542 words)


In some religions, the devil is a bad spirit or supernatural being that tries to create problems for people and distance them from God. Some people also use the words the Devil or Satan for the most powerful devil. The word devil comes from the Greek word diabolos which means someone who tells lies to hurt you. (Diabolos is translated to the English word slanderer.) The New Testament uses diabolos as a title for Satan, and so The Devil became another name for Satan in English.

In the Old Testament, there is the serpent and the shaitan, who may be two different characters. Shaitan in Hebrew means adversary, an enemy or opponent. Shaitan is also the word used for the devil in the Koran, who often appears as an animal and tries to get people to do the wrong thing.

In Christianity the Devil was originally an angel in heaven called Lucifer. But he refused to love the humans as much as his father, God, as he was instructed, and so he revolted against Heaven. After a hard fight he was defeated and thrown out of heaven. Some other angels who helped him were also thrown out.

After the Devil was thrown out of heaven, he started doing bad things on the earth. He wants people to worship him instead of God. Sometimes he tries to trick people by giving them false promises.

The other angels who were thrown out of heaven became evil spirits called demons. They obey the Devil and help him do evil things.

The Book of Revelation says that God will punish the Devil and his demons by throwing them into a Lake of Fire that burns in Hell. This will happen in the future.

Artists draw pictures of the Devil that show him as ugly and evil. But nobody knows what he may look like. Usually he is a spirit that nobody can see, but he can make himself look like a real person in order to trick people. Many modern depictions of the devil portray him as a red human-like being with horns and a pointed tail, carrying a red pitchfork or trident.

Not all religions believe in the devil. For example, some forms of Buddhism do not believe in the devil. In Wicca, the concept of the Devil and demons is also rejected, simply because, in Wiccan tradition, the creative energy is neither positive nor negative. According to Wiccans: We are the ones who use this energy for good or evil. Therefore, the consequence of this action is our entire responsibility, not of an evil supernatural being. The corniferous god Cernunnos of Wicca was confused with the Christian Devil, for having horns (in antiquity, given the horns were phallic, they were associated with virility (fertility)), and were soon symbols of ancient European religions. He was already worshipped by pagan religions before Christianity arrived in Europe and the British Isles. Many satanists believe in the devil or Satan only as a metaphor, not an actual being or person. In the Bahá'í Faith, the devil as a malevolent, supernatural entity is not believed to exist. These terms do, however, appear in the Bahá'í writings, where they are instead used as metaphors for the lower nature of man.




#Article 84: Diarrhea (471 words)


Diarrhea (DIE-uh-REE-uh), also spelled diarrhoea, happens when the body makes more watery feces than normal.  Diarrhea can occur in humans as well as most other mammals.

Diarrhea is not a disease.  But it may be a symptom of a disease.  The most common causes of diarrhea are:

In developing nations, diarrheal diseases are the second most common cause of death in children under age 5.  Every year in the world, diarrhea kills around 760,000 children under age 5.

In developing countries, diarrhea is also one of the most common causes of malnutrition in children under age 5.

When children die from diarrhea, the cause is often  dehydration (losing too much water from the body). Because diarrhea is watery, it takes away a lot of the water.  It also takes away electrolytes—important salts that the body needs to survive.  Dehydration is extra dangerous for small children because they have less water in their bodies to begin with.  This means they cannot lose as much water as adults before they start to have serious health problems.

In developing countries, diarrhea is usually caused by an infection in the intestines.  These infections can be caused by bacteria, viruses, or parasites.  These infections spread easily in some developing countries because of the following reasons:

Child deaths from diarrhea can be prevented in different ways.

When a child is sick with diarrhea, the best way to keep them from dying is to rehydrate them (give them the water and electrolytes (salts) they are losing by having diarrhea).  If the child can go to a clinic or hospital, this can be done by giving water and salts intravenously (through a needle placed into a vein).

If the child cannot go to a clinic or hospital, oral rehydration solution can be used.  (Oral means given by mouth; a solution is a mixture.)  Oral rehydration solution is a mixture of the most important things the body loses when it is dehydrated.  These things are clean water, salt, and sugar.  Some oral rehydration solutions have extra electrolytes, like potassium, in them also.

Some oral rehydration solutions come in packets and just need to be mixed with clean water.  Oral rehydration solution can also be made at home.  If the water in the area is not safe, it can be boiled to make it safe.  (Boiling the water will kill any bacteria, viruses, or parasites in the water.)  Salt and sugar are then mixed into the water.  Drinking this mixture, after the water cools, will re-hydrate the child, if he drinks enough.  Adding a banana or orange juice can add potassium to the mixture.

Breast milk will also re-hydrate a child with diarrhea.

There are some ways to prevent diarrhea, or the spread of diseases that cause diarrhea.  However, some of these ways are expensive and difficult to do.  These include:




#Article 85: Dimension (396 words)


Dimensions are the way we see, measure and experience our world, by using up and down, right to left, back to front, hot and cold, how heavy and how long, as well as more advanced concepts from mathematics and physics. One way to define a dimension is to look at the degrees of freedom, or the way an object can move in a specific space. There are different concepts or ways where the term dimension is used, and there are also different definitions. There is no definition that can satisfy all concepts. 

In a vector space  (with vectors being arrows with directions), the dimension of , also written as , is equal to the cardinality (or number of vectors) of a basis of  (a set which indicates how many unique directions  actually has). It is also equal to the number of the largest group of straight line directions of that space. Normal objects in everyday life are specified by three dimensions, which are usually called length, width and depth. Mathematicians call this concept Euclidean space.

Dimensions can be used to measure position too. The distance to a position from a starting place can be measured in the length, width and height directions. These distances are a measure of the position.

In some occasions, a fourth (4D) dimension, time, is used to show the position of an event in time and space.

In modern science, people use other dimensions. Dimensions like temperature and weight can be used to show the position of something in less simple spaces. Scientist study those dimension with dimensional analysis.

Mathematicians also use dimensions. In mathematics, dimensions are more general. Dimensions in mathematics might not measure things in the world. The rules for doing arithmetic with dimensions in mathematics might be different than usual arithmetic rules.

Vectors are used to show distances and directions. Vectors are often used in engineering and science, and sometimes in mathematics.

A vector is a list of numbers. There is one number for each dimension. There are arithmetic rules for vectors.

For example, if Jane wants to know the position of Sally, Sally can give Jane a vector to show the position. If Jane and Sally are in the world, there are three dimensions. Therefore, Sally gives Jane a list of three numbers to show her position. The three numbers in the vector Sally gives Jane might be:




#Article 86: Distance (107 words)


Distance is how far one thing is from another thing. It is also a measure of the space between two things. It can be measured along any path. Thus, someone who goes around in a circle has traveled a distance, even though his position has not changed.

In geometry, the distance between two points A and B is sometimes written as . Pythagorean theorem is often used in the calculation of distance. Distance is a scalar, and thus is different from displacement.  Displacement is a vector that measures distance with a straight line (and in only one path). Displacement is the shortest way to travel the distance.




#Article 87: Depth (113 words)


In math, the distance between the nearest end and farthest end of an  is its depth.

For example, Jane measures a box.  When she measures the distance between the end of the box closest to her and the end of the box farthest away, Jane measures the box's depth.

For liquids, the distance between the top or surface of the liquid and the bottom of the liquid is the liquid's depth.

For example, water is a liquid.  If you fill a container with water, the distance between the top of the water and the bottom of the container is the water's depth.  If the depth is big we say the water is deep. 




#Article 88: Dictionary (515 words)


A dictionary is a type of book which explains the meanings of words or, more precisely, lexemes. The words are arranged in alphabetical order so that they can be found quickly. The word dictionary comes from the Latin dictio (saying).

There are several types of dictionaries: dictionaries which explain words and how they are used, dictionaries which translate words from one language to another, dictionaries of biography which tell about famous people, technical dictionaries which explain the meanings of technical words or words connected to a particular subject (sometimes called a thesaurus). Some of these come close to being an encyclopedia, but an encyclopedia gives a lot of extra information about things (knowledge) and does not explain the use of the language. An encyclopedic dictionary gives less information about the topic than a real encyclopedia does, but more than a simple dictionary.

Dictionaries which explain what words mean will give a clear definition of the word (e.g. hippopotamus : a hoofed mammal with thick skin, large mouth and short legs that lives in rivers and lakes of Africa.)

A big dictionary will also give more information about the word. It will explain how it is pronounced. Usually the International Phonetic Alphabet is used for this. It will explain how the word is used. This is not a problem for a word like hippopotamus, but a word like put has so many different meanings that a large dictionary may have a whole page or more to explain how it can be used. It will also explain the origin of the word (e.g. Greek hippos horse and potamus river).

A dictionary may also give the form of the word in different tenses, plural form etc.

There are also dictionaries which translate words into foreign languages. Often one volume (one book) will translate both ways; for example, half the book might be translating from English to Dutch and the other half from Dutch to English.

When using a dictionary to find out how to say something in another language one has to be careful to choose the right word. A word like right has two basic meanings in English: 1) correct, and 2) the opposite of left. Other languages  have different words for these different meanings, but they have homonyms of their own. A word like put has many meanings. A good dictionary will have a large list of these meanings to help people find the word they want. In many languages, for example, the word “put” will be different according to whether something is being put onto something (e.g. a table) or into something (e.g. a cupboard).

Dictionaries need to be updated frequently because of the way language changes. New words are often brought into a language (e.g. lots of computer terms) or words change their meanings (e.g. gay or cool). In this sense, the most famous English Dictionary is the Oxford English Dictionary (or OED). Words are always being added to the OED. They are never taken out even if they are obsolete (not used any more). The OED can be accessed online (with a subscription).




#Article 89: Denmark (2234 words)


Denmark (), officially named the Kingdom of Denmark, is a Nordic country in Northern Europe. It is the furthest south of the Scandinavian countries, to the south of Norway and south-west of Sweden (which it is connected to by a bridge). It has a south border with Germany. It borders both the North Sea to the west and the Baltic Sea to the east. Denmark is a developed country with a large welfare state; In 2006 and 2007, surveys ranked Denmark as the happiest place in the world, based on standards of health, welfare, and education.

The capital city of Denmark is Copenhagen, on the island of Sealand. Denmark is a constitutional monarchy (meaning the head of state is a monarch who has few established powers) with a queen, Margrethe II. Denmark is a parliamentary state, meaning the people appoint a parliament to make decisions for them, and it has a democratic government headed by an elected Prime Minister, who currently is Mette Frederiksen since 2019.

In geography, Denmark is the land in northern Europe, where the Danes live. In the political sense, the Kingdom of Denmark also includes the Faroe Islands in the Atlantic Ocean, and Greenland in North America. All three parts of the country have different languages and culture.

Denmark was first united in the 10th century, during the Viking period, by the king Harald Bluetooth (), who first converted Denmark to Christianity. The Vikings are well known for invading countries.  In the 11th century, the Danish Vikings controlled England (the Danelaw) for a while. In 1397 Denmark, Sweden and Norway became a single country with one queen (this country was called the Kalmar Union) Sweden became a separate country again in 1523. Denmark and Norway (called Denmark-Norway) stayed united, until 1814. Denmark-Norway controlled many islands in the Atlantic Ocean, including the Faroe Islands, Iceland and Greenland. Iceland became independent from Denmark in 1944.

Denmark became a constitutional monarchy in June 5, 1849 when it adopted a constitution which took away powers from the King and gave rights to ordinary Danish people. June 5 is  now a holiday in Denmark, called Constitution Day.

Over the years Denmark lost many of the lands that it controlled in battle. Denmark's biggest war defeat was the Second Schleswig War (in 1864) when the duchies of Schleswig and Holstein was conquered by the Kingdom Prussia (now a part of Germany). This was a big loss for Denmark and, consequently, it began a policy of neutrality after the loss, meaning it would no longer take part in any wars or support other countries. Denmark did not take part in the First World War.

On April 9, 1940, Denmark was invaded by Nazi Germany and the Nazis stayed in Denmark throughout World War II. During the war, in 1943, Danes helped over 8,000 Jews to escape from Denmark into Sweden after the Nazis tried to arrest them.

After the liberation of Denmark, one part of the country was not. That was the island of Bornholm. The German Commandant von Kamptz who was stationed there, refused to surrender to the Soviets as the German were fleeing to Bornholm and further to Sweden. The Soviets then bombed the two biggest towns Rønne and Nexø. After the Germans were captured on May 9, 1945, the Soviet Army occupied the island until April 6, 1946.

After World War Two, Denmark became a member of NATO and the European Union. Greenland and the Faroe Islands are now part of the Kingdom of Denmark and have their own governments and limited power.

Denmark has three branches of power; the judiciary (the courts), the executive (the Prime Minister and the cabinet) and the legislature (the Danish parliament). The current Prime Minister of Denmark is Mette Frederiksen, who was elected in June 2019.

Denmark is a Kingdom which means it has a monarch (a king or queen). The current monarch is Queen Margrethe II. Margrethe II does not have a lot of power (she does not make any important decisions) and has a symbolic role. Denmark became a constitutional monarchy in 1849.

Elections to the parliament are held every four years, and the winner of the election is the party or coalition which gets the most votes and seats in the parliament. After the elections are done, several parties who are in agreement will group together to form a coalition government, and the leader of the largest party becomes the prime minister.

Here is a short summary of the biggest political parties in Denmark, from left to right on the political axis:

Denmark, like the other Nordic countries. is well known for being a large welfare state. The government provides many services to the public such as free health care, free education (school and college) and free housing for the poor. Danes pay high taxes to fund welfare.

Denmark is the smallest of the Scandinavian countries. The neighbours are Germany (to the south), Sweden (to the east), Norway (to the north) and the United Kingdom (to the west). The country is surrounded by the sea except for Jutland (Jylland), the largest part of Denmark. It is connected to Germany by land. To the south-east there is the Baltic Sea, to the west the North Sea, to the north the Skagerrak and to the north-east the Kattegat.

The western part of Denmark is the peninsula of Jutland (, pronounced yoo´-land), bordering Germany. This is the only part of Denmark that is not an island. The rest of Denmark includes 76 islands people live on, and many tiny islands. The largest islands are Zealand (Sjælland), and Funen (Fyn). To the east is the island of Bornholm in the Baltic Sea, the only place in Denmark where the bedrock can be seen.

The country is quite flat. The highest hill or mountain is Møllehøj, which is 170.86 metres (560.56 ft) tall.  There are many small hills, lakes, creeks, forests and farmland. Denmark's shore line covers 7,314 km (4,545 mi). Nobody in Denmark lives more than 60 km from the coast. The longest river in Denmark is the Gudenå.

The weather in Denmark is quite windy and rainy. In the winter, it does not get very cold; in most years, there are only a few weeks of snow. Every ten years or so, the sea around the islands freezes over, but in most winters, it does not. The climate and topography are not good for winter sports.

Most summers are not very hot. People always dress to be ready for rain or wind. There are also very sunny times, but nobody can know ahead of time when these will be. The best time of the year for outdoor activities is the months of May and June until midsummer.

Denmark is divided into five regions (Danish: regioner or region for one). The regions replaced the former counties (amter) in January 2007. The regions are in charge of hospitals and health care.

The regions are then subdivided into municipalities (). There are currently 98 municipalities, but before January 2007 there were 275. The number of municipalities was decreased when it was decided that, to become more efficient, each should have a population of at least 20,000 .

The biggest part (90.5%) of Denmark's population of just under 5.4 million is of Danish descent, according to 2009 statistics. Of the rest 8.9% who are immigrants or descendent from recent immigrants, many come from South Asia or the Middle East. There are also small groups of Inuit from Greenland and Faroese.

The Danes speak the national language, Danish, which is very similar to the other Scandinavian languages. Swedish and Norwegian are so close to Danish that most Danes understand them.

As well as Danish, most Danes speak a foreign language too, such as English, which is popular as an international language, or German. In the southern part of Jutland, a German minority speaks German. On the Faroe Islands, Faroese is spoken, and people living in Greenland speak Inuit.

Religion does not play a large part in the life of most Danes and church attendance is very low. However, even though many Danes are atheist, 80.4% are members of the Protestant Church of Denmark (, The National Church) which is the official state church of Denmark. The National Church is Lutheran, which means it separated from the Roman Catholic Church in the 16th Century. Other important faiths include Judaism, Islam (the number of Muslims is increasing), other Protestant groups and Catholicism.

Because of the many islands, Denmark has many bridges. The main parts of the country, and most of the bigger islands, are connected by roads and railroads. One of the world's longest bridges connects the eastern and the western parts of the country, and there is a large bridge to Sweden also. There is still no bridge across the Baltic Sea to Germany, but it will most likely be built in a few years.  The bridge to Sweden was expensive, took a long time to build, and required much planning by engineers.

There are still many islands with no bridges to the mainland. People have to go by boat or airplane to reach these islands. Many islands will never be reached by bridges, because they are too small or too far away.  If the island has too few people, bridges are often not built because it is expensive to build.

Cycling is very popular in Denmark because the ground is so flat. Copenhagen is a city that is very bicycle friendly, with bicycle lanes extending over 12,000 km.

The people of Denmark have always depended on the sea. In earlier days, people could not travel anywhere unless they went by boat. Many Danes were fishermen or merchants. Even today, many Danes spend much time near or at the sea.

Farming has always been one of the main occupations. Because of the climate and the soil, Denmark is a good place for agriculture. Export of food to the neighbouring countries is one of the most important sources of income for the country.  Danish hams and cookies are exported throughout the world.

Perhaps the most famous Dane is actually Hamlet, the title character of William Shakespeare's famous play, which was set in the real castle of Kronborg in Helsingør, north of Copenhagen. The play was based on an old Danish myth of the Viking Prince Amled of Jutland, and his quest for revenge against his father's killer. Another widely known Dane is Hans Christian Andersen, an author mostly famous for such fairy tales as The Little Mermaid, and The Ugly Duckling. Also Karen Blixen, Tycho Brahe and the philosopher Søren Kierkegaard are well-known worldwide. There are many famous Danish scientists, including Niels Bohr, the famous physicist who developed the first working model for the atom, and Ole Rømer, who discovered the speed of light. Hans Kirk, although less well-known outside of Denmark, is the author of the best-selling Danish novel of all time, The Fishermen.

Danes enjoy many different types of music, including ballets, jazz music, pop and rock. Denmark's most famous classical composer is  Carl Nielsen. Famous Danish bands include Aqua, a pop band, and The Raveonettes, an indie rock band. The most famous Danish rock star is Lars Ulrich of the band Metallica.

The cuisine of Denmark is like the other Nordic countries (Finland, Norway, Iceland, and Sweden), as well as that of northern Germany, consists mainly pork meat and fish. Traditional Danish food includes frikadeller (fried meatballs, often served with potatoes and various sorts of gravy). Fish is also widely eaten, especially on the west coast of Jutland.

Christmas () is the main feast of the year. Christmas is traditionally celebrated on the eve, December 24, and this is when the main Christmas meal is eaten and presents are unwrapped.

In midwinter, a fast is celebrated. Children are dressed up, and go from house to house begging for money. This practice has in the recent years been taken over by Halloween, and most people give candy not money. A barrel filled with candy is smashed with clubs. The person who makes the candy fall out is appointed queen of cats and the person who hits the last stick is appointed king of cats.

Midsummer is celebrated with a huge bonfire in the evening of June 23. Most Danes have a three-week summer holiday in July or August.

The most popular sport in Denmark is football (soccer). Sailing, swimming and other water sports are very popular because of the long coastline. Another common sport is cycling, (Copenhagen has been nicknamed the City of Cyclists because of the popularity of bicycles for moving around), which has become popular in Denmark partly because of the flat land all over the country. Indoor sports such as badminton and handball are also popular during the long winters.

Monarch is a word that means king or queen. Denmark is the oldest monarchy in Europe.  The current monarch is Queen Margrethe II, who has been the queen since 1972. Denmark does not currently have a King. Margrethe's husband was called a prince because he was the son-in-law, not the son, of the previous King. He died on 13. February 2018 at the age of 83. The royal couple have two children:

In 2008 Prince Joachim married for the second time. His new wife is from France and is called Marie, with whom he has a son and a daughter.




#Article 90: Death (1321 words)


Death is the end of a life in an organism. All biological and living activity of the living thing stop, including the mind and the senses. The usual signal for death in humans and many other animals is that the heart stops beating and cannot be restarted. This can be caused by many things. All living things have a limited lifespan, and all living things eventually die.

Living things that have died are normally described as being dead. Death of humans is often investigated for the cause, in case of crime (such as murder), accident or disease that may continue to kill other humans. About 150,000 people die every day around the world. About two thirds of these people die because of age. In addition to the physical body, some believe humans also have a soul and believe that the soul can continue without a body (afterlife), move into another body (reincarnation), or cease to exist (annihilationism). Religions have different beliefs about this issue. Many cultures have their own customs and rituals to respect the dead.

When people talk about things or events that lead to the death of a plant or animal, those things or events are usually described as being deadly, or fatal. In the case of diseases, they are described as terminal. Humans are no different from any other lifeform. Our bodies have an ability for self-repair, but that ability is limited. Finding the cause of death is a medical speciality called pathology. In medicine, death is when the heart stops beating for more than several minutes. There are special times in which people recover even though the heart has stopped for 30 minutes, such as near-drowning in very cold water. If machines are used to help the heart and lungs work, then the moment of death is more difficult to know.

Death is commonly a sad or unpleasant thing to people. It can make people think about their own death. People might miss or be sad for the person who has died. They might also be sad for the family and friends of the person who has died.

In any society, human death is surrounded by ritual - a wake or funeral is normal.  In some places it was common to eat the dead in a form of ritual cannibalism.  But this is no longer common, in part because disease like kuru can be passed this way. Human dead bodies are taboo in most societies and must be handled in special ways - for a combination of religious and hygiene reasons.  A human dead body must always be reported in law, to be sure it is disposed of properly.

Finding the cause of any human death and stopping a similar death from happening to someone else are the main reasons people look into human morbidity or let dead bodies be cut open and looked at in an autopsy.  Some religions do not allow autopsies, because they feel the body is holy. Autopsies are usually required by the state if someone dies and people do not know why. The autopsy helps find out if someone killed the person on purpose, tried to hurt them, or if they died from a sickness.

To prepare for their own death, humans can write a last will and testament to be clear about who gets their property and possessions.  A person will sometimes also volunteer to be an organ donor. This might mean giving the whole body to medical research.  It can also save the lives of others by making organ transplants possible.

For a long time, many people have been afraid of death and a lot of people have wondered about what may happen to people after they die.  This is one of the largest questions of philosophy and religion. Many people believe there is some form of afterlife.

Ancient rulers sometimes did insist not only that their own bodies, and much property, but even their servants and relatives be destroyed at their funeral.  

Christianity has a special focus on death because of the state killing of Jesus Christ by the Romans.  In Islam this is thought to demonstrate the injustice of human systems of dealing out death, and the ability of the best people to overcome it and even forgive it.  In Christianity itself it is thought to prove that Jesus himself was really God and so could lose his body and still have the power of resurrection. In Buddhism reincarnation is believed to occur. Reincarnation is an idea taken from Hinduism.

Confucianism advises respect for parents and forms of ancestor worship to respect both dead and living ancestors.

Every ethical tradition including the medical view of the body has some ritual surrounding death.  Often these excuse behaviours that might be hated if they did not have the ritual.  For instance, one may say that organ transplant is like cannibalism.

Very much of what happens at a human death is ritual.  People who wish theirs to be dealt with a certain way, and who wish a particular treatment like cremation of their body, should decide in advance and set up the necessary payments and agreements.  This makes it much easier for their family after they die, since there is no longer the ability to clearly communicate the wish.

For the same reason, saying goodbye is important.  Most of the  of death seems to come for loved ones who did not have a chance to say goodbye.

Maybe it is to relieve this stress that rituals are created, and to bring together those that knew someone so that the personal experience a person can no longer communicate for themselves, can be exchanged by others.

Some ritual, such as seances, claim to allow people to speak to the dead. This is not claimed to be very reliable, both by scientists and even by those who do them very often.

Aside from wills, goodbyes, organ donations and funerals, there is important personal experience to decide to pass on, or not, when someone knows they may soon die.  Palliative care focuses on basic decisions people make when they are very close to the end of their lives, and it ensures someone is always available to talk to them.  It is a replacement for heroic medical intervention that may keep them physically alive but with no quality of life.  Human psychology must prepare for death if it is anything other than a quick surprise:

Elizabeth Kubler-Ross wrote that there were several stages in dying, of which denial was the first, and acceptance was the last.  Recording one's life is often something people with acceptance will do to leave a memoir or a full autobiography:

Because events leave living memory, and may only be part of oral tradition, there are projects to record everything that people remember about World War I and the Shoah.  The first of these was to record everything remembered about the U.S. Civil War.  This discipline has changed history since we have so many more first person accounts of the times, and made social history much more standard.

There are other terms for death. Examples are, to pass away, to go to a better place, to buy the farm (generally used in the military), to leave the earth, big sleep, and to kick the bucket. the term gone may also be a term for describing death. for example: if a person has died, they are also said to be gone, as in gone to a better place or no longer here.

Old age is not the only thing that can end a person's life. People make other people die. This is called killing or murder. Three famous murders are John Wilkes Booth killing Abraham Lincoln, James Earl Ray killing Martin Luther King Jr. and Lee Harvey Oswald killing the President of the United States John F. Kennedy. People can also die by accidents resulting in terminal trauma, hypothermia, starvation, suicide and dehydration.




#Article 91: Diesel-electric (247 words)


A diesel-electric engine is a diesel generator, a diesel engine that drives an electric generator. The generator feeds electric power to an electric motor which turns a driveshaft.  Its efficiency is higher than when an engine drives a shaft through gears.  Most locomotives and many ships use diesel-electric drive.

Many diesel-electric drives, especially small ones, store the electricity in a battery. Some designs also store braking energy in a flywheel, which can also charge a battery. However, these add even more complexity and weight to the vehicle, so are more appropriate for city driving where service stations are always available and there is much stop and go driving.

Because they do not require any change or investment in stations nor much in vehicle design, diesel-electric vehicles are believed to be the most likely replacement for today's internal combustion engine. When properly tuned, they have low emissions and they use only about one-third of the fossil fuel of most gasoline engines powering similar vehicles.

Honda and Toyota are presently delivering consumer priced diesel-electric cars. By contrast, hydrogen infrastructure is thought to be decades off, and is not fully implemented even in Iceland where there is abundant free geothermal electricity.

In countries like India, government is focusing on fully electric trains rather than diesel electric. That too electricity will be produced by renewable sources like Solar.

Many activists feel that promoting hydrogen is a stall, a way to avoid forcing the shift to diesel-electric vehicles in the nearer term.




#Article 92: Europe (507 words)


Europe is the western part of the continent of Eurasia, sometimes thought of as its own continent. It is separated from Asia by the Ural Mountains in Russia and the Bosporus strait in Turkey.

Europe is bordered by water on three sides. On the west is the Atlantic Ocean. To the north is the Arctic Ocean. The Mediterranean Sea separates Southeastern Europe from Africa. On the eastern border of Europe are the Ural River and Ural Mountains.

There are at least 43 countries in Europe (the European identities of 5 transcontinental countries:Cyprus, Georgia, Kazakhstan, Russia and Turkey are disputed). Most of these countries are members of the European Union.

Europe covers about 10,180,000 square kilometers (3,930,000 square miles). This is 2% of the Earth's surface (6.8% of its land area).

As of 2017, about 510 million people lived in Europe.

Europe makes 44% of the world's wine.

Europe contains the world's second most-active volcano, which is Mount Etna that is currently the most-active volcano in the continent.

Europe is a major tourist attraction. People come from all over the world to see its many World Heritage Sites and other attractions.

Europe is named after a princess in Greek mythology called Europa. The myth says that Zeus kidnapped Europa and took her to Crete, where she became the mother of King Minos (from whom Europe’s first civilization gets its name, the Minoans).

The name Europa was later used to describe Greece. Then, as the rest of modern-day Europe started to have cities and empires, the entire area West of the Ural Mountains came to be called Europa.

The history of Europe is long and has many turns. Many great countries originated from Europe. Greek mythology and the beginning of western civilization came from European nations.

Some of the major periods in European history have been:

Andreas M. Kaplan describes modern Europe as a continent where many different cultures live closely together, embracing maximum cultural diversity at minimal geographical distances.

There are several major regions of Europe:

Within these regions, there are up to 48 independent European countries (with the identities of 5 transcontinental countries being disputed). The largest is the Russian Federation, which covers 39% of Europe.

The European city with the largest population is Istanbul. The country with the largest population is the Russian Federation. About 15% of Europeans live in Russia.

Two European countries, the United Kingdom and the Republic of Ireland, are on islands called the British Isles.

Most of Europe lies in temperate climate zones.

However, there are many different climates throughout Europe. For example, during the winter, it may be snowing and -30 degrees Celsius for 4–5 months in Finland. Yet it may be much warmer, with no snow at all except on high mountains, in Spain.

The European Union is a confederation of 27 European countries. These countries agree to follow common laws so that their citizens can move and trade in EU countries almost the same as they do in their own. Nineteen of these countries also share the same type of money: the euro.




#Article 93: Encyclopedia (412 words)


 

An encyclopedia or encyclopaedia is a collection (usually a book) of information.  Some are called encyclopedic dictionaries. 

All encyclopedias were printed, until the late 20th century when some were on CDs and the Internet. 21st century encyclopedias are mostly online by Internet.
The largest encyclopedia in the English language is English Wikipedia, which has more than 6 million articles. The second largest is the Encyclopædia Britannica, which is the largest one that is printed. Either kind of encyclopedia can inform us on many different topics.

Book series were used to summarize all knowledge have been published for thousands of years.  A famous early one was the Natural History by Pliny the Elder. The name encyclopedia is from the 16th century and meant complete knowledge. The French Encyclopédie of Denis Diderot was the first that had major parts written by many people from all around the world.

After the printing press was invented, dictionaries with long definitions began to be called encyclopedias that were books that has articles or subjects For example, a dictionary of science, if it included essays or paragraphs, it was thought of as an encyclopedia or knowledgeable book on the subject of science. Some encyclopedias then put essays on more than one subject in alphabetical order instead of grouping them together by subject. The word, encyclopedia, was put in the title of some encyclopedias. 

Companies such as Britannica were started for the purpose of publishing encyclopedias for sale to individuals, and for public use in libraries. Like dictionaries (which had definitions), these publishers hired hundreds of experts to write articles and read and choose articles. Some internet encyclopedias allowed their paying customers to submit articles from other encyclopedias. Other internet encyclopedias accepted writing from non-paying users (users who did not sign in) of the encyclopedia.

There are different types of encyclopedias. Some are general and have pages on lots of topics. The English language Encyclopædia Britannica and German Brockhaus are general encyclopedias. Some are about specific topics. For example, there are encyclopedias of medicine or philosophy. Others include the Dictionary of National Biography, the Dictionary of American Naval Fighting Ships, and Black's Law Dictionary. There are also encyclopedias that that cover many topics with one  or one cultural bias. They include the Great Soviet Encyclopedia and Conservapedia.

There are two main ways of organizing printed encyclopedias: from A to Z (the alphabetical way) or by categories. Most encyclopedias go from A to Z.

Many dictionaries have similar information to encyclopedias.




#Article 94: Earth science (136 words)


Earth science is an all-embracing term for the sciences related to the planet Earth. Earth science may also be called geoscience.

It is a broader term than geology because it includes aspects of planetary science, which is part of astronomy. The Earth sciences include the study of the atmosphere, oceans and biosphere, as well as the solid earth. Typically Earth scientists will use tools from physics, chemistry, biology, chronology and mathematics to understand the Earth, and how it evolved to its current state.

If there is one fact which underlies all Earth science it is this; the Earth is an ancient planet which has been changing the whole time since its formation. The extent of the changes is much greater than people used to think.

The following disciplines are generally recognised as being within the geosciences:




#Article 95: Earth (2674 words)


Earth is the planet we live on. It is the third planet from the Sun. It is the only planet known to have life on it. The Earth formed around 4.5 billion years ago. It is one of four rocky planets on the inside of the Solar System. The other three are Mercury, Venus, and Mars.

The large mass of the Sun makes Earth move around it, just as the mass of Earth makes the moon move around it. Earth also turns around in space, so that different parts face the Sun at different times. Earth goes around the Sun once (one year) for every 365 times it turns around (one day).

Earth is the only planet in the Solar System that has a large amount of liquid water. About 74% of the surface of Earth is covered by liquid or frozen water. Because of this, people sometimes call it the blue planet.

Because of its water, Earth is home to millions of species of plants and animals which require water to survive The things that live on Earth have changed its surface greatly. For example, early cyanobacteria changed the air and gave it oxygen. The living part of Earth's surface is called the biosphere.

Earth is part of the eight planets and many thousands of small bodies that move around the Sun as its solar system. The Solar System is moving through the Orion Arm of the Milky Way galaxy now, and will be for about the next 10,000 years.

Earth is about  away from the Sun (this distance is called an Astronomical Unit). It moves on its orbit at an average speed of about . Earth turns all the way around about 365 times in the time it takes for Earth to go all the way around the Sun. To make up this extra bit of a day every year, an additional day is used every four years. This is named a leap year.

The Moon goes around Earth at an average distance of . It is locked to Earth, so that it always has the same half facing Earth; the other half is called the dark side of the moon. It takes about 27 days for the Moon to go all the way around Earth, but because Earth is moving around the Sun at the same time, it takes about 29 days for the Moon to go from dark to bright to dark again. This is where the word month came from, even though most months now have 30 or 31 days.

Earth and the other planets formed about 4.6 billion years ago. They were made of the leftover gas from the nebula that made the Sun. The Moon may have been formed after a collision between the early Earth and a smaller planet (sometimes called Theia). Scientists believe that parts of both planets broke off — becoming (by gravity) the Moon.

Earth's water came from different places. Condensing water vapour, and comets and asteroids hitting Earth, made the oceans. Within a billion years (that is at about 3.6 billion years ago) the first life evolved, in the Archaean era. Some bacteria developed photosynthesis, which lets plants make food from the Sun's light and water. This released a lot of oxygen, which was first taken up by iron in solution. Eventually, free oxygen got into the atmosphere or air, making Earth's surface  for aerobic life (see Great Oxygenation Event). This oxygen also formed the ozone  which protects Earth's surface from bad ultraviolet radiation from the Sun. Complex life on the surface of the land did not exist before the ozone layer.

Earth's land and climate has been very different in the past. About 3 to 3.5 million years ago almost all land was in one place. This is called a supercontinent. The earliest known supercontinent was called Vaalbara. Much later, there was a time (the Cryogenian) when Earth was almost entirely covered by thick ice sheets (glaciers). This is discussed as the Snowball Earth theory.

Earth is rocky. It is the largest of the rocky planets moving around the Sun by mass and by size. It is much smaller than the gas giants such as Jupiter.

Overall, Earth is made of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%). The 1.2% left over is made of many different kinds of other chemicals. Chemicals that are very uncommon (such as gold and platinum) can be very valuable.

The structure of Earth changes from the inside to the outside. The center of earth (Earth's core) is mostly iron (88.8%), nickel (5.8%), sulfur (4.5%), and less than 1% other things. The Earth's crust  is largely oxygen (47%). Oxygen is normally a gas but it can join with other chemicals to make compounds like water and rocks. 99.22% of rocks have oxygen in them. The most common oxygen-having rocks are silica (made with silicon), alumina (made with aluminium), rust (made with iron), lime (made with calcium), magnesia (made with magnesium), potash (made with potassium), and sodium oxide, and there are others as well.

Earth's shape is a spheroid: not quite a sphere because it is slightly squashed on the top and bottom. The shape is called an oblate spheroid. As Earth spins around itself, centrifugal force forces the equator out a little and pulls the poles in a little. The equator, around the middle of Earth's surface, is about  long.

The highest mountain above sea levelmdash;the well-known Mount Everest (which is  above sea level)mdash;is not actually the one that is the farthest away from the center of the Earth. Instead, the sleeping volcano Mount Chimborazo in Ecuador is; it is only  above sea level but it is almost at the equator. Because of this, Mount Chimborazo is  from the center of the Earth, while Mount Everest is  closer to it. Similarly, the lowest point below sea level that we are conscious of is the Challenger Deep in the Mariana Trench in the Pacific Ocean. It is about  below sea level, but, again, there are probably places at the bottom of the Arctic Ocean that are nearer to the center of the Earth.

The deepest hole ever dug is only about . We know something about the inside of the Earth, though, because we can learn things from earthquakes and the times when volcanoes erupt. We are able to see how quickly the shock waves move through Earth in different places.

The inside of Earth is very different from the outside. Almost all of Earth's liquid water is in the seas or close to the surface. The surface also has a lot of oxygen, which comes from plants. Small and simple kinds of life can live far under the surface, but animals and plants only live on the surface or in the seas. The rocks on the surface of Earth (Earth's crust) are well known. They are thicker where there is land, between  thick. Under the seas they are sometimes only  thick. There are three groups of rocks that make up most of the Earth's crust. Some rock is made when the hot liquid rock comes from inside the earth (igneous rocks); another type of rock is made when sediment is laid down, usually under the sea (sedimentary rocks); and a third kind of rock is made when the other two are changed by very high temperature or pressure (metamorphic rocks). A very few rocks also fall out of the sky (meteorites).

Below the crust is warm and almost-liquid rock that is always moving around (the Earth's mantle). Then, there is a thin liquid layer of heated rock (the outer core). This is very hot: . The middle of the inside of the Earth would be liquid as well but all the weight of the rock above it pushes it back into being solid. This solid middle part (the inner core) is almost all iron. This is what makes the Earth magnetic.

The Earth's crust is solid but made of parts which move very slowly. The thin level of hard rock on the outside of the Earth rests on hot liquid material below it in the deeper mantle. This liquid material moves because it gets heat from the hot center of the earth. The slow movement of the plates is what causes earthquakes, volcanoes and large groups of mountains on the Earth.

There are three ways plates can come together. Two plates can move towards each other (convergent plate edges). This can form islands (such as Japan), volcanoes, and high mountain ranges (such as the Andes and Himalayas). Two plates can move away from each other (divergent plate edges). This gives the warm liquid rock inside the earth a place to come out. This makes special mountain ranges below the sea or large low lands like Africa's Great Rift Valley. Plates are able to move beside each other as well (transform plate edges, such as the San Andreas Fault). This makes their edges crush against each other and makes many shocks as they move.

The outside of the Earth is not even. There are high places called mountains, and high flat places called plateaus. There are low places called valleys and canyons. For the most part, moving air and water from the sky and seas damages rocks in high places and breaks them into small pieces. The air and water then move these pieces to lower places. Because of this, the Earth would have been very flat a long time before now. The fundamental cause of the differences in the Earth's surface is plate tectonics. The shape of the entire planet itself is not even a ball. Because of its velocity, Earth has a slight bulge at the Equator. Other than that, Earth is shaped more like a pear than an actual sphere.

All places on Earth are made of, or are on top of, rocks. The outside of the Earth is usually not uncovered rock. Over 70% of the Earth is covered by seas full of salty water. This salty water makes up about 97% of all Earth's water. The fresh water people can drink is mostly ice. Only a very small amount is in rivers and under the Earth for people to drink and use. The air above the Earth stops the water from going away into outer space. Also, much of the land on Earth is covered with plants, or with what is left from earlier living things. Places with very little rain are dry wastes called deserts. Deserts usually have few living things, but life is able to grow very quickly when these wastes have rainfall. Places with large amounts of rain may be large woods. Lately, people have changed the environment of the Earth a great deal.

All around the Earth is a large amount of air (the atmosphere). The mass of the Earth pulls the gasses in the air down and does not let them go into outer space. The air is mostly made of nitrogen (about 78%) and oxygen (about 21%) but there are a few other gasses as well. Most living things need the air (or parts of the air gripped in the water) to breathe and live. They use the gassesmdash;especially oxygen and carbon dioxidemdash;to make and use sugar and to give themselves power.

The air animals and plants use to live is only the first level of the air around the Earth (the troposphere). The day to day changes in this level of air are named weather; the changes between places far away from each other and from year to year are named the climate. Rain and storms are both in this level. Both come about because this part of the air gets colder as it goes up. Cold air becomes thicker and falls, and warm air becomes thinner and goes up. The turning Earth moves the air as well and air moves north and south because the middle of the Earth generally gets more power from the Sun and is warmer than the north and south points. At the same time, air over water (specially very warm water) gets water in it but, because cold air is not able to take in as much water, it starts to make clouds and rain as it gets colder. The way water moves around in a circle like this is called the water cycle.

Above this first level, there are four other levels. The air gets colder as it goes up in the first level; in the second level (the stratosphere), the air gets warmer as it goes up. This level has a special kind of oxygen called ozone. The ozone in this air keeps living things safe from damaging rays from the Sun. The power from these rays is what makes this level warmer and warmer. The middle level (the mesosphere) gets colder and colder with height; the fourth level (the thermosphere) gets warmer and warmer; and the last level (the exosphere) is almost outer space and has very little air at all. It reaches about half the way to the Moon. The three outer levels have a lot of electric power moving through them; this is called the ionosphere and is important for radio and other electric waves in the air. It is also where the Northern Lights are.

Even though air seems very light, the weight of all of the air above the outside of the Earth (air pressure) is important. Generally, from sea level to the top of the outer level of the air, a space of air one cm2 across has a mass of about 1.03 kg and a space of air one sq in across has a weight of about 14.7 lb. The mass of the air also keeps the Earth safe when rocks (meteorites) hit it from outer space. Without the air, the damage meteorites do would be much greater. Because of the air, meteorites generally burn up long before they get to the earth.

The air also keeps the Earth warm, specially the half turned away from the Sun. Some gasses ndash; especially methane and carbon dioxide ndash; work like a blanket to keep things warm. In the past, the Earth has been much warmer and much colder than it is now. Since people have grown used to the heat we have now, though, we do not want the Earth to be too much warmer or colder. Most of the ways people create electric power use burning kinds of carbonmdash;especially coal, oil, and natural gas. Burning these creates new carbon dioxide and can cause more warming. A large discussion is going on now about what people should do about the Earth's latest warming, which has gone on for about 150 years. So far, this warming has been good for people: plants have grown better and the weather has been better than when it was colder before. Some people who learn about science, though, say that many bad things will possibly come about if the warming goes on.

About seven billion people live on Earth. They live in about 200 different lands called countries. Some, for example, Russia, are large with many large cities. Others, for example, Vatican City, are small. The five countries with the most people are China, India, the United States, Indonesia, and Brazil. About 90% of people live in the north half of the world, which has most of the land. Scientists think that people originally came from Africa. Now, 70% of all people do not live in Africa but in Europe and Asia.

People change the Earth in many ways. They have been able to grow plants for food and clothes for about ten thousand years. When there was enough food, they were able to build towns and cities. Near these places, men and women were able to change rivers, bring water to farms, and stop floods (rising water) from coming over their land. People found useful animals and bred them so they were easier to keep.




#Article 96: Experiment (350 words)


An experiment is a test of an idea or a . It is often used by scientists and engineers. An experiment is used to see how well the idea matches the real world. Experiments have been used for many years to help people understand the world around them. Experiments are part of scientific method. Many experiments are controlled experiments or even blind experiments. Many are done in a laboratory.

Experiments can tell us if a theory is false, or if something does not work. They cannot tell us if a theory is true. When Einstein said that gravity could affect light, it took a few years before astronomers could test it. General relativity predicts that the path of light is bent in a gravitational field; light passing a massive body is deflected towards that body. This effect has been confirmed by observing the light of stars or distant quasars being deflected as it passes the Sun.

Now, a hundred years or so after Einstein published his ideas, there have been many tests, all of which have been consistent with Einstein's predictions. But, one day, we might find the theory has some limits beyond which it does not work. What we test are implications of the theory, because the theory itself is too large and complicated to test all at once.

A controlled experiment is a kind of comparison. It often compares the results from experimental samples against control samples. Control samples are the same as the experimental sample, except for one difference. This difference is the one thing whose effect is being tested (the independent variable). A good example would be a drug trial. The sample or group receiving the drug would be the experimental group (treatment group); and the one receiving the placebo or an older treatment would be the control group.

An observational study is used when an experiment would be difficult, unethical, or expensive. Observational studies are not experiments. Experiments can control for other variables, and it allows the researchers to change something. Observational studies often do not have random samples, and they often have many variables.




#Article 97: Ethics (188 words)


Ethics is the part of philosophy that deals with good and evil. Ethics tries to answer questions like:

When discussing ethics, the philosophy is generally separated into:

Morality is what someone thinks or feels is good or bad.
There are many different moralities, but they share some things.
For example, most people think that murder (killing somebody) is wrong.(compare Exodus 20:13)
Some philosophers have hope to find more things that moralities share.
They think that ethics should use the scientific method to study 
things that people think are good or bad. Their work can be used
to test the fairness of a situation, such as how people should treat
each other. An example of this kind of thinking is the categorical imperative.
Many countries have laws based on this idea of fairness.

Understanding ethics can help people decide what to do when they have choices. Many  think that doing anything or making any choice is a part of ethics.

Ethics is part of other fields of study in many ways. Here are some ways:

Along with aesthetics ethics forms part of axiology, the philosophy of what people like.




#Article 98: E Prime (392 words)


E Prime (it means English Prime) is a way of speaking English without using the verb to be in any way (be, is, am, are, was, were, been, and being). Instead, an E Prime speaker or writer uses different verbs like to become, to remain, and to equal or they might choose to rearrange the sentence to show that the thing does not actually act. For example, in E Prime, a writer would change the statement Mistakes were made to Joe made mistakes. This change in wording reveals an actor (Joe) where the previous form concealed the actor. Users of E Prime would consider the changed sentence more accurate.

D. David Bourland, Jr. first suggested E Prime in 1965. Bourland had studied the discipline (way of thinking) of General Semantics. The main idea of General Semantics is that people can only know what they observe and experience when they see, hear, touch, taste, smell, think, and feel, and furthermore, that what they observe and experience can affect how they observe and experience in the future. Because each person has different experiences throughout their lives, they interpret their experiences differently. 

Students of General Semantics and users of E Prime contend that to say This cat is soft leaves out many other attributes, and implies that the outside object of the cat is the same as the inside experience of softness. Instead, E Prime users say This cat feels soft TO ME to remind themselves of the following:

Although languages like Russian, Arabic, Turkish, and Cantonese do not always use a separate verb for to be, they do have the idea of being. For example, an English speaker might say This apple is red. An Arabic speaker might say This apple red. Most languages can be used to express the idea of a red apple. An E Prime user chooses to say This apple looks red to me to remind themselves that seeing red involves both the apple and the eye and brain of the person looking at the apple.

Many teachers of English encourage students to use verbs other than to be. To them, using more active verbs makes writing clearer and more interesting. These teachers want to improve their students' writing and may not agree with the ideas of General Semantics or E Prime.

In English, 'to be' can have different functions:




#Article 99: Einstein on the Beach (111 words)


Einstein on the Beach is an opera written by the minimalist composer Philip Glass and theater director and designer Robert Wilson. It was first acted for an audience in Avignon, France in 1976. 

It is a single act opera, about five hours long with no intermission. Because of the length and the minimalist (repetitive) nature of the music, audience members are free to enter and leave the opera as they wish. Glass's music tends to cycle round, but does not exactly repeat itself. Admittedly, he has described himself as a composer of music with repetitive structures. Though his earlier music fits what is normally called minimalist, he has since evolved stylistically.




#Article 100: Ethnic group (113 words)


An ethnic group is a group of people who are considered to be the same in some or multiple ways. They may all have the same ancestors, speak the same language, or have the same religion. They often live in the same or surrounding area.  

Sometimes almost all of the people in one country are of the same ethnic group, but not always. Often one country may have several different ethnic groups, or the people of one ethnic group may live in several different countries.

The International Covenant on Civil and Political Rights ensures the rights of ethnic groups in Article 27 and also gives them the right to use their own language.




#Article 101: Ebola virus (575 words)


Ebola virus is a very dangerous virus. It belongs to the family Filoviridae and is responsible for a severe disease characterized by the sudden onset of hemorrhagic fever accompanied by other non specific signs and symptoms.  Hemorrhagic means that the victim will bleed a lot, inside and outside their body. The virus attacks almost every organ and tissue of the human body resulting in multi-organ dysfunction. Out of every 100 people who get Ebola, on average 25 to 90 die. There are four kinds of Ebola virus that can cause the disease. The virus was first found in Sudan. It is found in Africa, with very few cases in Europe and the United States.

The Ebola virus that makes people sick lives in the blood and other liquids and wet things in some kinds of non-human animals without killing them. Scientists think the animals it lives in are mainly some kinds of monkeys or fruit bats. When people touch animals that have the virus, or wet things that came out of those animals, they can get sick.

Ebola cannot be caught through the air, or by being near sick people. The virus can only go from liquids into people's bodies. This means Ebola can be caught by touching a sick person's blood, saliva, mucus, semen, diarrhea, vomit, or other fluids that come out of a sick person's body.

If a person does not die from the disease, he can still give other people the infection by having sex for nearly another two months after they stop being sick. This is because the virus can still be in the man's semen after a long time.

When people get Ebola the first symptoms look like some other diseases. People get a fever and feel very tired. Their head, stomach, joints, and throat might hurt. Sometimes, people think they have other diseases like malaria or typhoid fever.

Later, people get much sicker. They bleed both inside and outside their bodies. They have blood in their diarrhea and vomit. They bleed from their noses, mouths, and genitals/sex organs. They get shock: low blood pressure, fast pulse (heart rate), and low blood circulation to the body. Their organs might stop working. Ebola also causes stiffness throughout the body which makes it hard for sick people to move.

Five to nine out of every ten people who get sick with Ebola die.

There is no cure for Ebola, but if people get care quickly from doctors and nurses at a hospital, more of them live. People with Ebola need a lot of fluids to replace fluids lost from diarrhea, vomiting, and bleeding. The most important care is giving them water with a very small amount of salt and sugar in it. This is called oral rehydration. It helps to replace their fluids and blood. It is also important to give medicines in case they get bad blood pressure and blood circulation.

In December 2016, a study found the VSV-EBOV vaccine to be very effective (in the neighborhood of 70–100%) against the Ebola virus, making it the first vaccine against the disease.

Many Ebola vaccine candidates had been developed in the decade prior to 2014, but as of October 2014, none had yet been approved by the United States Food and Drug Administration (FDA) for use in humans.

World Community Grid is a computing project that is seeking possible drug treatments. People donate the spare time on their computers to the project.




#Article 102: Ecology (400 words)


Ecology is the science that  studies the biota (living things), the environment, and their interactions. It comes from the Greek oikos = house; logos = study. 

Ecology is the study of ecosystems. Ecosystems describe the web or network of relations among organisms at different scales of organization. Since ecology refers to any form of biodiversity, ecologists research everything from tiny bacteria in nutrient recycling to the effects of tropical rain forests on the Earth's atmosphere.  Scientists who study these interactions are called ecologists. 

Terrestrial ecoregion and climate change research are two areas where ecologists now focus.

There are many practical applications of ecology in conservation biology, wetland management, natural resource management (agriculture, forestry, fisheries), city planning (urban ecology), community health, economics, and applied science. It provides a framework for understanding and researching human social interaction.

Ecology starts many powerful philosophical and political movements - including the conservation movement, wellness movement, environmental movement, and ecology movement we know today. When these are combined with peace movements and the Six Principles, they are called green movements. In general, these put ecosystem health first on a list of human moral and political priorities, as the way to achieve better human health and social harmony, and better economics. 

People with these beliefs are called political ecologists. Some have organized into the Green Parties, but there are actually political ecologists in most political parties. They very often use arguments from ecology to advance policy, especially forest policy and energy policy.

Also, ecology means that it is the branch of biology dealing with the relations and interactions between organisms and their environment, including other organisms.

Many ecologists also deal with human economics:

Ecological economics and human development theory try to separate the economic questions from others, but it is difficult. Many people think economics is just part of ecology now, and that economics that ignores it is wrong. Natural capital is an example of one theory combining both.

Sometimes ecology is compared to anthropology. Anthropology includes how our bodies and minds are affected by our environment, while ecology includes how our environment is affected by our bodies and minds. There is even a type of anthropology called ecological anthropology, which studies how people interact with the environment. 

Antoine de Saint-Exupery stated: The earth teaches us more about ourselves than all the books. Because it resists us. Man discovers himself when he measures himself against the obstacle.




#Article 103: Economics (496 words)


Economics is the social science which studies economic activity: how people make choices to get what they want. It has been defined as the study of scarcity and choice and is basically about the choices people make. It also studies what affects the production, distribution and consumption of goods and services in an economy.

Investment and income relate to economics. The word comes from Ancient Greek, and relates to οἶκος oíkos house and νόμος nomos custom or law. The models used in economics today were mostly started in the 19th century. People took ideas from political economy and added to them because they wanted to use an empirical approach similar to the one used in the natural sciences.

The subjects (actors) in economic study are households, business companies, the government (the state), and foreign countries. Households offer their factors of production to companies. This includes work, land, capital (things like machines and buildings) and information. In exchange for their factors of production, households get income which they use to consume (buy) goods from other subjects. 

Business companies produce and sell goods and services and buy factors of production from households and from other companies. 

The state or public sector includes institutions and organisations. The state takes some of the earnings from the business companies and households, and uses it to pay for public goods like streets or education, to be available for everyone. The last subject is foreign countries. This includes all households, business companies and state institutions, which are not based in one's own country. They demand and supply goods from abroad.

The objects (things acted upon) in economic study are consumer goods, capital goods, and factors of production. Consumer goods are classified as usage goods (for example, gasoline or toilet paper), as purpose goods (for example, a house or bicycle), and as services (for example, the work of a doctor or cleaning lady). Capital goods are goods which are necessary for producing other goods. Examples of these are buildings, equipment, and machines. Factors of production are work, ground, capital, information, and environment.

The ideas that economists have depend a lot on the times they live in. For example, Karl Marx lived in a time when workers' conditions were very poor, and John Maynard Keynes lived through the Great Depression of the 1930s. Today's economists can look back and understand why they made their judgments, and try to make better ones.

The two main branches of economics are microeconomics and macroeconomics.  

Macroeconomics is about the economy in general. For example, macroeconomists study things that make a country's wealth go up and things that make millions of people lose their jobs. Microeconomics is about smaller and more specific things such as how families and households spend their money and how businesses operate.

There are a number of other branches of economics:

Famous economists in history include:

Famous economists of the 19th and 20th century include Friedrich August von Hayek, Wassily Leontief,  Carl Menger, and Léon Walras.




#Article 104: Chemical element (620 words)


A chemical element is a substance that contains only one type of atom, which is the smallest particle of an element.  Atoms are made up of protons, neutrons, and electrons. 

The number of protons in an atom is called the atomic number. For example, all atoms with 6 protons are atoms of the chemical element carbon, and all atoms with 92 protons are atoms of the element uranium. The number of neutrons in the nucleus does not have to be the same in every atom of an element. Atoms of the same element with different numbers of neutrons are called isotopes. Saying that a substance contains only one type of atom really means that it contains only atoms that all have the same number of protons.

The number of protons in the nucleus causes its electric charge. This fixes the number of electrons in its normal (un-ionized) state. The electrons in their atomic orbitals determine the element's various chemical properties.

Elements are the basic building blocks for all types of substances. If a substance contains more than one type of atom, it is a compound or a mixture. The smallest particle of a compound is a molecule.

Chemical elements are commonly arranged in the periodic table. Where the elements are in the table tells us about their properties relative to the other elements.

Chemical elements are given a unique chemical symbol. Chemical symbols are used all over the world. This means that, no matter which language is spoken, there is no confusion about what the symbol means. Chemical symbols of elements almost always come from their English or Latin names. For example, carbon has the chemical symbol 'C', and sodium has chemical symbol 'Na', after the Latin natrium. Tungsten is called 'W' after its German name, wolfram. 'Au' is the symbol for gold and it comes from the Latin word for gold, aurum. Another symbol which comes from Latin is 'Ag'. This is the element silver and it comes from the Latin argentum. Lead's symbol, 'Pb', comes from the Latin plumbum and the English word plumber derives from this as pipes used to be made out of lead. Some more recently discovered elements were named after famous people, like einsteinium, which was named after Albert Einstein.

Elements can join (react) to form pure compounds (such as water, salts, oxides, and organic compounds). In many cases, these compounds have a fixed composition and their own structure and properties. The properties of the compound may be very different from the elements it is made from. Sodium is a metal that burns when put into water and chlorine is a poisonous gas. When they react together they make sodium chloride (salt) which is generally harmless in small quantities and edible.

Some elements mix together in any proportion to form new structures. Such new structures are not compounds. They are called mixtures or, when the elements are metals, alloys.

Most elements in nature consist of atoms with different numbers of neutrons. An isotope is a form of an element with a certain number of neutrons. For example, carbon has two stable, naturally occurring isotopes: carbon-12 (6 neutrons) and carbon-13 (7 neutrons). Carbon-14 (8 neutrons) is a naturally occurring radioactive isotope of carbon. At least two isotopes of each element are known (except for Oganesson, of which only a few atoms have been made).

Elements can be classified based on physical states. At room temperature and pressure, most elements are solids, only 11 are gases and 2 are liquids.

Elements can also be classified into metals and non-metals. There are many more metals than non-metals.

However, a few elements have properties in between those of metals and non-metals. These elements are called semimetals (or metalloids).




#Article 105: Egypt (879 words)


Egypt is a country in northeast Africa. Its capital city is Cairo. Egypt is famous for its ancient monuments, such as the Pyramids and the Sphinx.

Ancient Egypt has one of the longest histories of any country in the world as it used to be ruled by pharaohs. As a province of the Roman Empire, it became Christian and some Coptic Church people are there after more than a thousand years of Muslim rule. The Fatimid Caliphate ruled Egypt in the tenth through twelfth centuries. Mamlukes ruled it until 1798 when Napoleon defeated them. Muhammad Ali Pasha soon took over and started a dynasty of Khedives under the Ottoman Empire. The Empire fell apart after World War I. Egypt became an independent country in 1922 and the khedive became a king. Egypt is a member of the United Nations and the Arab League. It became a republic after the Army's revolution of 1952.

Egypt is a large country, but a large portion of it is desert. Most people (95% of Egypt's total people) live in areas around the coast of the Mediterranean Sea and along the Nile River. This includes the cities of Cairo, Alexandria, Aswan, and Port Said. Not many people live in the desert. Today, Egypt has about 90 million people. 

Egypt is divided into 29 areas, called Governorates of Egypt.

Egypt is a country which has had many different rulers and many political systems.  After World War II, Egypt was still ruled by a king, Farouk of Egypt (11 February 1920 – 18 March 1965). He was the last ruler of the Muhammad Ali dynasty.

Farouk was overthrown on 23 July 1952 by a military coup. The coup was led by Muhammad Naguib, and Gamal Abdel Nasser. From then on, Egypt had military rulers or rulers who had the backing of the army and many citizens. 

Nasser became President, from 1956 to 1970. Later rulers were Anwar Sadat, and Hosni Mubarak.  

Abdel Fattah el-Sisi became President in 2014.  

In January 2011, thousands of protesters gathered in Cairo. They wanted Hosni Mubarak to leave office. He had been the President for almost 30 years. On February 11, 2011, Vice President Omar Suleiman made an announcement. He said that Mubarak agreed to leave office. In 2012, Egypt had a democratic election for the post of President. The winner was the Muslim Brotherhood candidate, Mohamed Morsi. 

The events which followed are still controversial, but one aspect stands out. Morsi issued a declaration that in effect gave him unlimited powers. He had the power to legislate (make laws) without legal overview by the courts. This caused widespread protests. On 3 July 2013, he was unseated by a military coup council (a coup d'état). After an election in June 2014, Abdel Fattah el-Sisi became President of Egypt. Islamist movements, such as the Muslim Brotherhood, rejected the change of regime as a military coup, and not democratic.

Today, the people of Egypt are mostly Sunni Muslims. There are many Christians in Egypt today. Many of these belong to the Coptic Orthodox Church of Alexandria.

The official language in Egypt is Arabic. The majority speak Egyptian Arabic but many speak other dialects. Some Egyptians still speak Coptic and English. They also speak French and German in Egypt. These are taught in Egypt as additional languages.

Many famous people are from Egypt. Some of these include Omar Sharif, who was an international actor, Boutros Boutros-Ghali, who was the first person from Africa to lead the United Nations, and four Nobel Prize winners: Anwar Sadat, who won the Nobel Peace Prize in 1978, Naguib Mahfouz, who won the Nobel Prize in Literature in 1988, Ahmed Zewail, who won the Nobel Prize in Chemistry in 1999, and Mohamed ElBaradei, who won the Nobel Peace Prize in 2005. Mohamed Salah is a famous footballer who plays for Liverpool in England. A famous Egyptian singer is called Amr Diab.

Egypt is divided into 27 governorates. The governorates are divided into regions. The regions have towns and villages. Each governorate has a capital. Sometimes capital has the same name as the governorate.

Egypt is a country with an immense cultural mix. Life in the countryside differs from life in the large cities. There are differences between the families which are Muslim, and the smaller number which are Coptic Christians. There are noticeable differences in the standards of education.

Tourism is one of the most important national incomes in Egypt. In 2008, about 12 million tourists visited Egypt providing nearly $12 billion of national income to Egypt. Tourism affects the economy of the country as a whole.

Giza Necropolis is one of Egypt's iconic sites. It is a popular destination for tourists to visit. It includes the Great Pyramid of Giza, one of the Seven Wonders of the World.

There are methods of transport in Egypt. The Suez Canal carries ships of many countries. 

Cairo Metro is one of the most important projects in Egypt. It consists of 3 lines. Metro is the most preferable transport in Egypt due to persistent major traffic jams in the streets of Cairo. Metro line 4 is being developed to reach the New Cairo District.

Egypt established EgyptAir in 1932. The airline is based in Cairo International Airport and is owned by the government.




#Article 106: Everything2 (117 words)


Everything2 or E2 is a website.  It lets people make pages about many different things, and some people use it as a diary.

E2 users create pages called nodes and add stuff in writeups.  Only logged-in users can create writeups.  Only the person who created the writeup or someone who the website owners (called gods) choose can edit the writeup.  On the other hand, on Wikipedia, anyone can edit pages, but on Everything2 only those who can edit the writeup can edit pages.

Everything2 does not require a  like Wikipedia does. So, it is possible to have more than one article (writeups) under the same title (node), each by different authors, and presenting different points of view.




#Article 107: Execution (313 words)


Execution is where state authorities kill someone for having committed an extremely serious crime, usually treason or especially terrible murders. In most countries where the death penalty is still provided for by law, using it is an option available to the sentencing judge: even if the jury or judicial panel recommends the death penalty, the presiding judge still has the option to lock the convicted person in a prison for the rest of their life.

Beheading means cutting the convict's head off. It is one of the oldest execution methods and already mentioned in the Bible. Beheading used to be the standard method of execution in Scandinavia and Germany. Commoners were usually beheaded with an axe and noblemen with a sword. A special device, like guillotine, can also be used, as in France. Nazi Germany used guillotine to execute criminal convicts, such as murderers.

Centuries ago many countries used beheading as an execution for important people, including England. In England, many noblemen and even some kings and queens have been beheaded. There, the prisoner would be led up the scaffold and usually say a speech. Then, he/she would be blindfolded and put his/her neck onto a block. Then, the executioner would lift up his axe and swing it down onto the victim's neck. If the executioner was skilled and the axe was sharp, then the axe would usually cut through the bone and organs of the victim in one stroke. But if the executioner was inexperienced, then it may take many strokes before the head would be cut off.

Many countries do not allow executions as punishment any more, because it is too violent.  However, many states of the United States and some other foreign countries allow it.  Even in the United States, less violent ways of execution have had to be used.  Here are some other ways of execution other than hanging




#Article 108: February (865 words)


February (Feb.) is the second month of the year, coming between January and March, with 28 days in common years, and 29 days in leap years. In Sweden in 1732 the month had 30 days. This was to make the calendar match to the rest of the world. In 1930 and 1931, February had 30 days in the Soviet Union because the government changed all the months to be 30 days long. This year (2020), February will have 29 days in it because 2020 is a leap year. The name comes either from the Roman god Februus or else from februa, the festivals of purification celebrated in Rome every fifteenth of this month.

February begins on the same day of the week as March and November in common years, and August in leap years. February always ends on the same day of the week as October, and additionally, January in common years.

February is one of the last two months to be added to the calendar at the beginning of the year (the other is January). This is because in the original Roman calendar, the two months of winter, when not much would happen in agriculture, did not have names.

February is the second month of the year, coming between January and March, and is also the shortest month, with 28 days in a common year, and 29 days in a leap year. February begins on the same day of the week as March and November in common years and on the same day of the week as August in leap years. February ends on the same day of the week as January in common years and October every year, as each other's last days are exactly 4 weeks (28 days) and 35 weeks (245 days) apart respectively. In a leap year, February is the only month to begin and end on the same day of the week.

Every year, February starts on the same day of the week as June of the previous year, as each other's first days are exactly 35 weeks (245 days) apart. In common years, February finishes on the same day of the week as May of the previous year, and in leap years, August and November of the previous year.

In common years immediately before other common years, February starts on the same day of the week as August of the following year, and in leap years and years immediately before that, May of the following year. In years immediately before common years, February finishes on the same day of the week as July of the following year, and in years immediately before leap years, April and December of the following year.

February is also the only month of the calendar that, once every six years and twice every 11 years consecutively, either back into the past or forward into the future, will have four full 7-day weeks. In countries that start their week on a Monday, it occurs as part of a common year starting on Friday, in which February 1st is a Monday and the 28th is a Sunday, this was observed in 2010 and can be traced back 11 years to 1999, 6 years back to 1993, 11 years back to 1982, 11 years back to 1971 and 6 years back to 1965, and will be observed in 2021. In countries that start their week on a Sunday, it occurs in a common year starting on Thursday, with the next occurrence in 2026, and previous occurrences in 2015 (11 years earlier than 2026), 2009 (6 years earlier than 2015), 1998 (11 years earlier than 2009) and 1987 (11 years earlier than 1998). This works unless the pattern is broken by a skipped leap year, but no leap year has been skipped since 1900 and no others will be skipped until 2100.

From circa 700 BC, when Numa Pompilius, the second king of Rome, added it to the calendar, February had 23 days and 24 days on some of every second year, until 46 BC when Julius Caesar assigned it 29 days on every fourth year and 28 days otherwise. Leap year Day, February 29, is added in every year that can be divided equally by four, such as 2012 and 2016, but this does not apply when the year ending in 00 at the turn of the century does not divide equally into 400. This means that 1600 and 2000 were leap years in the Gregorian calendar, but 1700, 1800, and 1900 were rather common years. This is where the Julian calendar calculated dates differently, as it always repeated February 29 every four years.

February is a winter month in the Northern Hemisphere and a summer month in the Southern Hemisphere. In each hemisphere, it is the seasonal equivalent of August in the other. In weather lore, Groundhog Day, in the United States, is set to decide what the weather will be like for the rest of the winter.

February's flower is the violet and its birthstone is the amethyst. The meaning of the amethyst is sincerity. The zodiac signs for February are Aquarius (January 21 to February 19), and Pisces (February 20 to March 20).




#Article 109: Financial capital (289 words)


Financial capital is a form of capital. It is things that have value, but do not do anything by themselves. They are only valuable because people value (want) them. For example, money is a form of financial capital. You cannot do anything with money but it still has value.

Financial capital is used to pay for things, this is because there is always more of it and people always want it. This means that financial capital has a stable value and can be traded in most places and with most people.

Some forms of financial capital, such as stocks, gold or bonds are not wanted by everybody. However they can be traded with people for money or another type of financial capital. Because of this, these forms of financial capital do not have a stable price. This means that some people try to make a profit by buying and selling these types of financial capital in a market.

Some things are treated as financial capital, even though they do have a use. For example, some people buy and sell land but are not interested in doing anything with it. Some people think this sort of trade is bad because the land should be used and not just treated like money. Other types of capital, such as social capital and human capital are rarely treated like financial capital. This may be because they involve people. Treating useful capital like financial capital is called comodification.

In politics, a common question is how often the government should use financial capital. In particular, should the government use financial capital to make a profit? Traditionally, liberal politicians do not mind this kind of trading for profit, but socialist or conservative politicians are against it.




#Article 110: Fecund universes (367 words)


Fecund universes is a multiverse theory of Lee Smolin.  It relies on models of our universe and statistics from astrophysics but is more correctly a theory of cosmology.

In this theory, collapsing stars, or black holes, are always creating new universes with slightly different laws of physics.  Because these laws are only slightly different, each is assumed to be like a mutation of the original universe, as if each universe was a kind of single-celled organism.  It would reproduce by splitting in some sense.

This theory relies on many models of our universe to model these mutated alternative universes, the ones that Smolin supposes are generated or spun off by black holes. 

No human can ever be part of any of these other universes.  Observations from astrophysics can only say if the black holes exist or are common, and give some idea of how much the laws of physics can vary and still let the new universes produce new black holes.  

Smolin predicts that there would be many black holes in the universe humans can see, since they are likely in a very late born universe, by simple probability.  If there are many black holes, that is evidence for his theory, 

As this shows, cosmology has a very different standard of evidence and burden of proof than is required for models of our universe only, which humans (using mathematics) can observe and exchange knowledge on.

It is hard to separate science from religion on such questions.  It may be a simple matter of preference whether one wants to see one's universe as part of a system like biology or like mechanics - clockwork.  Smolin's theory is important mostly because it challenges the mechanistic paradigm.  

Even if it is wrong, it raises the idea that living beings might have to see their universe as also living to be able to understand or care about it at all.  Some compare Smolin's theory to Gaia philosophy which combines biology, geology and ecology to explain the Earth, our planet, as a living thing.  If both are right, humans are on a living planet in a living universe.  This idea is very appealing - which does not mean it is really right.




#Article 111: Food (671 words)


Food is what people and animals eat to live. Food usually comes from animals and plants. It is eaten by living things to provide energy and nutrition. Food contains the nutrition that people and animals need to be healthy. The consumption of food is normally enjoyable to humans. It contains protein, fat, carbohydrates, vitamins, water and minerals. Liquids used for energy and nutrition are often called drinks. If someone cannot afford food they go hungry.

Food for humans is mostly made through farming or gardening. It includes animal and vegetable sources. Some people refuse to eat food from animal origin, like meat, eggs, and products with milk in them. Not eating meat is called vegetarianism. Not eating or using any animal products is called veganism. 

Food produced by farmers or gardeners can be changed by industrial processes (the food industry). Processed food usually contains several natural ingredients and food additives (such as preservatives, antioxidants, emulsifiers, flavor enhancers). For example, bread is processed food.

Food processing at home is done in the kitchen, by the cook. The cook sometimes uses a cookbook. Examples of cooking utensils are pressure cookers, pots, and frying pans.

Food can also be prepared and served in restaurants or refectory (in particular for children in school).

The utensils used may be a plate, knife, fork, chopsticks, spoon, bowl, or spork.

Many people do not grow their own food. They have to buy food that was grown by someone else. People buy most of their food in shops or markets. But some people still grow most or all of their own food.

People may buy food and take it home to cook it. They may buy food that is ready to eat from a street vendor or a restaurant.

Originally, people got food as hunter-gatherers. The agricultural revolution changed that. Farmers grew crops including those invented and improved by selective breeding.  These improvements, for example the invention of maize, allowed feeding more people, and further improvements gave it a better taste.

Food shortage has been a big problem throughout history. Many people do not have enough money to buy the food that they need. Bad weather or other problems sometimes destroy the growing food in one part of the world. When people do not have enough food, we say that they are hungry. If they do not eat enough food for a long time, they will become sick and die from starvation. In areas where many people do not have enough food, we say that there is famine there.

Food and water can make people sick if it is contaminated by microorganisms, bad metals, or chemicals.

If people do not eat the right foods, they can become sick.

People may often have a variety of eating disorders that cause them to either eat too much, or not be able to eat certain things or amounts. Common diseases like Coeliac disease or food allergies cause people to experience ill effects from consuming certain foods that are normally safe. If people eat too much food, they can become overweight or obese. This causes numerous health problems. On the other hand, eating too little food, from lack of access or anorexia could cause malnutrition. Therefore, people have to balance the amount, the nutrition, and the type of food to be healthy. 

Many cultures or religions have food taboos. That means they have rules what people should not eat, or how the food has to be prepared. Examples of religious food rules are the Kashrut of Judaism and the Halal of Islam, that say that pig meat cannot be eaten. In Hinduism, eating beef is not allowed. Some Christians are vegetarian (someone who does not eat meat) because of their religious beliefs. For example, Seventh-day Adventist Church recommends vegetarianism.

In addition, sometime beliefs do not relate to the religion but belong to the culture. For example, some people pay respect to Guān Yīn mothergod and those followers will not consume beef as they believe that her father has a shape of the cow. 




#Article 112: Fine (102 words)


If someone is found guilty of a crime, their punishment may be to pay a fine, a certain amount of money. In many countries, fines can be ordered by police, court judges and some government officers.

When agreeing to a contract with a business, a customer may agree to certain rules. If the customer breaks the rules, then they agree to pay a fine for doing so. For example, when somebody hires a car and agrees to return it by Friday, they agree that if they do not return the car by Friday, they must pay a $50 fine to the business.




#Article 113: Fish (1270 words)


. They are camouflaged as floating seaweed.

Fish (plural: fish) are an aquatic group of vertebrates which live in water and respire (get oxygen) with gills. They do not have limbs, like arms or legs, and they do have digits (fingers  toes). This is a definition which does not quite work: some amphibia also live in water and have external gills, but they are not fish.

Fish used to be a class of vertebrates.  Now the term covers five classes of aquatic vertebrates:

There are more fish than tetrapods (land vertebrates): there are over 33,000 described species of fish. Fish are usually covered with scales. They have two sets of paired fins and several unpaired fins. Most fish are cold-blooded (poikilotherm). A fish takes in the oxygen from the water using gills. There are many different kinds of fish. They live in fresh water in lakes and rivers, and in salt water in the ocean. Some fish are less than one centimeter long. The largest fish is the whale shark, which can be almost 15 meters long and weigh 15 tons. Most fish live in the water. A group of fish called the lungfish have developed lungs because they live in rivers and pools which dry up in certain parts of the year. They burrow into mud and aestivate until the water returns.

'Fish' is a paraphyletic term in cladistics because it lacks a monophyletic group of descendants. It does not include the land vertebrates or tetrapods, which descended from fish.

Though often used interchangeably, these words have different meanings. Fish is used either as singular noun or to describe a group of specimens from a single species. Fishes describes a group of different species.

Fish, the oldest vertebrate group, includes a huge range of types, from the Middle Ordovician, about 490 million years ago, to the present day. These are the main groups:

Certain animals that have the word fish in their name are not really fish: Crayfish are crustaceans, and jellyfish are Cnidarians. Some animals look like fish, but are not. Whales and dolphins are mammals, for example.

Most kinds of fish have bones. Some kinds of fish, such as sharks and rays, do not have real bones. Their skeletons are made of cartilage, and so they are known as cartilaginous fish.

All fish are covered with overlapping scales, and each major group of fish has its own special type of scale. Teleosts ('modern' fish) have what are called leptoid scales. These grow in concentric circles and overlap in a head to tail direction like roof tiles. Sharks and other chondrichthyes have placoid scales made of denticles, like small versions of their teeth. These also overlap in a head to tail direction, producing a tough outer layer. Shark skin is available for purchase as shagreen, a leather which as original is smooth in one direction, and rough in the other direction. It may be polished for use, but is always rough in texture and resistant to slipping.

The scales are usually covered with a layer of slime which improves passage through the water, and makes the fish more slippery to a predator.

Species like these change their physiology to cope with the amount of salt in the water.

Fish swim by exerting force against the surrounding water. There are exceptions, but this is usually done by the fish contracting muscles on either side of its body in order to generate waves of flexion that travel the length of the body from nose to tail, generally getting larger as they go along. Most fishes generate thrust using lateral movements of their body  tail fin (caudal fin). However, there are also species which move mainly using their median and paired fins. The latter group profits from the gained manoeuvrability that is needed when living in coral reefs for example. But they can not swim as fast as fish using their bodies  caudal fins.

Fish can swim slowly for many hours using red muscle fibres. They also make short, fast bursts using white muscle. The two types of muscle have a fundamentally different physiology. The red fibres are usually alongside a much greater number of white fibres.

The white fibres get their energy by converting the carbohydrate glycogen to lactate (lactic acid). This is anaerobic metabolism, that is, it does not need oxygen. They are used for fast, short bursts. Once the lactic acid builds up in the muscles, they stop working, and it takes time for the lactate to be removed, and the glycogen replaced. Using their white fibres, fish can reach speeds of 10 lengths per second for short bursts.

Swimming for long periods needs oxygen for the red fibres. The oxygen supply has to be constant because these fibres only operate aerobically. They are red because they have a rich blood supply, and they contain myoglobin. Myoglobin transports the oxygen to the oxidising systems. Red muscle gets its energy by oxidising fat, which weight for weight has twice as much energy as carbohydrate or protein. Using their red fibres, fish can keep up a speed of 35 lengths per second for long periods.

Many fish swim in groups.  Schools of fish can swim together for long distances, and may be chased by predators which also swim in schools. Casual groups are called 'shoals'.

The shape of the body of a fish is important to its swimming. This is because  body shapes makes the water drag less. Here are some common fish shapes:-

The picture on the right shows a shark. This shark's shape is called fusiform, and it is an ovoid shape where both ends of the fish are pointy. This is the best shape for going through water quickly. Fishes with fusiform shapes can chase prey and escape predators quickly. Many live in the open ocean and swim constantly, like marlins, swordfish, and tuna. Ichthyosaurs, porpoises, dolphins, killer whales all have similar shapes. This is an example of convergent evolution.

The long, ribbon-like shape of an eel's body shows another shape.  This enables them to hide in cracks, springing out quickly to capture prey, then returning quickly to their hiding spot.

Flatfish live on the bottom of the ocean or lake. Most use camouflage: they change colors to match the ocean floor.

Fish with compressed shapes have flat, vertical bodies, with one eye on each side. They swim upright and can be very thin. They usually live in reefs where their flat bodies can slip in and out among the corals, sponges, and rocks, keeping hidden from predators. Angelfish, surgeonfish, and butterflyfish are all compressed fish.

Some people eat many different kinds of fish. These include carp, cod, herring, perch, sardines, sturgeon, tilapia, trout, tuna, and many others.  A person who buys and sells fish for eating is called a fishmonger.

The word to fish is also used for the activity of catching fishes.  People catch fish with small nets from the side of the water or from small boats, or with big nets from big boats.  People can also catch fish with fishing poles and fishhooks with bait.  This is often called angling.  Anglers also different types of fishing lures.

Because people are catching too many fish for food or other uses, there are less and less fish in the sea. This is a problem known as Overfishing.

Selective breeding of carp made them into the domesticated koi in Japan, and goldfish in China. This breeding began over 2,000 years ago. The Chinese brought their goldfish indoors during the Song Dynasty. They kept them in large ceramic vessels. That we now do in glass fish tanks.




#Article 114: Foot (375 words)


A foot (one foot, two or more feet) is a body part on the end of a leg. It is used when walking. It is also important for balance: it helps people stand straight. People also use it to kick, in both fighting and sports, football being an example.

People's hands and feet have the same shape: they both have five digits (the fingers and toes). Many other animals with backbones also have five digits. The part of the foot which joins it to the leg is called the heel. The bottom of the foot is called the sole. 

Most land vertebrates have feet, and there are many different sorts of foot. The feet of monkeys are much like the hands. The hard foot of an ungulate is a hoof. When an animal has soft feet, or feet with soft parts on the underside, we often call it a paw. Many invertebrates also have feet.

Many people like to use footwear, especially outside.  It has special names, for example sandals, shoes, and boots.  When people always wear footwear, especially in hot places or when they are very active, their feet can smell badly (foot odour).  Wearing footwear that is too big or small can be bad for the feet.  People who have foot, leg, and back problems can also get help from special shoes. 

People have different traditions in different parts of the world for when to wear footwear.  For example, in many countries, usually do not wear their shoes or boots in a home.  In the United States people often wear shoes inside a home.  In Japan, people do not wear shoes in homes, and floors are often made of very soft materials, too soft for shoes.  In cultures where people always wear shoes, people sometimes think it is bad not to wear them.  Not wearing shoes can be good for the feet, especially for children's feet.

Conditions like Athlete's foot affect the feet, causing the feet to feel dry and cracked.  Doctors who work with people's feet are podiatrists or chiropodists.

Half the bones in a human body are in the foot.  There are 26 bones there.  They are 14 phalanges (toes), 5 metatarsals (arch of the foot), and 7 tarsals (ankle bones).




#Article 115: France (2753 words)


France ( or ; ), officially the French Republic (, ), is a country whose metropolitan territory is located in Western Europe and that also comprises various overseas islands and territories located in other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean. It is often referred to as L’Hexagone (The Hexagon) because of the shape of its territory. France is a unitary semi-presidential republic with its main ideals expressed in the Declaration of the Rights of Man and of the Citizen.

Metropolitan France is bordered (clockwise from the north) by Belgium, Luxembourg, Germany, Switzerland, Italy, Monaco, Andorra, and Spain. The overseas departments and collectivities of France also share land borders with Brazil and Suriname (bordering French Guiana), and the Netherlands Antilles (bordering Saint-Martin). France is linked to the United Kingdom by the Channel Tunnel, which passes underneath the English Channel.

France is the largest country in the European Union and the second largest in Europe. It has been one of the world's foremost powers for many centuries. During the 17th and 18th centuries, France colonized much of North America; during the 19th and early 20th centuries, France built one of the largest colonial empires of the time, including large portions of North, West and Central Africa, Southeast Asia, and many Pacific islands. France is a developed country and possesses the fifth largest economy in the world, according to nominal GDP figures. It is the most visited country in the world, receiving 82 million foreign tourists annually. France is one of the founding members of the European Union, and has the largest land area of all members. It is also a founding member of the United Nations, and a member of the Francophonie, the G8, NATO, and the Latin Union. It is one of the five permanent members of the United Nations Security Council and owns the largest number of nuclear weapons with active warheads and nuclear power plants in the European Union.

France's official language is French, also being official in 29 other countries. Some other French speaking countries include Haiti, Cameroon, and Niger.

France is located in Western Europe. France shares its borders with Belgium, Luxembourg, Germany, Switzerland, Italy, Monaco, Andorra, and Spain. France has two mountain ranges near its borders: the Alps in the east and the Pyrenees in the south. There are many rivers in France, including the Seine and the Loire. In the north and the west of France, there are low hills and river valleys.

In France there are many different climates. The Atlantic has a major effect on the weather in the north and west. This means the temperature is about the same most of the year. It is in the marine west coast climate region. In the east, winters are cold and the weather is good. Summers are hot and stormy. In the south, winters are cool and wet. Summers are hot and dry. The north has a temperate climate similar to that of the United Kingdom and other Northern European countries.

France has the second-largest Exclusive Economic Zone (EEZ) in the world. It covers 11,035,000 km2 (4,260,637 sq mi). Only the United States has a larger one .

The name France comes from the Latin word Francia ', which means land of the Franks.

The borders of modern France are about the same as those of ancient Gaul. Celtic Gauls inhabited Ancient Gaul. Julius Caesar conquered Gaul for Rome in the 1st century BC. Eventually, the Gauls adopted Roman speech (Latin, from which the French language evolved) and Roman culture. Christianity first appeared in the 2nd and 3rd centuries AD. It became firmly established by the fourth and fifth centuries.

In the 4th century AD, the Germanic tribes, principally the Franks invaded the Gauls. This is how the name Francie appeared. The modern name France comes from the name of the Capetian Kings of France around Paris. The Franks were the first tribe of Europe after the fall of the Roman Empire to convert to  Christianity rather than Arianism. The French called themselves the most Christian Kingdom of France.

The Treaty of Verdun (843), divided Charlemagne's Empire into three parts. The biggest area was Western Francia. It is similar to modern France.

The Carolingian dynasty ruled France until 987, when Hugh Capet became King of France. His descendants, the Direct Capetians, the House of Valois and the House of Bourbon,  the country with many wars and dynastic inheritance. The monarchy was the most powerful during the 17th century and the reign of Louis XIV of France. At that time, France had the largest population in Europe. The country had a big influence over European politics, economy, and culture. French became the common language of diplomacy in international affairs. Much of the Enlightenment happened in France.  French scientists made big scientific discoveries in the 18th century. France also conquered many overseas possessions in the Americas and Asia.

France had a monarchy until the French Revolution in 1789. The Great King Louis XVI and his wife, Marie Antoinette, were executed in 1793. Thousands of other French citizens were killed. Napoleon Bonaparte took control of the Republic in 1799. He later made himself Emperor of the First Empire (1804–1814). His armies conquered most of continental Europe. The metric system was invented by French scientists during the French revolution.That time 3 estates were developed.

After Napoleon's final defeat in 1815 at the Battle of Waterloo, another  monarchy arose. Later Louis-Napoléon Bonaparte created the Second Empire in 1852. Louis-Napoléon was removed after the defeat in the Franco-Prussian war of 1870. The Third Republic replaced his regime.

The large French colonial empire in the 19th century included parts of West Africa and Southeast Asia. The culture and politics of these regions were influenced by France. Many ex-colonies officially speak the French language.

The country actively took part in both the First and Second World Wars, with battles taking place on its soil. During the First World War, millions were killed in the trenches including over a million in the Battle of the Somme. The conditions were extremely difficult for the soldiers on the front. The last surviving veteran was Pierre Picault who died on 20 November 2008 at the age of 109.
During the Second World War, Nazis  France. The Allies landed in Normandy on 6 June 1944 and began the Battle of Normandy. German forces lost France in just a few months.

The 13 regions and 96 departments of metropolitan France include Corsica. France is divided into (administrative) regions:

Corsica has a different status than the other 12 metropolitan regions. It is called collectivité territoriale.

France also has five overseas regions:

These four overseas regions have the same status as the metropolitan ones. They are like the overseas American states of Alaska and Hawaii.

Then France is divided into 101 departments. The departments are divided into 342 arrondissements. The arrondissements are re-divided into 4,032 cantons. The smallest subdivision is the commune (there are 36,699 communes). On January 1, 2008, INSEE counted 36,781 communes in France. 36,569 of them are in metropolitan France and 212 of them are in overseas France.

The government of France is  a semi-presidential system determined by the French Constitution of the French Fifth Republic. The constitution declares the nation to be an indivisible, secular, democratic, and social Republic. It provides for a separation of powers.

The French armed forces are divided into four branches:

France has about 359,000 military personnel. France spends 2.6% of its gross domestic product (GDP) on defense. This is the highest in the European Union. France and the UK spend 40% of the EU defence budget. About 10% of France's defence budget is for its nuclear weapons force.

France is a member of the United Nations. It is a permanent member of the United Nations Security Council and has veto rights. It is also a member of the World Trade Organisation (WTO). It hosts the headquarters of the OECD, UNESCO and Interpol. In 1953, the United Nations asked France to choose a coat of arms to represent them internationally. The French emblem is now on their passports.

France was a founding member of the European Union. In the 1960s, France wanted to exclude the United Kingdom from the organisation. It wanted to build its own economic power in continental Europe.  France and Germany became closer after World War II.  This was to try to become the most influential country in the EU.  It limited the influence of the new Eastern European members. France is a member of the North Atlantic Treaty Organisation (NATO). However, under President de Gaulle, it left the joint military command. In the early 1990s, France received criticism for its underground nuclear tests in French Polynesia. France vigorously opposed the 2003 invasion of Iraq. France retains strong political and economic influence in its former African colonies. For instance it has supplied economic aid and troops for peace-keeping missions in the Ivory Coast and Chad.

France is a member of the G8 group of   countries. France has the eighth-largest economy in the world by Gross domestic product (GDP) (which takes into account how much it costs to live in different countries and inflation rates). France and 11 other European Union members jointly launched the euro on 1 January 1999 and started using it in 2002.

France's economy has nearly 2.9 million registered companies. The government has a considerable influence over railway, electricity, aircraft, and telecommunications firms (as it owns big companies like SNCF and EDF (French electricity)). France has an important aerospace (design of aircraft and spacecraft) industry led by Airbus. It can also launch rockets from French Guiana.

France has invested a lot in nuclear power. This made France the smallest producer of carbon dioxide among the seven most industrialised countries in the world. As a result, 59 nuclear power plants generate  most of the electricity produced in the country (78% in 2006, up from only 8% in 1973, 24% in 1980, and 75% in 1990).

France is the leading agricultural producer and exporter in Europe. France exports wheat, poultry, dairy products, beef, and pork. It is also famous for its wine industry. France received 10 billion euros in 2006 from the European Community as subsidies to its farmers.

At one time, the Factory Act of 1833 limited the workday for women and children to 11 hours a day.

On 1 January 2008, it was estimated that 63.8 million people live in France, including in the Overseas Regions of France. 61,875,000 of these live in metropolitan France, the part of the country that is within Europe.

The major ethnic groups living in France today are descended from Celtic people and Roman people. The significant minority groups living in France are:

French is the official language of France. It belongs to the Romance language group, which includes Italian and Spanish. Many regional dialects are also used in France. Alsatian, a German dialect, is spoken in Alsace and in parts of Lorraine in eastern France. French was the language of diplomacy and culture in Europe between the 17th and 19th century and is still widely used.

Some people in France also speak Basque, Breton, Catalan, Corsican, German, Flemish, and Occitan.

France is a secular country and the constitution guarantees freedom of religion. The population is about 51% Roman Catholic, and 31% of people are agnostics or atheists. 5% are Muslim, 3% say they are Protestant and 1% say they are Jewish. 10% are from other religions or do not have an opinion about religion. There are also Zoroastrian, Unitarian Universalist, Jain and Wiccan communities. Religions founded in France include Raelism.

According to a Poll in 2007:

French literature began in the Middle Ages. French was divided into several dialects at the time. Some authors spelled words differently from one other.

During the 17th century, Pierre Corneille, Jean Racine, Molière, Blaise Pascal and René Descartes were the main authors.

In the 18th and 19th centuries, French literature and poetry reached its best. The 18th century saw writings of authors, essayists and moralists as Voltaire and Jean-Jacques Rousseau.
As for French children's literature in those times, Charles Perrault wrote stories such as Little Red Riding Hood, Beauty and the Beast, Sleeping Beauty and Puss in Boots.

Many famous French novels were written in the 19th century by authors such as Victor Hugo, Alexandre Dumas and Jules Verne. They wrote popular novels like The Three Musketeers, The Count of Monte-Cristo, Twenty Thousand Leagues Under the Sea, The Hunchback of Notre-Dame and Les Misérables. Other 19th century fiction writers include Emile Zola, Guy de Maupassant, Théophile Gautier and Stendhal.

Famous novels were written during the 20th century by Marcel Proust, Antoine de Saint-Exupéry, Albert Camus, Jean-Paul Sartre and Michel Houellebecq.

The Tour de France cycling race in July is one of the best-known sporting events. It is a three-week race of around 3,500 km that covers most of France and ends in the centre of Paris, on the Avenue des Champs-Elysées. Football is another popular sport in France. The French team won the FIFA World Cup in 1998 and 2018. They also won the UEFA European Football Championship in 1984 and 2000. France also hosts the 24 Hours of Le Mans car race. France also hosted the Rugby World Cup in 2007 and finished fourth.
France is closely associated with the Modern Olympic Games. At the end of the 19th century, the Baron Pierre de Coubertin suggested having the Olympic Games again. France hosted the Summer Olympics twice, in 1900 and 1924, in Paris. France will host the Summer Olympics in 2024, in Paris. France also hosted the Winter Games three times: in 1924 in Chamonix, in 1968 in Grenoble, and in 1992 in Albertville.

French cuisine has influenced the style of cooking throughout Europe, and its chefs work in restaurants throughout the world.

The roots of modern haute cuisine lie in chefs like La Varenne (1615–1678) and the notable chef of Napoleon, Marie-Antoine Carême (1784–1833). These chefs developed a lighter style of food compared to the food of the Middle Ages. They used fewer spices, and more herbs and creamy ingredients.

Typical ingredients like roux and fish stock, and techniques such as marinading, and dishes such as ragout, were invented. Carême was an expert pâtissier (pastry-maker), and this is still a mark of French cooking. He developed basic sauces, his 'mother sauces'; he had over a hundred sauces in his repertoire, based on the half-dozen mother sauces.

French cuisine was introduced in the 20th century by Georges Auguste Escoffier (1846–1935). He was a genius at organisation. He worked out how to run large restaurants, as in a big hotel or a palace; how the staff should be organised; how the menu was prepared. He had methods for everything. Escoffier's largest contribution was the publication of Le Guide Culinaire in 1903, which established the fundamentals of French cookery. Escoffier managed the restaurants and cuisine at the Savoy Hotel and Carlton Hotel in London, the Hôtel Ritz Paris, and some of the greatest cruise ships.

Escoffier, however, left out much of the culinary character to be found in the regions of France.

Gastro-tourism and the Guide Michelin helped to make people familiar with the rich bourgeois and peasant cuisine of the French countryside in the 20th century. Gascon cuisine has also had great influence over the cuisine in the southwest of France. Many dishes that were once regional have become common all over the country. Cheese and wine are a major part of the cuisine, playing different roles regionally and nationally. In the north of France, people often prefer to use butter to . In the south, they prefer olive oil and garlic. In France, each region has its own special dish; choucroute in Alsace, quiche in Lorraine, cassoulet in the Languedoc-Roussillon, and tapenade in Provence-Alpes-Côte d'Azur.

In November 2010, French gastronomy was added by UNESCO to its lists of the world's 'intangible cultural heritage'.

 
France is the number one tourist destination in the world. In 2007, 81.9 million foreign tourists visited France. Spain comes second (58.5 million in 2006) and the United States come third (51.1 million in 2006).
Some of the most famous attractions in Paris, are the Eiffel Tower and the Arc de Triomphe. Another one is Mont Saint Michel, in Normandy.

A European Disneyland is located in a suburb east of Paris. The resort opened in 1992 and is also a popular tourist destination in Europe.




#Article 116: Finland (1720 words)


Finland (Finnish: Suomi) is a country in Northern Europe and is a member state of the European Union. Finland is one of the Nordic countries and is also part of Fennoscandia. Finland is located between the 60th and 70th latitudes North. Its neighbours are Sweden to the west, Norway to the north, Russia to the east and Estonia to the south, beyond the sea called Gulf of Finland. Most of western and southern coast is on the shore of the Baltic Sea.

The capital of Finland is Helsinki; the second largest city is Tampere. The official currency of the country is the euro (EUR); before 2002 it was the markka, the Finnish mark (FIM). The president of Finland is Sauli Niinistö. 5.5 million people live in Finland. Finnish and Swedish both are the official languages of Finland; the most spoken languages is Finnish, mother tongue of about 90% of the population. Swedish is spoken by the Swedish speaking minority of Finland, called the Finnish Swedes, who make up 5% of the total population. Finland became independent of Russia on 6 December 1917.

The most important cities and towns in Finland are Helsinki, Espoo, Tampere, Vantaa, Turku, Oulu, Lahti, Kuopio, Jyväskylä and Pori.

Finland is a highly industrialised First World country. The most important Finnish industrial products are paper, and steel products such as machines and electronics. Nokia (the mobile company) is originally a company of Finland, named after a small town called Nokia.

Finland has been top of the list of least corrupt countries on the Corruption Perceptions Index more times than any other country.

The people of Finland are called Finns.  Most Finns speak Finnish as their mother tongue.  About six percent of Finns have the Swedish language as their mother tongue.  They live mostly in the western part of Finland and on Åland (Finnish Ahvenanmaa)

Finns also study mandatory English and Swedish in school. Most Finns work either in services (that is: shops, banks, offices or businesses) or in factories. Finns often like saunas and nature. Many Finnish families have summer cottages, small houses where they go to relax on their summer holidays. The most important festivals that Finnish people celebrate are Midsummer and Christmas.

The most popular sports in Finland are ice hockey, skiing, track and field and association football (soccer). Finns have also won events in swimming, motor sports and gymnastics.

There is a group of a few thousand Samis (also called Lapps) in the most northern part of Finland, called Lapland. Most of the Samis live in Norway and Sweden. Many Sami people farm reindeers. Originally, Samis were hunter-gatherers. In the past the Sami were nomads, but nowadays they live in regular houses.

Very few people in Finland are from other countries. In 2016 about 4% of residents were born in another country.

Most of Finland is covered by pine forest. The swan, which was considered holy long ago, is the national bird of Finland. Wood is the most important natural resource of Finland. It is estimated that up to one-third of all wood resources of the European Union are in Finland.

The national animal of Finland is the brown bear. The largest animal is the elk, a type of moose, which is a member of the deer family.

There are hundreds of rivers and thousands of fresh water lakes. Fishing is a popular sport. It is estimated there are almost 180,000 lakes in Finland.

Many islands in the Baltic Sea belong to Finland, too. Thousands of islands are part of the Åland archipelago. Tourists from all over the world come to see the fells and the northern lights in Lapland.

The highest mountain of Finland is Halti, which is 1328 meters high. The largest lake is Saimaa, 4,400 square kilometres. The longest river of Finland is Tornionjoki. The largest river (by watershed) is Kemijoki, 552 kilometres long.

The weather in Finland varies widely by season.  Summer usually lasts from May to early September, and temperatures can reach up to +35 °C.  Autumns are dark and rainy. Winter snow usually begins to fall in Helsinki in early December (in Lapland it can fall as early as October) and in the winter the temperature can drop to -30 °C.  Winter usually lasts to mid-March, when the snow melts in Helsinki (in Lapland the snow usually doesn't melt until early May), and Spring lasts till late May. Spring can be erratic, and the weather can change from frost to sunshine within a matter of days. The famed Northern Lights are common in Lapland.

People first came to Finland 10,000 years ago. That was just after an ice age, after a glacier that covered the ground had receded.

Some think the first people in Finland already spoke a language similar to the Finnish language that is spoken today. It is known that an early form of the Finnish language was spoken in Finland in the Iron Age. (The Iron Age in Finland was 2,500–800 years ago).

The first residents in Finland hunted animals, as hunter-gatherers.  Some people started to farm crops about 5,200 years ago. Farming slowly became more and more popular and became the major way of life until the modern age.

The ancient Finns were pagans. The most important god of the Finnish pantheon was Ukko. He was a god of sky and thunder, much like Odin, another Scandinavian god-king. These powers were common among the pagan god kings in pantheons ranging from the Finnish Ukko, to the Scandinavian/Germanic/Saxon Odin, all the way east to Zeus of the Greeks and Jupiter of the Romans.

Around a thousand years ago, when most of Europe was adopting Christianity, Finland also began following Christianity.  During the Reformation of Christianity in the 16th century, most Finns became Protestants. Some pagan practices still remain amongst the now Christian Finns, such as bear worship.

From the Middle Ages Finland was a part of Sweden. Then, in the year 1809, Russia took Finland from Sweden. Finland was a part of Russia, but after a short period of time it became autonomous. The Finns essentially controlled Finland, though the Tsar was in control officially. Finns could create their own laws and had their own currency, (called the markka), their own stamps and own customs. However, Finland did not have its own army.

During the 1905 Russian Revolution, in the Grand Duchy of Finland: 
the Social Democrats organised the general strike of 1905 (). The Red Guards were formed. On , Russian artillerymen and military engineers rose to rebellion in the fortress of Sveaborg (later called Suomenlinna), Helsinki. The Finnish Red Guards supported the Sveaborg Rebellion with a general strike, but the mutiny was quelled by loyal troops and ships of the Baltic Fleet within 60 hours.

On 6 December 1917, Finland became independent, which meant that it no longer was a part of Russia. There was a communist revolution in Russia and after 1922 Russia was a part of the Soviet Union. There were communists in Finland too, who tried to create a revolution in Finland
This attempt at revolution caused the Finnish civil war. The communists lost the civil war, and Finland did not change its old capitalist system

Stalin, who was the leader of the Soviet Union, did not like having a capitalist country as its neighbour. Stalin wanted Finland to become a communist state and be a part of the Soviet Union. The leaders of Finland refused: they wanted to stay independent. The Soviet Union sent many troops across the eastern border of Finland to try to make Finland join them, which resulted in the Winter War.  The Soviet Union eventually won, and took most of Karelia and other parts of Finland.

 
Adolf Hitler was the dictator of Germany, and he wanted to invade the Soviet Union. Finland wanted to retrieve the areas that it had lost, so they joined the German invasion, which started with Operation Barbarossa in 1941. The Finnish part of the Second World War is called the Continuation War in Finland. However, Finland was not a fascist or an antisemitic country. Finns were interested in freedom rather than dictatorship.

While Germany was losing the war, Finland had already progressed into the Soviet Union in order to regain the areas lost in the previous peace. Finland wanted to end the war with the Soviet Union, which resulted in peace. Once again Finland had to give up the areas they had conquered. This time, the peace with the Soviet Union made Finland and Germany enemies. Finns fought the Germans, and Germans retreated to Norway, burning down all of Lapland behind them. This is called the Lapland War.  Finland remained independent.

After the war, many factories were built in Finland. Many people moved from farms to cities. At that time, big factories manufactured products like paper and steel. More and more people worked in more advanced jobs, like high technology. Also, many people went to universities to get a good education. Finland was one of the first countries where most people had Internet connections and mobile phones. A well-known company that makes mobile phones, Nokia, is from Finland.

Finland joined the European Union in 1995. The Finnish currency was changed to the euro in 2002.

Finland has a mixed economy. Free market controls most of production and sales of goods, but public sector is involved in services. In 2013, taxes were 44% of gross national product. This is 4th largest in Europe, after Denmark, France and Belgium.

In 2014 services were 70% of the gross national product.

The largest company in 2014 was oil refinery Neste Oil. The second largest was Nokia. Two forest industries Stora Enso and UPM-Kymmene, were numbers three and four. Number five was Kesko which sells everyday goods in K-supermarkets.

Elections are organized to select 200 s to the Parliament of Finland. Also selected are the president of Finland, members of town and city councils and Finnish members to the European Parliament. The elections are secret and direct. People vote directly for the person they want to be elected. In presidential elections votes are only cast for a person, not for a political party. All the other elections are proportional. The system is a combination of voting for individuals and parties. The right to vote is universal and equal.  In general elections everybody has one vote.




#Article 117: Fruit (699 words)


In botany, a fruit is a plant structure that contains the plant's seeds. To a botanist, the word fruit is used only if it comes from the part of the flower which was an ovary. It is an extra layer round the seeds, which may or may not be fleshy. However, even in the field of botany, there is no general agreement on how fruits should be classified. Many do have extra layers from other parts of the flower.

In general speech, and especially in cooking, fruits are a sweet product, and many botanical fruits are known as vegetables. This is how ordinary people use the words. On this page, we describe what botanists call a fruit.

The fleshy part of a fruit is called the mesocarp. It is between the fruit's skin (exocarp) and the seeds. The white part of an apple, for example, is the fleshy part of the apple. Usually, when we eat a fruit, we eat the fleshy part.

If the entire fruit is fleshy, except for maybe a thin skin, we call the fruit a berry. A berry might contain one seed or many. Grapes, avocados, and blueberries are berries. They all have a thin skin, but most of the fruit is fleshy. Strawberries, however, are actually not berries, because the seeds are on the outside: on a real berry, the seed or seeds must be inside.

A pepo (pronounced pee' po) is a  berry. Its skin is hard and thick and is usually called a rind. Pumpkins and watermelons, for instance, are pepos.

A hesperidium is another modified berry. It has a leathery skin that is not as hard as the skin of a pepo. All citrus fruit like oranges and lemon are hesperidiums.

A pome (pohm) is a fruit that has a  surrounded by fleshy tissue that we can eat. The core is usually not eaten. Berries are different - the seeds are inside the fleshy part, not separated from it by a core. apples and pears are pomes.

Drupes are also called stone fruit. A drupe is a fleshy fruit with a hard stone around the seed. We usually call this 'stone' the 'pit' of the fruit. Peaches and olives are drupes. Actually, the almond fruit is a drupe, too, though we eat the seed that is inside the 'pit' of the almond fruit.

Since fruits are produced from fertilised ovaries in flowers, only flowering plants produce fruits. Fruits are an evolutionary 'invention' which help seeds get  by animals.

The botanical term includes many that are not 'fruits' in the common sense of the term. such as the vegetables squash, pumpkins, cucumbers, tomato, peas, beans, corn, eggplant, and sweet pepper and some spices, such as allspice and chillies.

An accessory fruit or false fruit (pseudocarp) is a fruit in which some of the flesh is derived not from the ovary but from some adjacent tissue.

A fig is a type of accessory fruit called a syconium. Pomes, such as apples and pears, are also accessory fruits: the core is the true fruit.

Strictly speaking, these are not botanical fruits: 

These are fruits which you can buy in shops, and which are also acceptable as botanical fruits:

Many fruits come from trees or bushes. For plants, fruits are a means of dispersal, usually by animals. When the fruit breaks apart, the seeds can go into the ground and begin to grow. Most fruits we eat contain a lot of water and natural sugars, and many are high in Vitamin C. They have a large amount of dietary fibre. Fruits are usually low in protein and fat content, but avocados and some nuts are exceptions to this. Not only humans, but our closest living relatives (primates) are keen fruit-eaters. So are many other groups of herbivorous mammals and many birds.

Seedlessness is an important feature of some fruits of commerce. Commercial bananas, pineapple, and watermelons are examples of seedless fruits. Some citrus fruits, especially oranges, satsumas, mandarin oranges, and grapefruit are valued for their seedlessness.

Seedless bananas and grapes are triploids, and seedlessness results from the abortion of the embryonic plant which is produced by fertilisation. The method requires normal pollination and fertilisation.




#Article 118: Farm (142 words)


A farm is a piece of land used to grow crops  and/or raise animals.

People who grow these plants or raise these animals are called farmers. This work is called farming.

Land that is used to grow plants is called farmland.  Land that is used to feed animals with its grass is called pasture.  Land that can be used to grow plants for food is called arable land.

Many farms are very large and can cause damage.  In some places farms are many and small, and can also cause damage.  Farms provides most of the food for people.  Some people farm to eat the food they produce (subsistence agriculture). Other farms, including large ones, sell their products to markets far away in urban areas (commercial or industrial farming). Most subsistence farms are in poorer countries, while industrial farms are in richer countries.




#Article 119: Geography (296 words)


Geography (from Greek: , geographia, literally earth description) is the study of earth and its people. Its features are things like continents, seas, rivers and mountains. Its inhabitants are all the people and animals that live on it. Its phenomena are the things that happen like tides, winds, and earthquakes.

A person who is an expert in geography is a geographer. A geographer tries to understand the world and the things that are in it, how they started and how they have changed.

Geography is divided into two main parts called physical geography and human geography. Physical geography studies the natural environment and human geography studies the human environment. The human environmental studies would include things such as the population in a country, how a country's economy is doing, and more. There is also environmental geography.

Maps are a main tool of geography, so geographers spend much time making and studying them. Making maps is called cartography, and people who specialize in making maps are cartographers.

Physical geography (or physiography) focuses on geography as an Earth science. It aims to understand the physical problems and the issues of lithosphere, hydrosphere, atmosphere, pedosphere, and global flora and fauna patterns (biosphere). 

Human geography is the social science that covers the study of people and their communities, cultures, economies and their interaction with the environment. Geographers studying the human environment may look at:

The oldest known world map dates back to ancient Babylon from the 9th century BC. The best known Babylonian world map is the Imago Mundi of 600 BC. Star charts (maps of the sky) are of similar age.

During the Middle Ages, people in Europe made fewer maps. People in the Islamic world made more. Abū Zayd al-Balkhī created the Balkhī school of mapping in Baghdad.




#Article 120: Grammar (685 words)


Grammar is the study of words, how they are used in sentences, and how they change in different situations. The Ancient Greeks used to call it grammatikē tékhnē, the craft of letters. It can have any of these meanings:

When we speak, we use the native person's grammar, or as near as we can. When we write, we try to write with correct grammar. So, speaking and writing a language each have their own style.

All languages have their own grammar. Most European languages are rather similar.

English makes few changes to its word endings ('suffixes'). In the Italic or 'Romance' languages (such as French, Italian, and Spanish), word endings carry a lot of meaning. In English we have just a few: plurals and possessives (John's) are the most common. In our verbs we have dropped most endings except one: I love, you love, but she loves. That final s comes from the Anglo-Saxon, which had more suffixes. Verbs do have endings which show changes in tense: walked, walking.

Word order is the other big difference. Romance languages normally put adjectives after the nouns to which they refer. For example, in English, a person may say I like fast cars, but in Spanish, it is Me gustan los coches rápidos. The order of the words has changed: if just the words, without the grammar, are translated into English, it would mean 'to me they please the cars fast'. This is because Spanish and English have different rules about word order. In German, verbs often come near the end of sentences (as: Die Katze hat die Nahrung gegessen), whereas in English we usually put them between subject and object, as: the cat has eaten the food.

Written grammar changes slowly but spoken grammar is more fluid. Sentences which English speakers find normal today, might have seemed strange 100 years ago. And they might not, because many of our favourite sayings come from the Authorized King James Version of the Bible, and from Shakespeare.

Different people speak with grammar that differs from that of other people.  For example, people who use the dialects called General American English and BBC English might say, I didn't do anything, while someone who speaks what is called African American Vernacular English or AAVE might say, I didn't do nothing. London working class version: I ain't done nuffink!  These are called double negatives, and are found almost entirely in spoken English, and seldom written.

These differences are called dialects. The dialect a person uses is usually decided by where they live. Even though the dialects of English use different words or word order, they still have grammar rules. However, when writing in American English, grammar uses the rules of General American English. When people talk about using 'proper English', they usually mean using the grammar of general British English, as described in standard reference works. The models for spoken English in Britain are often called Received Pronunciation or BBC English.

Grammar studies nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions, sentences, phrases, clauses, interjections.

Nouns are 'thing' words like 'table and 'chair'.  They are , things you see in everyday life.  Proper nouns are names of specific places, people, or other things like days of the week.  The name 'James' is a proper noun, as is 'Wednesday' and 'London'. Nouns can also be abstract things, such as 'suffering' or 'happiness'.

Verbs are words that describe : Ryan threw the ball. State: I am worried. The basic verb form is called the infinitive.  The infinitive for existence is to be.  A famous example is the speech of Hamlet: To be or not to be, that is the question.

Variations of the infinitive create verb tenses. 

Adjectives describe nouns. For example, the pretty in pretty bicycle says that the bicycle is pretty. In other words, the pretty is describing the bicycle. This can also happen with a place. For example, the tall in that's a tall building is describing the building.

Grammar studies syntax which is how the parts of speech fit together according to rules and create sentences.  Sentences fit together and create paragraphs.




#Article 121: Great Lakes (684 words)


The Great Lakes are five large lakes in east-central North America. They hold 21% of the world's surface fresh water. 

The lakes are:

Four of the Great Lakes are on the border between Canada and the United States of America. The other, Lake Michigan, is completely inside the United States.

All together, by volume, they are the largest group of fresh water lakes in the world. No one of the Lakes is larger than Lake Baikal (Russia) or Lake Tanganyika (East Africa).

The cities of Chicago, Illinois (9.8 million people, on Lake Michigan), Toronto, Ontario (5.5 million, on Lake Ontario); Detroit, Michigan (5.3 million, on the Detroit river); Montreal, Quebec (3.9 million, on the St. Lawrence River), Cleveland, Ohio (2.9 million, on Lake Erie), Buffalo, and Ottawa (1.2 million, Ontario, on the Ottawa River) are on the shores of the Great Lakes or their rivers.

Though the five lakes have separate basins, they form a single, connected body of freshwater. The lakes connect the east-central interior of North America to the Atlantic Ocean. Lakes Michigan, Huron and Erie are approximately equally high and ships can easily pass from one to the next. Water flows from Lake Superior and Lake Michigan into Lake Huron; then through the Detroit River into Lake Erie; then through Niagara Falls into Lake Ontario; and then through the Saint Lawrence River to the Atlantic Ocean. Water also drains from the Chicago River on the south.

Many rivers flow through a large watershed into the lakes. The lakes have about 35,000 islands. The Great Lakes region includes the five lakes and many thousands of smaller lakes, often called inland lakes.

Lake Michigan and Lake Huron hit all-time record low levels in 2013.

The unusual shape of the Great Lakes has created the possibility of large waves called seiche. If a storm causes a fast, strong increase in air pressure on one side of a lake, the water level on that side of the lake will drop and suddenly push up the water level on the opposite side of the lake.  A 10 foot tall wave in Chicago caused several deaths in 1954.

The Great Lakes are home to a variety of species of fish and other organisms. In recent years, overfishing caused a decline in lake trout. The drop in lake trout increased the alewife population. In response, the government introduced salmon as a predator to decrease the alewife population. This program was so successful that the salmon population rose rapidly, and the states surrounding Lake Michigan promoted 'salmon snagging'. This has been made illegal in all of the Great Lakes states except for a limited season in Illinois. Lake Michigan is now being stocked with several species of fish. However, several invader species such as lampreys, round goby, and zebra mussels threaten the native fish populations.

Accidentally introduced species are a big problem. Since the 19th century about 160 species have invaded the Great Lakes ecosystem, causing severe economic and ecological impacts. According to the Inland Seas Education Association, they deprive fish of food, cause blooms of toxic algae, and foul boats, spawning areas and drinking water intakes. On average a new invasive species enters the Great Lakes every eight months.

Two important infestations in the Great Lakes are the zebra mussel,  first discovered in 1988, and the quagga mussel in 1989. These molluscs are efficient filter feeders. They compete with native mussels, and also reduce available food and spawning grounds for fish.  

Also, the mussels hurt utility and manufacturing industries by clogging or blocking pipes. The U.S. Fish and Wildlife Service estimates that the economic impact of the zebra mussel will be about $5 billion over the next decade. Because the quagga mussel is good at filtering plankton from the lake water, sunlight reaches deeper into the lake. This increases the growth of algae.

Chemicals from industrial plants run off the land into rivers and arrive in the lakes. Some of these chemicals are highly toxic, such as mercury. Contaminated water from sewer overflows also reaches the lakes, and beaches get closed because of the threat of pathogenic bacteria.




#Article 122: GNU Free Documentation License (620 words)


The GNU Free Documentation License (GNU FDL or simply GFDL) is a copyleft license for open content such as software. It was made by the Free Software Foundation (FSF) for the GNU project. It was initially created for use with software documentation, but can be applied to other types of works as well, such as Wikipedia. 

As a copyright license, the GFDL is a type of contract between the creator of a copyrightable work (such as a book, an encyclopedia article, a painting, or a piece of music) and anyone else who might want to use it. The GFDL is considered copyleft because the license is meant to make it easier to use and re-use the copyrighted work, not to restrict its use. 

If a copyrightable work is released under the GFDL, the creator of the work is saying that anyone else may reproduce, distribute, or modify the work, as long as they follow a set of requirements specified in the GFDL. Among the requirements of the GFDL are that any new work created from the original work is also licensed under the GFDL—that is, once something is licensed as GFDL, it will always stay licensed as GFDL, and anything which uses it also is licensed as GFDL.

The GFDL also says that in order to distribute or modify a work licensed with the GFDL, the re-user must give credit to any previous authors of the work, and include a list of changes they made to the work. 

Finally, any work licensed with the GFDL must contain, somewhere, the entire text of the license. This provision has been criticized, because it is not always easy to include an entire, long license with a copyrighted work. In a book, for example, it is easy to include one extra page with the license, but if the work is something like a song, or a photograph, it is not easy. 

The GFDL has other requirements that are more complicated. For example, if part of the work is labeled as an invariant section, it cannot ever be removed or changed by someone using the work (invariant means does not change). 

Works licensed under the GFDL may be included in with non-GFDL-licensed works only if it is clear which parts of the work are licensed as the GFDL. For example, in a book of poetry it would be easy to label some poems as licensed under the GFDL and some not licensed under it. But it would not be easy to label if part of a song was licensed as GFDL and the rest was not, so this would not be allowed. 

Any use of GFDL material which violates the terms of the GFDL is potentially copyright infringement. Infringement issues are managed through a community based approach with the approval and assistance of the Free Software Foundation.

A number of online projects use the GFDL. An online project to license its content under the GFDL is Wikipedia.

The GFDL has been criticized by many people who wish that it made it even easier for content to be re-used. Among the criticisms are that it is very hard to combine GFDL material with other copyleft licenses, that it is not always clear and easy to understand, and that some of its requirements, such as the invariant sections, are not free at all.

The GFDL was released in draft form for feedback in September 1999. After revisions, version 1.1 was issued in March 2000, version 1.2 in November 2002, and version 1.3 in November 2008. The current state of the license is version 1.3.

Material licensed under the current version of the license can be used for any purpose, as long as the use meets certain conditions.




#Article 123: Glass (289 words)


Glass is a  material that can be made in many shapes.  It is usually transparent, but it can also be made in colours.  Glass is mainly made of silica; glass made of silica only is called silica glass. 

Glass used to make windows and bottles is a specific type called soda-lime glass, composed of about 75% silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide, also called lime (CaO), and several minor additives. 

By changing the proportions, and adding different ingredients, many kinds of glass can be made. Coloured glass is made by adding small amounts of metal oxides. For example, a blue colour is given by tiny amounts of cobalt oxide.

Crystal glass is made by adding lead and zinc oxides. It is not actually a crystal because all glass is a non-crystalline solid. Crystal glass is called cut glass if it has been cut by hand:

Because glass is used to make lenses, the word glasses often means eyeglasses.

The myth that glass is actually a liquid comes from the fact that old windows in houses and churches (200–300 years old) are sometimes a little out of shape: thicker at the bottom than the top.  This is actually due to the process of glass making in the past which led to the glass pane being thicker at one edge than the other.  It was sensible to install the windows with the thick edge at the bottom.  Sometimes a window can be found with the thick edge at the top of the window.

Glass can be recycled over and over. Glass bottles and jars can easily be recycled to make new glass bottles and jars or used in industry as aggregate (building material) or sand.




#Article 124: God (1416 words)


 

 

According to certain philosophies, religions and mythologies, God is the creator of the Earth and of everything else. Hinduism says that there is one God who can come in many forms. Theists believe that God created everything that s and has ever existed. In most religions, God is believed to be immortal (cannot die), and to have unlimited power.
The belief that God or gods exist is usually called theism. People who reject belief that God or any deities exist are called atheists. Agnostics think we cannot know for sure whether God or gods exist, but still might (or might not) believe at least one deity exists. People who believe in God but not in traditional religions are called deists. People who believe that the definition of God should be defined before taking a theological position are ignostic.

In some religions there are many gods. This is called polytheism. They may or may not believe in a Supreme Being above the gods. Some polytheistic religions are Hinduism, Shinto, Taoism, Wicca and variants of Buddhism that syncronised with traditional folk religions it came into contact with.  The belief that there is only one god is called monotheism. People who only believe in one god usually write God with an uppercase first letter.  Some monotheistic religions are Christianity, Judaism, Islam, Bahá'í Faith and Sikhism. In English the word gods is written in lowercase letters. God is usually written with an uppercase letter when it refers to the Supreme Being. Some polytheists also like to use uppercase when talking about their gods.

Many people have asked themselves if God exists. Philosophers, theologians, and others have tried to prove that it exists. Others have tried to disprove the theory. In philosophical terminology, such arguments are about the epistemology of the ontology of God. The debate exists mainly in philosophy, because science does not address whether or not supernatural things exist.

There are many philosophical issues with the existence of God. Some definitions of God are not specific. Arguments for the existence of God typically include metaphysical, empirical, inductive, and subjective types. Some theories are built around holes in evolutionary theory, as well as order and complexity in the world. Arguments against the existence of God typically include empirical, deductive, and inductive arguments. Conclusions sometimes include: God does not exist (strong atheism); God almost certainly does not exist (de facto atheism); no one knows whether God exists (agnosticism); God exists, but this cannot be proven or disproven (deism or theism); and God exists and this can be proven (theism). There are many variations on these positions, and sometimes different names for some of them. For example, the position God exists and this can be proven is sometimes called gnostic theism or strong theism.

There are different names for God in different religions. Some examples are Yahweh, Elohim in Judaism and Christianity, Allah in Islam, Baha in Bahá'í Faith, and Ahura Mazda in Zoroastrianism.

By the year 2000, approximately 53% of the world's population were part of one of the three main Abrahamic religions (33% Christian, 20% Islam,  less than 1% Judaism), 6% with Buddhism, 13% with Hinduism, 6% with traditional Chinese religion, 7% with various other religions, and less than 15% as non-religious. Most of these religious beliefs involve God or gods. Some religions do not believe in god or do not include the concept of god.

Abrahamic religions are very popular monotheistic ones. Well-known Abrahamic religions include Judaism, Christianity, and Islam. Monotheistic means the people in these religions believe there is only one God. The name of God is usually not allowed to be said in Judaism, but some Jews today call him YHWH (Yahweh) or Jehovah. Muslims say the word Allah, which is the Arabic word for God. 

Believers in the Abrahamic religions (except Islamic believers) believe that God has created human beings in his image, but this idea is not easily understood by humankind. One artistic idea is that of an wise elder man in use since the Renaissance.

The Christian Holy Bible talks about God in different ways. Within Christian canon the Old Testament talks about God the Father, whilst the   New Testament is about Jesus, or God the Son. Many Christians believe that Jesus was God's incarnation on Earth. Christians consider the  Holy Spirit to be God as well, the third person of God.

In the New Testament, there are three beings who are said to be God in different forms: the Father, the Son, and the Holy Spirit (also known as the Holy Ghost). This is called the Holy Trinity. Although the word Trinity is not in the Bible, the word used for God in chapter one of Genesis is actually plural, and the phrase in the name of the Father, Son and Holy Spirit' is used in the New Testament, (e.g. Matthew 28:19). Another word that Christians believe has exactly the same meaning as Trinity is the word Godhead, which is in the Holy Bible. 

Christians believe that God incarnated in a human body, through the normal birth process, normally growing up into a man named Jesus or (Yeshua), coming to Earth specifically to give every person an opportunity of salvation from their own evil, called sin. The effect of personal evil far transcends the repercussions humans cause to one another in the world, but affects one's relationship with God the Father, and that aspect of the self cannot be addressed through one's own self-improvement efforts, but requires God to intervene in order to set one right. When Jesus prayed and talked to God, he called him Father, and taught others to do the same.

Jesus also taught that one must be born again in order to receive God's Spirit, otherwise one remains separated from God, acting merely from their own mind, thus being vulnerable to deception by human philosophies or the many spiritual philosophies which do not come from God but from Fallen angels, which are within various false religions. After a person consciously accepts the free gift of eternal life, which Jesus's sacrifice offers, God comes to live in the individual, as God lived in humankind before the Fall.

In Hinduism, there is only one God, named Brahman, but Brahman is said to have taken on many different incarnations. Some of these are Rama, Krishna, Buddha, Shiva, Kali, Parvati, and Durga. To many outsiders, the worship of God's different incarnations is considered to be the worship of many gods. However, it is really only the worship of one God in different ways.

Some Hindus also believe that the spirit of God lives in everyone. This idea is called Advaita Vedanta, which is the Hindu term for Monism.

Religions like Buddhism and Confucianism involve the worship of many gods, or sometimes no gods at all.

In Shinto, there is not a single specific God, as is in most religions, but instead, a wide variety of deities called kami, they are the spirit and essence of all nature things, both animate and inanimate, even including rocks, trees and poetry, for example. As Shinto is a  polytheistic religion, it is usually believed that there are eight-million Kami (八百万の神 yaoyorozu-no-kami), in the Japanese language, the number eight-million is normally used to mean infinity.

Philosophers can talk about God or god; sometimes they talk about a specific god, but other times they are just talking about the idea of god.

One of the earliest Western philosophers to write about God in a monotheistic way was the Greek Aristotle, who describes god as the Supreme Cause. Aristotle saw God as a being that makes everything happen, but is not influenced by anything else.

The idea of an all powerful God raises some interesting questions. One of them is called the God paradox. It asks whether God can make a mountain (or rock) that is so heavy he cannot lift it. The question considers if a god who can do anything could do two things that are mutually contradictory. 

There have been several attempts to prove the existence of God with logic. Blaise Pascal said that it is better to believe there is a god, than to believe there isn't. This argument is known as Pascal's wager today. Note that Blaise Pascal was a mathematician, and he used this argument to illustrate the concept of expected value in statistics. Other attempts known as the ontological argument, the cosmoolgical argument, and teleological argument today. Kurt Gödel formulated an argument for the existence of God using modal logic in the 1970s.




#Article 125: Ghost (443 words)


A ghost is considered to be the spirit of a dead person. Scientists say that there are no real ghosts, but many people believe that there are.
There a are huge amount of   about ghosts in books and movies. Sometimes the ghost is the spirit of a person who was killed by someone or who was already dead. The ghost may stay on Earth because he or she has unfinished problems or is still trying to say good bye to people who they missed. Sometimes ghosts are said to live in a particular , for example an abandoned house.

Sometimes the ghosts in these stories exist because of some problem the person had during life or to say good bye to loved ones, that was not solved before he or she died. The ghost stays on the Earth trying to fix the problem. If the problem is fixed, the ghost can leave the Earth. Many people say they have seen or heard ghosts. People who try to talk to ghosts as their job are called mediums.

There can be bad ghosts and there can also be good ones. There have never been any ghosts that have actually hurt or killed people, although people tell stories about it.

Many people believe they have seen ghosts. Others believe they have felt ghosts near them. Often the ghost is said to appear as a feeling of cold and a light or a misty cloud, but sometimes people say they have seen ghosts that look more like people. Sometimes ghosts are said to come in human form. Some ghosts might cause fear in the person who sees them, by being seen suddenly. Some ghosts are said to be friendly and help people who have problems.

Ghosts are said to form right after they die, or even centuries later. Many people make up stories or urban legends. Many try to prove the existence of these paranormal creatures with special technology such as heat sensors. They also make TV shows dedicated to proving the existence of ghosts. They often investigate cases where a person has seen one or visit a place of sighting.

Stories of ghosts can be found all over the world. Chinese philosopher Confucius said Respect ghosts and gods, but keep away from them.

The most feared spirit in Thailand is Phi Tai Hong, the ghost of a person who has died suddenly of a violent death. The Koran discusses spirits known as jinn. In Europe there is the recurring fear of returning or revenant deceased who may harm the living. This includes the Scandinavian gjenganger, the Romanian strigoi, the Serbian vampir, the Greek vrykolakas among others.




#Article 126: Green (111 words)


Green is a color.  It is one of the colors of the rainbow. Green is between the yellow and blue colors in a rainbow. Green paint can be made by mixing yellow paint and blue paint together. 

Green light, like all light, is quanta—composed of photons.  The wavelength of green light is about 550 nanometers (one-billionth of a meter).

Most leaves of growing plants, such as trees and bushes, are green. This is because there is a chemical in leaves, called chlorophyll, which is colored green.

Green is a color, the perception of which is evoked by light having a spectrum dominated by range with a wavelength of roughly 570-520 nm.




#Article 127: Google (543 words)


Google is a multinational corporation from the United States of America. It is known for creating and running one of the largest search engines on the World Wide Web (WWW). Every day more than a billion people use it. Google's headquarters (known as the Googleplex) is in Mountain View, California, part of the Silicon Valley. The current motto of Google is Do the right thing.

Ever since the 2 September 2015, Google is owned by a new holding company called Alphabet Inc, which has taken over some of Google's other projects, such as its driverless cars. It is a public company that trades on the NASDAQ under the tickers  and . 

Google's search engine can find pictures, videos, news, Usenet newsgroups, and things to buy online. By June 2004, Google had 4.28 billion web pages on its database, 880 million pictures and 845 million Usenet messages — six billion things. Google's American website has an Alexa rank of 1, meaning it is the most widely visited website in the world. It is so widely known that people sometimes use the word [./google] as a verb that means to search for something on Google; but because more than half of people on the web use it, google has been used to mean to search the web.

Larry Page and Sergey Brin, two students at Stanford University, USA, started BackRub in early 1996. They made it into a company, Google Inc., on September 7, 1998 at a friend's garage in Menlo Park, California. In February 1999, the company moved to 165 University Ave., Palo Alto, California, and then moved to another place called the Googleplex.

In September 2001, Google's rating system (PageRank, for saying which information is more helpful) got a U.S. Patent. The patent was to Stanford University, with Lawrence (Larry) Page as the inventor (the person who first had the idea).

Google makes a percentage of its money through America Online and InterActiveCorp. It has a special group known as the Partner Solutions Organization (PSO) which helps make contracts, helps making accounts better, and gives engineering help.

Google makes money by advertising. People or companies who want people to buy their product, service, or ideas give Google money, and Google shows an advertisement to people Google thinks will click on the advertisement. Google only gets money when people click on the link, so it tries to know as much about people as possible to only show the advertisement to the right people. It does this with Google Analytics, which sends data back to Google whenever someone visits a web site. From this and other data, Google makes a profile about the person, and then uses this profile to figure out which advertisements to show.

The name Google is a misspelling of the word googol. Milton Sirotta, nephew of U.S. mathematician Edward Kasner, made this word in 1937, for the number 1 followed by one hundred zeroes (10100). Google uses this word because the company wants to make lots of stuff on the Web easy to find and use. Andy Bechtolsheim thought of the name. 

The name for Google's main office, the Googleplex, is a play on a different, even bigger number, the googolplex, which is 1 followed by one googol of zeroes 1010100




#Article 128: Government (1083 words)


A government is a group of people that have the power to rule  in a territory, according to the administrative law. This territory may be a country, a state or province within a country, or a region. 
 

Plato listed five kinds of government in The Republic:

The most common type of government in the Western world is called democracy. In democracies, people in a country can vote during elections for representatives or political parties that they prefer. The people in democracies can elect representatives who will sit on legislatures such as the Parliament or Congress. Political parties are organizations of people with similar ideas about how a country or region should be governed. Different political parties have different ideas about how the government should handle different problems. Democracy is the government of the people, by the people and for the people. 

However, many countries have forms of democracy which limit freedom of choice by the voters. One of the most common ways is to limit which parties who can for parliament, or limit the parties access to mass media such as television. Another way is to rig the voting system by removing votes from opposition voters and substituting votes for the party in power. Few countries are textbook democracies, and the differences between them has been much studied.

A monarchy is a government ruled by a king or a queen who inherits their position from their family, which is often called the royal family. There are two types of monarchies: absolute monarchies and constitutional monarchies. In an absolute monarchy, the ruler has no limits on their wishes or powers. In a constitutional monarchy a ruler's powers are limited by a document called a constitution. 

In modern times, monarchies still exist in Great Britain and the Commonwealth, the Netherlands, Spain, Japan, Saudi Arabia, and Thailand, along with several other countries. A monarch may have one of several titles: King or Queen, Emperor or Empress, or Emir.

An aristocracy is a government run by the people of a ruling class, usually people who come from wealthy families, families with a particular set of values, or people who come from a particular place. A person who rules in an aristocracy is an aristocrat. Aristocracy is different from nobility, in that nobility means that one bloodline would rule, an aristocracy would mean that a few or many bloodlines would rule, or that rulers be chosen in a different manner.

Under a dictatorship, the government is run by one person who has all the power over the people in a country. Originally, the Roman Republic made dictators to lead during time of war. The Roman dictators (and Greek tyrants) were not always cruel or unkind, but they did hold on to power all by themselves, rather than sharing power with the people. The Roman dictators only held power for a short period of time. 

In modern times, a dictator's rule is not stopped by any laws, constitutions, or other social and political institutions, and can last many years or even decades. After World War II, many governments in Latin America, Asia, and Africa were ruled by dictators. Examples of dictators include Josef Stalin, Adolf Hitler, Augusto Pinochet,  Idi Amin, Muammar al-Qaddafi, and Gamal Abdul Nasser. The rules of these dictators continued from when they took power until when they died, because they would not allow any other person or law to take power from them. There is no evidence of a woman serving as a dictator in modern times. 

An oligarchy is a government ruled by a small group of powerful people. These people may spread power equally or not equally. An oligarchy is different from a true democracy because very few people are given the chance to change things. An oligarchy does not have to be hereditary or passed down from father to son. An oligarchy does not have one clear ruler, but several powerful people. Some past examples of oligarchy are the former Union of Soviet Socialist Republics and Apartheid South Africa. A fictional example is the dystopian society of Oceania in the book Nineteen Eighty-Four. Some critics of representative democracy think of the United States as an oligarchy. This view is shared by anarchists.

The simplest idea of government is those who rule over  and land. This may be as small as a community or village or as big as a continent (like Australia and India). 

The people who rule can allow others to own land. It is a  by government that gives this right in the way that laws describe. Some think they have the right to hold land without government permission. This view is called libertarianism. Others think they can do without government. This view is called anarchism. 

Almost every place on Earth is connected to one and only one government. Places without government are where people follow traditions instead of government rules, small border disputed areas and the continent of Antarctica, because almost no people live there. For every other place on Earth there is a government that claims 'sovereign control' over it. The word sovereign is old and means control by a King (sovereign). Governments of villages, cities, counties and other communities are subordinate to the government of the state or province where they exist, and then to that of the country.

It is from Kings and feudalism that modern governments and nation states came. The capital of a country, for instance, is where the King kept his assets. From this we get the modern idea of capital in economics. A government may  trade as well as to rule over land.

Governments also control people and decide things about what morality to accept or punish. In  many countries, there are strict rules about sexual intercourse and drugs which are part of law and offenders are punished for disobeying them.

Tax is how government is paid for in most countries. People who buy, sell, import, invest, own a house or land, or earn money are made to pay some of the money to a government.

There are many theories of how to organize government better. These are called theories of civics. Many people think leaders must be elected by some kind of democracy. That way, they can be replaced at election. Many governments are not a democracy but other forms in which only a few people have power.

There are many theories of how to run a government better, and keep people from hurting each other. These theories are part of politics.




#Article 129: Galaxy (864 words)


A galaxy is a group of many stars, with gas, dust, and dark matter. In effect, the expansion of the universe takes place between groups of galaxies, not inside those groups. Gravity holds the galaxy together. The same applies to  groups and clusters of galaxies, such as our Local Group where the Milky Way is, and the Virgo Cluster, a collection of more than 1,000 (might even be 2,000) galaxies. The gravitation is produced by the matter and energy in a galaxy or group of galaxies. Everything in a galaxy moves around a centre of mass, which is also an effect of gravity.  

There are various types of galaxies: elliptical, spiral and lenticular galaxies, which can all be with or without bars. Then there are irregular galaxies. All galaxies exist inside the universe. The observable Universe contains more than 2 trillion (1012) galaxies and, overall, as many as an estimated  stars (more stars than all the grains of sand on planet Earth).

There are galaxies of different sizes and type. Typical galaxies range from dwarfs with as few as ten million (107) stars up to giants with a hundred trillion (1014) stars, all orbiting the galaxy's center of mass. Galaxies may contain many multiple star systems, star clusters, and various interstellar clouds. The Sun is one of the stars in the Milky Way galaxy; the Solar System includes the Earth and all the other objects that orbit the Sun.

Star clusters are not galaxies, they are inside galaxies. Globular clusters are spherical-shaped star clusters which are part of the outer halo of the Milky Way. One of the largest (and oldest) known star clusters, Messier 15, has several million stars, packed closely together, with a black hole at its centre. The stars are too closely packed to get an accurate count, but it certainly has more stars than some of the smaller galaxies. 

Within galaxy clusters, galaxies move relative to other galaxies. They can and do collide. When this happens, the stars generally move past each other, but gas clouds and dust interact, and can form a burst of new stars. Gravity pulls both galaxies into somewhat new shapes, forming bars, rings or tail-like structures.

Many galaxies continue to form new generations of stars. The Milky Way, and all spiral shaped galaxies like it (see right side image of NGC 2997), produce new stars at a rate of one or two stars per year. This star formation happens in the vast interstellar clouds that account for about 1% to 10% of the mass of these galaxies. Globular star clusters, on the other hand, are not currently forming stars because this activity happened billions of years ago and then stopped once all of the gas and dust clouds were used up. 

In the astronomical literature, the word 'Galaxy' with a capital G is used for our galaxy, the Milky Way. The billions of other galaxies are written as 'galaxy' with a lowercase g. The term Milky Way first came out in the English language in a poem by Chaucer.

When William Herschel wrote his  of deep sky objects, he used the name spiral nebula for objects like the Andromeda Galaxy. 200 years later astronomers discovered that they are made of stars as the Milky Way is, so the term 'nebula' is now only used for diffuse structures within a galaxy.

There are two main kinds of galaxies, spiral galaxy and elliptical galaxy. They are classified according to the Hubble Sequence. 

A spiral galaxy is a galaxy that has a spiral shape. Most of the galaxies in the universe observed by astronomers are spiral galaxies (about 77%). 

They are divided into two :

NGC 1300 and NGC 1672 are examples of barred spiral galaxies. The Whirlpool galaxy and Messier 81 are examples of unbarred spiral galaxies.

The identifying characteristics of a spiral galaxy are disk-shaped rotating, spiral arms, and a bulge in the galactic core.  The spiral arms are where new hot stars are born.  Bulge in the galactic core has old stars.  This feature is common to the most spiral galaxies.

An elliptical galaxy is a galaxy that has a ellipsoid (3D of ellipse) shape.  This type of galaxy are dominant in universe, especially in galaxy clusters.  The shape ranges from circle, ellipse, and cigar-shaped.  In Hubble Sequence, this shape can be represented as class :

Elliptical galaxies have a large range in size. The giant elliptical galaxy can be over a more 1 million light years and the smallest (know as dwarf elliptical galaxy) are less than one-tenth the size of Milky Way The size of an elliptical galaxy can be measured as an effective radius which defines the area from which half its light comes. The mass of elliptical galaxy is also large. A giant elliptical galaxy can have mass of 1013 (many trillions) of solar masses.

 

A lenticular galaxy is a galaxy seen in a disc shape.  Determining the shape of a lenticular galaxy is difficult because the shape can be between spiral galaxy and elliptical galaxy.  The shape can be known by looking at the bulge of the galactic center.  If the bulge is very bright, it is a spiral galaxy




#Article 130: Geometry (294 words)


Geometry is the part of mathematics that studies the size, shapes, positions and dimensions of things.  We can only see or make shapes that are  (2D) or solid (3D), but mathematicians (people who study math) are able to study shapes that are 4D, 5D, 6D, and so on.

Squares, circles and triangles are some of the simplest shapes in flat geometry. Cubes, cylinders, cones and spheres are simple shapes in solid geometry.

Plane geometry can be used to measure the area and perimeter of a flat shape. Solid geometry can also measure a solid shape's volume and surface area.

Geometry can be used to calculate the size and shape of many things. For example, geometry can help people find:

Geometry is one of the oldest branches of mathematics. Geometry began as the art of Surveying of land so that it could be shared fairly between people. The word geometry is from a Greek word that means to measure the land. It has grown from this to become one of the most important parts of mathematics. The Greek mathematician Euclid wrote the first book about geometry, a book called The Elements.

Plane and solid geometry, as described by Euclid in his textbook Elements is called Euclidean Geometry. This was simply called geometry for centuries. In the 19th century, mathematicians created several new kinds of geometry that changed the rules of Euclidean geometry. These and earlier kinds were called non-Euclidean (not created by Euclid). For example, hyperbolic geometry and elliptic geometry come from changing Euclid's parallel postulate.

Non-Euclidean geometry is more complicated than Euclidean geometry but has many uses. Spherical geometry for example is used in astronomy and cartography.

Geometry starts with a few simple ideas that are thought to be true, called axioms. Such as:




#Article 131: Graph theory (454 words)


Graph theory is a field of mathematics about graphs. A graph is an abstract representation of: a number of points that are connected by lines. Each point is usually called a vertex (more than one are called vertices), and the lines are called edges. Graphs are a tool for modelling relationships. They are used to find answers to a number of problems.

Some of these questions are:

 →
 →

A visualization of the Seven Bridges of Königberg. Leonhard Euler solved this problem in 1736, which led to the development of topology, and modern graph theory.

A graph is an abstract data structure. It holds nodes that are usually related to each other. A node is a dataset, typically in the form of ordered pairs. Nodes are either connected or not connected to another node. The relation between nodes is usually defined as an Edge. Graphs are useful for their ability to associate nodes with other nodes.
There are a few representations of Graphs in practice.

Leonhard Euler used to live in a town called Königsberg. (Its name changed to Kaliningrad in 1946). The town is on the river Pregel. There is an island in the river. There are some bridges across the river. Euler wanted to walk around and use each of the bridges once. He asked if he could do this. In 1736, he published a scientific article where he showed that this was not possible. Today, this problem is known as the Seven Bridges of Königsberg. The article is seen as the first paper in the history of graph theory.

This article, as well as the one written by Vandermonde on the knight problem, carried on with the analysis situs initiated by Leibniz. Euler's formula was about the number of edges, vertices, and faces of a convex polyhedron was studied and generalized by Cauchy and L'Huillier, and is at the origin of topology.

The fusion of the ideas coming from mathematics with those coming from chemistry is at the origin of a part of the standard terminology of graph theory. In particular, the term graph was introduced by Sylvester in an article published in 1878 in Nature.

One of the most famous and productive problems of graph theory is the four color problem: Is it true that any map drawn in the plane may have its regions colored with four colors, in such a way that any two regions having a common border have different colors?

Graph theory is an important part of mathematics and computer science. To many such problems, exact solutions do exist. Many times however, they are very hard to calculate. Therefore, very often, approximations are used. There are two kinds of such approximations, Monte-Carlo algorithms and Las-Vegas algorithms.




#Article 132: History (258 words)


History is the study of past events. People know what happened in the past by looking at  from the past including sources (like books, newspapers, and letters) and artifacts (like pottery, tools, and human or animal remains.) Libraries, archives, and museums collect and keep these things for people to study history. A person who studies history is called a historian. A person who studies pre-history and history through things left behind by ancient cultures is called an archaeologist. A person who studies mankind and society is called an anthropologist. The study of the sources and methods used to study and write history is called historiography.

People can learn about the past by talking to people who remember things that happened at some point in the past. This is called oral history. For example, when people who had been slaves and American Civil War survivors got old, some historians recorded them talking about their lives, so that history would not be lost. 

In old times people in different parts of the world kept separate histories because they did not meet each other very often. Some groups of people never met each other. The rulers of Medieval Europe, Ancient Rome and Ancient China each thought that they ruled the only important parts of the world and that other parts were barbarian. But they were still connected, even if they didn't realize it.

Current events, modern economic history, modern social history and modern intellectual history take very different views of the way history has affected the way that we think today.




#Article 133: Health (545 words)


Health is a state of complete physical, mental, and social well-being and not merely the absence of disease according to the World Health Organization (WHO). Physical is about the body. Mental is about how people think and feel. Social talks about how people live with other people. It is about family, work, school, and friends.

Physical fitness refers to good body health. It is dependent on genetic determinators and also on social, economic and ecological factors. That means, one's genes are partly responsible for one's physical health, but also other circumstances: where you live, how clean or polluted your water and the air around you is and also how good your social and medical system is. It is also the result of regular exercise, proper diet and nutrition, and proper rest for physical . A person who is physically fit will be able to walk or run without getting breathless and they will be able to carry out the activities of everyday living and not need help. How much each person can do will depend on their age and whether they are a man or woman. A physically fit person usually has a normal weight for their height. The relation between their height and weight is called their Body Mass Index. A taller person can be heavier and still be fit. If a person is too heavy or too thin for their height it may affect their health.

Mental health refers to a person's emotional and psychological well-being. A state of emotional and psychological well-being in which an individual is able to use his or her thinking and emotional (feeling) abilities,  in society, and meet the  demands of everyday life.

One way to think about mental health is by looking at how well a person functions. Feeling  and ; being able to handle normal levels of stress, have good friends and family, and lead an  life; and being able to bounce back, or  from hardships, are all signs of mental health.It’s normal for all of us to feel worried, sad, upset, or have difficult emotions from time-to-time. For most people though, these feelings are only temporary and are resolved without causing any long-term problems. However, for some people, these negative feelings can become worse over time and lead to a mental health problem such as depression, anxiety, stress or obsessive-compulsive disorder (OCD).

Public health refers to trying to stop a disease that is unhealthy to the community, and does not help in long life or promote your health. This is fixed by organized efforts and choices of society, public and private clubs, communities and individuals.

It is about the health of many people, or everybody, rather than one person. Public health stops instead of encouraging a disease through surveillance of cases. To prevent being sick, it is good to act according to some simple advice:  Hand washing, regular check-ups,  vaccination programmes, drinking clean water and using condoms. When infectious diseases break out, washing hands for about 30 seconds may be especially important. Sometimes it is necessary to avoid masses of people or wear a surgical mask to protect yourself and to stop the spreading of the disease. Teaching people how to live healthily and educate them, especially about sex and child-birth, is also very important.




#Article 134: Harbor (116 words)


Harbour means to shelter or keep safe. A harbor (or harbour) is a place where ships may shelter.  Some harbours are used as ports to load and unload ships.  The port will have quays or piers where the ships may be moored or tied up and a transport system for taking goods inland.  Often railway and road transport will be used.  Goods also move by pipeline transport and by smaller ships on rivers.

Harbors can be natural as in San Francisco or artificial as in ancient Carthage or a mix of both. During the D-Day operations of 1944, two artificial harbors (named mulberry) were built just off the beaches where the invasion was going to happen.




#Article 135: Hawaii (426 words)


Hawaii (sometimes spelled Hawai'i.) is a U.S. state and the only U.S. State that is in Oceania. It is the last state that joined the United States, becoming a state on August 21, 1959. It is the only state made only of islands. Hawaii is also the name of the largest island. The capital and largest city of Hawaii is Honolulu on the island named Oahu.

Hawaii is known as the Aloha State. Aloha is a Hawaiian word that has many meanings like welcome, hello and goodbye. Aloha also means love and care. The different meanings are brought together in the term Aloha Spirit to describe the friendly people of Hawaii.

Hawaii is an archipelago, a long chain of islands. There are eight main islands and many small islands and atolls. They are the tops of underwater volcanos. The main islands are Niihau, Kauai, Oahu, Molokai, Lanai, Kahoolawe, Maui and Hawaii.

The first people of Hawaii were Polynesians. They came to the islands sometime between 200 and 600 AD. Captain James Cook is given credit for discovering the islands for the Europeans in 1778. Others may have been there before him. Captain Cook named the islands the Sandwich Islands for the fourth Earl of Sandwich, John Montague.

Kamehameha I was the first king of Hawaii. He united the separate small Hawaiian kingdoms into one large kingdom in 1795. In 1893, American soldiers stopped Queen Liliuokalani from leading Hawaii when American business people took over the government and made their own laws. She was the last monarch of Hawaii. She also wrote the original words of the song called Aloha Oe.

The American business people made Hawaii into a republic for a short time. The new leader, Sanford Dole was called the President of Hawaii. In 1898, the United States of America took over the government and made Hawaii into a territory. In 1959, Hawaii became the fiftieth American state.

The biggest industry of Hawaii is tourism. Almost 7 million people visited in 2000. Important exports are sugar, pineapple, macadamia nuts, and coffee.

Popular tourist sites include Waikiki Beach, Hawaii Volcanoes National Park, Polynesian Cultural Center, and the USS Arizona Memorial at Pearl Harbor.

The state flower is the yellow hibiscus (Hibiscus brackenridgei or ). The state bird is the Hawaiian goose (nene). The state fish is the reef triggerfish, also called the . The state tree is the candlenut, also called kukui. The state song is Hawaii Ponoi. The state motto is . In English it says, The life of the land is perpetuated in righteousness.




#Article 136: Honolulu (174 words)


Honolulu is the capital city of the U.S. state of Hawaii. It is also the largest city in Hawaii and it has the most important harbor. It is on the south-east shore of the island of Oahu.

Honolulu means sheltered harbor in the Hawaiian language. No one knows for sure when Honolulu was first settled or when the name was first used.

Honolulu harbor was called Kulolia before foreigners came. The first foreigner was Captain William Brown of the English ship Butterworth, in 1794. He named the harbor Fair Haven. Other foreign captains is started calling it Brown's Harbor. The name Honolulu was used some time after that.

Honolulu quickly became the most important harbor of Hawaii. At that time, sandalwood was a big export. Honolulu was also an important supply point for whalers.

Kamehameha III made Honolulu the capital city of the Kingdom of Hawaii in 1850. It was also the capital of the Republic of Hawaii and the Territory of Hawaii. It stayed the capital when Hawaii became a state in 1959.




#Article 137: Hawaii (island) (191 words)


The Island of Hawaiʻi is the largest U.S. Hawaiian Island, and it is the farthest south. It is also called the Big Island. Its area is 4,038 sq. miles (10 458 square kilometers). The widest part of the island is 93 miles (150 km) across.
The Big Island has more than half (~62%) of the total land area of State of Hawaii. It is part of County of Hawaii.

The island is seven separate shield volcanos that erupted more or less one at a time, one partly covering the other. These are (from oldest to youngest): Kohala (extinct), Mauna Kea (dormant), Hualalai (dormant), Mauna Loa (active), Kulani (extinct, mostly buried), and Kilauea (very active). The volcanos were caused by the Pacific oceanic tectonic plate moving over a hotspot. There lava from the Earth's lower mantle or upper core is close to the surface.

The largest city on the island is Hilo. Hilo has many historic buildings, interesting shops, parks, many performances, festivals and events. It is on the rainy, east side of the island. The city of Kailua-Kona is on the dry, west side of Hawaii, and is popular with tourists.




#Article 138: History of Australia (1002 words)


People have lived in Australia for over 65,000 years. The first people who arrived in Australia were the Aboriginal people and Torres Strait Islanders.. They lived in all parts of Australia. They lived by hunting, fishing and gathering.

Aborigines invented tools like the boomerang and spear. There is also evidence that the Aboriginal people used farming methods.  Tradition was very important in their lives. Their religion is called the Dreamtime, which has lots of stories about the creation of the world by spirits. Aboriginal art started at least 30,000 years ago and there are lots of Dreaming stories painted on walls and cut in rocks all around Australia. Aboriginal music has songs about the Dreamtime, sometimes with special instruments like the didgeridoo.

In 1606 the first European, Dutch explorer Willem Janszoon (1571–1639), visited the west. Luis Vaez de Torres sailed through the water between Australia and New Guinea later that year.
Only after Dirk Hartog chanced upon the west coast in 1616 did other European vessels visit and map the coast. After sixty more ships visited the coast, enough was known for a map to be published in 1811. The land was dry because of not much rain; some was a desert. The explorers thought no crops could be grown and so it would be difficult for people to live there. They decided there would be no economic reasons to stay.

In 1642, Dutchman Abel Tasman, working for the Dutch East Indies Company reached Tasmania, which he called Antony van Diemenslandt. He then called the continent he charted the north coast of on his second visit in 1644 New Holland. In 1688, William Dampier became the first Englishman to reach Australia. But in 1770 a British sailor, Captain James Cook, found the fertile east coast of Australia. He called it New South Wales, and claimed it for Britain.
Englishman Matthew Flinders published his map of the coast in 1814, calling it Australia for the first time, a name later formally adopted by the authorities.

The British decided to use the land visited by Captain Cook as a prison colony. Britain needed a place to send its convicts (people who had been sent to jail for theft and other crimes) because its gaols were full and it had just lost its American colonies in the American War of Independence. In 1788 the British First Fleet of 11 ships, carrying about 1500 people arrived at Botany Bay (Sydney). Arthur Phillip led them as the first Governor of New South Wales. About 160 000 convicts were brought to Australia from 1788 until 1868. Free immigrants began arriving in the 1790s.

For the first few years they did not have much food, and life was very hard. But soon they began to farm, and more people came. Sydney grew, and new towns were started. Wool brought good money. By 1822, many towns had been set up and people from the towns often visited Sydney for additional economic resources.

Soon people from Sydney found other parts of Australia. George Bass and Matthew Flinders sailed south to Tasmania and a colony was started at Hobart in 1803. Hamilton Hume and William Hovell went south from Sydney by land. They found the Murray River, and good land in Victoria. Thomas Mitchell went inland, and found more rivers. In 1826, the first British military outpost was set up at King George Sound in Western Australia. The Swan River Colony was started in 1829, with townsites at Fremantle and Perth. In 1836, a free-settler colony was started in South Australia, where no convicts were ever sent. Queensland became a separate colony in 1859. As the towns and farms spread across Australia, the Aboriginal people were pushed off their land. Some were killed, and many died from illness and hunger. Soon, Australia's Aborigines were outnumbered by Europeans, and many were made to live on reserves.

The goldrushes of New South Wales and Victoria started in 1851 leading to large numbers of people arriving to search for gold. The population grew across south east Australia and made great wealth and industry. By 1853 the goldrushes had made some poor people very rich.

Convict transportation ended in the 1840s and 1850s and more changes came. The people in Australia wanted to run their own country, and self-govern. The first governments in the colonies were run by Governors chosen by London. Soon the settlers wanted local government and more democracy. The New South Wales Legislative Council, was created in 1825 to advise the Governor of New South Wales, but it was not chosen by voters. William Wentworth established the Australian Patriotic Association (Australia's first political party) in 1835 to demand democratic government for New South Wales. In 1840, the Adelaide City Council and the Sydney City Council were started and some people could vote for them (but only men with a certain amount of money). Then, Australia's first parliamentary elections were held for the New South Wales Legislative Council in 1843, again with some limits on who could vote. The Australian Colonies Government Act [1850] allowed constitutions for New South Wales, Victoria, South Australia and Tasmania. In 1850 elections for legislative councils were also held in the colonies of Victoria, South Australia and Tasmania.

In 1855, limited self-government was granted by London to New South Wales, Victoria, South Australia and Tasmania. A new secret ballot was introduced in Victoria, Tasmania and South Australia in 1856, allowing people to vote in private. This system was copied around the world. In 1855, the right to vote was given to all men over 21 in South Australia. The other colonies soon followed. Women were given the vote in the Parliament of South Australia in 1895 and they became the first women in the world allowed to stand in elections. In 1897, Catherine Helen Spence became the first female political candidate.

Australians had started parliamentary democracies all across the continent. But voices were getting louder for all of them to come together as one country with a national parliament.




#Article 139: History of Spain (987 words)


Spain is a country in Europe.

People have lived on the Iberian Peninsula for about 500,000 years. Neanderthal man came about 200,000 years ago. Modern humans first came about 40,000 years. Thousands of years ago Iberians and Celts lived there, and the Phoenicians made a few cities there to get tin and silver to trade.

The Roman Empire controlled Spain for three hundred years; then people from Eastern Europe called Visigoths fought for Spain, won it from the Romans, and controlled Spain for over two hundred years.

The Visigoths converted from Arian Christianity to Roman Catholics. The land was won after a war by Muslims who were Arab and Berber. Roman Catholics from Europe eventually decided to fight to take Spain from the Muslims. They fought wars for many hundreds of years, some of which were Crusades against other Christians like the Cathars. These were very cruel wars.

In the year 1492, they took the last part of Spain that had belonged to the Moors. Boabdil, the last Moorish Leader of Granada, gave the city to King Ferdinand of Aragon on 2 January 1492, and Christians now ruled all of Spain.

Before this, several different kings had ruled different countries in what is now called Spain. Two of these countries, Castile and Aragon, came together when the king of Aragon, Ferdinand II, married the queen of Castile, Isabella.

In the same year, 1492, they decided to send Christopher Columbus to explore the Atlantic Ocean. Columbus found a land there that the people of Europe did not yet know. These were the islands of the Caribbean Sea.

Columbus and other sailors explored more and found that there were two continents there - North America and South America. Spain sent many soldiers and businessmen to North and South America, and they took over very large parts of those two continents. Owning this empire made Spain very rich. But when they conquered that empire, they killed millions of the Native Americans who had lived there before. Spain owned this empire for more than three hundred years.

Meanwhile, at home, the Muslim manuscripts had been either burnt or spread to other countries. Jews had been expelled from Spain. The multicultural society was destroyed, and so was the learning. Among the few things kept and respected in Spain were in music: harmony and stringed instruments, and of course the buildings, many of which became churches, by adding crosses.

The Spanish Empire was the strongest in the world through most of the next two centuries, thanks to gold from the Americas. This new gold made rulers and colonial governors rich. Meanwhile, others' savings became worth less due to inflation. Spain became a society of very rich and very poor. Some of the poorest went to the new colonies in the Caribbean, Central America and South America, mostly to find gold.

Native American peoples were killed by diseases brought by the Spaniards, but most Spaniards did not know this. They found damaged and dying societies with people who had lost some of their most important leaders and thinkers. The Spaniards thought this meant they were inferior, and used this as an excuse to enslave the natives. Millions of natives died mining gold for the Spanish.

The Spanish Empire also at this time funded the Spanish Inquisition which tortured and killed anyone who disagreed with the Roman Catholic Church. The Reformation which created Protestant sects in Europe was not allowed into Spain, it was kept out and, as with Jews or Muslims, its believers were killed.

The nobles of Spain no longer had to fight anyone since the internal feuds were over. No one could challenge their power. In many ways it was held together as a reign of terror. People who challenged them were often called heretics, so that the Inquisition could torture them, and then nobles take the property.

For ordinary people on both sides of the Atlantic Ocean, life got worse. A few rulers got rich. Today we would say that these people were guilty of war crimes, genocide and crimes against humanity. Many Church people who had the power to speak out at that time, did so, and they said many of the same things as we would say today. But none of this mattered much to the rulers.

The great satire Don Quixote was written about this time.

In the 18th century, there was doubt over who should become king of Spain; this doubt led many of the kings of Europe to fight to become king of Spain. This was called the War of the Spanish Succession.

France occupied Spain for a long time. This made Spain very weak. It also made Spain lose its empire in North and South America; all of the parts of that empire became their own countries, or were taken over by other countries such as the United States of America.

There was not much peace in Spain during the first part of the 20th century. Some Spaniards tried to set up a government chosen by the people (a democracy), and they made the King of Spain leave the country. However, in 1936, two different groups of Spaniards went to war over whether the government should be a democracy, or take orders from one person. In 1939, those who wanted democracy were defeated, and a dictator named Francisco Franco took over the government.

Franco died in 1975. He had decided that Spain should have a king again, and he chose Juan Carlos, the grandson of the king who had been forced to leave the country, to be king. But the king did not rule as a dictator; instead, he chose to set up a democracy. Also since Franco's death, Spain appointed Adolfo Suárez to became Spain's first democratically elected prime minister. Now Spain is a modern democratic country, and does business with many countries around the world. It is a part of the European Union.




#Article 140: Human body (204 words)


The human body is the body of a person. It is the physical structure of a person.

The body is a thing that can be hurt or killed. Its functions are stopped by death. You need your muscles and your joints to move.

Some people study the human body. They look at where it is different from or the same as other animals' bodies. These animals can be alive today. Or they can be extinct animals like other hominids. (Hominids are primates that are close to humans. Neanderthals and Homo erectus were hominids.) Some people study how the human body works and lives in its environment. Some people study what people think about their body. Artists study how to draw or paint the human body.

Many different fields of study look at the human:

Various organ systems give the body the ability to live and do things.

The human body is like other animals. The skeleton, muscles and other parts are very much like those of other primates. Our body is also like other mammals, and somewhat like other vertebrates. DNA differences follow a similar pattern. The human genome is closer to that of other primates than to other vertebrates, and closest to chimpanzee.




#Article 141: Hydrogen (1011 words)


Hydrogen is a chemical element. It has the symbol H and atomic number 1.  It has a standard atomic weight of 1.008, meaning it is the lightest element in the periodic table. 

Hydrogen is the most common chemical element in the Universe, making up 75% of all normal (baryonic) matter (by mass). Most stars are mostly hydrogen. Hydrogen's most common isotope has one proton with one electron orbiting around it.

Hydrogen is classed as a reactive nonmetal, unlike the other elements appearing in the first column of the periodic table, which are classed alkali metals. The solid form of hydrogen is expected to behave like a metal, however.

When alone, hydrogen usually binds with itself to make dihydrogen (H2) which is very stable, due to its high bond dissociation energy of 435.7 kJ/mol. At standard temperature and pressure, this hydrogen gas (H2) has no colour, smell or taste. It is not toxic. It is a nonmetal and burns very easily.

Molecular hydrogen is flammable and reacts with oxygen:

At temperatures above 500 degrees Celsius, hydrogen spontaneously ignites in air.

While hydrogen gas in its pure form is not reactive, it does form compounds with many elements, particularly halogens, which are very electronegative. Hydrogen also forms vast arrays with carbon atoms, forming hydrocarbons. The study of the properties of hydrocarbons are known as organic chemistry. 

The H- anion (negatively charged atom) is called a hydride, although the term is not widely used. An example of a hydride is lithium hydride (LiH), which is used as a spark plug in nuclear weapons.

Acids dissolved in water typically contain high levels of hydrogen ions, in other words, free protons. The level of them is usually used to determine its pH, which basically means the content of hydrogen ions in a particular volume. For example, hydrochloric acid, found in people's stomachs, can dissociate into a chloride anion and a free proton, and the property of the free proton is how it can digest food by corroding it.

Although rare on Earth, the H3+ cation is one of the most common ions in the universe.

Hydrogen has 7 known isotopes, two of which are stable (1H and 2H), which are commonly referred to protium and deuterium. The isotope 3H is known as tritium and has a half life of 12.33 years, and is produced in small amounts by cosmic rays. The remaining 4 isotopes have half lives on the scale of yoctoseconds.

In its pure form on Earth, hydrogen is usually a gas. Hydrogen is also one of the parts that make up a water molecule. Hydrogen is important because it is the fuel that powers the Sun and other stars.
Hydrogen makes up about 74% of the entire universe. Hydrogen's symbol on the Periodic Table of Elements is H.

Pure hydrogen is normally made of two hydrogen atoms connected together. Scientists call these diatomic molecules. Hydrogen will have a chemical reaction when mixed with most other elements. It has no color or smell.

Pure hydrogen is very uncommon in the Earth's atmosphere, because nearly all primordial hydrogen would have escaped into space due to its weight. In nature, it is usually in water.  Hydrogen is also in all living things, as a part of the organic compounds that living things are made of.  In addition, hydrogen atoms can combine with carbon atoms to form hydrocarbons.  Petroleum and other fossil fuels are made of these hydrocarbons and commonly used to create energy for human use.

Some other facts about hydrogen:

Hydrogen was first separated in 1671 by Robert Boyle. Henry Cavendish in 1776 identified it as a distinct element and discovered that burning it made water.

Antoine Lavoisier gave Hydrogen its name, from the Greek word for water, 'υδορ (pronounced /HEEW-dor/) and gennen meaning to generate as it forms water in a chemical reaction with oxygen.

The main uses are in the petroleum industry and in making ammonia by the Haber process. Some is used elsewhere in the chemical industry. A little of it is used as fuel, for example in rockets for spacecraft. Most of the hydrogen that people use comes from a chemical reaction between natural gas and steam.

Nuclear fusion is a very powerful source of energy. It relies on forcing atoms together to make helium and energy, exactly as happens in a star like the Sun, or in a hydrogen bomb. This needs a large amount of energy to get started, and is not easy to do yet. A big advantage over nuclear fission, which is used in today's nuclear power stations, is that it makes less nuclear waste and does not use a toxic and rare fuel like uranium.  More than 600 million tons of hydrogen undergo fusion every second on the Sun.

Hydrogen is mostly used in the petroleum industry, to change heavy petroleum fractions into lighter, more useful ones. It is also used to make ammonia. Smaller amounts are burned as fuel. Most hydrogen is made by a reaction between natural gas and steam.

The electrolysis of water breaks water into hydrogen and oxygen, using electricity. Burning hydrogen combines with oxygen molecules to make steam (pure water vapor). A fuel cell combines hydrogen with an oxygen molecule, releasing an electron as electricity. For these reasons, many people believe hydrogen power will eventually replace other synthetic fuels.

Hydrogen can also be burned to make heat for steam turbines or internal combustion engines. Like other synthetic fuels, hydrogen can be created from natural fuels such as coal or natural gas, or from electricity, and therefore represents a valuable addition to the power grid; in the same role as natural gas. Such a grid and infrastructure with  is now planned by a number of countries including Japan, Korea and many European countries. This allows these countries to buy less petroleum, which is an economic advantage. The other advantage is that used in a fuel cell or burned in a combustion engine as in a hydrogen car, the motor does not make pollution. Only water, and a small amount of  nitrogen oxides, forms.




#Article 142: Helium (714 words)


Helium is a chemical element. It has the chemical symbol He, atomic number 2, and atomic weight of about 4.002602. There are 9 isotopes of helium, only two of which are stable. These are 3He and 4He. 4He is by far the most common isotope.

Helium is called a noble gas, because it does not regularly mix with other chemicals and form new compounds. It has the lowest boiling point of all the elements. It is the second most common element in the universe, after hydrogen, and has no color or smell. However, helium has a red-orange glow when placed in an electric field. Helium does not usually react with anything else. Astronomers detected the presence of helium in 1868, when its spectrum was identified in light from the Sun. This was before its discovery on Earth. 

Helium is used to fill balloons and airships because its density is lighter than air. It does not burn, so  is  safe for that kind of use. It is also used in some kinds of light bulbs. People can breathe in helium: it makes their voices sound higher than it normally does. This is a joke, but is dangerous as if they breathe in too much, hypoxia can injure or kill them as they are not breathing normal air. Breathing too much helium can also cause long-term effects to vocal cords.

Helium is created through the process of nuclear fusion in the Sun, and in similar stars. During this process, four hydrogen atoms are fused together to form one helium atom. On Earth it is made by the natural radioactive decay of heavy radioactive elements like thorium and uranium, although there are other examples. The alpha particles emitted by such decays consist of helium-4 nuclei. 

Helium was discovered by the French astronomer pierre Janssen on August 18, 1868, as a bright yellow line in the spectrum of the chromosphere of the Sun. The line was thought to be sodium. On the same year, English astronomer, Norman Lockyer, also observed it and found that it was caused by a new element. Lockyer and English chemist Edward Frankland named the element helium, from the Greek word for the Sun, ἥλιος (helios).

Helium is the second least reactive noble gas after neon. It is the second least reactive of all elements. It is chemically inert and monatomic in all standard conditions. Helium is the least water-soluble monatomic gas.

Helium is used as a shielding gas in growing silicon and germanium crystals, in making titanium and zirconium, and in gas chromatography, because it is inert. Helium is used as a shielding gas in arc welding.

Helium is mixed with oxygen and other gases for deep underwater diving because it does not cause nitrogen narcosis.

Helium is also used to condense hydrogen and oxygen to make rocket fuel. It is used to remove the fuel and oxidizer from ground support equipment before the rocket launches. It is used to cool liquid hydrogen in space vehicles before the rocket launches.

Helium is used as a heat-transfer medium in some nuclear reactors that are cooled down by gas. Helium is also used in some hard disk drives. Helium at low temperatures is used in cryogenics. 

Helium has become rare on Earth. If it gets free into the air it leaves the planet. Unlike hydrogen, which reacts with oxygen to form water, helium is not reactive. It stays as a gas. For many years after the 1925 Helium Act, the USA collected helium in a National Helium Reserve. American helium comes from wells in the Great Plains area. At present, more helium is supplied by Qatar than by the USA.

Several research organisations have released statements on the scarcity and conservation of helium. These organisations released policy recommendations as early as 1995 and as late as 2016 urging the United States government to store and conserve helium because of the natural limits to the helium supply and the unique nature of the element. For researchers, helium is irreplaceable because it is essential for producing very low temperatures. Helium at low temperatures is used in cryogenics, and in certain cryogenics applications. Liquid helium is used to cool certain metals to the extremely low temperatures required for superconductivity, such as in superconducting magnets for magnetic resonance imaging.




#Article 143: Home page (202 words)


The home page of a web site is the  that a web server sends to another computer's web browser application when it has been contacted without a request for specific information. That is, when one enters only a domain name in the Address box without specifying a directory or a file, the home page is usually the first part of the web site one would be taken to. The Home Page is also called the Main Page.

A properly written home page will tell a user about the information available in the web site, and how to view different parts of the web site.

The home page of simple.wikipedia.org can be found at this link.

Home Page was a popular computer application used for composing web pages.

In Linux-based servers, the homepage is default.html, default.php, etc. This is a problem for website administrators to install website applications like MediaWiki. Mainly because most website applications are created with the homepage as index.php for PHP applications.

However, in Windows-based servers, the homepage is default.html, default.php, etc. This is a problem for website administrators to install website applications like MediaWiki. Mainly because most website applications are created with the homepage as index.php (for PHP applications).




#Article 144: Hair (884 words)


 Hair is something that grows from the skin of mammals. Animal hair is usually called fur. Sheep and goats have curly hair, which is usually called wool. Hair is made of keratins, which are proteins.

Humans and some other animals have lost much of their hair through evolution, and some other mammals, such as the elephant and the whale, have almost none at all.

Hair can have different functions:

Some animals, for example certain insects and spiders also have hairs. However, these are not hair in the biological sense, but are actually bristles. The hairs found on certain plants are also not true hair, but trichomes.

In humans, hair grows mostly on the head, and the amount of body hair is different from race to race. Asians and native North Americans have the least amount of body hair, while Caucasians tend to have the most.

Hair color is passed down by parents only. Natural hair color can be given only by genes. It is impossible to have a hair color that is not passed down genetically by both mother and father. This relies on dominant and recessive genes carried by a parent.  These genes may not be the color of their hair, however, many people carry genes that are recessive and do not show in their traits or features.

Dyeing hair is to change the color of hair. It consists of a chemical mixture which can change the color of hair by a chemical reaction. Many people dye their hair to hide gray or white hairs.  This is because most people gain white or gray hairs as they grow older.

Two types of melanin pigment give hair its color: eumelanin and pheomelanin. Pheomelanin colors hair red. Eumelanin determines the darkness of the hair color. A low concentration of brown eumelanin results in blond hair, but more brown eumelanin will color the hair brown. High amounts of black eumelanin result in black hair, while low concentrations give gray hair. All humans have some pheomelanin in their hair.

The genetics of hair colors are not yet firmly established. According to one theory, at least two gene pairs control human hair color.

One phenotype (brown/blond) has a dominant brown allele and a recessive blond allele. A person with a brown allele will have brown hair; a person with no brown alleles will be blond. This explains why two brown-haired parents can produce a blond-haired child.

The other gene pair is a non-red/red pair, where the not-red allele  is dominant and the allele for red hair is recessive. A person with two copies of the red-haired allele will have red hair, but it will be either auburn or bright reddish orange depending on whether the first gene pair gives brown or blond hair, respectively.

The two-gene model does not account for all possible shades of brown, blond, or red (for example, platinum blond versus dark blonde/light brown), nor does it explain why hair color sometimes darkens as a person ages. Several other gene pairs control the light versus dark hair color in a cumulative effect (quantitative genetics).

Hair texture is also inherited genetically. The thickness of hair, its color and its tendency to curl are all inherited. There are also genetic differences between men and women. Body hair is limited in women, and thicker in men.

People have about 100,000 hairs on their head.  About 100 fall out each day, but they usually grow back. Some men are bald but girls and women may become bald if they lose their hair from a disease called alopecia.

Men often lose some of their hair as they grow older. This is known as baldness. Doctors call it male pattern baldness because hairs often fall out in similar places. It often begins by hair falling out first from the front of the head, and then from the top of the head. After a while, all that may be left is a some hair running above the ears and around the lower back of the head. Even though it is unusual for women to go bald, many women suffer from thinning hair over the top of their head as they grow old.

People have tried to find cures for hair loss for thousands of years. In an effort to get their hair back, men have tried cures like applying strange lotions or even having their heads packed in chicken manure. Many unproven cures are still marketed today. It is only in the last decade or so that treatments have been developed which do sometimes work. Some doctors do hair transplants, where they take tiny plugs of hair from areas like the back of the neck and plant them in the bald spots on the head. Some drugs have been tested and approved for sale as hair loss treatments. They encourage hair regrowth and thickening, but work better if applied before hair loss turns to baldness.

  People have been interested in hair on their heads for hundreds of thousands of years. For both men and women, styling and coloring hair have been ways to look good, and get attention. Sometimes society makes rules about hair, for example by not allowing people to cut their hair or beards, like in Sikhism (it is also good to do this in Islam, but not a requirement).




#Article 145: Ireland (1556 words)


Ireland (;  ; Ulster-Scots: ) is an island in the North Atlantic. It is about 486 kilometres (302 miles) long and about 288 kilometres (179 miles) wide. To the west of Ireland is the Atlantic Ocean; to the east of Ireland, across the Irish Sea, is the island of Great Britain. Over 6.4 million people lived on the island in 2016.

Today, the island of Ireland is made up of two countries: the Republic of Ireland and Northern Ireland:

From 1801 to 1921, all of Ireland was part of the same country, called the United Kingdom of Great Britain and Ireland. In 1919, a war broke out, the Irish War of Independence, and on December 6 1921, the Irish Free State became independent. After a new constitution came into effect in 1937, the state became a republic. Northern Ireland stayed with the UK, and this would lead to The Troubles beginning in the 1960s and ending with the Good Friday Agreement signed in 1998.

Ireland is traditionally divided into four provinces and thirty-two counties. Twenty-six counties are in the Republic and six in Northern Ireland. Three of the provinces are entirely within the Republic (Connacht, Leicester and Munster), and one province (Ulster) has some counties in both the Republic and in Northern Ireland.

Dublin is the largest city. It is the capital of the Republic of Ireland. Dublin was established as a Viking settlement in the 9th century. The population is 525,383 in Dublin City, and 1,270,603 in Co. Dublin.

Belfast is the capital of Northern Ireland. It has 483,000 people in the Greater Belfast urban area there are 267,000 in the city itself. Shipbuilding used to be a major industry here. The Titanic was built in Belfast at the Harland and Wolff shipyard.

Armagh is a city in Northern Ireland. It is often called the 'Ecclesiastic Capital of Ireland' as it is the seat of both the Catholic Church and the (Protestant) Church of Ireland. The population is 14,590.

Cork is the largest city in Munster. Corkonians often refer to it as 'the Real Capital'. The population is 119,230. but following a 2019 Cork boundary change|boundary extension in 2019, the population increased to c. 210,000.

Derry is the second largest city in Northern Ireland. Derry is notable for the Medieval city walls which still stand. Because the walls have never been breached, the city is nicknamed The Maiden City. In 2013 Derry was the UK Capital of Culture. Many cultural events took place there during the year. The population is 83,652.

During the last glacial period (the ice age), most of Ireland was covered with ice. After that, Ireland became covered with trees. The first people came to Ireland about 9,000 years ago, in the Middle Stone Age (Mesolithic period). They were nomadic. Once food ran out in the place they lived, they would move to another place. Evidence of these people was found in Mount Sandel, Co. Derry.

About 4000 BC, in the New Stone Age (Neolithic period), the first farmers arrived in Ireland. These people cleared openings in the forest and built permanent settlements with houses and farmland. When people in this age died, they were buried in tombs called megaliths. Many megaliths are left standing today, such as portal dolmens and passage tombs. The most famous megalith is Newgrange passage tomb in co. Meath.

New settlers came around 2000BC, marking the start of the Bronze Age. Copper was mined mainly in Mount Gabriel, Co. Cork and tin was imported from Cornwall. These people used bronze to make weapons, such as swords. They also used it to make early forms of jewellery, such as sun discs and torcs. These settlers buried the dead in court tombs or wedge tombs, and burial places have been found with stone circles.

It is unknown when the Celts came to Ireland, but it is likely they brought the use of iron with them. The use of iron marks the start of the Iron Age. It is known that by about 300BC, the use of iron and Celtic culture was widespread in Ireland. The Celts lived in ring forts, hill forts, promontory forts and crannógs. It is thought that only the richer families and settlements lived in crannógs. These were man-made islands in the middle of lakes with houses on them.

Celtic Ireland was split into around 150 kingdoms called tuath. The king was elected from the royal family. Below the king were the Nobles, and the Aos Dána, who were people with special skills, such as poets, Druids (priests), judges and craftsmen.

By the early 6th century, Ireland was mostly Christian through the work of St. Patrick and other missionaries. Druids were replaced by priests and monks. Monasteries soon were built such as Glendalough in co. Wicklow. Glendalough and other monasteries built round towers for safety when Vikings attacked. Small monasteries were also built in remote places, the most famous being Skellig Michael, off the coast of co. Kerry.

At this time many hand-written manuscripts were created by the monasteries. They include the Cathach, the Book of Durrow, and the Book of Kells. Monks also produced fine silver chalices, croziers and brooches, and carved high crosses.

In 1169, Anglo-Norman lords invaded Ireland. They were led by Strongbow who landed at Passage East, Co. Waterford. The Anglo-Normans conquered many parts of Ireland in the following 60 years. They introduced their way of life to the Irish people. The feudal system was soon introduced in Ireland as a means of organising land. Castles were built to defend the land like Trim Castle, Co. Meath. During the Middle Ages, Ireland's first proper towns were built.

From 1801 until 1921, all of Ireland was part of the United Kingdom of Great Britain and Ireland. In 1921 Northern Ireland was created and 'partitioned' from the south. Northern Ireland has stayed within the United Kingdom since then. The full name of the UK is 'The United Kingdom of Great Britain and Northern Ireland'.

In 1921 the south became the Irish Free State. In 1937 the Irish Free State adopted a new constitution which named the state 'Ireland', and in 1948 this state passed the Republic of Ireland Act which declared it to be a republic.

Many Irish people have left Ireland and moved to the United States, Canada, Australia, and South America. The Great Famine in the 1840s forced many to leave; it is estimated almost a million people died of starvation, and a million more emigrated. From a maximum of over 8 million in 1841, the total Irish population dropped to just over 4 million in the 1940s. Since then, the population has grown to over 6 million. This has been helped by the economic growth of the Celtic Tiger and since 2004 immigration from countries in Eastern Europe such as Poland.

Today almost 80 million people around the world are descended from Irish immigrants.

Ireland's main sports are Gaelic Games (Gaelic football, hurling, etc.) and soccer.

The many sports played and followed in Ireland include Gaelic games (mainly Gaelic football, hurling and camogie), horse racing, show jumping, greyhound racing, basketball, fishing, handball, motorsport, MMA, boxing, target shooting and tennis. Hockey, golf, rowing, cricket, rugby union and Olympic target shooting are organised on an all-island basis, with a single team representing the whole of Ireland in international competitions. Other sports, such as soccer and netball, have separate organizing bodies in Northern Ireland and the Republic of Ireland.

As Northern Ireland is a constituent nation of the United Kingdom it also sends a Northern Ireland Team to the Commonwealth Games. At the Olympic Games, a person from Northern Ireland can choose to represent either Ireland or Great Britain.

Soccer is the most popular team sport in terms of participation. According to the Irish Sports Monitor 2015 annual report, 4.8% of adults over 15 participate in Soccer. Gaelic football 2%, camogie 1.2, rugby 1.1%. Individual exercise pursuits are most popular with 43% of all sport participated by individuals on their own. Personal exercise 13.7%, running 8.2%, swimming 8%, cycling 5.5%, dancing 3%, golf 2.7%, weights 2.3%, yoga 1.5% and pilates 1.4%.

Soccer is by far the most popular team pursuit for males at 8.8% with Gaelic football attracting 3.4%. Personal exercise 13.4% and running 8.9% are the most popular male activities. Team sports do not figure highly amongst females with dancing at 4.6% and yoga 2.4% are two of the highest shared activities.

Given the variety of sports in Ireland, it is of interest to note how the government's Capital Sports programme 2017 allocated it's €56 million funds. €23.5 million went to the GAA which highlights the strength of the GAA lobby. €7.25 million to soccer, Rugby €3.1 million, tennis €2.64 million, golf €1.97 million, sailing €1.21 million, athletics just under €1 million, diving €451,000 while other sports did not fare so well.

Gaelic Football is one of the most popular sports in Ireland in terms of match attendance, and in 2003 had 34% of total sports attendances at events in the Republic of Ireland, followed by hurling at 23%, soccer at 16% and rugby at 8%. Initiative's ViewerTrack study, which measured 2005 sports audiences, showed the sport's highest-profile match, the All-Ireland Football Final, to be the most watched event of the nation's sporting year. Soccer is the most played team sport in Ireland.




#Article 146: Internet (387 words)


The Internet is the biggest world-wide communication network of computers. The Internet has millions of smaller domestic, academic, business, and government networks, which together carry many different kinds of information. The short form of internet is the 'net'. The World Wide Web is one of its biggest services. It is used by billions of people all over the world.

The Internet was developed in the United States by the United States Department of Defense Advanced Research Projects Agency (DARPA). The Internet was first connected in October of 1969 and was called ARPANET. The World Wide Web was created at CERN in Switzerland in 1990 by a British (UK) scientist named Tim Berners-Lee.

Today, people can pay money to access the Internet from internet service providers. Some services on the Internet cost nothing to use. Sometimes people who offer these free services use advertising to make money. Censorship and freedom of speech on the Internet can be controversial.

The Internet is used for many things, such as electronic mail, online chat, file transfer and other documents of the World Wide Web.

The most used service on the Internet is the World Wide Web (which is also called the Web or “www”). The web contains websites, including blogs and wikis like Wikipedia. Webpages on the Internet can be seen and read by anyone (unless the page needs a password, or it is blocked).

The second biggest use of the Internet is to send and receive e-mail. E-mail is private and goes from one  to another. Instant messaging is similar to email, but allows two or more people to chat to each other faster.

Some governments think the internet is a bad thing, and block all or part of it.  For example, the Chinese government thinks that Wikipedia is bad, so often no one in China can read it or add to it. Another example of the internet being blocked is in North Korea. Some parents and schools block parts of the Internet they think are bad for children to see.

The Internet makes communication easy, and communication can be dangerous too. People often send secret information, and sometimes other people can steal that information. They can use the Internet to spread lies or stolen secrets or dangerously bad advice. For example, Facebook has had some problems with privacy settings.  




#Article 147: Italy (1612 words)


Italy is a country in south Europe and a member of the European Union. Its official name is Repubblica Italiana. The Italian flag is green, white and red. Italy is a democratic republic and is a founding member of the European Union. Its President is Sergio Mattarella and its Prime Minister is Giuseppe Conte. 
Italy is also a member of the G8, as it has the eighth largest Gross Domestic Product in the world.

Before 1861, it was made up of smaller kingdoms and city-states. Italy has become famous for its wine, as well as its food. Some foods are different between regions. Famous dishes include various types of pasta, pizza, and grapes. Olives are much used.

The country's capital, Rome, is one of the most famous cities in the world, as it was the capital of the Roman Empire. Other famous cities in Italy include, Venice, Naples, Genoa, Florence, Palermo, and Milan.

Italy is a peninsula, meaning it is encompassed by the sea on all of its sides apart from one side of the country (its north side). Northern Italy is separated from France, Switzerland, and Austria by the Alps, a chain of mountains. Mont Blanc (Monte Bianco in Italian or white mountain in English), the highest mountain in western Europe, belongs to this chain. The second important chain of mountains in Italy is the Apennines (Appennini in Italian), which are in central and southern Italy.

The capital of Italy is Rome where the Roman Empire started. Other cities in Italy are Milan, Turin, Florence, Genoa, Naples, Palermo, and Venice. The country has a number of islands, the biggest of which are Sicily and Sardinia, which can be reached by ship or aircraft. It shares maritime borders with Libya to the south.

The Po River is the longest river in Italy. It flows through 5 cities: Torino, Piacenza, Cremona Ferrara and Rovigo. The Tiber River runs through the city of Rome.

Northern Italy has some of the biggest lakes in the country, such as Lake Garda, Lake Como, Lake Maggiore and Lake Iseo. Because it is surrounded by the sea, Italy has many kilometers of coast, which brings tourists from all over the world.  Tourists also come to see Italy's historical places.

Two very small separate countries are located within Italy. They are San Marino, which is surrounded by part of Northern Italy, and the Vatican City, which is inside Rome.

People from Italy are called Italians. Even if an Italian were to leave Italy, it is possible that their descendants could also claim Italian citizenship due to Italian nationality law relying mostly on ius sanguinis or right of blood in Latin. Nearly all the Italians are Christians, and most of these are Roman Catholics, which is based in the Vatican City and home to its leader, the Pope. Leonardo da Vinci is a famous artist, he is the creator of the Mona Lisa which is now in the louvre Paris.

The population of Italy is a little over 60 million. About 2.7 million of them live in Rome, and 1.3 million in Milan. As of 31 December 2015, over 5 million foreigners were living in Italy, which is 8.3% of the total population.

The official language of Italy is Italian and in some small areas German, Slovenian or French. People also speak dialects of Italian such as Sicilian and Sardinian.  There are many different dialects spoken in Italy.  They vary between regions and, in some cases, also between provinces.

The people of Italy are mostly descendant from the ancient Romans.

Italy is home to more World Heritage Sites than any other nation in the world. These sites are culturally important and valued according to UNESCO. About 60% of the works of art of the world are in Italy. Italy is also a big wine producer. In 2005 it made over 5 million tonnes.

Italy has a modern social welfare system. The labor market enjoys relative strength, with many foreigners, especially from Romania, working in Italy where the wages are much higher. But it could have been much more workers on the labor market because men and women already retired in the age of 57 and the unemployment rate is relatively high at 8.2 percent. Italy's modern society has been built up through loans and now the country has a catastrophic high debt of €1.9trn or 120 percent of the country's total GDP. And the government cannot pay back the loans during the time period the EU wish.

Most people in Italy are Roman Catholics, but the Catholic Church is no longer officially the state religion. 87.8% of the people said they were Roman Catholic.
Only about a third said they were active members (36.8%). There are also other Christian groups in Italy, more than 700,000 Eastern Orthodox Christians. 180,000 of them belong to the Greek Orthodox Church.

The country's oldest religious minority is the Jewish community. It has roughly 45,000 people. It is no longer the largest non-Christian group.
About 825,000 Muslims live in Italy. Most of them immigrated. (1.4% of the total population) Only 50,000 are Italian citizens. In addition, there are 50,000 Buddhists 70,000 Sikh and 70,000 Hindus in Italy.

During the celebration of Epiphany, it's traditional to eat a special cake called 'Rosca de Reyes' Three Kings Cake. A figure of Baby Jesus is hidden inside the cake. Whoever has the baby Jesus in their piece of cake is the 'Godparent' of Jesus for that year. Famous Italian foods include pasta or pizza.

Italy is  into 20 Regions (Regioni in Italian) and every Region is divided into Provinces.

There are 20 Regions. 5 of them have a special status, they are called autonomous. This means that they can make certain local laws more easily. These regions are marked with an asterisk (*) below.  

The Head of State is Sergio Mattarella, whose task began in February 2015. Mattarella is currently the President of the Italian Republic. The first president was Enrico De Nicola.

The Head of Government is Paolo Gentiloni, who became Prime Minister on December 12, 2016, succeeding Matteo Renzi. Renzi was previously the Mayor of Florence and is Italy's youngest-ever Prime Minister, at age 39 when taking office.

Italy was one of the first members of the European Union and in 2002 along with 11 other European countries, it changed to using the euro as its official currency. Before this, the Italian lira had been used since 1861.

Anyone who wants to be President of Italy must have Italian citizenship, be at least 50 years old, and must be able to hold political and civil rights.

Before 1861, Italy was not a state.  The area was made of a group of separate states, ruled by other countries (such as Austria, France, and Spain).  In the 1850s the Earl of Camillo Benso, Count of Cavour was the Head of Government of the State of Sardinia. He talked to the Austrians in Lombardy and Veneto and said they should create a Northern Italian state. This happened, but other Central and Southern Italian states also joined Piedmont to create a bigger state.

In 1860, Giuseppe Garibaldi took control of Sicily, creating the Kingdom of Italy in 1861. Victor Emmanuel II was made the king. But in 1861, Latium and Veneto were still not part of Italy, because they were ruled by the Pope and Austrian Empire.

Veneto was made part of Italy in 1866 after a war with Austria, and Italian soldiers won Latium in 1870. That was when they took away the Pope's power. The Pope, who was angry, said that he was a prisoner to keep Catholic people from being active in politics. That was the year of Italian unification.

Italy participated in World War I as an ally of Great Britain, France, and Russia against the Central Powers. Almost all of Italy's fighting was on the Eastern border, near Austria. After the Caporetto defeat, Italy thought they would lose the war. But, in 1918, the Central Powers ed, and Italy gained the Trentino-South Tyrol, which once was owned by Austria.

In 1922, a new Italian government started. It was ruled by Benito Mussolini, the leader of Fascism in Italy. He became Head of Government and dictator, calling himself duce - which means leader in Italian. He became friends with German dictator Adolf Hitler. Germany, Japan, and Italy became the Axis Powers and entered World War II together in 1940 against France, Great Britain, and later the Soviet Union. During the war, Italy controlled most of the Mediterranean Sea.

On July 25, 1943, Mussolini was removed by the Great Council of Fascism, and, on September 8, 1943, Badoglio said that the war as an ally of Germany was ended. Italy started fighting as an ally of France and the UK, but Italian soldiers did not know whom to shoot. In Northern Italy, a  called Resistenza started to fight against the German invaders.

Mussolini tried to make a small Northern Italian fascist state, the Republic of Salò, but it failed. On April 25, 1945, Italy became free. The state became a republic on June 2, 1946, and, for the first time, women were able to vote. Italian people ended the Savoia dynasty and adopted a republic government.

In February 1947, Italy signed a peace treaty with the Allies losing all the colonies and some territorial areas: (Istria and parts of Dalmatia).

Since then Italy has joined NATO and the European Community (as a founding member), becoming one of the seven biggest industrial economies in the world.

The railway  in Italy totals , the 17th longest in the world. High speed trains include ETR-class trains which travel at .




#Article 148: Island (107 words)


An island is a piece of ground that is surrounded by a body of water such as a lake, river or sea. Water is all around an island. Islands are smaller than continents. The largest island in the world is Greenland, unless Australia is believed to be an island.

Most people think Australia is a continent because it is more than three times bigger than Greenland. 

Some islands are their own countries. Examples of islands that are their own countries include Cuba, Iceland, and Cyprus. There are many others. Other islands have more than one country, such as Borneo and Hispaniola.

There are many kinds of island: 




#Article 149: Idiom (416 words)


An idiom is a common phrase which means something different from its literal meaning but can be understood because of their popular use. 

Because idioms can mean something different from what the words mean it is difficult for someone not good at speaking the language to use them properly. Some idioms are only used by some groups of people or at certain times. The idiom shape up or ship out, which is like saying improve your behavior or leave if you don't, might be said by an employer or supervisor to an employee, but not to other people.

Idioms are not the same thing as slang. Idioms are made of normal words that have a special meaning known to almost everyone. Slang is usually special words, or special meanings of normal words that are known only to a particular group of people.

To learn a language a person needs to learn the words in that language, and how and when to use them. But people also need to learn idioms separately because certain words together or at certain times can have different meanings. In order to understand an idiom, one sometimes needs to know the culture from which the idiom comes.

To know the history of an idiom can be useful and interesting, but is not necessary to be able to use the idiom properly.  For example, most native British English speakers know that No room to swing a cat means there was not much space and can use the idiom properly.  However, few know this is because 200 years ago sailors were punished by being whipped with a cat o' nine tails. A big space was cleared on the ship so that the person doing the whipping had room to swing the cat.

An idiom is a phrase whose meaning cannot be understood from the dictionary definitions of each word taken separately. The linguist's term for the real meaning of an idiom is the subtext.

Articles by Oxfam and the BBC have said that many idioms in English are unclear, or ambiguous. Many are understood differently in different countries. Many of the examples are taken from face-to-face talk, but may also apply in written reports.

Vocables are sounds that are not proper words, but mean something, and are often ambiguous.  One is a long drawn-out sound hmmmmmm.

One suggestion is that these idioms are used to smooth over difficult areas in social interaction. They cover passive-aggressive statements which might cause more conflict if openly expressed.




#Article 150: Ink (228 words)


Ink is a liquid that is used to write, draw, print, or make marks. The word ink is from Latin and means colored water. Ink is used in pens, in some computer printers, and in printing presses. In some countries, people write by using ink and brushes. People usually write or print using black ink, but ink can be any color. The first ink was used in Egypt about 2600 BC.

The first inks were carbon inks, made from soot, which is 80% carbon, water and gum arabic. Red ink would need iron oxide (such as haematite) from ground rocks instead of soot. Later, in Europe, people used iron gall ink. This is the kind of ink Johann Sebastian Bach and Leonardo da Vinci used. Now ink colours are produced by man-made dyes.

A disadvantage of many kinds of ink is that they may smudge when wet, spoiling the picture or writing. If water-based ink is used, the writing situation needs to be stable, with the writer seated at a table. Ink in a ballpoint pen (biro) is a kind of gel. It is held in a thin long cylinder (tube) inside the pen. The ink does not fall out of the cylinder as it sticks to the sides of the tube. Therefore ballpoint pens can be used in a wider range of circumstances compared to water-based inks.




#Article 151: Inch (301 words)


The inch is a unit of length in the Imperial system and the United States customary system. The abbreviation for inches is in or . There are 12 inches in a foot. One inch is equal to 2.54 centimetres.

The word inch came from Middle English unche, which came from Old English ynce, from Latin uncia meaning a twelfth part.

The inch was originally defined as 3 barleycorns. The inch was finally standardised in the International Yard and Pound Treaty in 1959 between the United States, the United Kingdom, South Africa, Australia, New Zealand and Canada. The international yard was made equal to 0.9144 metres. From this, subdivisions and multiples of the yard were specifically defined.

In Britain and the United States, people use inches more than they use millimetres or centimetres. In the rest of the world, international units are almost always used. The inch is not used by scientists.

In the United Kingdom, road signs that show how high a vehicle can be in order to pass through a tunnel are required to be in feet and inches. Theme parks and drive thru signs usually show it in metres. People regularly measure their height in feet and inches. Official medical records, however, are required to record people's height in metric measurements only.

In Canada, a mix of centimetres and inches are used in height. Older generations, especially, use Imperial units. A lot of exposure to Americanized phrases leads to younger generations often having a good understanding of both the Imperial and metric systems.

In the United States, height is always in feet and inches. Science is the only field to use metric measurements.

Other Commonwealth countries, including Ireland, Australia, New Zealand, South Africa and Jamaica use inches to varying degrees. From every day use to exclusively the older community.




#Article 152: Pint (263 words)


The pint (abbreviated pt) is a unit of volume in imperial units and United States customary units. There are three types of pints used in different countries. An imperial pint and US pint both equal  of a quart and  of a gallon.

An imperial fluid ounce is approximately 4% smaller than a US fluid ounce although an imperial pint has 4 more fluid ounces than a US pint, making an imperial pint approximately 20% larger than a US pint.

The imperial pint is the pint used in England, Canada, Ireland, and Burma. The unit may appear in other Commonwealth. Confusion in Canada often arises as liquids are occasionally sold in U.S. pints, near the border, although the official and only pint that is legal in Canada is the imperial pint. The imperial system has no dry pint and volume in dry units, since solid objects are measured by mass. 1 imperial pint equals 568,261.25 mm3.

An imperial fluid ounce is approximately 4% smaller than a US fluid ounce although an imperial pint has 4 more fluid ounces than a US pint, making an imperial pint approximately 20% larger than a US pint.

The US wet pint, or more commonly 'pint', is the unit used to measure volume in the United States. It is more common than the dry pint which is used for non-liquid volume measurements. 1 US pint is exactly equal to 473,176.473 mm3, defined by the international yard and pound agreement.

The US dry pint was a unit used for measuring the volume of solid objects instead of mass or quantity. 




#Article 153: India (2649 words)


India or the Republic of India (official name) is a country in Asia. It has an area of . It is at the center of South Asia. India has more than 1.2 billion (1,210,000,000) people, which is the second largest population in the world. It is the seventh largest country in the world by area and the largest country in South Asia. It is also the most populous democracy in the world.

India has seven neighbours: Pakistan in the north-west, China and Nepal in the north, Bhutan and Bangladesh in the north-east, Myanmar in the east and Sri Lanka, an island, in the south.

The capital of India is New Delhi. India is a peninsula, bound by the Indian Ocean in the south, the Arabian Sea on the west and Bay of Bengal in the east. The coastline of India is of about  long. India has the third largest military force in the world and is also a nuclear weapon state.

India's economy became the world's fastest growing in the G20 developing nations in the last quarter of 2014, replacing the People's Republic of China. India's literacy and wealth are also rising. According to New World Wealth, India is the seventh richest country in the world with a total individual wealth of $5.6 trillion. However, it still has many social and economic issues like poverty and corruption. India is a founding member of the World Trade Organisation (WTO), and has signed the Kyoto Protocol.

India has the fourth largest number of spoken languages per country in the world, only behind Papua New Guinea, Indonesia, and Nigeria. People of many different religions live there, including the five most popular world religions: Hinduism, Buddhism, Sikhism, Islam, and Christianity. The first three religions came from the Indian subcontinent along with Jainism.

The National emblem of India shows four lions standing back-to-back. The lions symbolise power, pride, confidence, and courage (bravery). Only the government can use this emblem, according to the 

The name India comes from the Greek word, Indus. This came from the word sindhu, which in time turned into Hind or Hindi or Hindu. The preferred native name or endonym is Bharat in Hindi and other Indian languages as contrasted with names from outsiders. Some of the national symbols are:

National anthem- jana gana mana

National song- vande mataram 

National animal- royal bengal tiger

National bird- peacock

National flower- lotus 

National tree- banyan

National river- ganges(ganga)

National fruit- mango

National heritage animal- elephant

National heritage bird- Indian Eagle

Two of the main classical languages of the world Tamil language and Sanskrit language were born in India. Both of these languages are more than 3000 years old. The country founded a religion called Hinduism, which most Indians still follow. Later, a king named Chandragupt Maurya built an empire called  the Maurya Empire in 300 BC. It made most of South Asia into one whole country. From 180 BC, many other countries invaded India. Even later (100 BC  AD 1100), other Indian dynasties (empires) came, including the Chalukyas, Cholas, Pallavas, and Pandyas. Southern India at that time was famous for its science, art, and writing. The Cholas of Thanjavur were pioneers at war in the seas and invaded Malaya, Borneo, Cambodia. The influence of Cholas are still well noticeable in SE Asia.

Many dynasties ruled India around the year 1000. Some of these were the Mughal, Vijayanagara, and the Maratha empires. In the 1600s, European countries invaded India, and the British controlled most of India by 1856.

In the early 1900s, millions of people peacefully started to  against British control. One of the people who led the freedom movement was Mahatma Gandhi, who only used peaceful tactics, including a way called ahimsa, which means non-violence. On 15 August 1947, India peacefully became free and independent from the British Empire. India's constitution was founded on 26 January 1950. Every year, on this day, Indians celebrate Republic Day. The first official leader (Prime Minister) of India was Jawaharlal Nehru.

After 1947, India had a socialist planned economy. It is one of the founding members of the Non-Aligned Movement and the United Nations. It has fought many wars since independence from Britain, including the wars in 1947-48, 1965, 1971, and 1999 with Pakistan and in 1962 with China. It also fought a war to capture Goa, a Portuguese-built port and a city which was not a part of India until 1961. The Portuguese refused to give it to the country, and so India had to use force and the Portuguese were defeated. India has also done nuclear tests in 1974 and 1998, and it is one of the few countries that has nuclear bombs. Since 1991, India has been one of the fastest-growing economies in the world.

India is the largest democracy in the world.

India's government is divided into three parts: the Legislative (the one that makes the laws, the Parliament), the Executive (the government), and the Judiciary (the one that makes sure that the laws are obeyed, the supreme court).

The legislative branch is made up of the Parliament of India, which is in New Delhi, the capital of India. The Parliament of India is divided into two houses: the upper house, Rajya Sabha (Council of States); and the lower house, Lok Sabha (House of People). The Rajya Sabha has 250 members, and the Lok Sabha has 552 members.

The executive branch is made up of the President, Vice President, Prime Minister, and the Council of Ministers. The President of India is elected for a period of five years. The President can choose the Prime Minister, who has most of the power. The Council of Ministers, such as the Minister of Defence, help the Prime Minister. Narendra Modi became the Prime Minister of India on May 16, 2014. He is the 19th Prime Minister of India. The president has less power than the prime minister.

The judicial branch is made up of the courts of India, including the Supreme Court. The Chief Justice of India is the head of the Supreme Court. Supreme Court members have the power to stop a law being passed by Parliament if they think that the law is illegal and contradicts (opposes) the Constitution of India. In India, there are also 24 High Courts.

India is the seventh biggest country in the world. It is the main part of the Indian subcontinent. The countries next to India are Pakistan, Bangladesh, Myanmar, China, Bhutan, and Nepal. It is also near Sri Lanka, an island country.

India is a peninsula, which means that it is surrounded on three sides by water. One of the seven wonders of the world is in Agra: the Taj Mahal. In the west is the Arabian Sea, in the south is the Indian Ocean, and in the east is the Bay of Bengal. The northern part of India has many mountains. The most famous mountain range in India is the Himalayas, which have some of the tallest mountains in the world. There are many rivers in India. The main rivers are the Ganges, the Brahmaputra, the Yamuna, the Godavari, the Kaveri, the Narmada, and the Krishna.

India has different climates. In the South, the climate is mainly tropical, which means it can get very hot in summer and cool in winter. The northern part, though, has a cooler climate, called sub-tropical, and even alpine in mountainous regions. The Himalayas, in the alpine climate region, can get extremely cold. There is very heavy rainfall along the west coast and in the Eastern Himalayan foothills. The west, though, is drier. Because of some of the deserts of India, all of India gets rain for four months of the year. That time is called the monsoon. That is because the deserts attract water-filled winds from the Indian Ocean, which give rain when they come into India. When the monsoon rains come late or not so heavily, droughts (when the land dries out because there is less rain) are possible. Monsoons normally come around July - August.

The Indian Armed Forces is the military of India. It is made up of an Army, Navy and Air Force. There are other parts like Paramilitary and Strategic Nuclear Command.

The President of India is the Commander-in-Chief. However, it is managed by the Ministry of Defence. In 2010, the Indian Armed Forces had 1.32 million active personnel. This makes it one of the largest militaries in the world.

The Indian Army is becoming more modern by buying and making new weapons. It is also building defenses against missiles of other countries. In 2011, India imported more weapons than any other nation in the world.

From its independence in 1947, India fought four wars with Pakistan and a war with China.

For administration purposes, India has been divided into smaller pieces. Most of these pieces are called states, some are called union territories. States and union territories are different in the way they are represented. Most union territories are ruled by administrators sent by the central government. All the states, and the territories of Delhi, and Puducherry elect their local government themselves. In total, there are twenty-eight states, and nine union territories.

Union territories:

There are  about certain parts of the Indian borders. Countries do not agree on where the borders are. Pakistan and China do not recognise the disputed territory of Jammu and Kashmir. The Indian government claims it as an Indian state. Similarly, the Republic of India does not recognise the Pakistani and Chinese parts of Kashmir.

In 1914, British India and Tibet agreed on the McMahon Line, as part of the Simla Accord. In July 1914, China withdrew from the agreement. Indians and Tibetans see this line as the official border. China does not agree, and both mainland China and Taiwan do not recognize that  Arunachal Pradesh belongs to India. According to them, it is a part of South Tibet, which belongs to China.

The economy of the country is among the world's fastest growing. It is the 7th largest in the world with a nominal GDP of $2,250 billion (USD), and in terms of PPP, the economy is 3rd largest (worth $8.720 trillion USD). The growth rate is 8.25% for fiscal 2010. However, that is still $3678 (considering PPP) per person per year. India's economy is based mainly on:

India's economy is diverse. Major industries include automobiles, cement, chemicals, consumer electronics, food processing, machinery, mining, petroleum, pharmaceuticals, steel, transportation equipment, and textiles.

However, despite economic growth, India continues to suffer from poverty. 27.5% of the population was living in poverty in 2004–2005. In addition, 80.4% of the population live on less than USD $2 a day, which was lowered to 68% by 2009.

There are 1.21 billion people living in India. India is the second largest country by the number of people living in it, with China being the first. Experts think that by the year 2030, India will be the first. About 65% of Indians live in rural areas, or land set aside for farming. The largest cities in India are Mumbai, Kolkata, Delhi, Chennai, Bangalore, Hyderabad, and Ahmedabad. India has 23 official languages. Altogether, 1,625 languages are spoken in India.

There are many different languages and cultures in India. The only geographical place with more different languages and cultures is the African continent. There are two main language families in India, the Indo-Aryan and the Dravidian languages. About 69% of Indians speak an Indo-Arayan language, about 26% speak a Dravidian language. Other languages spoken in India come from the Austro-Asiatic group. Around 5% of the people speak  a Tibeto-Burman language.

Hindi is the official language in India with the largest number of speakers. It is the official language of the union. Native speakers of Hindi represent about 41% of the Indian population (2001 Indian census). English is also used, mostly for business and in the administration. It has the status of a 'subsidiary official language'. The constitution also recognises 21 other languages. Either many people speak those languages, or they have been recognised to be very important for Indian culture. The number of s in India is as high as 1,652.

In the south of India, many people speak Kannada, Telugu, Tamil and Malayalam. In the north, many people speak Chhattisgarhi, Punjabi, Bengali, Gujarati, and Marathi, Odia, and Bihari.

India has 27 official languages. Its constitution lists the name of the country in each of the languages. Hindi and English (listed in boldface) are the official languages of the union (Union meaning the Federal Government in Delhi); Tamil,Sanskrit, Telugu, Kannada, Malayalam, and Odia are officially the classical languages of India.

Cave paintings from the Stone Age are found across India. They show dances and rituals and suggest there was a prehistoric religion. During the Epic and Puranic periods, the earliest versions of the epic poems Ramayana and Mahabharata were written from about 500–100 BCE, although these were   for centuries before this period. Other South Asian Stone Age sites apart from Pakistan are in modern India, such as the Bhimbetka rock shelters in central Madhya Pradesh and the Kupgal petroglyphs of eastern Karnataka, contain rock art showing religious rites and evidence of possible ritualised music.

Several modern religions are linked to India, namely modern Hinduism, Jainism, Buddhism and Sikhism. All of these religions have different schools (ways of thinking) and traditions that are related. As a group they are called the Eastern religions. The Indian religions are similar to one another in many ways: The basic beliefs, the way worship is done and several religious practices are very similar. These similarities mainly come from the fact that these religions have a common history and common origins. They also influenced each other.

The religion of Hinduism is the main faith followed by 79.80% of people in the Republic of India; Islam – 14.23%; Christianity – 2.30%; Sikhism – 1.72%; Buddhism – 0.70% and Jainism – 0.37%.

It's the first time ever since independence that Hindu population percentage fell below 80%.

India sent a spacecraft to Mars for the first time in 2014. That made it the third country and only Asian country to do so, successfully. India is the only country to be successful in its very first attempt to orbit Mars. It was called the Mars Orbiter Mission.

ISRO launched 104 satellites in a single mission to create world record. India became the first nation in the world to have launched over a hundred satellites in one mission. That was more than the 2014 Russian record of 37 satellites in a single launch.

India has the largest movie industry in the world. Based in Mumbai (formerly Bombay), the industry is also known as Bollywood. It makes 1,000 movies a year, about twice as many as Hollywood. It produces movies almost everyday.

Indians have excelled in Hockey. They have also won eight gold, one silver and two bronze medals at the Olympic games. However, cricket is the most popular sport in India. The Indian cricket team won the 1983 and 2011 Cricket World Cup and the 2007 ICC World Twenty20. They  the 2002 ICC Champions Trophy with Sri Lanka and won the 2013 ICC Champions Trophy.Cricket in India is controlled by the Board of Control for Cricket in India or BCCI. Domestic tournaments are the Ranji Trophy, the Duleep Trophy, the Deodhar Trophy, the Irani Trophy and the Challenger Series. There is also the Indian cricket league and Indian premier league Twenty20 competitions.

Tennis has become popular due to the victories of the India Davis Cup team. Association football is also a popular sport in northeast India, West Bengal, Goa and Kerala. The Indian national football team has won the South Asian Football Federation Cup many times. Chess, which comes from India, is also becoming popular. This is with the increase in the number of Indian Grandmasters. Traditional sports include kabaddi, kho kho, and gilli-danda, which are played throughout India.




#Article 154: Insult (179 words)


An insult is a description of someone that will  them. It may or may not be true. It is called derogatory language. Terms like , ,  and  are insults, because they say that a person's mind is not quick or smart.

Insulting someone's mother directly is a serious insult in many cultures.

Ritual insults are part of many cultures. For example, they can be found in sports and military training. They are also very common in jargons. For example, the word newbie is a part of net jargon. Calling someone a newbie is usually insulting.

One should be very careful when using new words to describe others.

Usually, someone insults others because they want to feel like they are better or have more power (influence) than the people they insult. They may want this because they are actually afraid that they are worse or less powerful than the people they are insulting.

When someone is insulted, his or her pride is hurt. He or she may want to fight back by insulting the person who insulted him or her.




#Article 155: Immunology (785 words)


Immunology is the study of the immune system. The immune system is the parts of the body which work against infection and parasitism by other living things. Immunology deals with the working of the immune system in health and diseases, and with malfunctions of the immune system.

An immune system is present in all plants and animals. We know this because biologists have found genes coding for toll-like receptors in many different metazoans. These toll-like receptors can recognise bacteria as 'foreign', and are the starting-point for immune reactions. The type of immunity which is triggered by the toll-like receptors is called innate immunity. This is because it is entirely inherited in our genome, and is fully working as soon as our tissues and organs are properly developed.

Vertebrates, and only vertebrates, have a second type of immunity. This is called adaptive immunity, because it 'remembers' previous infections. Then, if the same infection occurs again, the reaction is much stronger and faster. This immunological memory confers a tremendous survival advantage and with it vertebrates can survive over a long lifetime in a pathogen-filled environment.

The innate immune system is usually means all of the cells and systems that does not have to be exposed to a particular pathogen before they can work.

Innate immunity starts with the skin, which is an excellent barrier to infection.

The adaptive immune system includes cells and systems that do require previous exposure to a pathogen. It explains the unique ability of the mammalian immune system to remember previous infections and mount a rapid and robust reaction to secondary infections.  This immunological memory is due to the biology of T-cells and B-cells.

Vaccines boost the acquired immune system by offering weak forms of infection that the body can fight off. The system remembers how to do it again when a stronger infection happens. If the vaccine works, the body can then fight off a serious infection.

The distribution of vaccines and other immune system affecting cures can be considered another level of acquired immune system, one governed by access to vaccination and medicine in general.  The intersection of this with the spread of disease (as studied in epidemiology) is part of the field of public health.

Errors of the immune system may cause damage. In autoimmune diseases, the body attacks parts of itself because the system mistakes some parts of the body as 'foreign'. Some kinds of arthritis are caused this way.

Sometimes serious pathogens slip in because their surface is disguised as something the host cell walls can accept. That is how viruses work. Once inside a cell, their genetic material controls the cell. Infections like HIV get in this way, and then attack cells which are the basis of the immune system. Artificial means are often used to restore immune system function in an HIV-challenged body, and prevent the onset of AIDS.  This is one of the most complex issues in immunology as it involves every level of that system.  This research during the 1980s and 1990s radically changed the view of the human immune system and its functions and integration in the human body.

Immunology is a science that examines the structure and function of the immune system. It originates from medicine and early studies on the causes of immunity to disease. The earliest known mention of immunity was during the plague of Athens in 430 BC. Thucydides (460–395 BC) noted that people who had recovered from a previous bout of some diseases could nurse the sick without contracting the illness a second time.

In the 18th century, Pierre-Louis Moreau de Maupertuis made experiments with scorpion venom and observed that certain dogs and mice were immune to this venom. This and other observations of acquired immunity led to Louis Pasteur (1822–1895) developing vaccination and the germ theory of disease. Pasteur's theory was in direct opposition to contemporary theories of disease, such as the miasma theory. It was not until the proofs Robert Koch (1843–1910) published in 1891 (for which he was awarded a Nobel Prize in 1905) that microorganisms were confirmed as the cause of infectious disease. Viruses were confirmed as human pathogens in 1901, when the yellow fever virus was discovered by Walter Reed (1851–1902).

Immunology made a great advance towards the end of the 19th century, through rapid developments, in the study of humoral immunity and cellular immunity. Particularly important was the work of Paul Ehrlich (1854–1915), who proposed the side-chain theory to explain the specificity of the antigen-antibody reaction. The Nobel Prize for 1908 was jointly awarded to Ehrlich and the founder of cellular immunology, Ilya Mechnikov (1845–1916).

The simplest form of immunity is the DNA restriction system in bacteria that prevents infection by bacteriophages.




#Article 156: Infinity (558 words)


Infinity is about things which never end. 
Sometimes, it is also written . Infinity means many different things, depending on when it is used. The word is from Latin origin, meaning without end. Infinity goes on forever, so sometimes space, numbers, and other things are said to be 'infinite', because they never come to a stop.

Infinity is usually not an actual number, but it is sometimes used as one. Infinity often says how many there is of something, instead of how big something is. For example, there are infinitely many whole numbers (called integers), but there is no integer which is infinitely big. But different kinds of math have different kinds of infinity. So its meaning often changes.

There are two kinds of infinity: potential infinity and  infinity. Potential infinity is a process that never stops. For example, adding 10 to a number. No matter how many times 10 is added, 10 more can still be added. Actual infinity, on the other hand, refers to objects that are accepted as infinite entities (such as transfinite numbers).

Mathematicians have different sizes of infinity and three different kinds of infinity.

The number of things, beginning with 0, 1, 2, 3, ..., to include infinite cardinal numbers. There are many different cardinal numbers. Infinity can be defined in one of two ways: Infinity is a number so big that a part of it can be of the same size; Infinity is larger than all of the natural numbers. There is a smallest infinite number, countable infinity. It is the counting number for all of the whole numbers. It is also the counting number of the rational numbers. The mathematical notation is the Hebrew letter aleph with a subscript zero; . It is spoken aleph naught.

It was a surprise to learn that there are larger infinite numbers. The number of real numbers, that is, all numbers with decimals, is larger than the number of rational numbers, the number of fractions. This shows that there are real numbers which are not fractions. The smallest infinite number greater than  is  (aleph one). The number of mathematical functions is the next infinite cardinal number, .
And these numbers, called aleph numbers, go on without end.

A different type of infinity are the ordinal numbers, beginning first, second, third, .... The order first, second, third, ... and so on to infinity is different from the order ending ..., third, second, first. The difference is important for mathematical induction. The simple first, second, third, ...  has the mathematical name: the Greek letter omega with subscript zero: . (Or simply omega .) The infinite series ending ... third, second, first is .

The third type of infinity has the symbol . This is treated as addition to the real numbers or the complex numbers. It is the result of division by zero, or to indicate that a series is increasing (or decreasing) without bound. The series 1, 2, 3, ... increases without upper bound. This is written: the limit is . In calculus, the integral over all real numbers is written: 

Each kind of infinity has different rules.

 Addition with alephs is commutative.

 Multiplication with alephs is commutative.

.

. Addition with omegas is not commutative.

. Multiplication with omegas is not commutative.

 Otherwise, division by infinity is not meaningful. Subtraction with infinity is not meaningful.




#Article 157: January (552 words)


January (Jan.) is the first month of the year in the Julian and Gregorian calendars, coming between December (of the previous year) and February (of the current year). It has 31 days. 

January begins on the same day of the week as October in common years, and April and July in leap years.  January ends on the same day of the week as February and October in common years, and July in leap years.

January is named for Janus, the Roman god of doors and gates.

January and February were put on the calendar after all the other months. This is because in the original Roman calendar, winter did not have months. Although March was originally the first month, January became the new first month because that was when people chose the new consuls (Roman leaders). The month has 31 days.

January is a winter month in the Northern Hemisphere and a summer month in the Southern Hemisphere. In each hemisphere, it is the seasonal equivalent of July in the other. Perihelion, the point in its orbit where the Earth is closest to the Sun, also occurs in this month, between January 2 and January 5. January begins on the same day of the week as October in common years and on the same day of the week as April and July in leap years. January ends on the same day of the week as February and October in common years and on the same day of the week as July in leap years. January is the only month of the year that always has a twin - a month that both begins and ends on the same day of the week as it does. In a common year, this is October, and in a leap year, July.

Every year, January both starts and finishes on the same day of the week as May of the previous year, as each other's first and last days are exactly 35 weeks (245 days) apart.

In common years immediately before other common years, January starts on the same day of the week as April and July of the following year, and in leap years and years immediately before that, September and December of the following year. In common years immediately before other common years, January finishes on the same day of the week as July of the following year, and in leap years and years immediately before that, April and December of the following year.

January's flower is the carnation with its birthstone being the garnet. The meaning of the garnet is constancy.

The first day of January is called New Year's Day. It is said that it became this date when Roman consuls took office on this day in 153 BC. Different calendars across Europe made this the start of the New Year at different times, as some observed it on March 25.

Reaching over from December, the Christmas season in Christianity also extends into this month. Eastern churches celebrate Christmas on January 6 or January 7, and Epiphany on January 18 or January 19 - In Western Christianity this occurs on January 6, with Christmas occurring on December 25.

January 1 is celebrated the Solemnity of Mary, the Mother of God, that is a feast day of precept of the Blessed Virgin Mary.




#Article 158: June (386 words)


June is the sixth month of the year, coming between May and July. It has 30 days. In Sweden in 1732 the month had 31 days. June never begins on the same day of the week as any other month, but always ends on the same day of the week as March.

June comes between May and July and is the sixth month of the year in the Gregorian calendar. It is one of four months to have 30 days.

June and May are the only two months that do not begin on the same day of the week as any other month in any year. June ends on the same day of the week as March every year, as each other's last days are 13 weeks (91 days) apart.

In common years, June starts on the same day of the week as September and December of the previous year, and in leap years, April and July of the previous year. In common years, June finishes on the same day of the week as September of the previous year, and in leap years, April and December of the previous year.

Every year, June starts on the same day of the week as February of the following year, as each other's first days are exactly 35 weeks (245 days) apart. In years immediately before common years, June starts on the same day of the week as March and November of the following year, and in years immediately before leap years, August of the following year. In years immediately before common years, June finishes on the same day of the week as August and November of the following year, and in years immediately before leap years, May of the following year.

June is one of two months to have a solstice (the other is December, its seasonal equivalent in both hemispheres), and in this month the Tropic of Cancer in the Northern Hemisphere is turned towards the Sun, meaning that June 20 or June 21 is the Northern Summer Solstice and the Southern Winter Solstice. This means that this date would have the most daylight of any day in the Northern hemisphere, and the least in the Southern Hemisphere. There are 24 hours of daylight at the North Pole and 24 hours of darkness at the South Pole.




#Article 159: July (465 words)


July is the seventh month of the year in the Gregorian calendar, coming between June and August. It has 31 days. July was named after Julius Caesar. The mid-way point of the year is either on July 2 or in the night of July 1-2.

July always begins on the same day of the week as April, and additionally, January in leap years. July doesn't end on the same day of the week as any other month in common years, but ends on the same day of the week as January in leap years.

In each hemisphere, it is the seasonal equivalent of January in the other hemisphere. In the North, it is summer and in the South it is winter.

In the Northern Hemisphere, July is often the warmest month of the year, and major sporting events and music festivals are held around this time. In the Southern Hemisphere, it is a winter month, with the coldest-recorded temperature having been measured in Antarctica in this month.

July begins on the same day of the week as April every year and on the same day of the week as January in leap years. No other month in common years ends on the same day of the week as July, but July ends on the same day of the week as January in leap years.

In common years, July starts on the same day of the week as October of the previous year, and in leap years, May of the previous year. In common years, July finishes on the same day of the week as February and October of the previous year, and in leap years, May of the previous year. In common years immediately after other common years, July both starts and finishes on the same day of the week as January of the previous year.

In years immediately before common years, July starts on the same day of the week as September and December of the following year, and in years immediately before leap years, June of the following year. In years immediately before common years, July finishes on the same day of the week as April and December of the following year, and in years immediately before leap years, September of the following year.

July's flower is a variety of the water lily. Its birthstone is the ruby. The meaning for the birthstone ruby is contented mind. Astrological signs for July are Cancer (June 21 - July 21) and Leo (July 22 - August 21).

In the old Roman calendar, July was called Quintilis, meaning Fifth Month, because, in the old calendar, the year began in March. Augustus later renamed it July in honor of Julius Caesar, whose birthday was in this month. Augustus later also named the following month, August, after himself.




#Article 160: Jargon (156 words)


Jargon is a special way to use words that are shared only by a certain group of people.  They do not mean what the dictionary says they mean.  They have different meanings to the people using them than their everyday meaning.

For example, the ordinary words boot, net, and web also have special meanings for users of computers, the Internet, and the World Wide Web.  These, and to flame, to ping and many acronyms are part of net jargon.

An acronym means that only some of the letters in the word or phrase are used.  Often this is the first letter of each word. Other acronyms found online are simply common shorthand.

Usually, more jargon is created over time.

Jargon is also common in the military. It includes phrases like SNAFU.

Jargon can be used by a clique to prevent others from joining or understanding, but it also is often just used because it is shorter.




#Article 161: Jupiter (1741 words)


Jupiter is the largest planet in the Solar System. It is the fifth planet from the Sun. Jupiter is a gas giant, both because it is so large and made up of gas. The other gas giants are Saturn, Uranus, and Neptune.

Jupiter has a mass of 1.8986×1027 kg. (318 earths). This is twice the mass of all the other planets in the Solar System put together.

Jupiter can be seen even without using a telescope. The ancient Romans named the planet after their god Jupiter (Latin: Iuppiter). Jupiter is the third brightest object in the night sky. Only the Earth's moon and Venus are brighter.

Jupiter has 79 moons. Of these, around 50 are very small and less than five kilometres wide. The four largest moons of Jupiter are Io, Europa, Ganymede, and Callisto. They are called the Galilean moons, because Galileo Galilei discovered them. Ganymede is the largest moon in the Solar System. It is larger in diameter than Mercury. In 2018 another ten very small moons were discovered 

Jupiter is the biggest planet in the Solar System with a  of 142,984 km. This is eleven times bigger than the diameter of Earth.

The atmosphere near the  of Jupiter is about 88 to 92% hydrogen, 8 to 12% helium, and 1% other gases.

The lower atmosphere is so heated and the pressure so high that helium changes to liquid. It rains down onto the planet. Based on spectroscopy, Jupiter seems to be made of the same gases as Saturn. It is different from Neptune or Uranus. These two planets have much less hydrogen and helium gas.

The very high temperatures and pressures in Jupiter's core mean scientists cannot tell what materials would be there. This cannot be found out, because it is not possible to create the same amount of pressure on Earth.

Above the unknown inner core is an outer core. The outer core of Jupiter is thick, liquid hydrogen. The pressure is high enough to make the hydrogen solid, but then it melts because of the heat.

The planet Jupiter is sometimes called a failed star because it is made of the same elements (hydrogen and helium) as is the Sun, but it is not large enough to have the internal pressure and temperature necessary to cause hydrogen to fuse to helium, the energy source that powers the sun and most other stars. It gives off more heat than it gets from the sun.
Jupiter is 11 times the width of Earth and 318 times as massive. The volume of Jupiter is 1,317 times the volume of Earth. In other words, 1,317 Earth-sized objects could fit inside it.

Jupiter has many bands of clouds going  across its surface. The light parts are zones and the darker are belts. The zones and belts often  with each other. This causes huge storms. Wind speeds of 360 kilometres per hour (km/h) are common on Jupiter. To show the difference the strongest tropical storms on Earth are about 100 km/h.

Most of the clouds on Jupiter are made of ammonia. There may also be clouds of water vapour like clouds on Earth. Spacecrafts such as Voyager 1 have seen lightning on the surface of the planet. Scientists think it was water vapour because lightning needs water vapour. These lightning bolts have been measured as up 1,000 times as powerful as those on Earth.
The brown and orange colours are caused when sunlight passes through or refracts with the many gases in the atmosphere.

One of the biggest features in Jupiter's atmosphere is the Great Red Spot. It is a huge storm which is bigger than the entire Earth. It is on record since at least 1831, and as early as 1665. Images by the Hubble Space Telescope have shown as many as two smaller red spots right next to the Great Red Spot. Storms can last for hours or as long as hundreds of years in the case of the Great Red Spot.

Jupiter has a magnetic field like Earth's but 11 times stronger. It also has a magnetosphere much bigger and stronger than Earth's. The field traps radiation belts much stronger than Earth's Van Allen radiation belts, strong enough to endanger any spacecraft travelling past or to Jupiter. The magnetic field is probably caused by the large amounts of liquid metallic hydrogen in the core of Jupiter. The four largest moons of Jupiter and many of the smaller ones orbit or go around the planet within the magnetic field. This protects them from the solar wind. Jupiter's magnetic field is so large, it reaches the orbit of Saturn 7.7 million miles (12 million km) away. The Earth's magnetosphere does not even cover its moon, less than a quarter of a million miles (400,000 km) away.

Jupiter also has a thin planetary ring system. These rings are difficult to see and were not discovered until 1979 by NASA's Voyager 1 probe. There are four parts to Jupiter's rings. The closest ring to Jupiter is called the Halo Ring. The next ring is called the Main Ring. It is about  wide and only  thick. The Main and Halo rings of Jupiter are made of small, dark particles.  The third and fourth rings, called the Gossamer Rings, are transparent (see through) and are made from microscopic debris and dust. This dust probably comes from small meteors striking the surface of Jupiter's moons. The third ring is called the Amalthea Gossamer Ring, named after moon Amalthea. The outer ring, the Thebe Gossamer Ring, is named after the moon Thebe. The outer edge of this ring is about  from Jupiter.

The orbit of a planet is the time and path it takes to go around the Sun. In the amount of time it takes for Jupiter to orbit the Sun one time, the Earth orbits the Sun 11.86 times. One year on Jupiter is equal to 11.86 years on Earth. The  distance between Jupiter and the Sun is 778 million kilometres. This is five times the distance between Earth and the Sun. Jupiter is not tilted on its axis as much as Earth or Mars. This causes it to have no seasons, for example summer or winter. Jupiter rotates, or spins around very quickly. This causes the planet to  in the middle. Jupiter is the fastest spinning planet in the Solar System. It completes one rotation or spin in 10 hours. Because of the bulge, the length of the equator of Jupiter is much longer than the length from pole to pole.

Jupiter is the third brightest object in the night sky, after the Moon and Venus. Because of that, people have always been able to see it from Earth. The first person known to really study the planet was Galileo Galilei in 1610. He was the first person to see Jupiter's moons Io, Europa, Ganymede and Callisto. This was because he used a telescope, unlike anyone before him.

No new moons were discovered for more than two hundred years. In 1892, astronomer E.E Barnard found a new moon using his observatory in California. He called the moon Amalthea. It was the last of Jupiter's 67 moons to be discovered by human observation through a telescope.
In 1994, bits of the comet Shoemaker Levy-9 hit Jupiter. It was the first time people saw a collision between two Solar System objects.

Seven spacecraft have flown past Jupiter since 1973. These were Pioneer 10 (1973), Pioneer 11 (1974), Voyagers 1 and 2 (1979), Ulysses (1992 and 2004), Cassini (2000) and New Horizons (2007).

The Pioneer missions were the first spacecraft to take close up pictures of Jupiter and its moons. Five years later, the two Voyager spacecraft discovered over 20 new moons. They captured photo evidence of lightning on the night side of Jupiter.

The Ulysses probe was sent to study the Sun. It only went to Jupiter after it had finished its main mission. Ulysses had no cameras so it took no photographs.
In 2006, the Cassini spacecraft, on its way to Saturn, took some very good, very clear pictures of the planet. Cassini also found a moon and took a picture of it but it was too far away to show the details.

The Galileo mission in 1995 was the first spacecraft to go into orbit around Jupiter. It flew around the planet for seven years and studied the four biggest moons. It launched a probe into the planet to get information about Jupiter's atmosphere. The probe travelled to a depth of about 150 km before it was crushed by the weight of all the gas above it. This is called pressure. The Galileo spacecraft was also crushed in 2003 when NASA steered the craft into the planet. They did this so that the craft could not crash into Europa, a moon which scientists think might have life.

NASA have sent another spacecraft to Jupiter called Juno. It was launched on  August 5, 2011 and arrived at Jupiter on July 4, 2016. NASA published some results from the Juno mission in March 2018. Several other missions have been planned to send spacecraft to Jupiter's moons Europa and Callisto. One called JIMO (Jupiter Icy Moons Orbiter) was cancelled in 2006 because it cost too much money.

Jupiter has 79 known moons. The four largest were seen by Galileo with his primitive telescope, and nine more can be seen from Earth with modern telescopes. The rest of the moons have been identified by spacecraft. The smallest moon (S/2003 J 12) is only one kilometre across. The largest, Ganymede, has a diameter of 5,262 kilometres. It is bigger than the planet Mercury. The other three Galilean moons are Io, Europa and Callisto. Because of the way they orbit Jupiter, gravity affects three of these moons greatly. The friction caused by the gravity of Europa and Ganymede pulling on Io makes it the most volcanic object in the Solar System. It has over 400 volcanoes, more than three times as many as Earth.

Jupiter's large gravity has had an effect on the Solar System. Jupiter protects the inner planets from comets by pulling them towards itself. Because of this, Jupiter has the most comet impacts in the Solar System.

Two groups of asteroids, called Trojan asteroids, have settled into Jupiter's orbit round the Sun. One group is called the Trojans and the other group is called the Greeks. They go around the Sun at the same time as Jupiter.




#Article 162: King (145 words)


A king is a man who rules a country, because of inheritance. A king usually comes to power when the previous monarch dies, who is usually a family member of his. Sometimes a person may become king due to the previous monarch's abdication, for example George VI. For most of history, most countries were ruled in this way, especially in Europe. Some countries, such as France, are no longer monarchies. Some, such as the United Kingdom, still have a royal family. In some countries, people chose a new king from other people to decide from. 

The wife of a king is called a queen. A woman who becomes a ruler because of inheritance is also called a queen.

If a country has a king or a queen, that means it is a monarchy. A country which a king or queen rules is called a kingdom.




#Article 163: Knowledge (423 words)


Knowledge means the things which are true, as opposed to opinion. Information which is correct is knowledge. Knowledge can always be supported by evidence. If a statement is not supported by evidence, then it is not knowledge. The evidence makes it justified;        .

Knowledge can refer to a theoretical or practical understanding of a subject. This was the point of Ryle's distinction between knowing that and knowing how.  It can be implicit (as with practical skill or expertise) or explicit (as with the theoretical understanding of a subject); it can be more or less formal or systematic. In philosophy, the study of knowledge is called epistemology. The philosopher Plato defined knowledge as justified true belief. This definition is the subject of the Gettier problems. 

All knowledge is a claim to be true, but the claim can be incorrect. The only claims (propositions) which are certainly true are circular, based on how we use words or terms. We can correctly claim that there are 360 degrees in a circle, since that is part of how circles are defined. The point of Aristotle's syllogism was to show that this kind of reasoning had a machine-like form:

But actually, in the real world, not all swans are white.

The most widely accepted way to find reliable knowledge is the scientific method. Yet one thing all philosophers of science agree is that scientific knowledge is just the best we can do at any one time. All scientific knowledge is provisional, not a claim of absolute truth.

Knowledge in religion is different in that it depends on faith, belief and the authority of religious leaders, not on evidence of a scientific or legal kind. There are differing views on whether religious statements should be regarded as knowledge.

In many expressions of Christianity, such as Catholicism and Anglicanism, knowledge is one of the seven gifts of the Holy Spirit.
In the Garden of Eden knowledge is the factor that made humans greedy and treacherous. But in the Book of Proverbs it states: 'to be wise you must first obey the LORD' (9:10).

In Islam, knowledge has great significance. The All-Knowing (al-ʿAlīm) is one of the Names of God, reflecting distinct properties of God in Islam. The Qur'an asserts that knowledge comes from God () and various hadith encourage getting knowledge. Muhammad is reported to have said Seek knowledge from the cradle to the grave and Verily the men of knowledge are the inheritors of the prophets. Islamic scholars, theologians and jurists are often given the title alim, meaning 'knowledgeable'.




#Article 164: Kauai (192 words)


Kauai (Kaua'i in Hawaiian) is the oldest and fourth largest of the main Hawaiian Islands, in the United States. Known also as the Garden Isle, Kaua'i lies 105 miles (170 kilometers) across the Kaua'i Channel, northwest of Honolulu on O'ahu. It is of volcanic origin. The highest point is Mount Waialeale, at the center of the island, 5,148 feet (1,570 meters) above sea level. The wettest spot on Earth, with average rainfall of 460 inches (11,648 millimeters) a year, is just east of Mount Waialeale. The high yearly rainfall has eroded deep valleys in the central mountain. It has made canyons with many scenic waterfalls.

The city of Lihue, on the island's southeast side, is the seat of Kauai County. It is the main city on the island. Waimea, on the island's southwest side and once the capital of Kauai, was the first place visited by explorer Captain James Cook in 1778. The city is at the head of one of the most beautiful canyons in the world, Waimea Canyon, whose gorge is 900 meters (3,000 feet) deep.

The island of Kauai was featured in Disney's 2002 animated feature film Lilo  Stitch.




#Article 165: Kahoolawe (396 words)


Kahoolawe is the smallest of the eight main volcanic islands of Hawaii.  It is west of Maui and south of Lanai.  It is roughly 11 miles long by  across (). The highest point, Lua Makika, is  above sea level. The island is dry because its low elevation does not cause much rain (orographic precipitation) to fall from the northeastern trade winds.

Kahoolawe was used as a gunfire and bombing target by the United States military during World War II.  It was a defense training area by the United States Navy from around 1941 until May 1994.  Popular opinion in the state against this practice brought the end to this use. Navy has since been trying to cleanup unexploded ordnance (bombs and explosive shells) from the island.  Ordnance is still buried or lying on the ground. Other items have washed down gullies and still other unexploded ordnance is underwater offshore. In 1981, the entire island was included on the National Register of Historic Places.

The island is planned to be given back to the Hawaiian people.  In 1993, the U.S. Congress passed a law that recognized the cultural importance of the island, required the Navy to return the island to the State, and directed the Navy to do an unexploded ordnance (UXO) cleanup and environmental restoration  . The turnover officially occurred on November 11, 2003, but the cleanup has not yet been completed. The U.S. Navy was given $400 million and 10 years to complete the large cleanup task, but this work has gone much slower than planned.

In 1993, the Hawaii State Legislature established the Kahoolawe Island Reserve. It is made up of the whole island and waters out to  from shore. By State Law, Kahoolawe and its waters can only be used for Native Hawaiian cultural, spiritual, and subsistence purposes; fishing; environmental restoration; historic preservation; and education. Commercial uses are not allowed. The Legislature also created the Kahoolawe Island Reserve Commission (KIRC) to manage the Reserve while it is held in trust for a future Native Hawaiian Sovereignty entity  . 

After the cleanup is finished, the restoration of Kahoolawe will need ways to control erosion, restore the plant life, recharge the water table, and slowly replace alien plants with native ones. Plans will include methods for damming gullies and reducing rainwater runoff. Non-natives will temporarily stabilize some areas before the permanent planting of native plants.




#Article 166: Killing (119 words)


Killing a living thing is when someone or something ends that life and makes the living thing die. It means causing a death. When a human being kills another human being, it is called murder or homicide, such as manslaughter.  

Pesticides and herbicides are poisons for killing bad wild small animals or plants, respectively.

When a soldier kills another in war, it is called combat.  When the state kills a convict sentenced to capital punishment, it is called execution. When someone kills a  powerful person it is called assassination. When a person who wants to die kills himself it is suicide, or euthanasia if killed by another. When people kill other people to eat them, it is called cannibalism.




#Article 167: Kilometre (134 words)


The kilometre is a common unit used for longer distances on Earth. The international unit for measuring distances is the metre and a kilometre is 1000 metres. It is used in some countries for measuring road and sea distances. In the UK and the USA, the mile is used more than kilometres for road distances and the nautical mile for sea distances.

It is often used to measure the speed of cars, planes and boats by saying how many kilometres it can travel in an hour. This is shown as km/h.

It is also spelled kilometer. This spelling is used in American English.

One kilometre is 0.6214 miles (3280.84 feet). This means that one mile is 1.6093 kilometres.

One kilometre is the approximate distance a healthy adult human being can walk in ten minutes.




#Article 168: Language (515 words)


Language is the normal way humans communicate. Only humans use language, though other animals communicate through other means.

Human language has syntax, a set of rules for connecting words together to make statements and questions. Language can also be changed, by adding new words, for example, to describe new things. Other animals may inherit a set of calls which have pre-set functions.

Language may be done by speech or by writing or by moving the hands to make signs. It follows that language is not just any way of communicating. Even some human communication is not language: see non-verbal communication. Humans also use language for thinking.

When people use the word language, they can also mean:

UNESCO says that 2,500 languages are at risk of becoming extinct.

All languages share certain things which separate them from all other kinds of communication.

There are many more things in common between languages.

The capacity to learn and use language is inherited. Normally, all humans are born with this capability. Which language is learned by a child depends on which language is spoken by the child's community. The capacity is inherited, but the particular language is learned.

Children have a special period, from about 18 months to about four years, which is critical for learning the language. If this is seriously disrupted, then their language skills will be damaged.  Older people learn differently, so they seldom learn a second language as well as they learn their native language.

Mathematics and computer science use created languages called formal languages (like computer programming languages), but these may or may not be 'true' languages. Mathematics itself is seen as a language by many. Some people consider musical notation to be a way of writing the musical language.

Chinese is the language with the most native speakers in the world, but Chinese is not really a language. It is a close family of dialects, some of which are as different as Romance languages are from one another.

English is often called the international language, or lingua franca. It is the main second language of the world and the international language of science, travel, technology, business, diplomacy, and entertainment. French had a similar status until the 20th century, and other languages had it at other times.

Some languages are made up so that a lot of people around the world can learn them, without the new languages being tied to any specific country or place. These are called constructed languages. One of the most popular of these languages is Esperanto, which is sometimes called La Internacia Lingvo, or The International Language. Another of these languages is called Volapük, which was popular about a hundred years ago but is much less popular now. It has mostly been replaced by languages like Esperanto, Interlingua, and Ido. Dialects are basically other versions of a language. For example Hoffish is a dialect of swedish.

Part of the reason that Volapük became unpopular is that some sounds are hard to say for people who speak Spanish or English, two of the most widely spoken languages in the world.




#Article 169: Leisure (170 words)


Leisure (or free time) is when a person can choose what to do. During a person's leisure time, they do not have an obligation to be at school or work at a job. During leisure time, people can do  activities, family activities, or other non-work activity, such as hobbies.  

Common forms of recreation or leisure are:

A vacation or holiday is the setting aside of time specifically for leisure. During their vacation, some people travel to a different region or country, and stay at a hotel so that they can do things they could not do near home. Other people prefer to spend their vacation time at home in their own community.

In rich industrialized countries such as the US and Canada, as well as in most European countries, workers are allowed to stay home on the weekend (usually Saturday and Sunday), and use it as leisure time. People in poorer developing countries usually have less leisure time, as they have to work longer hours and more days per year.




#Article 170: Life (497 words)


 
Life is a biological concept regarding the characteristics, state, or mode that separates a living thing from dead matter.
The word itself may refer to a living being or ongoing processes of which living things are a part of. It may also refer to the period during which something is functional (as between birth and death), the condition of an entity that has been born but yet has to die or that which makes a living thing alive.

The study of life is called biology, and people who study life are called biologists. A lifespan is the average length of life in a species. Most life on Earth is powered by solar energy, the only known exceptions being the chemosynthetic bacteria living around the hydrothermal vents on the ocean floor. All life on Earth is based on the chemistry of carbon compounds, specifically involving long-chain molecules such as proteins and nucleic acid. With water, which is essential, the long molecules are wrapped inside membranes to form cells. This may or may not be true of all possible forms of life in the Universe: it is true of all life on Earth today.

Living organisms can be explained as open systems. They are always changing, because they exchange materials and information with their environment. They undergo metabolism, maintain homeostasis, possess a capacity to grow, respond to stimuli and reproduce.

Through natural selection, they adapt to their environment in successive generations. More complex living organisms can communicate through various means. Many life forms can be found on Earth. The properties common to these organisms—plants, animals, fungi, protists, archaea, and bacteria—are a carbon and water-based cellular form with complex organization and heritable genetic information.

At present, the Earth is the only planet humans have detailed information about. The question of whether life exists elsewhere in the Universe is open. There have been a number of claims of life elsewhere in the Universe. None of these have been confirmed so far. The best evidence of life outside of Earth is are nucleic acids that have been found in certain types of meteorites.

One explanation of life is called the cell theory. The cell theory has three basic points: all living things are made up of cells. The cell is the smallest living thing that can do all the things needed for life. All cells must come from pre-existing cells.

Something is often said to be alive if it:

However, not all living things fit every point on this list.

They do, however, fit the biochemical definitions: they are made of the same kind of chemicals.

The thermodynamic definition of life is any system which can keep its entropy levels below maximum (usually through adaptation and mutations).

A modern definition was given by Humberto Maturana and Francisco Varela in 1980, to which they gave the name autopoiesis:

Roth commented that In short, organisms are self-reproducing and self-maintaining, or 'autopoietic', systems. This approach makes use of molecular biology ideas and systems science ideas.




#Article 171: Law (1414 words)


Law is a set of rules decided by a particular place or authority meant for the purpose of keeping the peace and security of society. 

Courts or police may enforce this system of rules and punish people who break the laws, such as by paying a fine, or other penalty including jail. In ancient societies, laws were written by leaders, to set out rules on how people can live, work and do business with each other. But many times in history when laws have been on a false basis to benefit few at the expense of society, they have resulted in conflict. To prevent this, in most countries today, laws are written and voted on by groups of politicians in a legislature, such as a parliament or congress, elected (chosen) by the governed peoples. Countries today have a constitution for the overall framework of society and make further laws as needed for matters of detail. Members of society generally have enough freedom within all the legal things they can choose to do. An activity is illegal if it breaks a law or does not follow the laws.

A legal code is a written code of laws that are enforced. This may deal with things like police, courts, or punishments. A lawyer, jurist or attorney is a professional who studies and argues the rules of law. In the United States, there are two kinds of attorneys - transactional attorneys who write contracts and litigators who go to court. In the United Kingdom, these professionals are called solicitors and barristers respectively.

The Rule of Law is the law which says that government can only legally use its power in a way the government and the people agree on. It limits the powers a government has, as agreed in a country's constitution. The Rule of Law prevents dictatorship and protects the rights of the people. When leaders enforce the legal code honestly, even on themselves and their friends, this is an example of the rule of law being followed. The rule of law, wrote the ancient Greek philosopher Aristotle in 350 BC, is better than the rule of any individual.

Culture is usually a major source of the principles behind many laws, and people also tend to trust the ideas based on family and social habits. In many countries throughout history, religion and religious books like the Vedas, Bible or the Koran have been a major source of law.

Civil law is the legal system used in most countries around the world today. Civil law is based on legislation that is found in constitutions or statutes passed by government. The secondary part of civil law is the legal approaches that are part of custom. In civil law governments, judges do not generally have much power, and most of the laws and legal precedent are created by Members of Parliament.
 
Common law is based on the decisions made by judges in past court cases. It comes from England and it became part of almost every country that once belonged to the British Empire, except Malta, Scotland, the U.S. state of Louisiana, and the Canadian province of Quebec. It is also the predominant form of law in the United States, where many laws called statutes are written by Congress, but many more legal rules exist from the decisions of the courts. Common law had its beginnings in the Middle Ages, when King John was forced by his barons to sign a document called the Magna Carta.

Religious law is law based on religious beliefs or books. Examples include the Jewish Halakha, Islamic Sharia, and Christian Canon law.

Until the 1700s, Sharia law was the main legal system throughout the Muslim world. In some Muslim countries such as Saudi Arabia and Iran, the whole legal systems still base their law on Sharia law. Islamic law is often criticised because it often has harsh penalties for crimes. A serious criticism is the judgement of the European Court that sharia is incompatible with the fundamental principles of democracy.

The Turkish Refah Party's sharia-based plurality of legal systems, grounded on religion was ruled to contravene the European Convention for the Protection of Human Rights and Fundamental Freedoms. The Court decided Refah's plan would do away with the State's role as the guarantor of individual rights and freedoms and infringe the principle of non-discrimination between individuals as regards their enjoyment of public freedoms, which is one of the fundamental principles of democracy.

The history of law is closely connected to the development of human civilizations. Ancient Egyptian law developed in 3000 BC. In 1760 BC King Hammurabi, took ancient Babylonian law and organized it, and had it chiseled in stone for the public to see in the marketplace. These laws became known as the Code of Hammurabi.

The Torah from the Old Testament is an old body of law. It was written around 1280 BC. It has moral rules such as the Ten Commandments, which tell people what things are not permitted. Sometimes people try to change the law. For example, if prostitution is illegal, they try to make it legal.

In democracies, the people in a country usually choose people called politicians to represent them in a legislature. Examples of legislatures include the Houses of Parliament in London, the Congress in Washington, D.C., the Bundestag in Berlin, the Duma in Moscow and the Assemblée nationale in Paris. Most legislatures have two chambers or houses, a 'lower house' and an 'upper house'. To pass legislation, a majority of Members of Parliament must vote for a bill in each house. The legislature is the branch of government that writes laws, and votes on whether they will be approved.

The judiciary is a group of judges who resolve people's disputes and determine whether people who are charged with crimes are guilty. In some jurisdictions the judge does not find guilt or innocence but instead directs a jury, how to interpret facts from a legal perspective, but the jury determines the facts based on evidence presented to them and finds the guilt or innocences of the charged person.  Most countries of common law and civil law systems have a system of appeals courts, up to a supreme authority such as the Supreme Court or the High Court. The highest courts usually have the power to remove laws that are unconstitutional (which go against the constitution).

The executive is the governing center of political authority. In most democratic countries, the executive is elected from people who are in the legislature. This group of elected people is called the cabinet. In France, the US and Russia, the executive branch has a President which exists separately from the legislature.

The executive suggests new laws and deals with other countries. As well, the executive usually controls the military, the police, and the bureaucracy. The executive selects ministers, or secretaries of state to control departments such as the health department or the department of justice.

In many jurisdictions the Head of State does not take part in the day-to-day governance of the jurisdiction and takes a largely ceremonial role. This is the case in many Commonwealth nations where the Head of State, usually a Governor almost exclusively acts on the advice of the head of the Executive (e.g. the Prime Minister, First Minister or Premier). The primary legal role of the Head of State in these jurisdictions is to act as a check or balance against the Executive, as the Head of State has the rarely exercised power to dissolve the legislature, call elections and dismiss ministers.

The police enforce the criminal laws by arresting people suspected of breaking the law. Bureaucrats are the government workers and government organizations that do work for the government. Bureaucrats work within a system of rules, and they make their decisions in writing.

Lawyers are people who have learned about laws. Lawyers give people advice about their legal rights and duties and represent people in court. To become a lawyer, a person has to complete a two- or three-year university program at a law school and pass an entrance examination. Lawyers work in law firms, for the government, for companies, or by themselves.

Civil society is the people and groups that are not part of government that try to protect people against human rights abuses and try to protect freedom of speech and other individual rights. Organizations that are part of civil society include political parties, debating clubs, trade unions, human rights organizations, newspapers and charities.




#Article 172: L. L. Zamenhof (203 words)


Ludwik Lejzer Zamenhof (; , ;  – ), credited as L. L. Zamenhof and sometimes as the pseudonymous Dr. Esperanto, was an eye doctor, linguist (who creates a language), and  who created the international language Esperanto.

Zamenhof was born in 1859 in the town of Białystok, Poland. At the time, Poland was a part of the Russian Empire. Bialystok contained three major groups: Poles, Belorussians, and Yiddish-speaking Jews. Zamenhof thought that one common language would join these groups and stop fights between them.

His first language was said to be Polish. His parents spoke Russian and Yiddish at home. His father was a German teacher, so Zamenhof learned that language from an early age and spoke the language fluently. Later he learned French, Latin, Greek, Hebrew and English. He also had an interest in Italian, Spanish and Lithuanian.

Zamenhof decided that the international language must have a simple grammar and be easier to learn than Volapük, an earlier international language. He  to create the international language with a grammar that was , and . The basics of Esperanto were published in 1887.

His grandson, Louis-Christophe Zaleski-Zamenhof, was an engineer.

He was 14 times nominated for the Nobel Peace Prize between 1907 and 1917.




#Article 173: Provinces and territories of Canada (158 words)


Canada, a country and sovereign state in the northern part of North America, is made up of thirteen administrative divisions: ten provinces and three territories. The different levels of government in Canada are based on the principles of a federation: those of each of the provinces and territories share power with the federal government. The territories' governments have a more limited set of powers versus the federal government than that of the provinces'.

The provinces are in the south of Canada, near the border with the United States. They go from the Atlantic Ocean in the east to the Pacific Ocean in the west. The territories are to the north, where fewer people live, close to the Arctic Circle and Arctic Ocean.

Here is a list of the provinces and territories, and their standard abbreviations, with their capitals (the cities where their governments are based) and largest cities. Canada's national capital, where the federal government meets, is Ottawa.




#Article 174: Las Vegas (222 words)


Las Vegas is a city in the American state of Nevada. There were 640,932 people living in the city in 2015, and more than 2,000,000 people living in the metropolitan area. It is the largest city in Nevada. Las Vegas is also the county seat of Clark County. Carolyn Goodman became the mayor in 2011.Las Vegas and Las Vegans are often stereotypically characterized as fun-loving.

Las Vegas leans to the left. 3 of the 4 congressional districts in Nevada include parts of Las Vegas, and all three congresspeople representing those districts are a.) from Las Vegas and b.) Democrats.

Native Americans, the Paiute tribe, first lived there. It was called Las Vegas by the Spanish. The name means The Meadows in the Spanish language. They had a lot of these in 1854. The city is known for its dry weather, as is the rest of southern Nevada. It is surrounded by deserts. 

The US Army built Fort Baker there in 1864. Las Vegas has springs so people used to stop there for water when they were going to Los Angeles or other places in California.

In 1905, 110 acres owned by William A. Clark, on which he built a railroad to Southern California were auctioned and Las Vegas was founded as a railroad town. Las Vegas officially became a city in 1911.




#Article 175: Lanai (211 words)


Lanai (or Lānaʻi) is sixth largest of the Hawaiian Islands, in the United States. It is also known as the Pineapple Island. The island is almost a circle in shape and is 18 miles wide in the longest direction. The land area is 140 sq. miles (367 km2). It is separated from the island of Moloka'i by the Kalohi Channel to the north.

Lana'i was first seen by Europeans on 25 February 1779 by Captain Clerke, with HMS Resolution on the James Cook Pacific Ocean trip. Clerke took command of the ship after Capt. Cook was killed at Kealakekua Bay on February 14, and was leaving the islands for the North Pacific. 

In 1922, Jim Dole, the president of Dole Pineapple Company, bought the island of Lana'i. He made a large part of it into the world's largest pineapple plantation. 

Tourism on Lana'i started not long ago. That was when the growing of pineapple was slowly coming to an end in the Islands. On Lana'i, you can be with nature and feel the mood of the Hawaiian countryside. Not like nearby O'ahu, the only town (Lana'i City) is small. It has no traffic or shopping centers. Tourists come mainly to relax.

There are three hotels on Lana'i and several golf courses.




#Article 176: Leap year (329 words)


A leap year is a year in which an extra day is added to the Gregorian calendar, which is used by most of the world. While an ordinary year has 365 days, a leap year has 366 days. The extra day, February 29, is added to the month of February. In an ordinary year, February has 28 days, but in a leap year, it has 29 days. The extra day, called a leap day, is the same day of the week as the first day of the month, February 1. Also, in a leap year, the months of January, April, and July all start on the same day of the week.

A leap year comes once every four years. Because of this, a leap year can always be evenly divided by four. For example, 2020 was a leap year. But a year is a common year if it can be evenly divided by 100 but not by 400. This is why 1600, 2000, and 2400 are leap years, but 1700, 1800, 1900, 2100, 2200, 2300, and 2500 are common years.

We have leap years because instead of 365 days, the Earth really takes a few minutes less than 365-1/4 days (365.24219) to go completely around the Sun. Without leap years, the seasons would start one day earlier on the calendar every four years. After 360 years, spring in the Northern Hemisphere and autumn in the Southern Hemisphere (which usually begins on March 21) would begin on December 21 (which is when winter in the Northern Hemisphere and summer in the Southern Hemisphere presently begins).

A number of countries use a lunar calendar (based on the Moon, instead of the Sun, like our solar calendar is). They have leap years when they add an extra lunar month. Different calendars add the extra month in different ways. So a year which has 366 days instead of 365 days where the month of February has 29 days is called a leap year.




#Article 177: Leather (342 words)


Leather is the skin of an animal made into a durable material by tanning. The skins of cows, pigs, and goats are often used to make leather. Skins of snakes, alligators or crocodiles, and ostriches are sometimes used to make fancier leather. Shoes, bags, clothes, and balls are often made of leather. Sometimes people make leather out of whales, ducks, giraffes, and African elephants, but all of these ways of making leather are very simple but can also be very hard and rare sometimes.

The way leather is made is divided into three processes. They are preparing the leather, tanning it, and crusting.

In preparing the leather, many things are done to make it ready for tanning. They include soaking it, removing the hair, liming, deliming, bating, bleaching, and pickling.

Tanning is a process that makes the proteins, especially collagen, in the raw hide stable. It increases the thermal and chemical stability of the animal skins. The difference between fresh and tanned animal skin is that fresh animal skin dries to make it hard and stiff. When water is added to it, it becomes bad. But, animal skin that is tanned dries to make it flexible. It does not become bad when water is added to it.

Crusting is a process that makes the leather thin and lubricates it. Chemicals added when crusting must be set in place. Crusting ends with drying and making the leather soft. It may include splitting, shaving, dyeing, whitening or other methods.

Today, most leather is made from the skin of cattle, which makes up about 65% of all the leather made. Other animals that are used include sheep (about 13%), goats (about 11%), and pigs (about 10%).

Horse skin is used to make strong leather. Lamb and deerskin are used for soft leather. It is used in work gloves and indoor shoes.

Kangaroo leather is used to make things that must be strong and flexible. It is used in bullwhips.

In Thailand, stingray leather is used in wallets and belts. Stingray leather is tough and durable.




#Article 178: License (470 words)


A license (or licence) allows someone to do something that they otherwise are not allowed to do. A person usually has to pay some money, and maybe pass a test to get a license. A license is usually written but it does not have to be. Most kinds of licenses can only be used by the person they were given to. Licenses may be temporary or permanent. Some licenses can not be taken away once they are given. A person with a license is called a licensee.

For example, John has a license to sell vegetables in the market for 10 years from 2010 to 2020. John grants an exclusive license to Jane to sell vegetables for 4 years from 2012 to 2016.  Here, John will be referred as licensor and Jane will be referred as licensee.

In many countries, if a person tries to do something without the correct license to do it, he might have to pay a fine or go to prison.

There are many different types of licenses.

The laws of most countries say that people are only allowed to drive cars if they have a driver's license.  If a person does not have a license, they may have to pay a fine if they are caught by the police.  In many countries, a person must take a test and pay money to get a license. The test would check that they know the road rules, and have the skill to drive a car.

Other licenses give permission to shoot animals (often called a hunting license). The hunting license usually says when a person may hunt. A hunter may have to pass a test to show that he understands the rules about hunting.

In the United Kingdom and the Republic of Ireland, if someone has a television set, they must buy a television licence every year.

Copyright is a law that gives the owner of a creative work the right to decide what other people can do with it. A person or a company can give a license to a copyright that they own. So in order for another person to use an owner's copyright they need permission from the owner. For example, when someone buys computer software, they also need a license from the creator of the software (a copyright owner) allowing the buyer to use the software.

In American English there is no difference in spelling between the verb to license  meaning to give permission, and the noun a license meaning the permission to do something.

A degree in medicine is a qualification showing a person has successfully studied medicine. It is awarded for life. A licence to practice medicine is a legal permission to do so within the territory covered by the licensing authority. The licence may be taken away under certain situations.




#Article 179: Link (252 words)


A link, also hyperlink in computing, is a part of a chain. A chain is made of many pieces of metal; each piece is a link. 

Today, people also use the word link in a new way. The World Wide Web on the Internet is made of many different Web pages. The computer software that people use to make these pages (HTML) lets us go to other pages in a very fast and easy way. 

The person who makes the web page can tell the computer to show a word or a picture on the Web page as a link. This means that when we click on the link with our computer mouse, the computer will show us the new page we want to see. Most links are blue, but they can be any color.

The color of the link will change to dark blue when clicked as the web browser recognises it in the browser's cache. Unless the cache is cleared, the link will always stay dark blue.

There are many ways in making a link on a web page. The process is different for different internet software.

In .htm and .html files, a link can be created using this code:

WikiSyntax like MediaWiki uses a simpler way of making links. To create a link to another page of the same website:

Link text or just Page name.

To link to an external website:

, , or just 

BB code is used in forum software. To create a link:

[url]or [url=text[/url]




#Article 180: Library (847 words)


A library is a place where many books are kept. Most libraries are public and let people take the books to use in their home. Most libraries let people borrow books for several weeks. Some belong to institutions, for example, companies, churches, schools, and universities. Also a person's bookshelves at home can have many books and be a library. The people who work in libraries are librarians. Librarians are people who take care of the library.

Other libraries keep famous or rare books. There are a few Copyright libraries which have a copy of every book which has been written in that country. Some libraries also have other things that people might like, such as magazines, music on CDs, or computers where people can use the Internet. In school they offer software to learn the alphabet and other details.With the spread of literacy, libraries have become essential tools for learning. Libraries are very important for the progress and development of a society.Libraries are collections of books and other informational materials. People come to libraries for reading, study or reference. Libraries contain a variety of materials. They contain printed materials, films, sound and video recordings, maps, photographs, computer software, online databases, and other media.

A library is not a bookstore (a store that sells books).

The prime purpose of a library is to provide access to knowledge and information. To fulfil this mission, libraries preserve a valuable record of culture. Then they pass down this to the coming generations. Therefore, they are an essential link between the past, present and future.

People use libraries to work. They also use library resources to learn about personal interests. Sometimes, they get recreational media such as films and music. Students use libraries to study.

Libraries help the students to develop good reading and study habits. Public officials use libraries for research and public issues. The libraries provide information and services that are essential for learning and progress.

Many places have a public library, where anybody can join if they live in the area. With a library card, people can borrow books and take them home for several weeks. It does not cost money to get a library card at most public libraries.

Books are kept on shelves in a special order so they are easy to find. Public libraries have lot of books on various topics including story books and many others. Many public libraries have books and CDs about learning English. Stories are kept in alphabetical order by the last name of the person who wrote them, the author. Books about other things are often given a special number, that refers to what they are about. They are then put on the shelf in number order. One number system used by many libraries is the Dewey decimal system.

Many colleges and universities have large academic libraries.  These libraries are for the use of college students, professors, and researchers.  Academic libraries are used mainly for doing research like studying the solar system or how earthquakes happen.  These libraries do not have the same types of books you would find in a public library.  They usually do not have fiction books or books for children (unless they are being studied).  Academic libraries can have many books, sometimes more than a million.

Special libraries are those libraries that are not public libraries or academic libraries.  They are usually small.  Many times a special library holds books on a particular subject or even a special kind of book.  Some special libraries keep just old books or books by Shakespeare.  A special library can be owned by a business for use only by that business.  For example, Disney World in Orlando has its own library that is not open to the public but for the use of the people who work for the company.

A librarian is a person who works in a library. Librarians help people find books and information. They can teach people how to find books and use the library.  A professional librarian is a person who went to school to study library science.  They can earn a degree called a Masters in Library Science.

The earliest known library was discovered in Iraq and belonged to the ancient civilization in Sumer.  They didn't use paper books but instead wrote everything on clay tablets using a style of writing called cuneiform.  These tablets are over 5,000 years old.  The Library of Alexandria, in Egypt, was the largest and most important library of the ancient world.  It was destroyed when the Romans conquered Egypt in 30 BC.  Rome’s first public library was established by Asinius Pollio who was a lieutenant of Julius Caesar.  Eventually Rome would build 28 public libraries within the city.  When the Roman Empire fell in 330 AD, many books went east to the city of Byzantium where a large library was built.  Other libraries were built in monasteries and public homes.

Libraries began to appear in many Islamic cities, where science and philosophy survived after the fall of the Roman Empire.  Christian monks and Islamic libraries exchanged books to copy.




#Article 181: Political divisions of China (171 words)


There are twenty-three provinces, four municipalities, five autonomous regions and two special administrative regions in the People's Republic of China. The island of Taiwan is claimed as a province by the People's Republic of China (PRC), but it is not under their control. Taiwan is an island known as Republic of China (Taiwan).

There are 23 provinces in the People's Republic of China.

There are 4 municipalities in the People's Republic of China. Municipality is the common English name for the Chinese zhíxiáshì, meaning a city directly controlled by the national government.

There are 5 autonomous regions in the People's Republic of China. Autonomous region is the common English name for the Chinese zìzhìqū, meaning an area with greater levels of self-government to accommodate minority groups.

There are 2 special administrative regions in the People's Republic of China. Special administrative region is the common English name for the Chinese tèbié xíngzhèng qū, meaning an area under special administration as a result of treaties that returned former European colonies to Chinese control.




#Article 182: Legislature (131 words)


Legislature is a word that comes from the Latin language, meaning those who write the laws. A legislature is therefore a group of people who vote for new laws, for example in a state or country.

Each person in the legislature is usually either elected or appointed. The constitution of that state or country usually tells how a legislature is supposed to work.

In many countries, the legislature is called a Parliament, Congress, or National Assembly. Sometimes there are two groups of members in the legislature. This is called a bicameral legislature. A unicameral legislature has only one group of members.

A country, district, city, or other small area may also have something like a legislature. These are often called councils, and they make smaller laws for their areas. 

File:Unibicameral Map.png|400px|thumb|


#Article 183: Linear algebra (200 words)


Linear algebra is a branch of mathematics. It came from mathematicians trying to solve systems of linear equations. Vectors and matrices are used to solve these systems. The main objects of study currently are vector spaces and linear mappings between vector spaces. Linear algebra is useful in other branches of mathematics (e.g. differential equations and analytic geometry). It can also be applied to the real world in areas such as engineering, physics and economics.

Linear algebra describes ways to  and manipulate (rearrange) systems of linear equations.

For example, consider the following equations:

These two equations form a system of linear equations.
It is linear because none of the variables are raised to a power.
The graph of a linear equation in two variables is a straight line.
The solution to this system is:

This is because it makes all of the original equations valid, that is, the value on the left side of the equals sign is exactly the same as the value on the right side for both equations.

Linear algebra uses a system of notation for describing system behavior, called a matrix. For the previous example, the coefficients of the equations can be stored in a coefficient matrix.




#Article 184: London (955 words)


London is the capital and largest city of England and the United Kingdom, and is the largest urban area in Greater London. The River Thames travels through the city.

London is the biggest city in western Europe, and the world's largest financial centre.

London is about 2,000 years old.  London was founded by the Romans.  It was called Londinium by the Romans. London was also called Lunnainn in Scottish Gaelic,  Llundain in Welsh and Londain in Irish.

For a long time, London was a small city. All its people lived inside the walls that were built by the Romans. This area is still called the City of London. There were many villages around the city. Gradually, more people came to live there. Then, step by step, the villages joined together into one huge city.

London is one of the world's most important cities for business, finance  and politics. It is also important for culture, media, entertainment, fashion and art.

The population of London is 8.63 million. Most people in London are British. However, London also has many immigrants. These people come from many different countries. They speak many different languages and have different religions and cultures. There are also many people from different countries who stay in London on business. Many people visit London as tourists. They may see the famous Sights of London. These sights include palaces, churches and museums.

The Romans built the city of Londinium along the River Thames in the year AD 43  The name Londinium (and later 'London') came from the Celtic language of the Ancient Britons. In the year AD 61, the city was attacked and destroyed. Then the Romans rebuilt the city, and London became an important trading hub.

After the decline of the Roman Empire, few people remained in London. This was partly because the Anglo-Saxon people of Sub-Roman Britain were primarily agricultural. Once the Romans had gone, trade with Continental Europe dwindled. In the 9th century, more people started living in London again. It became the largest city in England. However, it did not become the capital city of England until the 12th century.

After the railways were built, London grew very big. Greater London has 33 London Boroughs (neighbourhoods) and a mayor. The old City of London is only a square mile in size but has its own Lord Mayor.

Another famous old part of Greater London is Westminster, which was always a different city from the City of London. In Westminster is Westminster Abbey (a cathedral), The Palace of Westminster (the Houses of Parliament, with Big Ben), and 10 Downing Street (where the Prime Minister lives).

London has an oceanic, or temperate climate. It is not usually very hot or cold. It is often cloudy.

London has many celebrations, festivals and events.

London has five major business districts: the City, Westminster, Canary Wharf, Camden  Islington and Lambeth  Southwark.

The London Stock Exchange is the most international stock exchange and the largest in Europe.

London's largest industry is finance.  This includes banks, stock exchanges, investment companies and insurance companies  The Bank of England is located in London and is the second oldest bank in the world.

London has many professional services such as law and accounting firms.

The British Broadcasting Company (BBC), which has many radio and TV stations, is in London.

Tourism is one of London's biggest industries. London is the most visited city in the world by international tourists with 18.8 million international visitors per year. Within the UK, London is home to the ten most-visited tourist attractions. Tourism employed about 350,000 full-time workers in London in 2003.  Tourists spend about £15 billion per year.

A growing number of technology companies are based in London.

London is a major retail centre, and in 2010 had the highest non-food retail sales of any city in the world, with a total spend of around £64.2 billion. The UK's fashion industry, centred on London, contributes tens of billions to the economy.

For the 19th and much of the 20th centuries London was a major manufacturing centre (see Manufacturing in London), with over 1.5 million industrial workers in 1960. Many products were made in London including ships, electronics and cars.  Nowadays, most of these manufacturing companies are closed but some drug companies still make medicine in London.

London has twin and sister city agreements with these cities:

London also has a partnership agreement with Tokyo, Japan.

The city has a huge network of transport systems including trains, metros (underground) and five main airports.

The Victorians built many train systems in the mid-19th century (1850s). Their main stations are in London, and the lines go to every part of Great Britain. There were originally five major companies but the five companies became a national rail network in modern times.

There are five airports, though only one is actually in London (London City Airport). There is the London end of the LondonBirmingham canal, which was important to the industrial 19th century.  The most used airport is Heathrow International Airport  although it is actually outside the city.

The metro or London Underground is a system of electric trains which are in London, United Kingdom. It is the oldest underground railway in the world. It started running in 1863 as the Metropolitan Railway. After the opening the system was copied in many other cities, for example New York and Madrid. Even though it is called the Underground about half of it is above the ground. The Tube is a slang name for the London Underground, because the tunnels for some of the lines are round tubes running through the ground. The Underground has got 274 stations and over 408 km of track. From 2006–2007 over 1 billion passengers used the underground.




#Article 185: Litre (485 words)


A litre (international spelling) or liter (American spelling) is one of the metric units of volume. It is not an SI unit.

One litre is the volume of 1000 cubic centimetres, that is a cube of 10 × 10 × 10 centimetres (1000 cm3). One litre of water at  has the mass of exactly one kilogram. This results from the definition given in 1795, where the gram was defined as the weight of one cubic centimetre of melting ice.

The symbol for litre is l or ℓ.

For smaller volumes, the decilitre is used: 10 dl = one litre.

For smaller volumes, the centilitre is used: 100 cl = one litre.

For smaller volumes, the millilitre is used: 1000 ml = one litre.

The capital letter L is preferred by some people as the small l can look like the number one 1.

The metric system was first introduced in France in 1791. That system did not have its own unit of capacity or volume because volume can be measured in cubic metres. In 1793 work to make the metric system compulsory in France was started by the Temporary Commission of Republican Weights and Measures. Due to public demand, the commission said that the cubic metre was too big for everyday use. They said that a new unit based on the old cadil should be used instead. One cadil was to be 0.001 cubic metres. This was equivalent to a cube with sides 10 cm. The cadil was also known as the pinte or the litron. The pinte had been an old French unit of measure of capacity. In 1795 the definition was revised. The cadil was given the name litre.

In 1795 the kilogram was defined to be exactly one litre of water at 4 °C. In 1799 the kilogram was redefined. The new definition said that the kilogram was the mass of the kilogram des archives. In 1901 scientists measured the volume of one litre of water at 4 °C very carefully.  They found that it occupied about  dm3. The BIPM redefined the litre as being exactly the volume of one kilogram of water at 4 °C.

In 1960 the SI was introduced.  The BIPM changed the definition of the litre back to one dm3. The litre is not part of SI. The BIPM defined the litre as a Non-SI unit accepted for use with the SI. This was because it is used in many  countries. The BIPM said that the litre should not be used for very accurate work.

According to SI rules, the symbol for the litre should be l. This is because the litre was not named after somebody whose name was Litre. However the symbol l and the number 1 are easily confused. In 1979 the BIPM made an exception for the symbol for the litre. They said that people could use either L or l as its symbol.




#Article 186: Lime (138 words)


Lime is a green fruit, and the tree fruit itself. They are citrus fruits similar to lemons. Limes are rich in vitamin C. Sailors from Britain were given lemon or lime juice to stop them falling ill with scurvy. This is how they got the nickname Limey. There are several citrus trees whose fruits are called limes. They include the key lime Citrus aurantiifolia, the Persian lime, the kaffir lime, and the desert lime Citrus glauca.

Limes are small, round and bright green. If they stay on the tree for a long time they turn yellow. Then they look like small round lemons.

Lime juice is used in cooking and in drinks. Lime oils are often used in perfumes, used for cleaning, and used for aromatherapy.

Lime tastes acidic and bitter. Lime juice is also made from limes.




#Article 187: Mathematics (498 words)


Mathematics is the study of numbers, shapes and patterns. The word comes from the Greek word μάθημα (máthema), meaning science, knowledge, or learning, and is sometimes shortened to maths (in England, Australia, Ireland, and New Zealand) or math (in the United States and Canada). The short words are often used for arithmetic, geometry or simple algebra by students and their schools.

Mathematics includes the study of:

Mathematics is useful for solving problems that occur in the real world, so many people besides mathematicians study and use mathematics. Today, some mathematics is needed in many jobs. People working in business, science, engineering, and construction need some knowledge of mathematics.

Mathematics solves problems by using logic. One of the main tools of logic used by mathematicians is deduction. Deduction is a special way of thinking to discover and prove new truths using old truths. To a mathematician, the reason something is true (called a proof) is just as important as the fact that it is true, and this reason is often found using deduction. Using deduction is what makes mathematics thinking different from other kinds of scientific thinking, which might rely on experiments or on interviews.

Logic and reasoning are used by mathematicians to create general rules, which are an important part of mathematics. These rules leave out information that is not important so that a single rule can cover many situations. By finding general rules, mathematics solves many problems at the same time as these rules can be used on other problems. These rules can be called theorems (if they have been proved) or conjectures (if it is not known if they are true yet). Most mathematicians use non-logical and creative reasoning in order to find a logical proof.

Sometimes, mathematics finds and studies rules or ideas that we don't understand yet. Often in mathematics, ideas and rules are chosen because they are considered simple or neat. On the other hand, sometimes these ideas and rules are found in the real world after they are studied in mathematics; this has happened many times in the past. In general, studying the rules and ideas of mathematics can help us understand the world better. Some examples of math problems are addition, subtraction, multiplication, division, calculus, fractions and decimals. Algebra problems are solved by evaluating certain variables. A calculator answers every math problem in the four basic arithmetic operations.

These theorems have interested mathematicians and people who are not mathematicians.

These are theorems and conjectures that have greatly changed mathematics.

Progress in understanding the nature of mathematics also influences the way mathematicians study their subject.

Mathematics in history, and the history of mathematics.

There is no Nobel prize in mathematics. Mathematicians can receive the Abel prize and the Fields Medal for important works.

The Clay Mathematics Institute has said it will give one million dollars to anyone who solves one of the Millennium Prize Problems.

There are many tools that are used to do mathematics or to find answers to mathematics problems.




#Article 188: March (493 words)


March is the third month of the year in the Gregorian calendar, coming between February and April. It has 31 days. March is named after Mars, the Roman god of war.

March always begins on the same day of the week as November, and additionally, February in common years.  March always ends on the same day of the week as June.

In ancient Rome, March was called Martius. It was named after the war god (Mars) and the Romans thought that it was a lucky time to begin a war. Before Julius Caesar's calendar reform, March was the first month of the year in the Roman calendar, as the winter was considered to be a monthless period.

March is one of seven months to have 31 days. March begins on the same day of the week as February in common years and November every year, as each other's first days are exactly 4 weeks (28 days) and 35 weeks (245 days) apart respectively. March ends on the same day of the week as June every year, as each other's last days are exactly 13 weeks (91 days) apart.

In common years, March starts on the same day of the week as June of the previous year, and in leap years, September and December of the previous year. In common years, March finishes on the same day of the week as September of the previous year, and in leap years, April and December of the previous year.

In years immediately before common years, March starts on the same day of the week as August of the following year, and in years immediately before leap years, May of the following year. In years immediately before common years, March finishes on the same day of the week as August and November of the following year, and in years immediately before leap years, May of the following year.

In leap years, the day before March 1 is February 29. This determines the position of each day of the year from there on. As an example, March 1 is usually the 60th day of the year, but in a leap year is the 61st day.

In terms of seasons, March is one of two months to have an equinox (the other is September, its seasonal equivalent in both  hemispheres), with daylight and darkness of roughly the same number of hours, halfway between the December and June solstices. In the Northern Hemisphere, spring starts in this month, while it is autumn in the Southern Hemisphere. 

The official start of either season is March 1, though the equinox can fall on March 20 or 21, occasionally on March 19. The northern spring equinox marks the start of the Iranian New Year and Baha'i New Year. It is from the March 21 date that Easter's date is calculated, on the Sunday after the first full moon in spring, meaning it can fall between March 22 and April 25 in Western Christianity. 




#Article 189: May (476 words)


May is the fifth month of the year, coming between April and June. It has 31 days. The month of May might have been named for the Roman goddess Maia, or more likely the Roman goddess of fertility Bona Dea, whose festival was held in May.

May never begins or ends on the same day of the week as any other month.

May's flower is the Lily of the Valley. Its birthstone is the emerald. The meaning of the emerald is success in love.

May comes between April and June and is the fifth month of the year in the Gregorian calendar. It is one of seven months to have 31 days. In the older Roman calendar, May was the third month of the year. It is a spring month in the Northern Hemisphere and an autumn month in the Southern Hemisphere. In each hemisphere, it is the seasonal equivalent of November in the other. May is likely to have been named after the Roman goddess Maia, though there is a theory that May might have its name from the Latin Maiores, meaning Seniors. The same theory suggests that June would then be named from Iuniores, meaning Juniors.

May is the only month that does not begin or end on the same day of the week as any other month in any year.

In common years, May starts on the same day of the week as August of the previous year, and in leap years, March and November of the previous year. In common years, May finishes on the same day of the week as August and November of the previous year, and in leap years, March and June of the previous year. In leap years and years immediately after that, May starts on the same day of the week as February of the previous year. 

Every year, May both starts and finishes on the same day of the week as January of the following year, as each other's first and last days are exactly 35 weeks (245 days) apart. In years immediately before common years, May starts on the same day of the week as October of the following year, and in years immediately before leap years, April and July of the following year. In years immediately before common years, May finishes on the same day of the week as February and October of the following year, and in years immediately before leap years, July of the following year.

In the Northern Hemisphere, May is in late Spring, and May Day on May 1 and Walpurgis Night, during the night of April 30 to May 1, are symbolic of the transition from winter to summer. In the Southern Hemisphere, it is in autumn, and comes just before the Antarctic winter, when emperor penguins breed there.

Special devotions to the Virgin Mary take place in May. 

 




#Article 190: Music (3160 words)


Music is a form of art that uses sound  in time. Music is also a form of entertainment that puts sounds together in a way that people like, find interesting or dance to. Most music includes people singing with their voices or playing musical instruments, such as the piano, guitar, drums or violin.

The word music comes from the Greek word (mousike), which means (art) of the Muses. In Ancient Greece the Muses included the goddesses of music, poetry, art, and dance. Someone who makes music is known as a musician.

Music is sound that has been organized by using rhythm, melody or harmony. If someone bangs saucepans while cooking, it makes noise. If a person bangs saucepans or pots in a rhythmic way, they are making a simple type of music.

There are four things which music has most of the time:

There is no simple definition of music which covers all cases. It is an art form, and opinions come into play. Music is whatever people think is music. A different approach is to list the qualities music must have, such as, sound which has rhythm, melody, pitch, timbre, etc.

These and other attempts, do not capture all aspects of music, or leave out examples which definitely are music. According to Thomas Clifton, music is a certain reciprocal relation established between a person, his behavior, and a sounding object.p10 Musical experience and the music, together, are called phenomena, and the activity of describing phenomena is called phenomenology.

Even in the stone age people made music. The first music was probably made trying to imitate sounds and rhythms that occurred naturally. Human music may echo these phenomena using patterns, repetition and tonality. This kind of music is still here today. Shamans sometimes imitate sounds that are heard in nature. It may also serve as entertainment (games), or have practical uses, like attracting animals when hunting.

Some animals also can use music. Songbirds use song to  their territory, or to attract a mate. Monkeys have been seen beating hollow logs. This may, of course, also serve to defend the territory.

The first musical instrument used by humans was probably the voice. The human voice can make many different kinds of sounds. The larynx (voice box) is like a wind instrument.

The oldest known Neanderthal hyoid bone with the modern human form was found in 1983, indicating that the Neanderthals had language, because the hyoid supports the voice box in the human throat.

Most likely the first rhythm instruments or percussion instruments involved the clapping of hands, stones hit together, or other things that are useful to keep a beat. There are finds of this type that date back to the paleolithic. Some of these are ambiguous, as they can be used either as a tool or a musical instrument.

The oldest flute ever discovered may be the so-called  Divje Babe flute, found in the Slovenian cave Divje Babe I in 1995. It is not certain that the object is really a flute. The item in question is a fragment of the femur of a young cave bear, and has been dated to about 43,000 years ago. However, whether it is truly a musical instrument or simply a carnivore-chewed bone is a matter of ongoing debate.

In 2008, archaeologists discovered a bone flute in the Hohle Fels cave near Ulm, Germany. The five-holed flute has a V-shaped mouthpiece and is made from a vulture wing bone. The researchers involved in the discovery officially published their findings in the journal Nature, in June 2009. The discovery is also the oldest confirmed find of any musical instrument in history. Other flutes were also found in the cave. This flute was found next to the Venus of Hohle Fels and a short distance from the oldest known human carving. When they announced their discovery, the scientists suggested that the finds demonstrate the presence of a well-established musical tradition at the time when modern humans colonized Europe.

The oldest known wooden pipes were discovered near Greystones, Ireland, in 2004. A wood-lined pit contained a group of six flutes made from yew wood, between 30 and 50 cm long, tapered at one end, but without any finger holes. They may once have been strapped together.

In 1986 several bone flutes were found in Jiahu in Henan Province, China. They date to about 6,000 BC. They have between 5 and 8 holes each and were made from the hollow bones of a bird, the Red-crowned Crane. At the time of the discovery, one was found to be still playable. The bone flute plays both the five- or seven-note scale of Xia Zhi and six-note scale of Qing Shang of the ancient Chinese musical system.

It is not known what the earliest music of the cave people was like. Some architecture, even some paintings, are thousands of years old, but old music could not survive until people learned to write it down. The only way we can guess about early music is by looking at very old paintings that show people playing musical instruments, or by finding them in archaeological digs (digging underground to find old things). The earliest piece of music that was ever written down and that has not been lost was discovered on a tablet written in Hurrian, a language spoken in and around northern Mesopotamia (where Iraq is today), from about 1500 BC. The Oxfords Companion to Music, ed. Percy Scholes, London 1970

Another early piece of written music that has survived was a round called Sumer Is Icumen In. It was written down by a monk around the year 1250. Much of the music in the Middle Ages (roughly 450-1420) was folk music played by working people who wanted to sing or dance. When people played instruments, they were usually playing for dancers. However, most of the music that was written down was for the Catholic church. This music was written for monks to sing in church. It is called Chant (or Gregorian chant).

In the Renaissance (roughly 1400–1550) there was a lot of music, and many composers wrote music that has survived so that it can be performed, played or sung today. The name for this period (Renaissance) is a French word which means rebirth. This period was called the rebirth because many new types of art and music were reborn during this time.

Some very beautiful music was written for use in church services (sacred music) by the Italian composer Giovanni da Palestrina (1525–1594). In Palestrina's music, many singers sing together (this is called a choir). There was also plenty of music not written for the church, such as happy dance music and romantic love songs. Popular instruments during the Renaissance included the viols (a string instrument played with a bow), lutes (a plucked stringed instrument that is a little like a guitar), and the virginal, a small, quiet keyboard instrument.

In the arts, the Baroque was a Western cultural era, which began near the turn of the 17th century in Rome. It was exemplified by drama and grandeur in sculpture, painting, literature, dance, and music. In music, the term 'Baroque' applies to the final period of dominance of imitative counterpoint, where different voices and instruments echo each other but at different pitches, sometimes inverting the echo, and even reversing thematic material.

The popularity and success of the Baroque style was encouraged by the Roman Catholic Church which had decided at the time of the Council of Trent that the arts should communicate religious themes in direct and emotional involvement. The upper class also saw the dramatic style of Baroque architecture and art as a means of impressing visitors and expressing triumphant power and control. Baroque palaces are built around an entrance of courts, grand staircases and reception rooms of sequentially increasing opulence. In similar profusions of detail, art, music, architecture, and literature inspired each other in the Baroque cultural movement as artists explored what they could create from repeated and varied patterns. Some traits and aspects of Baroque paintings that differentiate this style from others are the abundant amount of details, often bright polychromy, less realistic faces of subjects, and an overall sense of awe, which was one of the goals in Baroque art.

The word baroque probably derives from the ancient Portuguese noun barroco which is a pearl that is not round but of unpredictable and elaborate shape. Hence, in informal usage, the word baroque can simply mean that something is elaborate, with many details, without reference to the Baroque styles of the seventeenth and eighteenth centuries.

In western music, the classical period means music from about 1750 to 1825. It was the time of composers like Joseph Haydn, Wolfgang Amadeus Mozart and Ludwig van Beethoven. Orchestras became bigger, and composers often wrote longer pieces of music called symphonies that had several sections (called movements). Some movements of a symphony were loud and fast; other movements were quiet and sad. The form of a piece of music was very important at this time. Music had to have a nice 'shape'. They often used a structure which was called sonata form.

Another important type of music was the string quartet, which is a piece of music written for two violins, a viola, and a violoncello. Like symphonies, string quartet music had several sections. Haydn, Mozart and Beethoven each wrote many famous string quartets.

The piano was invented during this time. Composers liked the piano, because it could be used to play dynamics (getting louder or getting softer). Other popular instruments included the violin, the violoncello, the flute, the clarinet, and the oboe.

The 19th century is called the Romantic period. Composers were particularly interested in conveying their emotions through music. An important instrument from the Romantic period was the piano. Some composers, such as Frederic Chopin wrote subdued, expressive, quietly emotional piano pieces. Often music described a feeling or told a story using sounds. Other composers, such as Franz Schubert wrote songs for a singer and a piano player called Lied (the German word for song). These Lieder (plural of Lied) told stories by using the lyrics (words) of the song and by the imaginative piano accompaniments. Other composers, like Richard Strauss, and Franz Liszt created narratives and told stories using only music, which is called a tone poem. Composers, such as Franz Liszt and Johannes Brahms used the piano to play loud, dramatic, strongly emotional music.

Many composers began writing music for bigger orchestras, with as many as 100 instruments. It was the period of Nationalism (the feeling of being proud of one's country) when many composers made music using folksong or melodies from their country. Lots of famous composers lived at this time such as Franz Schubert, Felix Mendelssohn, Frederic Chopin, Johannes Brahms, Pyotr Tchaikovsky and Richard Wagner.

From about 1900 onwards is called the modern period. Many 20th century composers wanted to compose music that sounded different from the Classical and Romantic music. Modern composers searched for new ideas, such as using new instruments, different forms, different sounds, or different harmonies.

The composer Arnold Schoenberg (1874–1951) wrote pieces which were atonal (meaning that they did not sound as if they were in any clear musical key). Later, Schoenberg invented a new system for writing music called twelve-tone system. Music written with the twelve-tone system sounds strange to some, but is mathematical in nature, often making sense only after careful study. Pure twelve-tone music was popular among academics in the fifties and sixties, but some composers such as Benjamin Britten use it today, when it is necessary to get a certain feel.

One of the most important 20th-century composers, Igor Stravinsky (1882–1971), wrote music with very complicated (difficult) chords (groups of notes that are played together) and rhythms. Some composers thought music was getting too complicated and so they wrote Minimalist pieces which use very simple ideas. In the 1950s and 1960s, composers such as Karlheinz Stockhausen experimented with electronic music, using electronic circuits, amplifiers and loudspeakers. In the 1970s, composers began using electronic synthesizers and musical instruments from rock and roll music, such as the electric guitar. They used these new instruments to make new sounds.

Composers writing in the 1990s and the 2000s, such as John Adams (born 1947) and James MacMillan (born 1959) often use a mixture of all these ideas, but they like to write tonal music with easy tunes as well.

Music can be produced electronically. This is most commonly done by computers, keyboards, electric guitars and disk tables. They can mimic traditional instruments, and also produce very different sounds. 21st-century electronic music is commonly made with computer programs and hardware mixers.

Jazz is a type of music that was invented around 1900 in New Orleans in the south of the USA. There were many black musicians living there who played a style of music called blues music. Blues music was influenced by African music (because the black people in the United States had come to the United States as slaves. They were taken from Africa by force). Blues music was a music that was played by singing, using the harmonica, or the acoustic guitar. Many blues songs had sad lyrics about sad emotions (feelings) or sad experiences, such as losing a job, a family member dying, or having to go to jail (prison).

Jazz music mixed together blues music with European music. Some black composers such as Scott Joplin were writing music called ragtime, which had a very different rhythm from standard European music, but used notes that were similar to some European music. Ragtime was a big influence on early jazz, called Dixieland jazz. Jazz musicians used instruments such as the trumpet, saxophone, and clarinet were used for the tunes (melodies), drums for percussion and plucked double bass, piano, banjo and guitar for the background rhythm (rhythmic section). Jazz is usually improvised: the players make up (invent) the music as they play. Even though jazz musicians are making up the music, jazz music still has rules; the musicians play a series of chords (groups of notes) in order.

Jazz music has a swinging rhythm. The word swing is hard to explain. For a rhythm to be a swinging rhythm it has to feel natural and relaxed. Swing rhythm is not even like a march. There is a long-short feel instead of a same-same feel. A swinging rhythm also gets the people who are listening excited, because they like the sound of it. Some people say that a swinging rhythm happens when all the jazz musicians start to feel the same pulse and energy from the song. If a jazz band plays very well together, people will say that is a swinging jazz band or that band really swings well.

Jazz influenced other types of music like the Western art music from the 1920s and 1930s. Art music composers such as George Gershwin wrote music that was influenced by jazz. Jazz music influenced pop music songs. In the 1930s and 1940s, many pop music songs began using chords or melodies from jazz songs. One of the best known jazz musicians was Louis Armstrong (1900–1971).

Modern pop music grew out of 1950's rock and roll, (for example Chuck Berry, Bo Diddley and Little Richard) and rockabilly (for example Elvis Presley and Buddy Holly). In the 1960s, The Beatles became a famous pop music group. In the 1970s, other styles of music were mixed with pop music, such as funk and soul music. Pop music generally has a heavy (strong) beat, so that it is good for dancing. Pop singers normally sing with microphones that are plugged into an amplifier and a loudspeaker.

Solfège (sometimes called solfa) is the way tones are named. It was made in order to give a name to the several tones and pitches. For example, the eight basic notes Do, Re, Mi, Fa, So, La, Ti, Do are just the names of the eight notes that confirm the major scale.

Music can be written in several ways. When it is written on a staff (like in the example shown), the pitches (tones) and their duration are represented by symbols called notes. Notes are put on the lines and in the spaces between the lines. Each position says which tone must be played. The higher the note is on the staff, the higher the pitch of the tone. The lower the notes are, the lower the pitch. The duration of the notes (how long they are played for) is shown by making the note heads black or white, and by giving them stems and flags.

Music can also be written with letters, naming them as in the solfa Do, Re, Mi, Fa, So, La, Ti, Do or representing them by letters. The next table shows how each note of the solfa is represented in the Standard Notation:

The Standard Notation was made to simplify the lecture of music notes, although it is mostly used to represent chords and the names of the music scales.

These ways to represent music ease the way a person reads music. There are more ways to write and represent music, but they are less known and may be more complicated.

People can enjoy music by listening to it. They can go to concerts to hear musicians perform. Classical music is usually performed in concert halls, but sometimes huge festivals are organized in which it is performed outside, in a field or stadium, like pop festivals. People can listen to music on CD's, Computers, iPods, television, the radio, casette/record-players and even mobile phones.

There is so much music today, in elevators, shopping malls, and stores, that it often becomes a background sound that we do not really hear.

People can learn to play an instrument. Probably the most common for complete beginners is the piano or keyboard, the guitar, or the recorder (which is certainly the cheapest to buy). After they have learnt to play scales, play simple tunes and read the simplest musical notation, then they can think about which instrument for further development. They should choose an instrument that is practical for their size. For example, a very short child cannot play a full size double bass, because the double bass is over five feet high. People should choose an instrument that they enjoy playing, because playing regularly is the only way to get better. Finally, it helps to have a good teacher.

Anyone can make up his or her own pieces of music. It is not difficult to compose simple songs or melodies (tunes). It's easier for people who can play an instrument themselves. All it takes is experimenting with the sounds that an instrument makes. Someone can make up a piece that tells a story, or just find a nice tune and think about ways it can be changed each time it is repeated. The instrument might be someone's own voice.

The fact is, there are tons of instruments in the world.




#Article 191: Madrid (1163 words)


Madrid (pronounced: “mah-DRID” or /məˈdrɪd/) is the capital and largest city of Spain. Madrid is in the middle of Spain, in the Community of Madrid. The Community is a large area that includes the city as well as small towns and villages outside the city. 7 million people live in the Community. More than 3 million live in the city itself. It is the largest city of Spain and, at 655 m (2,100 ft) above sea level, the second highest capital in Europe (after the Andorran capital Andorra la Vella).  It is the third largest city in the European Union.  As it is the capital city, Madrid is where the monarch lives and also where the government meets. Madrid is the financial centre of Spain. Many large businesses have their main offices there. It has four important footballs teams, Real Madrid, Atlético Madrid, Getafe, and Rayo Vallecano. People who live in Madrid are called madrileños. 

Madrid was ruled by the Romans from the 2nd century. After AD 711 it was occupied by the Moors. In 1083 Spain was ruled again by Spaniards. Catholic kings ruled the country. By the mid-16th century it had become the capital of a very large empire. Spain was ruled by monarchs from the House of Habsburg, then the House of Bourbon. After the Spanish Civil War it was ruled by a dictator until the mid-1970s when it became a democracy.

Although it is a modern city, a lot of its history can be seen and felt as one walks along the streets and in the large squares of the city. There are beautiful parks, famous buildings, art galleries and concert halls. 

During the history of Spain many different people have lived there. The Phoenicians came in 1100 BC, followed by Carthaginians, Romans, Vandals, Visigoths and Moors. It was not until 1492, when the Catholic Monarchs got power, that Spain became a united country. Jews and Moors, who had lived happily there for many years, were driven away. Spain became very rich because it conquered many overseas countries, especially in Central and South America. However, Spain fought many wars and lost much of its treasure. It was very poor in 1936 when the Civil War was fought. General Franco became a harsh dictator until 1975 when Juan Carlos I was brought back to Spain and made king. There is now a democratic government.

In prehistoric times people lived in the area which is now Madrid. The Romans lived there for several centuries. The origin of today’s city really starts in the 9th century when Muhammad I had a small palace built where the Palacio Real stands today. The Moors built strong forts in Madrid in 865 and put a wall round the city. These walls stood until 1476 when they were knocked down. In 1561 Felipe I moved the royal court from Toledo to Madrid. Madrid had now become the capital of a very large empire. Over the next years and decades the Plaza Mayor was built and many great buildings and monuments, many of which still stand.

When Ferdinand II of Aragon and Queen Isabella of Castile came to Madrid, Spain had become a very rich country. The 16th and 17th centuries are now known as the “Golden Century”. Their grandson was the famous Charles I of Spain (also known as Charles V, Holy Roman Emperor). He liked his court to be in Seville. His son, Philip II (1527–1598) moved the court to Madrid in 1561. 
  
In the late 1800s there was a revolt, known as the First Spanish Republic. Later the monarchy was restored, but then there was a Second Spanish Republic followed by the Spanish Civil War. The Second Spanish Republic started on 14 April 1931 and was celebrated in La puerta del Sol which is the center of the city. Madrid suffered a lot in this war. It was bombed by airplanes.

During the dictatorship of Francisco Franco, especially during the 1960s, south Madrid became very industrialized, and many people from the rural areas moved to Madrid especially to the south east of the city.

When General Franco died and democracy was restored, Madrid became more prosperous. During the 1980s and 1990s many new buildings were put up.

Madrid has been attacked many times by terrorists. This includes the bombing of a restaurant in 1985, killing 18 people and the of trains in 2004, killing over 190 people.

Madrid has a hot-summer Mediterranean climate (Csa in the Köppen climate classification). Most rain falls in autumn and spring. The winters are cool because it is high up, and occasionally it snows. The summers are hot and dry. Often the temperature is above 30 °C (86 °F) in July and can often reach 40 °C (104 °F). At night it is much cooler. This is why people have a sleep (siesta) in the afternoon when it is hot. Then they come out again in late afternoon and often eat dinner late at night.

Spain's Royal Palace is in Madrid. It is one of the largest palaces in all of Western Europe. But the king and his family do not live there anymore; they live in a smaller palace, and only use the Royal Palace for important events, like meeting other kings and other official ceremonies. One can go inside the Royal Palace and learn about the history of Spanish monarchy.

Other famous buildings are: The Prado Museum, the Temple of Debod, the Santiago Bernabeú Stadium and the Cuatro Torres Business Area.

There are a lot of very big and important art museums in Madrid. The most famous ones are the Prado Museum, the Queen Sofia Museum, and the Thyssen-Bornemisza museum. These show off paintings, sculptures, and other works of art from some of the most famous artists in the world.

Many famous, important, and valuable works of art are in these museums. For example, the Queen Sofia museum has a famous painting by Pablo Picasso, called Guernica. Picasso painted this painting to show how sad and angry it made him when the German Nazis destroyed a town in Spain called Guernica in 1937. Picasso had said that the painting should never return to Spain until it was a democracy again. Once that happened, they built the Queen Sofia museum just to have a good place to put it.

There are many other sights to see in Madrid. Many people go to see the Plaza Mayor which was a market place. The Plaza de la Villa was another famous market place. There are a lot of shops along the Gran Via. Real Madrid football fans celebrate at the Plaza de Cibeles. Two famous gates to see are the Puerta del Sol and the Puerta de Alcalá. A more recent landmark is the Almudena Cathedral.

Madrid has some lovely parks. The Retiro Park is the most famous. The Cristal Palace can be found in this park.

The Plaza de Toros is visited by many tourists. Bullfights take place there.




#Article 192: Montreal (557 words)


Montreal (, spelled Montréal in French) is a city in the country of Canada. It is the largest city in the province of Quebec and the second-largest city in Canada. It is the second-largest French-speaking city in the world after Paris.

Montreal is built on an island sitting in the Saint Lawrence River. More than three million people live in the Montreal region. At the centre of Montreal is a mountain called Mount Royal. The suburb of Westmount, is a very affluent suburb of Quebec.

Most of the people who live in Montreal speak French, but English is also commonly spoken, as a second language.

The name 'Montréal' comes from Mont Royal, which means 'Royal Mountain' in French. It was originally called Ville-Marie, or City of Mary.

Montreal has always played a very important part in the history and development of Canada. It continues to be a large Canadian industrial and commercial centre, as well as a major seaport (via the Saint Lawrence River). It once was the largest city in Canada, before Toronto grew to be larger.

Tourists visit Montreal for its historical and cultural interest. One can visit the Old City in horse-drawn carriages, where many buildings from the earliest years stand and remind of the way of life that started in the New World, when Montreal was just a fur trading outpost belonging to France over 350 years ago.

Montreal is in the southwest of Quebec, 530 kilometres north of New York City. The city itself is located on an island, the Island of Montreal. Near the downtown area, there is a hill called Mount Royal (Mont Royal in French).

Montreal's economy is the second largest in Canada. The city's port is the biggest inland port (a port that is not on the sea) in the world. Many large corporations have their main offices in Montreal. It also hosts many international organizations like ICAO, the World Anti-Doping Agency, and IATA. The city is home to four major Universities, welcoming students from all parts of Canada and from all over the world.

Montreal is also known for its cultural production sector. Because the city has many different buildings, movies are easy to film there. The circus troupe (group) Cirque du Soleil is from Montreal. The city is also known for its festivals, like the Montreal Jazz Festival and Just For Laughs.

Some video game companies also have studios in Montreal.

Montreal has many beautiful churches (Montreal is referred to locally as 'the city of a hundred churches'), including the largest church in Canada, and also many important art, history, and science museums. You can also visit the location of the 1967 World's Fair, where today, as well as many other attractions, one will find the Circuit Gilles Villeneuve Formula One automobile race course. Also of interest is the site where the 1976 Summer Olympic Games were held, and the modern architecture of the Olympic stadium (the 'Big O') and its tall inclined observation tower (the highest inclined tower in the world); now a landmark of Montreal.

A lot of Montrealers are interested in hockey, and Montreal is home to its own ice hockey team called the Montreal Canadiens who play in the National Hockey League (NHL).

Montreal Stations

CBMT CBC

CFCF CTV Television Network

CIVM Tele-Quebec

CJNT CH

CFTU Canal Savoir

CKMI Global Television Network




#Article 193: Macadamia nut (207 words)


The macadamia nut is the fruit of a tree that first came from the east coast of Australia. There is 
more than one kind of Macadamia tree. Only one kind is grown for food.

The tree is an evergreen (stays green all year long). It grows up to  high. It has groups of small white flowers. It grows best in subtropical (wet and always warm) climates. It needs well-drained soil (water can flow away easily) and  of rain a year.

The nutmeat (the soft part inside the shell that can be eaten) is mostly a creamy white color. Sometimes it looks a bit yellow. It has a flavor that many people like. Macadamias are eaten roasted (cooked) by themselves. They are used in cookies, cakes, pastries, and candies. People use them like almonds and cashews as part of cooked meals. This is an Oriental style of cooking.

The first commercial orchard was started in Australia in the late 1880s. Commercial production started in Hawaii during the 1920s. Production later spread to California, Mexico, and other places with warm climate.

Macadamias are poisonous to dogs. A dog usually needs 24 to 48 hours to recover fully after eating macadamias.The plant is in the Proteaceae family of flowering plants.




#Article 194: Maui (184 words)


Maui is the second largest of the Hawaiian Islands, in the United States.
It has a population of just over 100,000 and is 727 square miles (1883 km²) in size. Maui is part of Maui County, Hawaii. The larger (or better known) towns include Kahului, Wailuku, Lahaina, Hana, and Wailea. Main industries are agriculture and tourism.

Maui was named for the demi-god Maui. In Hawaiian legend, he raised all the islands from the sea. Maui is also known as the Valley Isle for the large fertile isthmus (narrow land connection) between two volcanoes.

Maui is a volcanic doublet: an island formed from two volcanic mountains that are joined together. The older volcano, Mauna Kahalawai, is much older and has been very worn down. In common talk it is called the West Maui Mountain. The larger volcano, Haleakala, rises above 10,000 feet (3,050 m). The last eruption of Haleakala happened over 200 years ago, and this lava flow can be seen between Ahihi Bay and La Perouse Bay on the southeast shore. 

Other places on Maui popular with visitors include: 

Golf courses on Maui include:




#Article 195: Molokai (146 words)


Molokai (sometimes mistakenly called Molokaʻi) is the fifth largest island in the U.S. Hawaiian Islands.  The island is 38 miles long and 10 miles across. Its land area is 261 square miles.  The highest mountain is named Kamakou, and it is 4,970 feet (1,514 meters) high. 

Molokai has many local indigenous names including Molokai 'Aina Momona (land of abundance), Molokai Pule O'o (land of powerful prayer), and Molokai Nui A Hina (of the goddess Hina). It is one of the least developed of the Hawaiian islands.

The only big town is named Kaunakakai, which is also the main or chief port on the island.  The airport is in Central Molokai. Also on the island is  Kalaupapa, which is a place for people who have a diease called leprosy. 

Molokai has many Hawaiian fish ponds along its south shore. Many of these have been cleaned and fixed.




#Article 196: Money (793 words)


Money can be defined as anything that people use to buy goods and services. Money is what many people receive for selling their own things or services.
There are many kinds of money in the world. Most countries have their own kind of money, such as the United States dollar or the British pound.
Money is also called many other names, like currency or cash.

The idea of bartering things is very old. A long time ago, people did not buy or sell with money. Instead, they traded one thing for another to get what they wanted or needed. One person who owned many cows could trade with another person who had a lot of wheat. Each would trade a little of what he had with the other. This would support the people on his farm. Other things that were easier to carry around than cows also came to be held as valuable. This gave rise to trade items such as jewelry and spices.
 
When people changed from trading in things like, for example, cows and wheat to using money instead, they needed things that would last a long time. They must still have a known value, and could be carried around. The first country in the world to make metal coins was called Lydia. These first appeared during the 7th century BC, in the western part of what is now Turkey. The Lydian coins were made of a weighed amount of precious metal and were stamped with a picture of a lion. This idea soon spread to Greece, the rest of the Mediterranean, and the rest of the world. Coins were all made to the same size and shape. In some parts of the world, different things have been used as money, like clam shells or blocks of salt.

Besides being easier to carry than cows, using money had many other advantages. Money is easier to divide than many trade goods. If someone own cows, and wants to trade for only half a cow's worth of wheat, he probably does not want to cut his cow in half. But if he sells his cow for money, and buys wheat with money, he can get exactly the amount he wants.

Cows die, and wheat rots. But money lasts longer than most trade goods. If someone sells a cow for money, he can save that money away until he needs it. He can always leave it to his children when he dies. It can last a very long time, and he can use it at any time.

Not every cow is as good as another cow. Some cows are sick and old, and others are healthy and young. Some wheat is good and other wheat is moldy or stale. So if a person trades cows for wheat, he might have a hard time arguing over how much wheat each cow is worth. However, money is standard. That means one dollar is worth the same as another dollar. It is easier to add up and count money, than to add up the value of different cows or amounts of wheat.

Later, after coins had been used for hundreds of years, paper money started out as a promise to pay in coin, much like an I.O.U. note. The first true paper money was used in China in the 10th century AD. Paper money was also printed in Sweden between 1660 and 1664. Both times, it did not work well, and had to be stopped because the banks kept running out of coins to pay on the notes. Massachusetts Bay Colony printed paper money in the 1690s. This time, the use became more common.

Today, most of what people think of as money is not even things you can hold. It is numbers in bank accounts, saved in computer memories. Many people still feel more comfortable using coins and paper, and do not totally trust using electronic money on a computer memory.

 
Many types of money have been used at different times in history. These are:

Commodity money can be used for other purposes besides serving as a medium of exchange. We say it possesses intrinsic value, because it is useful or valuable by itself. Some examples of commodity money are cattle, silk, gold and silver. Convertible paper money is money that is convertible into gold and silver. Gold and Silver certificates are convertible paper money as they can be fully convertible into gold and silver.

Inconvertible money is money that cannot be converted into gold and silver. Notes and coins are inconvertible money. They are inconvertible and are declared by the government money. Such fiat money is a country's legal tender. Today, notes and coins are the currencies used in bank deposits.

Types of bank deposits:




#Article 197: Multiplication (425 words)


Multiplication is an arithmetic operation for finding the product of two numbers in mathematics. It is often represented by symbols such as  and . Multiplication is the third operation in math, after addition which is the first, and subtraction which is the second. It can also be defined on non-number mathematical objects as well.

With natural numbers, multiplication gives the number of tiles in a rectangle, where one of the two numbers equals the number of tiles on one side, and the other number equals the number of tiles on the other side.

With real numbers, multiplication gives the area of a rectangle where the first number is the same as the size of one side, and the second number is the same as the size of the other side.

For example, three multiplied by five is the  of five threes added together, or the total of three fives. This can be written as 3 × 5 = 15, or spoken as three times five equals fifteen. Mathematicians refer to the two numbers to be multiplied as coefficients, or multiplicand and multiplicator separately (where Multiplicand × multiplicator = product).

Multiplication between numbers is said to be commutative—when the order of the numbers does not influence the value of the product. This is true for the integers (whole numbers), e.g. 4 × 6 is the same as 6 × 4, and also for the rational numbers (fractions), and for all the other real numbers (representable as a field in the continuous line), and also for complex numbers (numbers representable as a field in the plane). However, it is not true for quaternions (numbers representable as a ring in the four-dimensional space), vectors or matrices.

The definition of multiplication as repeated addition provides a way to arrive at a set-theoretic interpretation of multiplication of cardinal numbers. A more accurate representation is to think of it as scaling quantities. This animation illustrates 3 being multiplied by 2, giving 6 as a result. Notice that the blue dot in the blue segment of length 3 is placed at position 1, and the blue segment is scaled so that this dot is placed at the end of the red segment (of length 2). For multiplication by any X, the blue dot will always start at 1 and end at X. This works even if X is smaller than 1, or negative.

The opposite of multiplication is division.

Teachers usually require their pupils to memorize the table of the first 9 numbers when teaching multiplication, so that more complex multiplication tasks can be performed.




#Article 198: Microsoft (389 words)


Microsoft Corporation (NASDAQ:) is a company that makes computer software and video games for users around the world. Bill Gates and Paul Allen founded the company in 1975. Microsoft makes Microsoft Windows, Microsoft Office (including Microsoft Word), Edge, MSN and Xbox, among others. Most Microsoft programs cannot be downloaded for free - people have to buy them in a shop or online. Some products (like the Windows operating system) are often already installed when people buy a new computer.

Although Microsoft is best known for its software products, the company also runs a number of web services. They include:

Microsoft has also made a wide variety of hardware over the years. Among them are computer accessories like mice, keyboards, and webcams.

The company also makes and promotes a video game console, Xbox. It lets people play video games on their televisions. The games were first stored on CDs, but many recent games are downloaded from the Internet. There have been three generations of Xbox. The first generation came out in 2001 and was just called Xbox, while the second, the Xbox 360, was released in 2005. The third and newest model is the Xbox One in May 2013. Beginning with the Xbox 360, Microsoft introduced Xbox Live, which lets people play games online against other people anywhere in the world. The Xbox has become very popular and more than 100 million units have been sold worldwide. Because of this, Microsoft is considered one of the three big companies that make video game consoles, along with Nintendo and Sony.

Most recently, Microsoft has also started to make its own PCs, called the Surface. The first model was announced in 2012 and the Surface line now includes tablets that use either ARM or Intel processors, two models of laptops called the Surface Book and Surface Laptop, an all-in-one PC called the Surface Studio, and an interactive whiteboard, the Surface Hub.

In 2014, Microsoft bought the mobile phone division of Nokia, a Finnish company, which then became Microsoft Mobile. The sale included the Lumia family of smartphones, which use Microsoft's own Windows Phone platform. From 2014 to 2016, Microsoft Mobile also made feature phones with the Nokia brand. Then the feature phone business was sold to HMD global, which continues to produce  both feature phones and Android smartphones under license from Nokia.




#Article 199: Islamic world (815 words)


The Islamic World consists of all people who are in Islam. It is not an exact location, but rather a community. When they do things together as Muslims, they are the umma, which means community referring to all of the believers. The faith emphasizes unity and defense of fellow Muslims, so it is common for these nations to cooperate. Recent conflicts in the Muslim World have sometimes spread because of this desire to cooperate (see below). It is also likely that some have been made shorter and less damaging because of it. Some might even have never started.

Muslims are in many countries. In 52 nations, Muslims are the majority. Almost all are Sunni. They speak about 60 languages and come from all ethnic backgrounds. 

The Al-Jazeera satellite TV network in the Arabic language is a news source many Muslims watch.

In most Muslim nations, the government is the main source of news. This sometimes makes it very difficult or dangerous to make anti-government statements.

There are, however, many other news programmes and websites in the Muslim world.

So, in most of the Muslim world, people are very conservative, especially about alcohol, adultery, abortion and women working in jobs where they are used to lure customers.

Muslim women often dress extremely modestly, and many do so by choice. But in some countries they have been forced to do so against their will. This is one of the things that causes tension between the Western World and that of Muslims.

Islamic economics bans debt but in most Muslim countries Western banking is allowed. This is another issue that many Muslims have with the Western world.

One quarter of the world population share Islam as an ethical tradition. 

Many people in these countries also see Islam as a political movement. In democratic countries there is usually at least one Islamic party.

Political Islam is powerful in all Muslim-majority countries. Islamic parties in Pakistan and Algeria have taken power. 

Many in these movements call themselves Islamists, which also sometimes describes more militant Islamic groups. The relationships between these groups and their views of democracy are complex.

Some of these groups are called terrorists because they attack civilians of other non-Muslim nations, to make a political point.

Israel is very unpopular in the Muslim world, because of the Israeli-Palestinian conflict and the way that the state of Israel came into being in 1948 which many Arabs thought was unfair.

Some Muslims see this as a fight against Judaism or Jews, but not all. In Morocco for instance, the Islamists recently invited Jews to join the party. Jewish groups also cooperate with Arabs in the West Bank, where Neturei Karta (anti-Zionist orthodox Jewish) leader Rabbi Mosche Hirsch served as the Minister for Jewish Affairs in the Fatah before there was a Palestinian Authority. Like the Arabs, this small group of Jews thought the way Israel was created was not right. However, very few Jews believe this, and most support Israel as a state.

In 1979 there was a big shift in the way the Muslim world dealt with the rest of the world. In that year, Egypt made peace with Israel, Iran became an Islamic state after a revolution, and there was an invasion of Afghanistan by the Soviet Union. A lot of things changed in that year. By 2001 the Soviet Union was gone, Jordan had also made peace with Israel, and on September 11, 2001 there were major attacks on the U.S. - which most people believe were made to drive the United States out of the Muslim world, especially Saudi Arabia. In many ways the events of 1979 led to the events of 2001.

The 2001 invasion of Afghanistan and 2003 invasion of Iraq are called part of a War on Terrorism by the United States. Many or most Muslims see it as a War on Islam. After the invasion, the Islamic parties won more seats, and a majority of Muslims polled in many nations expressed support for Osama bin Laden and said he would do the right thing. Olivier Roy is a French scholar who thinks that this does not express support for al-Qaeda or militant Islam but opposing colonialism and what many Muslims call racism - favourable treatment for Jews especially those living in West Bank settlements, many of whom have American or British passport, and which the United Nations says have no right to live there.

The situation is very complicated and there are many different views of it.

The Organization of Islamic Conference formed in 1969 lets the Muslim nations work as a group. Russia joined in 2003.

The Arab League is a smaller group of only the Arab countries.

OPEC is another forum where issues between the Muslim and non-Muslim world come up. In 1973 to protest U.S. support for Israel there was an oil embargo which caused the 1973 energy crisis.




#Article 200: Multiverse (146 words)


A multiverse is the theory of a conjectured set of multiple possible universes, including ours, which make up reality. These universes are sometimes called parallel universes. A number of different versions have been considered.

The term multiverse was  in 1895 by psychologist William James as a philosophical concept.

The cosmological multiverse tries to explain why the universe we observe i.e. our universe seems so welcoming to the emergence of life. Even small changes to the way physics works would make life impossible. In a multiverse a vast number of universes are randomly created and some happen to favour life emerging there. Many inhospitable universes would also have been created, but there would be no life there to observe their existence.

The quantum multiverse is another version in which our universe splits into alternative futures with every quantum event. This is called many-worlds interpretation of quantum mechanics.




#Article 201: Mechanistic paradigm (388 words)


The mechanistic paradigm, also known as the Newtonian paradigm, assumes that things in the environment around humans are more like machines than like life.  It was more common in the 19th century.  This is a set of loosely related beliefs that affects all sciences:

Believers in this paradigm sometimes say that those who do not believe in it are following a cognitive paradigm - but almost no one uses this term, since it is redundant - cognitive science is already accepted as the most basic idea in the philosophy of science.  But mechanists reject some of the ideas of cognitive scientists, like cognitive science of mathematics.

Mechanistic thinking also assumes that philosophy of perception is much less important than cognitive scientists say it is - that humans and their beliefs and equipment do not generally add a lot of bias to a scientific theory.  Thomas Kuhn said otherwise, that these things matter, and that the major assumptions of science, can shift drastically.  This he called a paradigm shift.  The shift from mechanistic to cognitive paradigm is an example of this.
Later he used other words to describe the assumptions and beliefs, like mind-set, but the word paradigm is still used.  Some say it is much over-used.

Economics is often said to suffer from assumptions of the mechanistic paradigm.  Sometimes those who believe in neoclassical economics and also in the mechanistic paradigm say they seek to unify physics and economics, as if people and particles behaved as two examples of the same kind of thing.

Technology is often easier to make if people accept a mechanistic paradigm - but it may be harder to say why it does not work, if one believes in these ideas.  For instance, creating diagnostic trees might be easier if one works from experience, not from an idea of how a technology should or must work.

A controversial idea is that mechanistic ideas are just an older idea called scholasticism, with more mathematics.  Both tried to work from what should or must be, instead of what experiment seemed to show.

Another controversial idea is that scientism, belief in science as if it were a religion or ethical tradition, comes from this paradigm.  Most scientists who are mechanistic do not say they see science as a guide to ethics, but try to keep them separate.




#Article 202: MediaWiki (472 words)


MediaWiki is the name of the software that runs all of the Wikimedia projects.  MediaWiki was released in 2003.  It is free server-based software which is licensed under the GNU General Public License (GPL).  The software is licensed under the GPL. This means it is free content, or open source.

MediaWiki is designed to be run on a large web server farm for a website that gets millions of hits per day.  MediaWiki is a very powerful, scalable software and a feature-rich wiki implementation, that uses PHP to process and display data stored in its MySQL database.  Pages use MediaWiki's Wikitext format, so that users without knowledge of XHTML or CSS can edit them easily.

When a user submits an edit to a page, MediaWiki writes it to the database, but without deleting the previous versions of the page, thus allowing easy reverts in case of vandalism or spamming. MediaWiki can manage image and multimedia files, too, which are stored in the filesystem. For large wikis with lots of users, MediaWiki supports caching and can be easily coupled with Squid proxy server software.

All Wikimedia projects run on MediaWiki version  .

Because MediaWiki is flexible, many websites that want people to contribute information use MediaWiki rather than other types of wiki software. Those operated by Wikia are among them.

There are also some websites that use MediaWiki as a content management system.

In MediaWiki, a system administrator can choose to install extensions which are provided on the main MediaWiki website. Some are from the MediaWiki developers, while others are from programmers from all around the world.

Most extensions can be download from Wikimedia's Subversion repository. However, there are some other extensions that other people host themselves.

Some extensions had been added to the main software along the development of MediaWiki. For example, the  extension is an extension to promote a user into an administrator or a bureaucrat.

There were a total of 2124 extensions as of October 4, 2013.

In the default installation of MediaWiki, the software has 17 namespaces(18 actually, but one does not have a namespace), namely:

Additional namespaces can be added using the  from the installation of MediaWiki.

As MediaWiki is a complex software, there would always be bugs in the software, especially for new extensions. Therefore, Wikimedia has created a bugzilla website for people who see a bug to tell the developers of MediaWiki.

Some extensions of MediaWiki use the , while some just use the talk pages of the extension page.

Users can customize MediaWiki for different appearance. They may use one of the several skins. At different times different skins have been default. For example, Wikipedia once used Monobook before adopting the new Vector skin in version 1.16.

A survey done by Wikimedia showed that more people prefer the Vector skin.

More information about the software:




#Article 203: Mustache (128 words)


The hair that grows on the upper lip of some men is called a mustache. The hair that grows on the sides of the face and the chin of some men is called a beard. Some men have a lot of hair and a big mustache, and some have very little. In the modern world, many men shave part or all of their mustaches, or cut their mustache so it does not get very long. A chin beard with no mustache is called a goatee, whilst a chin beard with a mustache is known as a Van Dyke.

Mustache in United Kingdom and Commonwealth of Nations is spelled moustache.

Some animals such as walruses also have hair like this, and people sometimes also call this hair a mustache.




#Article 204: Mile (215 words)


A mile is a unit of length. There are many different kinds of mile but mile on its own usually means the statute mile.

In the US and the UK the word mile usually means the statute mile. 

The nautical mile is used for sea or air travel. 

The nautical mile was originally defined as one minute of arc along a line of longitude of the Earth.  There are 60 minutes of arc in one degree or arc (60' = 1°). So there were 10,800 nautical miles from the North Pole to the South Pole.

Now the nautical mile is defined as 1,852 metres.

The speed of a ship that travels one nautical mile in one hour is called one knot

The mile was first used by the Romans.  It comes from the Latin phrase mille passus (plural: milia passuum).  This means one thousand paces. A pace is the distance each foot moves when taking one step.

Different miles have been used throughout history in various parts of the world. In Norway and Sweden, for example, a mil is a unit of length which is equal to 10 kilometres.

Even in English-speaking countries that use the metric system (for example, Australia, Canada, and New Zealand), the mile is still used in many idioms. These include:




#Article 205: Milky Way (740 words)


The Milky Way is our home galaxy. It contains over 200 billion stars, including our Sun.

The Milky Way has a diameter of about 170,000 or 200,000 light years, and is a barred spiral galaxy. The idea that the Milky Way is made of stars goes back to the Ancient Greek philosopher Democritus.

The Milky Way has three main parts:  a disk, where the Solar System is, a bulge at the core, and an outer halo all around it. Although the word disk suggests it is flat, the Milky Way is actually not quite flat. It is slightly warped and twisted.

This galaxy belongs to the Local Group of three large galaxies and over 50 smaller galaxies. The Milky Way is one of the largest galaxies in the group, second to the Andromeda Galaxy. Its closest neighbour is the Canis Major Dwarf Galaxy, which is about 25,000 light years away from the Earth. The Andromeda Galaxy is moving towards the Milky Way Galaxy, and will collide with it in about 3.75 billion years. The Andromeda Galaxy moves with a speed of about 1,800 kilometres per minute.

The stellar disk of the Milky Way Galaxy is approximately 200,000 light-years (9×1017 km) in diameter, and is considered to be, on average, about 1000 light years thick.

It is estimated to contain at least 200 billion stars and possibly up to 400 billion stars. The figure depends on the number of very low-mass, or dwarf stars, which are hard to detect, especially more than 300 light years from our sun. Therefore, present estimates of the total number are uncertain. This can be compared to the one trillion (1012) stars of the neighbouring Andromeda Galaxy.

The stellar disc of the Milky Way does not have a sharp edge, a radius beyond which there are no stars. Rather, the number of stars drops smoothly with distance from the centre of the Galaxy. Beyond a radius of about 40,000 light years, the number of stars drops much faster, for reasons that are not understood.

Extending beyond the stellar disk is a much thicker disk of gas. Recent observations indicate that the gaseous disk of the Milky Way has a thickness of around 12000 light years–twice the previously accepted value. As a guide to the relative physical scale of the Milky Way, if the Solar System out to the orbit of Pluto were reduced to the size of a US quarter (about an inch or 25 mm in diameter), the Milky Way would have a diameter of 2,000 kilometers. At 220 kilometers per second it takes the Solar System about 240 million years to complete one orbit of the Galaxy (a galactic year).

The Galactic halo extends outward, but is limited in size by the orbits of two Milky Way satellites, the Large and the Small Magellanic Clouds, whose closest approach is at about 180,000 light years. At this distance or beyond, the orbits of most halo objects would be disrupted by the Magellanic Clouds, and the objects would likely be ejected from the vicinity of the Milky Way.

The galactic disc, which bulges outward at the galactic center, has a diameter of 170–200,000 light years.

The exact distance from the Sun to the galactic center is debated. The latest estimates give distances to the Galactic center of 25–28,000 light years.

Movement of material around the galactic center shows that it has a compact object of very large mass. The intense radio source named Sagittarius A*, thought to mark the center of the Milky Way, is now confirmed to be a supermassive black hole. Most galaxies are believed to have a supermassive black hole at their center.

The nature of the galaxy's bar is also actively debated, with estimates for its half-length and orientation spanning from 3,300–16,000 light years (short or a long bar) and 10–50 degrees. Viewed from the Andromeda Galaxy, it would be the brightest feature of our own galaxy.

In Greek mythology, Zeus places his son (the baby Heracles) whose mother was a  woman on Hera's breast while she is sleeping so that the baby will drink her divine milk and become immortal. However, Hera wakes up while she is breastfeeding the baby and realizes she is nursing a baby she does not know. According to Greek mythology, she then pushes the baby away and a stream of her milk sprays the night sky, making a  band of light known as the Milky Way.




#Article 206: Movement (385 words)


Movement, or motion,  is the state of changing something's position—that is, changing where something is.  A flying bird or a walking person are moving, because they change where they are from one place to another.  There are many kinds of science and math related to movement.

Thanks to the work of scientists including Galileo Galilei and Issac Newton, we know that position and motion are relative. This means that an object's position depends on where it exists in relation to other objects.  For example, a ball can be 5 feet away from a box, 3 feet away from a chair, and a foot away from a table. Here, the box, chair and the table helped me to decide the position of the ball. In other words, they acted as the reference points for my observation. By telling you how far the ball was from other objects, I told you its relative position.

Similarly, an object's motion is also relative. It depends on how its position changes in relation to other objects. Let us understand this with an example: 

Suppose you are sitting inside a train. The train has not started moving yet. Let us call this Train A. You look out from the window and see another train moving in the opposite direction. Let us call this Train B. Now, when you look at Train B, it appears as if Train A is moving in the forward direction. But when you look at a nearby electric pole, you notice that train A was actually at rest and Train B was moving backwards.

From this, we conclude that we cannot decide whether a body is moving or at rest, unless we choose a frame of reference. In the above example, when we chose Train B as our frame of reference, Train A appeared to be moving forward. On the other hand, when we chose the electric pole as frame of reference, Train A appeared to be at rest and Train B appeared to move backward.

The study of motion, without considering its cause is called kinematics. In kinematics, we come across terms like speed, velocity, and acceleration. Dynamics is the branch of physics concerned with the study of causes and effects of motion. In dynamics we come across terms like force, inertia, work, energy and momentum.




#Article 207: Metaphor (544 words)


Metaphor  is a term for a figure of speech. It does not use a word in its basic literal sense. Instead, it uses a word in a kind of comparison. We run, and we also say rivers run. We may run into trouble, especially if we run up a bill at the bar.

So a metaphor uses words to make a picture in our mind. It takes a word from its original context, and uses it in another.

Metaphors are an essential part of language: it is not possible to speak or write without them. A simple example is the word run. This has a basic meaning of moving quickly or go with quick steps on alternate feet, never having both feet on the ground at the same time. The Concise Oxford Dictionary then gives

We use metaphors to make indirect , but without using 'like' or 'as' – because that would be a simile. A simile is a direct comparison: Jane is like a child.

A metaphor very often uses the verb 'to be': love is war, for example, not love is like war (that is a simile).
Poetry includes much metaphor, usually more than prose.

Spam is an example that any email user knows about – this word was originally a metaphor, from 'Spam', a type of canned meat. Servers putting unwanted email into somebody's inbox was similar to waiters putting unwanted Spam into food.  This was originally suggested by a Monty Python scene. When we use a metaphor very often and we forget the old meaning, or forget that the two meanings are connected, this is a 'dead metaphor'.

Originally metaphor was a Greek word for 'transfer'. It came from meta ('beyond') and pherein ('carry'). So the word metaphor in English was a metaphor, too. Today in Greek, metaphor is a trolley (a thing that is pushed for carrying shopping or bags).

A simple metaphor has a single link between the subject and the metaphoric vehicle. The vehicle thus has a single meaning which is transferred directly to the subject.

In the simple metaphor, the effort to understand what the author or speaker intends is relatively low, and hence it may easily be used with a wider and less sophisticated audience.

A complex metaphor happens where a simple metaphor is based on a secondary metaphoric element. For example, using a metaphor of 'light' for 'understanding' may be complexified by saying 'throwing light' rather than 'shining light'. 'Throwing' is an extra metaphor for how light arrives.

A compound metaphor is one where there are multiple parts in the metaphor that are used to snag the listener. These parts may be enhancement words such as adverbs, adjectives, etc.

Each part in the compound metaphor may be used to signify an additional item of meaning.

Compound metaphors are like a multiple punch, hitting the listener repeatedly with metaphoric elements. Where the complex metaphor uses stacked layers to enhance the metaphor, the compound metaphor uses sequential words. The compound metaphor is also known as a loose metaphor.

A live metaphor is one which a reader notices. A dead metaphor is one no-one notices because it has become so common in the language.

Two people walk off a tennis court. Someone asks the loser: What happened?.




#Article 208: Metabolism (260 words)


 Metabolism is the chemical reactions which keep us alive. It happens in the cells of living organisms.

Reactions catalyzed by enzymes allow organisms to grow, reproduce, maintain their structures, and respond to their environments. The word ‘metabolism’ can also refer to digestion and the transport of substances into and between different cells.

Metabolism is usually divided into two categories. Catabolism breaks down organic matter and harvests energy by way of cellular respiration. Anabolism uses energy to construct molecules such as proteins and nucleic acids.

The chemical reactions of metabolism are organized into metabolic pathways, or cycles, like the Krebs cycle. One chemical is transformed through a series of steps into another chemical by a series of enzymes.

The metabolic system of an organism decides which substances it finds nutritious and which poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals. The speed of metabolism, the metabolic rate, influences how much food an organism will need, and how it is able to get that food. 

A striking feature of metabolism is the similarity of the basic metabolic pathways and components between even vastly different species. For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all known organisms, being found in species as diverse as the unicellular bacterium Escherichia coli and huge multicellular organisms like elephants. These striking similarities in metabolic pathways are likely due to their early appearance in the evolution of life, and kept because of their efficiency.




#Article 209: Microscope (323 words)


A microscope is a scientific instrument. It makes small objects look larger. This lets people see the small things. People who use microscopes frequently  in their jobs include doctors and scientists. Students in science classes such as biology also use microscopes to study small things.
The earliest microscopes had only one lens and are called simple microscopes. Compound microscopes have at least two lenses. In a compound microscope, the lens closer to the eye is called the eyepiece. The lens at the other end is called the objective. The lenses multiply up, so a 10x eyepiece and a 40x objective together give 400x magnification.

Microscopes make things seem larger than they are, to about 1000 times larger. This is much stronger than a magnifying glass which works as a simple microscope.

There are many types of microscopes. The most common kind of microscope is the compound light microscope. In a compound light microscope, the object is illuminated: light is thrown on it. The user looks at the image formed by the object. Light passes through two lenses and makes the image bigger.

The second most common kind are a few kinds of electron microscopes. Transmission electron microscopes (TEMs) fire cathode rays into the object being looked at. This carries information about how the object looks into a magnetic lens. The image is then magnified onto a television screen. Scanning electron microscopes also fire electrons at the object, but in a single beam. These lose their power when they strike the object, and the loss of power results in something else being generated—usually an X-ray. This is sensed and magnified onto a screen. Scanning tunneling microscopes were invented in 1984.

A fluorescence microscope is a special kind of light microscope. In 2014, the Nobel Prize in Chemistry was awarded to Eric Betzig, William Moerner, and Stefan Hell for the development of super-resolved fluorescence microscopy. The citation says it brings optical microscopy into the nanodimension.




#Article 210: Mass (339 words)


The mass of an object is a measure of the amount of matter in a body. A mountain has typically more mass than a rock, for instance. Mass should not be confused with the related but quite different concept of weight. A large mass like the Earth will attract a small mass like a human being with enough force to keep the human being from floating away. Mass attraction is another word for gravity, a force that exists between all matter.

The unit of mass in the International System of Units is the kilogram, which is represented by the symbol 'kg'. Fractions and multiples of this basic unit include the gram (one thousandth of a kg, symbol 'g') and the tonne (one thousand kg), amongst many others.

In some fields or applications, it is convenient to use different units to simplify the discussions or writings. For instance,

Traditional units are still in encountered in some countries: imperial units such as the ounce or the pound were in widespread use within the British Empire. Some of them are still popular in the United States, which also uses units like the short ton (2,000 pounds, 907 kg) and the long ton (2,240 pounds), not to be confused with the metric tonne (1,000 kg).

Mass is an intrinsic property of the object: it does not depend on its volume, or position in space, for instance. For a long time (at least since the works of Antoine Lavoisier in the second half of the eighteen century), it has been known that the sum of the masses of objects that interact or of the chemicals that react remain conserved throughout these processes. This remains an excellent approximation for everyday life and even most laboratory work.

However, Einstein has shown through his special theory of relativity that the mass m of an object moving at speed v with respect to an observer must be higher than the mass of the same object observed at rest m0 with respect to the observer. The applicable formula is




#Article 211: Mercury (planet) (1188 words)


Mercury is the smallest planet in the Solar System.  It is the closest planet to the sun. It makes one trip around the Sun once every 87.969 days. Mercury is bright when it is visible from Earth, ranging from −2.0 to 5.5 in apparent magnitude. It cannot be easily seen as it is usually too close to the Sun.  Because Mercury is normally lost in the glare of the Sun, Mercury can only be seen in the morning or evening twilight or during a solar eclipse.

Less is known about Mercury than about other planets of our Solar System.  Telescopes on the Earth show only a small, bright crescent, and putting a satellite in orbit around it is difficult.  The first of two spacecraft to visit the planet was Mariner 10, which mapped only about 45% of the planet’s surface from 1974 to 1975. The second is the MESSENGER spacecraft, which finished mapping the planet in March 2013.

Mercury looks like Earth's Moon.  It has many craters and areas of smooth plains, no moons around it and no atmosphere as we know it.  However, Mercury does have an extremely thin atmosphere, known as an exosphere.  Unlike Earth's Moon, Mercury has a large iron core, which gives off a magnetic field about 1% as strong as that of the Earth. It is a very dense planet due to the large size of its core. Surface temperatures can be anywhere from about 90 to  (−183 °C to 427 °C, −297 °F to 801 °F), with the subsolar point being the hottest and the bottoms of craters near the poles being the coldest.

Known sightings of Mercury date back to at least the first millennium BC. Before the 4th century BC, Greek astronomers thought that Mercury was two different objects: one able to be seen only at sunrise, which they called Apollo; the other that was only able to be seen at sunset, which they called Hermes. The English name for the planet is from the Romans, who named it after the Roman god Mercury, which they thought to be the same as the Greek god Hermes. The symbol for Mercury is based on Hermes' staff.

Even though Mercury is the closest planet to the Sun, it is not the warmest. This is because it has no greenhouse effect, so any heat that the Sun gives to it quickly escapes into space. The hottest planet is Venus.

Mercury is one of four inner planets in the Solar System, and has a rocky body like the Earth. It is the smallest planet in the Solar System, with a radius of . Mercury is even smaller than some of the largest moons in the solar system, such as Ganymede and Titan. However, it has a greater mass than the largest moons in the solar system. Mercury is made of about 70% metallic and 30% silicate material. Mercury's density is the second highest in the Solar System at 5.427 g/cm³, only a little bit less than Earth’s.

Mercury's surface looks similar to the surface of the Moon. It has plains that look like mares and has lots of craters. Mercury was hit by a lot of comets and asteroids 4.6 billion years ago. Mercury was also hit during a period called the Late Heavy Bombardment. Mercury has lots of craters because it does not have any atmosphere to slow objects down. Images gotten by MESSENGER have shown that Mercury may have shield volcanoes. 

The surface temperature of Mercury ranges from 100 to 700 K (−173 to 427 °C; −280 to 800 °F) at the most extreme places. Even though the temperature at the surface of Mercury in the day is very high, observations suggest that there is frozen water on Mercury.

Mercury is too small and hot for its gravity to keep any thick atmosphere for a long time. It does have a thin exosphere that contains hydrogen, helium, oxygen, sodium, calcium, potassium. This exosphere is lost and replenished from lots of sources. Hydrogen and helium may come from the solar wind. Radioactive decay of elements inside the crust of Mercury is another source of helium, and also sodium and potassium.

Mercury has the most eccentric orbit of all the planets; its eccentricity is 0.21. Its distance from the Sun ranges from 46,000,000 to 70,000,000 km (29,000,000 to 43,000,000 mi). It takes 87.969 Earth days to go around the Sun. Mercury's axial tilt is 0.027 degrees which is best measurement of the axial tilt.

Many man-made satellites have been sent to Mercury to study it. They are:

The first spacecraft to visit Mercury was NASA's Mariner 10. It stayed in Mercury's orbit from 1974–1975. Mariner 10 provided the first close-up pictures of Mercury's surface. It showed many types of geological features, such as the craters. Unfortunately, the same face of the planet was day at each time Mariner 10 flew close to Mercury. This made close observation of both sides of the planet impossible. In the end, less than 45% of the planet's surface was mapped.

The Mariner 10 came close to Mercury three times. At the first time, instruments found a magnetic field, which surprised planetary geologists because Mercury's rotation was too slow to generate a magnetic field. The second time was mainly used to take pictures of Mercury's surface. At the third time, more information about the magnetic field were obtained. It showed that the planet's magnetic field is much like Earth's.

On March 24, 1975, just eight days after its final close approach, Mariner 10 ran out of fuel. Because its orbit could no longer be controlled, mission controllers instructed the probe to shut down. Mariner 10 is thought to still be orbiting the Sun.

The second satellite to reach Mercury is NASA's MESSENGER. It stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging. It was launched on August 3, 2004. It made a fly-by of Earth in August 2005. It made another fly-by of Venus in October 2006. It made its first fly-by of Mercury happened on January 14, 2008, a second on October 6, 2008, and a third on September 29, 2009. Most of the hemisphere not mapped by Mariner 10 was mapped during these fly-bys. The satellite entered an elliptical orbit around the planet on March 18, 2011. The first image of Mercury orbiting the Sun was gotten on March 29, 2011.

MESSENGER was made to study Mercury's high density, the history of Mercury's geology, its magnetic field, the structure of its core, whether it has ice at its poles, and where its thin atmosphere comes from. MESSENGER crashed into Mercury's surface on April 30, 2015.

The European Space Agency and the Japanese Space Agency developed and launched a joint mission called BepiColombo. It will orbit Mercury with two probes: one to map the planet and the other to study its magnetosphere. It was launched on October 20, 2018. BepiColombo is expected to reach Mercury in 2025. It will release the probe that will study the magnetosphere into an elliptical orbit. It will then release the probe the will make a map of Mercury into a circular orbit.




#Article 212: Mars (2248 words)


Mars is the fourth planet from the Sun in the Solar System and the second smallest planet. Mars is a cold terrestrial planet with polar ice caps of  water and carbon dioxide. It has the largest volcano in the Solar System, and some very large impact craters. Mars is named after the mythological Roman god of war because it appears of red color.

Space probes such as the Viking program landers are the main tools for the exploration of Mars.

Mars is a terrestrial planet and made of rock. The ground there is red because of iron oxide (rust) in the rocks and dust. The planet's atmosphere is very thin. It is mostly carbon dioxide with some argon and nitrogen and tiny amounts of other gases including oxygen. The temperatures on Mars are colder than on Earth, because it is farther away from the Sun and has less air to keep heat in. There is water ice and frozen carbon dioxide at the north and south poles. Mars does not have any liquid water on the surface now, but signs of run-off on the surface were probably caused by water.

The average  of the planet's crust is about 50 km (31 mi), with a maximum thickness of 125 km (78 mi).

Mars has two small moons, called Phobos and Deimos.

The origin of Mars' moons is unknown and controversial. One theory is that the moons are captured asteroids. However, the moons' near circular orbits and low inclination relative to the Martian equator are not in agreement with the capture hypothesis. 

Estimates of the mass ejected by a large Borealis-size impact vary. Simulations suggest that a body about 0.02 of Mars mass (~0.002 Earth mass) in size can produce a sizable debris disk in Martian orbit. Much of the material would stay close to Mars. There are several other large impact basins on Mars that could also have ejected enough debris to form the moons.

In the next billion years, Phobos will probably be reformed into a ring around Mars.

Mars does not have a global magnetic field. Despite this, observations show that parts of the planet's crust have been magnetized. This suggests that polarity reversals have occurred in the past. This paleomagnetism  is similar to the magnetic striping found on Earth's ocean floors. One theory is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo stopped working and the planet's magnetic field faded.

A Martian day is called a sol, and is a little longer than an Earth day.  Mars rotates in 24 hours and 37 minutes.  It rotates on a tilted axis, just like the Earth does, so it has four different seasons.  Of all the planets in the Solar System, the seasons of Mars are the most Earth-like, due to their similar axial tilt.  The lengths of the Martian seasons are almost twice those of Earth's, as Mars's greater distance from the Sun leads to the Martian year being almost two Earth years long.

Martian surface temperatures vary from lows of about  (at the winter polar caps) to highs of up to  (in equatorial summer). The wide range in temperatures is due mostly to the thin atmosphere which cannot store much solar heat. The planet is also 1.52 times as far from the Sun as Earth, resulting in just 43% of the amount of sunlight.

A 2015 report says Martian dark streaks on the surface were affected by water.

Liquid water cannot exist on the surface of Mars due to its low atmospheric pressure (there's not enough air to hold it in), except at the lowest elevations for short periods. The two polar ice caps appear to be made largely of frozen water. The amount of ice in the south polar ice cap, if melted, would be enough to cover the entire planet's surface 11 meters deep. A permafrost mantle stretches from the pole to latitudes of about 60°.

Geological evidence gathered by unmanned missions suggest that Mars once had much liquid water on its surface. In 2005, radar data revealed the presence of large quantities of water ice at the poles, and at mid-latitudes. The Mars rover Spirit sampled chemical compounds containing water molecules in March 2007. The Phoenix lander found water ice in shallow Martian soil in July  2008.
Landforms seen on Mars strongly suggest that liquid water at some time existed on the planet's surface. Huge areas of ground have been scraped and eroded.

Mars has two permanent polar ice caps. During a pole's winter, it lies in continuous darkness, chilling the surface and causing the deposition of 25–30% of the atmosphere into slabs of CO2 ice (dry ice). When the poles are again exposed to sunlight, the frozen CO2 sublimes (turns to vapor), creating enormous winds that sweep off the poles as fast as 400 km/h. Each season this moves large amounts of dust and water vapor, giving rise to Earth-like frost and large cirrus clouds and dust storms. Clouds of water-ice were photographed by the Opportunity rover in 2004.

The polar caps at both poles consist primarily of water ice.

Mars has a very thin atmosphere with barely any oxygen (it is mostly carbon dioxide).  Because there is an atmosphere, however thin it is, the sky does change colour when the sun rises and sets.  The dust in the Martian atmosphere makes Martian sunsets somewhat blue.  Mars's atmosphere is too thin to protect Mars from meteors, which is part of the reason why Mars has so many craters.

After the formation of the planets, all experienced the Late Heavy Bombardment. About 60% of the surface of Mars shows a record of impacts from that era. Much of the remaining surface is probably lying over the immense impact basins caused by those events. There is evidence of an enormous impact basin in the northern hemisphere of Mars, spanning , or roughly four times larger than the largest impact basin yet discovered. This theory suggests that Mars was struck by a Pluto-sized body about four billion years ago. The event is thought to be the cause of the difference between the Martian hemispheres. It made the smooth Borealis Basin that covers 40% of the planet.

Some meteorites hit Mars with so much force a few pieces of Mars went flying into space  even to Earth! Rocks on Earth are sometimes found which have chemicals that are exactly like the ones in Martian rocks. These rocks also look like they fell really quickly through the atmosphere, so it is  to think they came from Mars.

Mars is home to the highest known mountain in the Solar System, Olympus Mons. Olympus Mons is about 17 miles (or 27 kilometres) high. This is more than three times the height of Earth's tallest mountain, Mount Everest. It is also home to Valles Marineris, the third largest rift system (canyon) in the Solar System, 4,000 km long.

Our records of watching and recording Mars start with ancient Egyptian astronomers in the 2nd millennium BC.

Detailed observations of the location of Mars were made by Babylonian astronomers who developed methods using math to predict the future position of the planet. The ancient Greek philosophers and astronomers developed a model of the solar system with the Earth at the center ('geocentric'), instead of the sun. They used this model to explain the planet's motions.  Indian and Islamic astronomers estimated the size of Mars and its distance from Earth. Similar work was done by Chinese astronomers.
 
In the 16th century, Nicholas Copernicus proposed a model for the Solar System in which the planets follow circular orbits about the Sun. This 'heliocentric' model was the beginning of modern astronomy. It was revised by Johannes Kepler, who gave an elliptical orbit for Mars which better fit the data from our observations.

The first observations of Mars by telescope was by Galileo Galilei in 1610. Within a century, astronomers discovered distinct albedo features (changes in brightness) on the planet, including the dark patch and polar ice caps. They were able to find the planet's day (rotation period) and axial tilt.

Better telescopes developed early in the 19th century allowed permanent Martian albedo features to be mapped in detail. The first crude map of Mars was published in 1840, followed by better maps from 1877 onward. Astronomers mistakenly thought they had detected the spectroscopic mark of water in the Martian atmosphere, and the idea of life on Mars became  among the public.

Yellow clouds on Mars have been observed since the 1870s, which were windblown sand or dust. During the 1920s, the range of Martian surface temperature was measured; it ranged from 85 to 7 oC. The planetary atmosphere was found to be arid with only traces of oxygen and water. In 1947, Gerard Kuiper showed that the thin Martian atmosphere contained extensive carbon dioxide; roughly double the quantity found in Earth's atmosphere. The first standard naming of Mars surface features was set in 1960 by the International Astronomical Union.

Since the 1960s, multiple robotic spacecraft and rovers have been sent to explore Mars from orbit and the surface. The planet has remained under observation by ground and space-based instruments across a broad range of the electromagnetic spectrum (visible light, infrared and others). The discovery of meteorites on Earth that came from Mars has allowed laboratory examination of the chemical conditions on the planet.

During the 1877 opposition, Italian astronomer Giovanni Schiaparelli used a  telescope to help produce the first detailed map of Mars. What caught people's attention was that the maps had features he called canali.  These were later shown to be an optical illusion (not real). These canali were supposedly long straight lines on the surface of Mars to which he gave names of famous rivers on Earth. His term canali was popularly mistranslated in English as canals, and thought to be made by intelligent beings.

Other astronomers thought they could see the canals too, especially the American astronomer Percival Lowell who drew maps of an artificial network of canals on Mars.

Although these results were widely accepted, they were contested. Greek astronomer Eugène M. Antoniadi and English naturalist Alfred Russel Wallace were against the idea; Wallace was extremely outspoken. As bigger and better telescopes were used, fewer long, straight canali were observed. During an observation in 1909 by Flammarion with a  telescope, irregular patterns were observed, but no canali were seen.

Because Mars is the one of the closest planets to Earth in the Solar System, many have wondered if there is any kind of life on Mars. Today we know that the kind of life, if any, would be some simple bacteria-type organism.

NASA maintains a catalog of 34 Mars meteorites, that is, meteorites which originally came from Mars. These assets are highly valuable since they are the only physical samples available of Mars.

Studies at NASA's Johnson Space Centre show that at least three of the meteorites contain possible evidence of past life on Mars, in the form of microscopic structures resembling fossilized bacteria (so-called biomorphs). Although the scientific evidence collected is reliable, and the rocks are correctly described, what made the rocks look like they do is not clear. To date, scientists are still trying to agree if it really is evidence of simple life on Mars.

Over the past few decades, scientists have agreed that when using meteorites from other planets found on Earth (or rocks brought back to Earth), various things are needed to be sure of life. Those things include:

For people to agree on past life in a geologic sample, most or all of these things must be met. This has not happened yet, but investigations are still in progress. Re-examinations of the biomorphs found in the three Martian meteorites are underway.

Liquid water is necessary for life and metabolism, so if water was present on Mars, the chances of life evolving is improved. The Viking orbiters found evidence of possible river valleys in many areas, erosion and, in the southern hemisphere, branched streams. Since then, rovers and orbiters have also looked closely and eventually proved water was on the surface at one time, and is still found as ice in the polar ice caps and underground.

So far, scientists have not found life on Mars, either living or extinct. Several space probes have gone to Mars to study it. Some have orbited (gone around) the planet, and some have landed on it. There are pictures of the surface of Mars that were sent back to Earth by the probes. Some people are interested in sending astronauts to visit Mars. They could do a better search, but getting astronauts there would be difficult and expensive. The astronauts would be in space for many years, and it could be very dangerous because of radiation from the sun.  So far we have only sent unmanned probes.

The most recent probe to the planet is the Mars Science Laboratory.  It landed on Aeolis Palus in Gale Crater on Mars on 6 August 2012. It brought with it a mobile explorer called 'Curiosity'. It is the most advanced space probe ever. Curiosity has dug up Martian soil and studied it in its laboratory. It has found sulfur, chlorine, and water molecules.  In 1938, Orson Welles broadcast a radio version of this story in the United States, and many people thought it was really happening and were very afraid. Beginning in 1912, Edgar Rice Burroughs wrote several novels about adventures on Mars.




#Article 213: Apple Macintosh (222 words)


The Apple Macintosh or just “Mac” is a line of personal computers made by the American company Apple Inc. The Macintosh was one of the first computers in which the people could use a mouse for pointing on a screen which had icons. This new way of working with a computer (interface) was known as graphical user interface. It was this feature of the Macintosh that made it so popular.

The Apple–Intel transition was when Apple changed the CPU of Macintosh computers from PowerPC processors to Intel x86 processors.  It was announced at the 2005 World Wide Developers Conference. Steve Jobs announced it.

Macintoshes were different than other personal computers for many years based on their central processor unit (CPU). At the start, Macs used Motorola 68000 chips instead of Intel chips. Later, Macs used PowerPC chips. In 2006, Macs started to use Intel chips. Today, Macs are sold with Intel quad-core i7 chips.

The Mac does not have the Windows operating system installed on it. It has its own range of operating systems, known as macOS. The newest operating system is known as “Catalina.  Macs can run both Windows and macOS at the same time with help of a program called “Boot Camp”, which comes on every Mac.

In general, Macintosh computers cost more than other computers of the same speed.




#Article 214: Magnifying glass (120 words)


A magnifying glass is a lens through which can be used to make things appear bigger, so you can see them better. It is used in many applications and manual operations, e.g., for examining postage stamps in philately.

The magnifying glass consists of a piece of convex-shaped glass or plastic. It has to be held at the right distance between the eye and the object for the object to be in focus. The magnifying glass usually comes with a handle. A telescope is a more advanced kind of magnifying glass and consists of at least two glass lenses. 

A pair of binoculars is like a telescope for each eye. Spectacles or eyeglasses also use lenses to correct a person's vision.




#Article 215: Molecule (405 words)


A molecule is the smallest amount of a chemical substance that can exist. If a molecule were split into smaller pieces, it would be a different substance.

Molecules are made up of atoms that are stuck together in a particular shape or form. Not all combinations of atoms are equally possible; atoms make certain shapes in preference to others.  Also, they have different valency.  For example, oxygen atoms always have two bonds with other atoms, carbon atoms always have four bonds with other atoms, and nitrogen atoms always have three bonds with other atoms.

In the , the term molecule is often used for any gaseous particle regardless of its composition. According to this definition, noble gas atoms are considered molecules as they are in fact monoatomic molecules.

In gases like air, the molecules are just flying around. In liquids like water, the molecules are stuck together but they can still move. In solids like sugar, the molecules can only vibrate.  In the fourth state of matter known as plasma, the atoms are ionized and cannot form molecules.

With a molecular formula, you can write down the numbers of all atoms in a molecule. For example, the molecular formula of glucose is C6H12O6. That means that one molecule of glucose is made up of six carbon atoms, twelve hydrogen atoms and six oxygen atoms.

For a molecule to exist, atoms have to stick together. This happens when two atoms share electrons. Instead of circling just one atom, the electron now circles around two. This is called a covalent bond.  Sometimes, more than one electron is shared. The more electrons are shared, the stronger the bond gets and the stronger the atoms stick together.

Bonds can also be broken apart. Since most bonds require energy to form, they also give off energy when they are broken. But before most bonds break, the molecule has to be heated. Then the atoms start to move, and when they move too much, the bond breaks. Molecules that require less energy to break than they give off when broken are called fuels. For example, a candle will just sit there and nothing happens. But when you use a match to light it, it will burn for a long time. The match brings the energy to break the first bonds, which release enough energy to break the bonds below them, until the candle has burned down.

There are also ionic bonds.




#Article 216: Moral reasoning (105 words)


Moral reasoning is a topic studied in psychology and in moral philosophy. It studies how people think about moral issues, problems, and questions. Psychologists who have studied it include Lawrence Kohlberg and Elliot Turiel. Kohlberg said that moral understanding develops in three main stages as a person gets older, but Turiel said that there are three domains of moral understanding that develop at the same time as a person gets older.

Moral philosophy, or ethics, is a major branch of philosophy. It is the study of value or quality. It covers the analysis and use of concepts such as , , good, evil, and responsibility.




#Article 217: Mosque (3349 words)


A mosque is a place where Peoples worship. The word mosque comes from the Arabic word masjid.  A larger, 'collective', mosque is called a masjid jāmi. Larger mosques offer more services to their community.

For many Muslim people, a mosque is more than a place of worship. Muslims worship, study and discuss Islam, and do many other things in a mosque and its compounds. In the United Kingdom, many mosques are used as community centres. They are also used to teach about Islam. Religious festivals and gatherings are held in mosques. Weddings are one example. Mosques have rules to control what people do inside. One of these is that it is disrespectful to disturb another person who is worshipping.

Many mosques are known for their Islamic architecture. The earliest mosques, opened in 7th century were open-air spaces. They are the Quba Mosque and Masjid al-Nabawi.  Later Mosques were buildings that were specially designed. Nowadays, mosques are in every continent, except Antarctica.

Many mosques are famous works of architecture. They are often built in a style that has stayed the same for many centuries. Many mosques have prayer halls, domes, and minarets. They may also have a courtyard. Mosques are often built with patterned walls.

Mosques were first built on the Arabian Peninsula. The Muslims who built them used old architectural styles. They also combined these styles in new ways. A major influence was the palaces built during the Parthian and Sassanid dynasties of Persia. The Sarvestan palace from the Sassanid era is a good example of this. It has an arched entrance and a central dome. These features already existed in Persia before Islam.

After the Arab invasion of Persia, the new style, with its Sassanid influence, was used for the new Islamic world. Many forms of mosques have developed in different regions of the Islamic world. Important mosque types include the early Abbasid mosques, T-type mosques, and the central-dome mosques of Anatolia. In the 20th century, many countries that grew rich from oil paid for the building of many new mosques. The rulers of these countries often hired leading architects to design these mosques. They included non-Muslims.

Many early mosques have a square or rectangular plan. They also have a prayer hall and an enclosed courtyard. This is known as Arab-plan. The first mosques of this type were built during the Umayyad Dynasty.

The flat roof of the prayer hall was supported by columns. Many rows of columns were needed to support such roofs; this is called hypostyle architecture. One of the most famous hypostyle mosques is the Mezquita de Córdoba in Spain. It is supported by over 850 columns.

In the warm Mediterranean and Middle Eastern climates, the courtyard served to hold the large number of worshippers during Friday prayers. Often, hypostyle mosques have outer arcades. They allow the visitors to enjoy the shade. Arab-plan mosques were built mostly during the Umayyad and Abbasid dynasties. The Arab plan was very simple, which did not allow for much further development. This caused that style of mosque to fall out of favour.

The Ottomans began building central dome mosques in the fifteenth century. These mosques have a large dome centered over the prayer hall. There may also be smaller domes, which are off-center over the prayer hall or the rest of the mosque. This style was heavily influenced by the Byzantine religious architecture with its use of central domes.

Iwan mosques are famous for their domed rooms and iwans. Iwans are spaces with an arched roof. They have an opening at one end. One or more iwans face a central courtyard that serves as the prayer hall. The style borrows from pre-Islamic Iranian architecture. Most mosques with this style are in Iran.

Most mosques have minarets. Minarets are tall towers. Usually they are at one of the corners of the mosque. The top of the minaret is the highest point in the mosque, and usually the highest point in the area around the mosque. The tallest minaret in the world is in the Hassan II Mosque in Casablanca, Morocco.

The first mosques had no minarets. The most conservative Islamic groups, like Wahhabis, still avoid building minarets. They see them as simply a fancy decoration and unnecessary. The first minaret was built in 665 in Basra during the reign of the Umayyad caliph Muawiyah I. Muawiyah encouraged the building of minarets, as they were supposed to be the same as bell towers on Christian churches. Because of this, mosque architects used the shape of the bell tower for their minarets. Both the minaret and the bell tower serve the same purpose — to call the faithful to prayer.

Before the five required daily prayers, a muezzin calls the worshippers to prayer from the minaret. In many countries like Singapore where Muslims are not the majority, mosques are stopped from loudly playing the call to prayer. The main problem is the use of electronic amplification of the call, which is now widely used by mosques.

The domes were often placed directly above the main prayer hall. They represent the universe that Allah created. At first, these domes were small. They only took up a small part of the roof near the mihrab. Later, they took the whole roof above the prayer hall.
Domes normally have the shape of a hemisphere. The Mughals in India popularized onion-shaped domes in South Asia and Persia. Some mosques have several domes, as well as the main large dome. The other domes are often smaller.

Domes would help the imam be heard, as the sound waves would bounce in and then out of the dome making the voice louder.

All mosques have a prayer hall, which is also called musalla. Normally, there is no furniture in it except for prayer  or rugs. These are necessary, as Islamic prayer is usually done kneeling.

Some mosques have Arabic calligraphy and Qur'anic verses on the walls to help worshipers focus on the beauty of Islam and its holiest book, the Qur'an, as well as for decoration.

The qiblah wall is usually at the other side of the entrance to the prayer hall. This wall is specially decorated. In a properly sited mosque, it will be set  to a line leading to Mecca. People pray in rows parallel to the qiblah wall. They arrange themselves so they face Mecca. In the qiblah wall, usually at its center, is the mihrab, a niche or depression showing the direction of Mecca. The mihrab serves as the place where the imam leads the five daily prayers.

All people must wash themselves before they pray. Mosques often have fountains or other facilities for washing in their entrances or courtyards, so that people can perform the washing ritual before prayer.
At very small mosques, worshippers may use restrooms for their ritual washing, or wu'du. In traditional mosques, there is often a building specially for washing. This is often in the center of the courtyard. In the prayer halls, people must not wear shoes for much the same reason.

Modern mosques should appeal to the community they serve. For this reason, other facilities may also be available at the mosque, like health clinics, libraries, and sports halls.

There may be decorative tiles, plaster or coloured mosaics on the walls. There are no pictures or statues.

Adult Muslims are expected to pray five times a day. Most mosques have formal prayers for each of these times. If performing the prayer is difficult, for example for ill people, then exceptions are made.

Mosques also hold a special prayer service, called jumuah. This is done once a week. It is a form of Sabbath and replaces the Friday prayers at the mosque. Daily prayers can be done anywhere. However, Muslims are expected to do their Friday prayer at the mosque.

When a Muslim dies, a funeral prayer is normally held. It is held outdoors in a courtyard or square close to the mosque. The prayers have all the worshippers present, including the imam, taking part. During eclipses, mosques will host special prayers called eclipse prayers.

There are two large holidays (Eids) in the Islamic calendar. During these days, there are special prayers at mosques in the morning. Larger mosques will normally hold them for their own communities as well as the people from smaller local mosques. Mosques, especially those in countries where Muslims are the majority, will also host Eid prayers outside in courtyards or town squares.

There are many events in Ramadan, Islam's holiest month. During Ramadan, Muslims must fast during the day. Mosques organise iftar dinners after sunset. These are done after the fourth required prayer of the day. Part of the food is given by members of the community, which creates nightly potluck dinners. The community contribution to these dinners is required. For this reason, mosques with smaller communities may not be able to hold the iftar dinners daily.

Some mosques will also hold meals in the morning before dawn. Mosques will often invite poorer members of the community to these meals. Islam sees giving charity during Ramadan as good acts.

Larger mosques sometimes offer special, optional prayers. They are done after the last required prayer of the day. During each night of prayers, one member of the community who has memorized the entire Qur’an will recite a part of the book. It can last for up to two hours. Sometimes, several such people (not necessarily of the local community) take turns to do this. During the last ten days of Ramadan, larger mosques will host all-night programs to observe Laylat al-Qadr. It is the night Muslims believe that the Islamic prophet Muhammad first received Qur'anic revelations. On that night, between sunset and sunrise, mosques employ speakers to teach the worshipers about Islam. Mosques or the community usually provide meals at times through the night.

During the late twentieth century, more and more mosques have been used for political purposes. Modern-day mosques in the Western world want to educate good citizens. The details differ greatly from mosque to mosque and from country to country.

Countries with small Muslim populations use mosques as a way to support civic participation. They are more likely to do this than Muslim-majority countries of the Greater Middle East. American mosques host voter registration and civic participation drives. In the United States, Muslims are often immigrants, or the children of immigrants. Mosques want to interest these people for politics. They also want to keep them informed about issues that concern the Muslim community. People who attend the services at the mosque regularly are more likely to take part in protests, to sign petitions, and to involve themselves in political matters.

A link between political views and mosque attendance can still be seen in other parts of the world. After the al-Askari Mosque bombing in February 2006, imams and other Islamic leaders used mosques and Friday prayers to call for calm and peace during the widespread violence.

Beginning in the late twentieth century and continuing into the early twenty-first century, a small number of mosques have also become a base for extremist imams to support terrorism and extreme Islamic ideals. Finsbury Park Mosque in London is a mosque that has been used in this manner.

Like other places of worship, mosques can be at the center of social conflicts.

Babri Mosque was the centre of such a conflict up until the early 1990s when it was . Before a solution could be found, the mosque was destroyed by about 200,000 Hindus. It took place on 6 December 1992. The mosque was built by Babur to mark the birthplace of Ram. It was believed to be on a site of an earlier Hindu temple. The conflict over the mosque was directly linked to rioting in Bombay (present-day Mumbai) as well as bombings in 1993 that killed 257 people.

In February 2006, a bombing seriously damaged Iraq's al-Askari Mosque. This increased the existing tensions. The conflict between two Muslim groups in Iraq had already led to other bombings. However mosque bombings are not limited to Iraq. In June 2005, a suicide bomber killed at least 19 people at an Afghan mosque. In April 2006, there were two explosions at India's Jama Masjid.

After the September 11 attacks, several American mosques were targets of attacks. These ranged from simple vandalism to arson.

The Jewish Defense League was suspected of plotting to bomb the King Fahd Mosque in Culver City, California. There were similar attacks in the United Kingdom after the 7 July 2005 London bombings. Outside the Western world, in June 2001, the Hassan Bek Mosque was the target of attacks. The attacks involved hundreds of Israelis angry at Arabs for a previous attack.

Saudi involvement in building mosques around the world only goes back to the 1960s.
In the 1980s, the Saudi Arabian government began to pay for the building of mosques in countries around the world. An estimated US$45 billion has been spent by the Saudi Arabian government for mosques and Islamic schools in foreign countries. Ain al-Yaqeen, a Saudi newspaper, reported in 2002 that Saudi money may have helped to build as many as 1,500 mosques and 2,000 other Islamic centers. Saudi citizens have also given a lot of money to mosques in the Islamic world, especially in countries where they see Muslims as poor and oppressed. Following the fall of the Soviet Union, in 1992, mosques in Afghanistan received money from Saudi citizens. The King Fahd Mosque in Culver City, California and the Islamic Cultural Center of Italy in Rome are two of Saudi Arabia's largest investments in foreign mosques as former Saudi king Fahd bin Abdul Aziz al-Saud gave US$8 million and US$50 million to the two mosques, respectively.

In a mosque, people should keep focused on worshiping Allah. For this reason, there are a number of rules about the correct behaviour in a mosque. Some of these rules are the same all over the world, such as no shoes should be worn in the prayer hall. Other rules are different from mosque to mosque.

It is generally seen as good to have someone who leads the prayers, though this is not strictly necessary. The person who usually leads the prayers is called imam. He must be a free and honest man. He should also be an authority when it comes to answering questions on religion. In mosques that were built or that are kept up by the government, the imam is selected by the ruler. In private mosques, the community selects the imam, through majority voting.

Only men may lead prayers for men.  Women are allowed to lead prayers for congregations where there are only women.

In addition to washing, there are other rules that also apply to those who enter the mosque, even if they do not wish to pray there. It is forbidden to wear shoes in the carpeted area of the prayer hall. Some mosques also do not allow wearing shoes in other parts, even though these may not be devoted to praying.

Islam requires that its believers wear clothes that show modesty. As a result, both men and women must follow this rule when they attend a mosque (though mosques may not always enforce the rules). Men are supposed to come to the mosque wearing loose and clean clothes that do not show the shape of the body. Similarly, women who come to the mosque are expected to wear loose clothing, shirts, pants that cover to the wrists and ankles and cover their heads such as with a hijab. Many Muslims, regardless of their ethnic background, wear Middle eastern clothing associated with Arabic Islam to special occasions and prayers at mosques.

Mosques are places of worship. For this reason, those inside the mosque should be respectful to those who are praying. Loud talking or discussion of topics that could be disrespectful, is forbidden in areas where people are praying. It is also considered as rude to walk in front of Muslims in prayer or otherwise disturb  them.

Islamic law requires men and women to be separated in the prayer hall. Ideally, women should pray behind men.  The second caliph Umar at one time stopped women from attending mosques, especially at night, because he feared they may be teased by males, so he made them to pray at home. Sometimes a special part of the mosque was railed off for women; for example, the governor of Mecca in 870 had ropes tied between the columns to make a separate place for women.

Many mosques today will put the women behind a barrier or partition or in another room. Mosques in South and Southeast Asia put men and women in separate rooms, as the divisions were built into them centuries ago. In nearly two-thirds of American mosques, women pray behind partitions or in separate areas, not in the main prayer hall; some mosques do not admit women at all. Although there are sections only for women and children, the Grand Mosque in Mecca is desegregated.

A few scholars of Islamic law believe that non-Muslims may be allowed into mosques, as long as they do not sleep or eat there. Followers of the Maliki school of Islamic jurisprudence disagree. They say that non-Muslims may not be allowed into mosques at all.

Different countries have different opinions on the question. Nearly all the mosques in the Arabian Peninsula as well as Morocco do not allow non-Muslims. The Hassan II Mosque in Casablanca is one of only two mosques in Morocco currently open to non-Muslims.

In modern-day Saudi Arabia, the Grand Mosque and all of Mecca are open only to Muslims. Likewise, the Masjid al-Nabawi and the city of Medina that surrounds it are also off-limits to those who do not practice Islam. For mosques in other areas, it has most commonly been taken that non-Muslims may only enter mosques if granted permission to do so by Muslims and if they have a proper reason.

In modern Turkey non-Muslim tourists are allowed to enter any mosque, but must obey the rules of decorum. Visiting a mosque is allowed only between prayers; visitors must wear long trousers and take off their shoes; women must cover their heads; no photos; no loud talk is allowed. No references to other religions are allowed (no crosses on necklaces, no cross gestures etc.).

However, there are also many other places in the west as well as the Islamic world where non-Muslims are welcome to enter mosques. Most mosques in the United States, for example, report receiving non-Muslim visitors every month. Many Mosques throughout the United States welcome non-Muslims as a sign of openness to the rest of the community and to encourage conversions to Islam.

Dogs are usually banned from entering mosques, but on 24 September 2008, the Muslim Law Council UK made special ruling, called a fatwa, which granted a blind Muslim permission to take his guide dog into the mosque.

It is common for a smaller mosque to serve as a hostel for Muslims on haj (pilgrimage to Mecca). Sometimes mosques are used for refugees, or as temporary homes for homeless people. Obligations to neighbours in Islam are very strict, and specific. In the Qur'an Mohammed(pbuh) said that a person who helps others in the hour of need, and who helps the oppressed; that person God will help on the Day of Travail (agony). There are other commands, such as helping the poor and being nice to people. An important part of being Muslim, or just being part of the mosque, is taking care of people who need help. A mosque is a social, as well as a religious, group.

A madrassa is a little different from a mosque. A madrassa focuses on teaching Islam, usually to children and young people.

When Spain was under Muslim control, some of the most beautiful buildings were mosques. After 1491, Spain was under Christian control. However, the Christians did not tear down the mosques. They simply put a crucifix in them to make them into churches. These mosques influenced the Renaissance architecture (way of building) in Europe.




#Article 218: Mammal (1206 words)


The class Mammalia are a group of vertebrate animals. They have fur or hair and a very precise kind of temperature regulation.

With the exception of the monotremes, all mammals bear live young. Unlike other vertebrates, they are the only animals that produce milk for the young through their mammary glands. Parental care of the young is universal among mammals, sometimes for extended periods.

Most marsupial and eutherian mammals have a reproductive cycle known as the oestrous cycle (U.S: estrous cycle). Females are sexually active only during the oestrous stage, when they are 'on heat' for a few days each month. If an ovum is not fertilized, the endometrium (uterus lining) is resorbed. Oestrus cycles may occur once or twice a year, or many times a year. Each group of mammals has its own frequency.

Humans and primates, are quite different. They have a menstrual cycle. In this case, females are sexually receptive at any time, but only fertile when an ovum is released from an ovary. In this case, the endometrium (if not needed for an fertilised egg) is discarded. The endometrium is shed, and takes with it a certain amount of blood. In this system, eggs are released from the ovaries mostly in the middle of the cycle, away from the menstrual period. This ovulation is 'concealed', meaning, it is not obvious when it occurs. This process, so it is thought, tends to keep the male and female together, which is unusual in mammals with the oestrous cycle.

One diagnostic feature is the lower jaw which, unlike earlier forms, is composed of a single bone, the dentary. This is one feature which can be seen in fossils, or at least those which are complete enough to have the lower jaw. Mammals have three little bones in their inner ear, the ear ossicles. The ear ossicles are bones which were, long ago, part of the lower jaw in early proto-mammals.

There are quite a number of other features, particularly in the skull and limbs, so that it is usually possible to identify and describe a mammal from its skeleton alone.

Another diagnostic feature is the neocortex of the brain, which no other vertebrate has. This is involved in the kind of flexible behavior and learning typical of mammals. Reptiles and birds have much of their behavior controlled by inherited behavior chains, which roughly translates as instincts. Almost all animals can do some learning, but mammals do far more than other vertebrates. Their behavior is much more flexible than lizards, for example, and that is made possible by their neocortex.

Other things in the life of mammals seem to be connected with this flexibility  and learning. Play is a kind of early learning period in which, according to one theory, mammals develop skills which they will need in life. All mammalian young play, and this is very obvious in the more intelligent mammals (primates, cats).

The emotions of mammals are very noticeable, and rather similar to ours. It is possible, and quite common, for humans to have a friendly relationship with another mammal. It is quite impossible for a human to have any kind of relationship with a snake or a gecko (for example). This is because the reptile simply does not have the same basic emotions as a human.

There are about 50 characters which are typical of mammals, and some of the most important are discussed above. A few more examples will make it clear that mammals are very different from reptiles and birds:

In the language of cladistics, these 50 unique characters are apomorphies which prove that mammals are a clade descended from a common ancestor.

All mammals feed milk to their young, and protect and look after them.

The vast majority of mammal species give birth to live young, these are the placental mammals, most of which are classified as Eutheria and a small number are classified as marsupials.

Marsupials are mammals with pouches to carry young in, like the kangaroo.

There are only five species (the monotreme mammals) that lay eggs, the duck-billed platypus Ornithorhynchus, and four species of spiny anteater Echidna. The monotremes are confined to Australia and New Guinea, and are the sole survivors of an earlier group of mammals.

In terms of number of species mammals, with 5488 species, are not the most successful vertebrates. Birds, with about 10,000 species have nearly twice as many, and reptiles have just as many as birds. Fish have even more species. There are 27,000 species of fish, of which nearly 26,000 are bony fish.

Despite this, many zoologists do regard mammals as a successful group of animals. One reason is that they are successful in all habitats on Earth. In the air, in the water, in forests, in the colder regions of the world, and above all on grasslands, where they are outstandingly successful.

In the air, the bats (Chiroptera) are the mammalian order with the most species. They 'own' the nighttime, since birds are largely diurnal (daytime) animals. Bats are hugely successful, mostly as nighttime predators of insects.

Seagoing mammals, the Cetacea and the pinnipeds, are very successful and significant predators. This includes the whales, seals, walrus, dolphins and others.

The terrestrial mammals are fewer in number of species than lizards, but they are huge in individual numbers, and far more important in the life of the terrestrial biomes. Their ability to move from place to place and adapt has made them a most effective group. Many mammals live in cold places. These mammals have thick hair or blubber to keep them warm. Others may live in rainforests. On land the rodents (rats, mice) are hugely successful, more common in numbers than any other mammals. Large mammals on land have been hunted to extinction in some parts of the world, but the ones which remain are now better protected.

Last, but certainly not least, are the primates. Their natural habitat, with few exceptions, are the forests. Most live in the trees, with hands that grasp, good colour vision, and intelligence. In the Pliocene period some moved out onto the savannahs as grassland replaced forests. Mankind is the result of this shift into the savannahs.

The evolutionary relationships among land vertebrates is as follows:

This sort of classification is not traditional, but it does reflect our knowledge of palaeontology and evolution.

A somewhat standardized classification system has been adopted by most current mammalogy classroom textbooks. It is based on living animals. The following taxonomy of extant and recently extinct mammals is from Vaughan et al. 2000.

Class Mammalia

Mammals can be divided in a number of orders:

Because two quite different dates are given in the taxobox, an explanation is needed. Rowe defines mammals as the taxon originating with the most recent common ancestor of extant [living] Monotremata and Theria. That puts the emphasis heavily on living mammals, where, as Rowe points out, the database of characters is extensive.

Kemp explains the problem with that approach: If the definition of a mammal is based rigorously upon possession of all the characters of living mammals, then some fossil forms that are extremely mammalian in anatomy... are excluded.

This difference in outlook explains the difference in the two dates given in the taxobox.




#Article 219: Number (1680 words)


A number is a concept from mathematics, used to count or measure. Depending on the field of mathematics, where numbers are used, there are different definitions:

Numbers are also used for other things like counting. Numbers are used when things are measured. Numbers are used to study how the world works. Mathematics is a way to use numbers to learn about the world and make things. The study of the rules of the natural world is called science. The work that uses numbers to make things is called engineering.

There are different ways of giving symbols to numbers. These methods are called number systems. The most common number system that people use is the base ten number system. The base ten number system is also called the decimal number system. The base ten number system is common because people have ten fingers and ten toes. There are 10 different symbols {0, 1, 2, 3, 4, 5, 6, 7, 8, and 9} used in the base ten number system. These ten symbols are called digits.

A symbol for a number is made up of these ten digits. The position of the digits shows how big the number is. For example, the number 23 in the decimal number system really means (2 times 10) plus 3. Similarly, 101 means 1 times a hundred (=100) plus 0 times 10 (=0) plus 1 times 1 (=1).

Another number system is more common for machines. The machine number system is called the binary number system. The binary number system is also called the base two number system. There are two different symbols (0 and 1) used in the base two number system. These two symbols are called bits.

A symbol for a binary number is made up of these two bit symbols. The position of the bit symbols shows how big the number is. For example, the number 10 in the binary number system really means 1 times 2 plus 0, and 101 means 1 times four (=4) plus 0 times two (=0) plus 1 times 1 (=1). The binary number 10 is the same as the decimal number 2. The binary number 101 is the same as the decimal number 5.

English has special names for some of the numbers in the decimal number system that are powers of ten. All of these power of ten numbers in the decimal number system use just the symbol 1 and the symbol 0. For example, ten tens is the same as ten times ten, or one hundred. In symbols, this is 10 × 10 = 100. Also, ten hundreds is the same as ten times one hundred, or one thousand. In symbols, this is 10 × 100 = 10 × 10 × 10 = 1000. Some other powers of ten also have special names:

When dealing with larger numbers than this, there are two different ways of naming the numbers in English. Under the long scale, a new name is given every time the number is a million times larger than the last named number. It is also called the British Standard. This scale used to be common in Britain, but is not often used in English-speaking countries today. It is still used in some other European nations. 

Another scale is the short scale, under which a new name is given every time a number is a thousand times larger than the last named number. This scale is a lot more common in most English-speaking nations today.

A salamander is not a number; it is an amphibian.

Natural numbers are the numbers which we normally use for counting: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Some people say that 0 is a natural number, too. The set of all natural numbers is written as .

Another name for these numbers is positive numbers. These numbers are sometimes written as +1 to show that they are different from the negative numbers. But not all positive numbers are natural (for example,  is positive, but not natural).

If 0 is called a natural number, then the natural numbers are the same as the whole numbers. If 0 is not called a natural number, then the natural numbers are the same as the counting numbers. So if the words natural numbers are not used, then there will be less confusion about whether zero is included or not. But unfortunately, some say that zero is not a whole number, while others say that whole numbers can be negative. Positive integers and non-negative integers are another way to include zero or exclude zero, but only if people know those words.

Negative numbers are numbers less than zero.

One way to think of negative numbers is to use a number line. We call one point on this line zero. Then we will label (write the name of) every position on the line by how far to the right of the zero point is. For example, the point one is one centimeter to the right, and the point two is two centimeters to the right.

However, the point one centimeter to the left of the zero point cannot be point one, since there is already a point called one. We therefore call this point minus one (−1, as it is one centimeter away but in the opposite direction).

A drawing of a number line is below.

All the normal operations of mathematics can be done with negative numbers:

Since finding the square root of a negative number is impossible for real numbers (as negative times negative equals positive for real numbers), the square root of -1 is given a special name: i. This is also called the imaginary unit.

Integers are all the natural numbers, all their opposites, and the number zero. Decimal numbers and fractions are not integers.

Rational numbers are numbers which can be written as fractions. This means that they can be written as a divided by b, where the numbers a and b are integers, and b is not zero.

Some rational numbers, such as 1/10, need a finite number of digits after the decimal point to write them in decimal form. The number one tenth is written in decimal form as 0.1. Numbers written with a finite decimal form are rational. Some rational numbers, such as 1/11, need an infinite number of digits after the decimal point to write them in decimal form. There is a repeating pattern to the digits following the decimal point. The number one eleventh is written in decimal form as 0.0909090909 ... .

A percentage could be called a rational number, because a percentage like 7% can be written as the fraction 7/100. It can also be written as the decimal 0.07. Sometimes, a ratio is considered as a rational number.

Irrational numbers are numbers which cannot be written as a fraction, but do not have imaginary parts (explained later).

Irrational numbers often occur in geometry. For example, if we have a square which has sides of 1 meter, the distance between opposite corners is the square root of two, which equals 1.414213 ... . This is an irrational number. Mathematicians have proved that the square root of every natural number is either an integer or an irrational number.

One well-known irrational number is pi. This is the circumference (distance around) of a circle divided by its diameter (distance across). This number is the same for every circle. The number pi is approximately 3.1415926535 ... .

An irrational number cannot be fully written down in decimal form. It would have an infinite number of digits after the decimal point, and unlike 0.333333 ..., these digits would not repeat forever.

Real numbers is a name for all the sets of numbers listed above:

The real numbers form the real line. This is all the numbers that do not involve imaginary numbers.

Imaginary numbers are formed by real numbers multiplied by the number i. This number is the square root of minus one (−1).

There is no number in the real numbers which when squared, makes the number −1. Therefore, mathematicians invented a number. They called this number i, or the imaginary unit.

Imaginary numbers operate under the same rules as real numbers:

Imaginary numbers were called imaginary because when they were first found, many mathematicians did not think they existed. The person who discovered imaginary numbers was Gerolamo Cardano in the 1500s. The first to use the words imaginary number was René Descartes. The first people to use these numbers were Leonard Euler and Carl Friedrich Gauss. Both lived in the 18th century.

Complex numbers are numbers which have two parts; a real part and an imaginary part. Every type of number written above is also a complex number.

Complex numbers are a more general form of numbers. The complex numbers can be drawn on a number plane. This is composed of a real number line, and an imaginary number line.

            3i|_
              |
              |
            2i|_          . 2+2i
              |
              |
             i|_
              |
              |
  |_____|_____|_____|_____|_____|_____|_____|_____|
 −2    −1     0     1     2     3     4     5     6
              |
            −i|_                .3−i
              |
              |
  .−2−2i   −2i|_
              |
              |
           −3i|_
              |

All of normal mathematics can be done with complex numbers:

To multiply two complex numbers is more complicated. It is easiest to describe in general terms, with two complex numbers a + bi and c + di.

For example, (4 + 5i) × (3 + 2i) = (4 × 3 − 5 × 2) + (4 × 2 + 5 × 3)i = (12 − 10) + (8 + 15)i = 2 + 23i.

A real or complex number is called a transcendental number if it can not be obtained as a result of an algebraic equation with integer coefficients.

Proving that a certain number is transcendental can be extremely difficult. Each transcendental number is also an irrational number. The first people to see that there were transcendental numbers were Gottfried Wilhelm Leibniz and Leonhard Euler. The first to actually prove there were transcendental numbers was Joseph Liouville. He did this in 1844.

Some well-known transcendental numbers include:




#Article 220: November (488 words)


November (Nov.) is the eleventh and penultimate (second-last) month of the year in the Gregorian calendar, coming between October and December. It has 30 days. Its name is from the Latin word novem, which meant nine. It was the ninth month of the year before January and February were added to the Roman Calendar.

November always begins on the same day of the week as March, and additionally, February in common years.  November always ends on the same day of the week as August.

November is the eleventh month of the year in the Gregorian calendar, after October and before December, which is the last month. November has 30 days. It was the ninth month in the old Roman calendar, which is where its name comes from. It kept its name when January and February were added to the beginning of the year, despite becoming the eleventh month. The ninth month is now September.

November begins on the same day of the week as February in common years and March every year, as each other's first days are exactly 39 weeks (273 days) and 35 weeks (245 days) apart respectively. November ends on the same day of the week as August every year, as each other's last days are exactly 13 weeks (91 days) apart.

In common years, November starts on the same day of the week as June of the previous year, and in leap years, September and December of the previous year. In common years, November finishes on the same day of the week as March and June of the previous year, and in leap years, September of the previous year.

In years immediately before common years, November starts on the same day of the week as August of the following year, and in years immediately before leap years, May of the following year. In years immediately before common years, November finishes on the same day of the week as May of the following year, and in years immediately before leap years, February and October of the following year.

In the Northern Hemisphere, November is an Autumn (Fall) month, and the further north in the hemisphere, the more likely it is to get colder as December approaches. In the Southern Hemisphere it is a Spring month. In each hemisphere, it is the seasonal equivalent of May in the other.

Several observances around the beginning of the month are believed to be related, linked to the old Celtic celebration of Samhain on November 1. These events include Halloween (October 31), Day of the Dead in Mexico (October 31 to November 2), All Saints Day (November 1) and All Souls Day (November 2).

In several mainly Christian countries, it is month in which people who died in war are commonly remembered, mainly related to the end of World War I on November 11, 1918. Near the end of the month Advent, the period leading up to Christmas, begins.




#Article 221: Name (873 words)


A name is a word (or a set of words) given to things and people. 

For example, cat is the name of a kind of animal. Ryan is a name of a person, usually a male.  Julia is a common female name. 

The word 'name' can also be used as a verb. To name something is to give it a name.

In many cultures, there are rules and customs about how to give a person a name. 

Some of the rules are defined by laws, and others are defined by traditions (doing things in the way they have been done for a long time). 

There are rules about different aspects of the names and naming, including the following:

In some cultures, a person has a one-part name, such as ShiningWater. 

In other cultures, a person has a two-part name, such as John Smith.

In some cultures, a person can have any number of name parts. In the United States, for example, some people have three: first name, middle name, and last name. Other people have only two: a first and last name.

In Chinese cultures, it is typical for a person to have three-part name, such as Cheah Ching San, where Cheah is the surname. Written in English format a comma is introduced making it Ching San, Cheah.

In some cultures, people have the same family name (or surname) as their parents. For example, the father of John Smith may be Mike Smith. And Mike Smith's father may be James Smith. The Smith part is the same for all the family. 

In other cultures, a person has the same name as his or her father, but the name is in a different place. For example, Shafiq Hanif's son may be Hanif Kamal. Hanif is in both the father's and son's name. 

In some cultures, a name changes when people marry, divorce, go through some religious ceremony, etc. For example, in some Spanish-speaking countries, people use two last names: their mother's father's name and their father's name. If Elena Rodriguez Gomez and Jose Sanchez Soria marry, she may change her name to Elena Rodriguez de Sanchez, and their child could be named Pilar Sanchez Rodriguez, taking the names of both of her grandfathers. 

In some cultures, personal names come from history. In most European countries, some first names are taken from the Bible. In some cultures, names are taken from a relative. In other cultures, a name shows what the parents hope their child will be like. A baby may be given a name Wisdom because parents hope the baby will be a wise girl or boy. 

Some cultures avoid giving people a name of an animal. For example, there is no name like dog, cat, snake, owl, or fish in Japanese people's first names. But in some cultures animal names may be good. 

In some languages and cultures, you can tell if a word is a person's name or not by just looking at the spelling or listening to its pronunciation. There are some other linguistic patterns. For example, many Chinese names are made up of three syllables. 

In some cultures, people use names when they call each other. In other cultures, people use their nicknames. In some other cultures, people use their titles (father, professor, etc.) when they call each other.

Taking note of names is taken a step farther by those who elect to celebrate a name (e.g., Celebrate Your Name Week) whether their own name, someone else's name, or names in general, complete ownership of one's name might very well include celebrating it. 

While some people might choose to hide a middle name for any number of reasons (i.e., they consider the middle name they were given to be an embarrassment), others have taken to celebrating their middle name (e.g., Middle Name Pride Day).

In the English language, names exclusively are usually pronounced in correlation with the spelling, however can be pronounced as desired, e.g. John is (jon) but can also be (ned). However, not probable, is held true in the English rules of grammar.

Examples of names

Sarah, Lucy, Ellen, Claire, Ben.

Names can be shortened e.g. Isabelle can become Izzy or Belle.

Here are some things that are often found in Japanese names today. In the past, people went by different rules.  

Japanese names have two parts. One is the family name and the other is the given name. 

Only some members of the royal family do not have a family name. 

A newborn baby gets a family name from their parents. The parents have the same family name. So, a son of Ono Yoko (female) and Ono Ken (male) is Ono something. 

The family name Ono is mostly shared by the paternal (male) part of the family. So Ono Ken's parents have the family name Ono, but Ono Yoko's parents probably do not. 

Names of people change when they marry and divorce. It is a custom in many parts of the world that women change their family name to that of their new husband when they marry. However, in Europe and North America especially, many women no longer do this even though their mothers and grandmothers may have. Sometimes, the man will take the woman's family name. 




#Article 222: Niihau (285 words)


Niihau (or Niʻihau) is the smallest of the inhabited islands of Hawaii, in the United States. It has a land area of 70 sq. miles (184 km2). It is the oldest of the eight main islands.

The whole island is owned by the Robinson family. They bought it from the Kingdom of Hawaii for $10,000. It was said that the buyer, Elizabeth Sinclair (later Sinclair-Robinson), liked the island better than other places such as Waikiki, Pearl Harbor, and the island of Lanai. There is a small US Navy base where a handful of Navy people work.

The island has a few hundred  inhabitants. Almost all of them are native Hawaiians. They support themselves largely with small family farms. Many work for the ranch owned by the Robinsons. The native Hawaiians lead a rural, low-tech life. They speak the Hawaiian language and keep traditions alive. This is because Ms. Sinclair promised to help preserve Hawaiian culture and tradition when she bought the island. Niihau is the only one of the Hawaiian islands where the Hawaiian language is the main language.

Niihau is also known as the Forbidden Island. This is due to the fact that until recently, the island was off-limits to all but family members, US Navy personnel, government officials and expressly invited s. Now, tourists can go on one of a limited number of supervised tours or hunting safaris.

On the beaches of the island are found shells which are the only shells to be classified as gems. Niihau shells and the jewelry made from them are very popular. Many, especially those with darker and richer color, are collectors items. The sale of shells and shell jewelry brings extra money for the local people.




#Article 223: Nēnē (171 words)


The Nēnē, or Hawaiian goose (Branta sandvicensis) is a species of goose. It is found today on only three Hawaiian islands. It gets its name from its soft call.

This is an unmistakable species, with its generally brown plumage (feathers) and darker head. Its strong toes have much reduced webbing (skin between the toes), an adjustment to the lava flows on which it breeds. The Nēnē goes about on land much more than other water birds. When moulting (dropping old feathers and growing new ones), the Nēnē cannot fly, as do other geese, a factor which made it vulnerable to hunting.

The Nēnē was once among the most  waterfowl species around the world. Once common, hunting and predators brought to the islands such as mongooses, pigs and cats reduced the population to only 30 birds in the 1950s. However, this species breeds well in captivity (zoos and bird parks), and has been successfully re-introduced. There are also good numbers in wild bird collections.

The Nēnē is the state bird of Hawaii.




#Article 224: Internet slang (280 words)


Internet slang is slang words which are used on the internet. Most of these words are new, such as Wiki and blog, which were not used before the internet became popular.

Some old words were given new meanings, such as mail (which now means email).  This makes many metaphors on the Internet, such as boot (which otherwise mean a shoe) and link (which otherwise means a joint in a metal chain).  Some existing acronyms, such as AFK (To mean Away from keyboard) and IRL (To mean In real life) were used on bulletin board systems before the internet became popular.  These are now used on the internet, such as in chat rooms and on instant messenger software.

People have also created some verbs and adjectives to describe things that only happen on the internet:

Shorthand is where a word is written in a shorter way because it is quicker and easier to type. It is also done to fit more  into a limited space.

Internet slang uses many acronyms because they are quicker and easier to type.  They are often shorthand for common phrases and idioms, but they can show somebody's emotions and their .

Leet speak (written as: L33T or 1337) is the most common language on MMORPGs because rude words are not stopped by filters. This language is changing all the time because new words are made and used. A lot of the words use numbers instead of letters but some were made because of typing errors which are now done on purpose. Also, some suffixes are used, such as -age and -ness.

Some of the numbers and symbols used instead of letters are in the table below.




#Article 225: Nauru (555 words)


Nauru, ( ) officially the Republic of Nauru, is a sovereign island nation located in the Micronesian South Pacific. Its nearest neighbour is Banaba Island in the Republic of Kiribati,  due east. Nauru is the world's smallest island nation, covering just , the smallest independent republic, and the only republican state in the world without an official capital. With 10,670 residents, it is the third least-populated country after Vatican City and Tuvalu.

Nauru is a phosphate rock island, and its primary economic activity since 1907 has been the export of phosphate mined from the island. English and Nauruan are the official languages of Nauru. The current president of Nauru is Lionel Aingimea.

Nauru is a  oval-shaped island in the southwestern Pacific Ocean,  south of the Equator. The island is surrounded by a coral reef, which is exposed at low tide and dotted with pinnacles. The presence of the reef has prevented the establishment of a seaport, although channels in the reef allow small boats access to the island. A fertile coastal strip  wide lies inland from the beach.

Coral cliffs surround Nauru's central plateau. The highest point of the plateau, called the Command Ridge, is  above sea level. The only fertile areas on Nauru are on the narrow coastal belt, where coconut palms flourish. The land surrounding Buada Lagoon supports bananas, pineapples, vegetables, pandanus trees, and indigenous hardwoods such as the tomano tree.

Nauru was one of three great phosphate rock islands in the Pacific Ocean (the others were Banaba (Ocean Island) in Kiribati and Makatea in French Polynesia). The phosphate reserves on Nauru are now almost entirely depleted. Phosphate mining in the central plateau has left a barren terrain of jagged limestone pinnacles up to  high. Mining has stripped and devastated about 80 per cent of Nauru's land area, and has also affected the surrounding Exclusive Economic Zone; 40 per cent of marine life is estimated to have been killed by silt and phosphate runoff.

There are only about 60 recorded vascular plant species native to the island, none of which are endemic. Coconut farming, mining, and introduced species have caused serious disturbance to the native vegetation. There are no native land mammals, but there are native insects, land crabs, and birds, including the endemic Nauru Reed Warbler. The Polynesian rat, cats, dogs, pigs, and chickens have been introduced to Nauru from ships.

There are limited natural fresh water resources on Nauru. Rooftop storage tanks collect rainwater, but the islanders are mostly dependent on three desalination plants housed at Nauru's Utilities Agency. Nauru's climate is hot and very humid year-round because of its proximity to the equator and the ocean. Nauru is hit by monsoon rains between November and February, but does not typically experience cyclones. Annual rainfall is highly variable and is influenced by the El Niño-Southern Oscillation, with several significant recorded droughts. The temperature on Nauru ranges between  and  during the day and between  and  at night.

As an island, Nauru is vulnerable to climate and sea level change. Nauru is the seventh most global warming threatened nation due to flooding. At least 80 per cent of the land of Nauru is well elevated, but this area will be uninhabitable until the phosphate mining rehabilitation programme is implemented.

Nauru is divided into fourteen administrative districts which are grouped into eight electoral constituencies.




#Article 226: Noun (789 words)


A noun is a kind of word (see part of speech) that is usually the name of something such as a person, place, thing, animal, or idea. In English, nouns can be singular or plural.

Nouns often need a word called an article or  (like the or that). These words usually do not go with other kinds of words like verbs or adverbs. (For example, people do not also describe nouns). In English, there are more nouns than any other kind of word.

Every language in the world has nouns, but they are not always used in the same ways. They also can have different properties in different languages. In some other languages, nouns do not change for singular and plural, and sometimes there is no word for the.

Examples of nouns: time, people, way, year, government, day, world, life, work, part, number, house, system, company, end, party, information.

The word noun comes from the Latin nomen meaning name. Words like nouns were described in early days by the Sanskrit grammarian  and ancient Greeks like Dionysios Thrax.

In English sentences, nouns can be used as a subject, object, or complement. They often come after prepositions, as the 'object of preposition'.

Nouns can sometimes describe other nouns (such as a soccer ball). When they do this, they are called modifiers or adjuncts.

There are also verb forms that can be used in the same way as nouns (such as 'I like running.')  These are called verbals or verbal nouns, and include participles (which can also be adjectives) and infinitives.

Nouns are classified into common and proper. Pronouns have commonly been considered a different part of speech from nouns, but in the past some grammars have included them as nouns

Proper nouns (also called proper name) are specific names. Examples of proper nouns are: London, John, God, October, Mozart, Saturday, Coke, Mr. Brown, Atlantic Ocean. Proper nouns are individual things with names, not general nouns.

Proper nouns begin with an  (capital) letter in English and many other languages that use the Roman alphabet.  (However, in German, all nouns begin with an upper case letter.) The word I is really a pronoun, although it is capitalized in English, like a proper noun.

Some common nouns (see below) can also be used as proper nouns. For example, someone might be named 'Tiger Smith' -- even though he is not a tiger or a smith.

Common nouns are general names that are unspecific. Sometimes the same word can be either a common noun or a proper noun, depending on how it is used; for example:

In English and many other languages, nouns have 'number'. But some nouns are only singular (such as furniture, physics) and others are only plural (such as clothes, police). Also, some nouns are countable (for example, one piece, two pieces) but others are uncountable (for example, we do not say one furniture, two furnitures).

The plural form of most nouns is created simply by adding the letter(s) -(e)s.

Despite plural forms being written using the letter(s) -(e)s, the pronunciation of the letter(s) will pronounced as /-s/, /-z/, or /-ız/ depending on which type of phoneme, or unique sound, comes before it. These variations of the plural morpheme are called allomorphs.

Note that some dictionaries list busses as an acceptable plural for bus. Presumably, this is because the plural buses looks like it ought to rhyme with the plural of fuse, which is fuses. Buses is still listed as the preferable plural form. Busses is the plural, of course, for buss, a seldom used word for kiss.

There are several nouns that have irregular plural forms. Plurals formed in this way are sometimes called mutated (or mutating) plurals.

Many of the above irregular plural forms stem from Old English, which had more complex rules for making plural forms.

And, finally, there are nouns that maintain their Latin or Greek form in the plural. (See media and data and alumni, below.)

Nouns are words for things, and since things can be possessed, nouns can also change to show possession in grammar. In English, we usually add an apostrophe and an s to nouns to make them possessive, or sometimes just an apostrophe when there is already an s at the end, like this:

Most adjectives become nouns by adding the suffix -ness. Example: Take the adjective 'natural', add 'ness' to get 'naturalness', a noun. To see a list of 100 adjectives used in Basic English, click here.

A noun phrase is a phrase where the head word is a noun. In English, the word order of most noun phrases is that determiners, adjectives, and modifying nouns in respective order must appear before the head word, and relative clauses must appear after the head word.




#Article 227: Nature (267 words)


The words nature and natural are used for all the things that are normally not made by humans. Things like weather, organisms, landforms, celestial bodies and much more are part of nature. Scientists study the way the parts of nature work. Things that have been made by people are said to be man-made or called artifacts.

There are natural sciences that study different parts of nature, for example the science of ecology is about plants and animals as a whole, while biology studies every type of living thing.

From one point of view, humans are a prime example of nature, and are the most widely studied natural inhabitants of the planet earth. Humans interact with each other in their natural environment on a constant basis. Every part of nature  everything from the air to the dirt on the ground  is interdependent. Medicine studies humans in health and sickness. 

From another point of view, humans and nature can be said to be in conflict. Nature is often seen by humans as natural resources. People cut down trees, mine ores, and grow crops. Fires, cars, and factories make a lot of smoke and harm many places. People who like to leave nature unharmed and those who feel they need to use more of nature often fight about what they should do. In the modern world, with many more people and many big cities, these problems are becoming more serious.

Nature, in the broadest sense, means the physical world as a whole. This is the meaning that physics, the study of nature (etymologically), takes.

A useful definition of natural is 




#Article 228: Natural resource (407 words)


A natural resource is what people can use which comes from the natural environment. Examples of natural resources are air, water, wood, oil, wind energy, natural gas, iron, and coal. 

The dividing line between natural resources and man-made resources is not clear-cut. Hydro-electric energy is not a natural resource because people use turbines to convert the energy from moving water. Petroleum and iron ores are natural, but need work to make them into usable refined oil and steel. Atomic energy comes from metallic nuclear fuels, like fissionable uranium and plutonium, but natural rocks need technical work to make them into these nuclear fuels.

We often say there are two sorts of natural resources: renewable resources and non-renewable resources.

Most natural resources are limited. This means they will eventually run out. A perpetual resource has a never-ending supply. Some examples of perpetual resources include solar energy, tidal energy, and wind energy. There may be a limit to how much can be taken in a given day or year, but that amount can be taken again next day or next year. 

Some of the things influencing supply of resources include whether it is able to be recycled, and the availability of suitable substitutes for the material. Non-renewable resources cannot be recycled. For example, fossil fuels cannot be recycled.

The demand for resources can change with new technology, new needs, and new economics (e.g. changes in cost of the resources). Some material can go completely out of use, if people do not want it any more. Demand of many natural resources is very high, but availability of some, such as precious metals, is very low.

Different places have different natural resources.  When people do not have a certain resource they need, they can either replace it with another resource, or trade with another country to get the resource.  People have sometimes fought to have them (for example, spices, water, arable farmland, gold, or petroleum).

When people do not have some resources, their quality of life can get lower.  So, people protect resources.  When they can not get clean water, people may become ill; if there is not enough wood, trees will be cut and the forest will disappear over time (deforestation); if there are not enough fish in a sea, people can die of starvation.  Renewable resources include crops, wind, hydroelectric power, fish, and sunlight.  Many people carefully save their natural resources so that others can use them in future.




#Article 229: Negentropy (170 words)


Negentropy is reverse entropy. It means things becoming more in order. By 'order' is meant organisation, structure and function: the opposite of randomness or chaos. One example of negentropy is a star system such as the Solar System. Another example is life.

As a general rule, everything in the universe tends towards entropy. Star systems eventually become dead. All energy has gone, and everything in the system is at the temperature of the surrounding space. The opposite of entropy is negentropy. It is a temporary condition in which certain things are hotter and more highly organised than the surrounding space. This is the second law of thermodynamics:

Life is considered to be negentropic because it converts things which have less order, such as food, into things with more order, such as cells in the body, tissues, and organs. In doing so, it gives off heat.  Another example of negentropic things are societies, or social systems, because they take disorderly things such as communications, and make them more orderly and useful.




#Article 230: North America (132 words)


North America is a large continent in the Northern and Western Hemispheres of Earth. It is to the east of the Pacific Ocean, the west of the Atlantic Ocean, the south of the Arctic Ocean, and it is the northern part of the Americas. The southernmost part is Central America. It is the third largest continent in the world, after Asia and Africa. 

Hundreds of millions of years ago, North America was part of a larger ancient supercontinent named Laurasia. A few million years ago, a new land bridge arose and connected North America to South America. Beringia connected North America to Siberia a few times during ice ages in the past 20,000 years. North America has a population of 527 million and is the 4th most populous continent in the world. 




#Article 231: Neptune (3131 words)


Neptune (), is the eighth and last planet from the Sun in the Solar System. It is an ice giant. It is the fourth largest planet and third heaviest. Neptune has four rings which are hard to see from the Earth. It is seventeen times heavier than Earth and is a little bit heavier than Uranus. It was named after the Roman God of the Sea.

Neptune's atmosphere is mostly made up of hydrogen and helium. It also contains small amounts of methane which makes the planet appear blue. Neptune's blue color is much darker compared to the color of Uranus, which has a similar amount of methane, so there might be another reason why Neptune is blue. Neptune also has the strongest winds of any planet in the solar system, measured as high as 2,100 km/h or 1,300 mph.

Neptune was discovered by the astronomers Urbain Le Verrier and John Couch Adams. They were both honored for the discovery.  The planet was the first to be discovered by mathematical calculations instead of using a telescope.  Uranus was moving oddly in its orbit around the Sun, so astronomers searched for another new planet.

The planet was visited by only one spacecraft, Voyager 2 on August 25, 1989.  Neptune once had a huge storm known as the Great Dark Spot which was discovered in 1989 by Voyager 2.  However, the dark spot was not seen in 1994, and new spots were found since then.  It is not known why the dark spot disappeared.  Visits by more space probes have been proposed.

The first possible sighting of Neptune is thought to be by Galileo as his drawings showed Neptune near Jupiter. But Galileo was not credited for the discovery since he thought Neptune was a fixed star instead of a planet. Because of Neptune's slow movement across the sky, Galileo's small telescope was not strong enough to detect Neptune as a planet.

In 1821, Alexis Bouvard published the astronomical tables of the orbit of Uranus. Later observations showed that Uranus was moving in an irregular way in its orbit, making some astronomers think of another large body being the cause of the irregular motions of Uranus. In 1843, John Couch Adams calculated the orbit of an eighth planet that would possibly be influencing the orbit of Uranus. He sent his calculations to Sir George Airy, the Astronomer Royal, who asked Adams for an explanation. Adams began to make a copy of the reply, but never sent it.

In 1846, Urbain Le Verrier, who was not working with Adams, made his own calculations but also failed to get much attention from French astronomers. However, in the same year, John Herschel began to support the mathematical method and encouraged James Challis to search for the planet.  After much delay, Challis began his unwilling search in July 1846.  Meanwhile, Le Verrier had convinced Johann Gottfried Galle to search for the planet.

Although Heinrich d'Arrest was still a student at the Berlin Observatory, he suggested that a newly drawn map of the sky, in the region of Le Verrier's predicted area, could be compared with the current sky to look for the change of position of a planet, as compared to a fixed star. Neptune was then discovered that very night on September 23, 1846, within 1° (one degree (angle) of where Le Verrier had predicted it to be, and about 10° from Adams' prediction. Challis later found out that he had seen the planet twice in August, failing to recognize it owing to his careless approach to the work.

After the news of the discovery of Neptune spread, there was also a lot of arguing between the French and the British about who was to deserve credit for the discovery. Later, an international agreement decided that both Le Verrier and Adams together deserved credit. However, historians reviewed the topic after the rediscovery in 1998 of the Neptune papers (historical documents from the Royal Greenwich Observatory), which had seemingly been stolen and kept by astronomer Olin Eggen for nearly three decades and were only rediscovered (in his ownership) shortly after his death. After reviewing the documents, some historians now think that Adams does not deserve equal credit with Le Verrier.

Shortly after its discovery, Neptune was temporarily called the planet exterior to Uranus or Le Verrier's planet. The first suggestion for a name came from Galle. He proposed the name Janus. In England, Challis suggested the name Oceanus. In France, Arago suggested that the new planet be called Leverrier, a suggestion which was met with a lot of opposition outside France. French almanacs promptly reintroduced the name Herschel for Uranus and Leverrier for the new planet.

Meanwhile, on separate and different reason, Adams suggested changing the name Georgian to Uranus, while Leverrier (through the Board of Longitude) suggested Neptune for the new planet. Struve gave support of that name on December 29, 1846, to the Saint Petersburg Academy of Sciences. Soon Neptune was internationally agreed among many people and was then the official name for the new planet. In Roman mythology, Neptune was the god of the sea, identified with the Greek god, Poseidon.

At 10.243 kg, Neptune's mass puts the planet between Earth and the largest gas giants; Neptune has seventeen Earth masses but just 1/18th the mass of Jupiter. Neptune and Uranus are often considered to be part of a sub-class of gas giant known as ice giants, given their smaller size and big differences in composition compared to Jupiter and Saturn. In the search for extrasolar planets, Neptune has been used as a reference to determine the size and structure of the discovered planet. Some discovered planets that have similar masses like Neptune are often called Neptunes. just as astronomers refer to various extra-solar Jupiters.

The atmosphere of Neptune is made up mostly of hydrogen, with a smaller amount of helium. A tiny amount of methane is also detected in the atmosphere. Important absorption bands of methane happen at wavelengths above 600 nm, in the red and infrared portion of the spectrum. This absorption of red light by the atmospheric methane gives Neptune its blue hue.

Because Neptune orbits so far from the Sun, it gets very little heat with the uppermost regions of the atmosphere at  and is the coldest planet in our solar system. Deeper inside the layers of gas, however, the temperature rises slowly. Like Uranus, the source of this heating is unknown, but the differences are larger: Neptune is the farthest planet from the Sun, yet its internal energy is strong enough to create the fastest winds seen in the Solar System. Several possible explanations have been suggested, including radiogenic heating from the planet's core, the continued radiation into space of leftover heat made by infalling matter during the planet's birth, and gravity waves breaking above the tropopause.

The structure of the inside of Neptune is thought to be very similar to the structure of the inside of Uranus. There is likely to be a core, thought to be about 15 Earth masses, made up of molten rock and metal surrounded by a mixture of rock, water, ammonia, and methane. The heavy pressures keep the icy part of this surrounding mixture as solids, in spite of the large temperatures near the core. The atmosphere, extending about 10 to 20% of the way towards the center, is mostly hydrogen and helium at high altitudes. More mixtures of methane, ammonia, and water are found in the lower areas of the atmosphere. Very slowly this darker and hotter area blends into the superheated liquid interior. The pressure at the center of Neptune is millions of times more than that on the surface of Earth. Comparing its rotational speed to its degree of oblateness shows that it has its mass less concentrated towards the center unlike Uranus.

One difference between Neptune and Uranus is the level of  activity that has been observed (seen or measured). When the Voyager spacecraft flew by Uranus in 1986, that winds on that planet were observed to be mild. When Voyager flew by Neptune in 1989, powerful weather events were observed. The weather of Neptune has extremely active storm systems. Its atmosphere has the highest wind speeds in the solar system, thought to be powered by the flow of internal heat. Regular winds in the equatorial region have speeds of around 1,200 km/h (750 mph), while winds in storm systems can reach up to 2,100 km/h, near-supersonic speeds.

In 1989, the Great Dark Spot, a cyclonic storm system the size of Eurasia, was discovered by NASA's Voyager 2 spacecraft. The storm resembled the Great Red Spot of Jupiter. However, on November 2, 1994, the Hubble Space Telescope did not see the Great Dark Spot on the planet. Instead, a new storm similar to the Great Dark Spot was found in the planet's northern hemisphere. The reason why the Great Dark Spot has disappeared is unknown. One possible theory is that heat transfer from the planet's core disrupted the atmospheric balance and existing circulation patterns. The Scooter is another storm, a white cloud group farther south than the Great Dark Spot. Its nickname was given when it was first noticed in the months leading up to the Voyager encounter in 1989: it moved faster than the Great Dark Spot. Later images showed clouds that moved even faster than Scooter. The Wizard's Eye/Dark Spot 2 is another southern cyclonic storm, the second most strongest storm seen during the 1989 encounter. It originally was completely dark, but as Voyager came closer to the planet, a bright core developed and is seen in most of the highest resolution images.

Unlike other gas giants, Neptune's atmosphere shows the presence of high clouds making shadows on a thick cloud deck below. Though Neptune's atmosphere is much more active than that of Uranus, both planets are made up of the same gases and ices. Uranus and Neptune are not exactly the same type of gas giants like to Jupiter and Saturn, but are rather ice giants, meaning they have a larger solid core and are also made of ices. Neptune is very cold, with temperatures as low as −224 °C (−372 °F or 49 K) recorded at the cloud tops in 1989.

Neptune also has similarities with Uranus in its magnetosphere, with a magnetic field strongly tilted comparative to its rotational axis at 47° and offset at least 0.55 radii (about 13,500 kilometres) from the planet's physical center. Comparing the magnetic fields of the two planets, scientists think the extreme course may be characteristic of flows in the interior of the planet and not the result of Uranus' sideways rotational movement.

Very small blue colored rings have been discovered around the blue planet, but they are not as well known as the rings of Saturn. When these rings were discovered by a team led by Edward Guinan, originally they thought that the rings may not be complete rings. However, this was proven wrong by Voyager 2. Neptune's planetary rings have a weird clumpy arrangement. Although the cause is currently unknown but some scientists think that it may be because of the gravitational contact with small moons that orbit near them.

Proof that the rings are incomplete first began in the mid-1980s, when stellar occultation were found to rarely show an extra blink just before or after the planet occulted the star. Pictures from Voyager 2 in 1989 solved the problem, when the ring system was found to have several faint rings. The farthest ring, Adams, has three famous arcs now named Liberté, Egalité, and Fraternité (Liberty, Equality, and Fraternity).

The existence of arcs is very hard to understand because the laws of motion would predict that arcs spread out into a single ring in a very short time. The gravitational effects of Galatea, a moon just inward from the ring, are now thought to have created the arcs.

Several other rings were discovered by the Voyager cameras. Also with the thin Adams Ring about 63,000 km from the center of Neptune, the Leverrier Ring is at 53,000 km and the wider, smaller Galle Ring is at 42,000 km. A very small outward expansion to the Leverrier Ring has been named Lassell; it is surrounded at its outer edge by the Arago Ring at 57,000 km.

New Earth-based observations published in 2005 appeared to show that Neptune's rings are a lot more unstable than thought before. To be exact, it looks like that the Liberté ring might disappear maybe quickly in less than 100 years. The new observations seems to puzzle our understanding of Neptune's rings into a lot of confusion.

Neptune has a total of 14 known moons. As Neptune was the Roman god of the sea, the planet's moons were named after lesser sea gods or goddesses. The largest, and the only one big enough to have the shape of a sphere is Triton, (pronounced:) discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons, Triton has a retrograde orbit, showing that the moon was probably captured, and maybe was once a Kuiper belt object. It is close enough to Neptune to be locked into a synchronous orbit, and is slowly moving into Neptune and will one day be torn apart when it passes the Roche limit. Triton is the coldest object that has been measured in the solar system, with temperatures of −235 °C (38 K, −392 °F). Its diamter is 2700 km, (80% of Earth's Moon, Luna), its mass is 2.15×1022 kg (30% of Luna), its orbital diameter is 354,800 km (90% of Luna) and its orbital period is 5.877 days (20% of Luna).

Neptune's second known moon (by order of distance), the odd moon Nereid, has one of the most unusual orbits of any satellite in the solar system.

From July to September 1989, Voyager 2 discovered six new moons of Neptune. Of these, the lumpy-shaped Proteus is the biggest known object that has not been shaped into a sphere by its own gravity. Although it is the second most massive Neptunian moon, it has only one quarter of one percent of the mass of Triton. Neptune's closest four moons, Naiad, Thalassa, Despina, and Galatea, orbit close enough to be inside Neptune's rings.

The next farthest out, Larissa was originally discovered in 1981 when it had occulted a star. The moon was credited for causing Neptune's ring arcs when Voyager 2 observed Neptune in 1989. Five new unusual moons discovered between 2002 and 2003 were announced in 2004. The latest moon was discovered from examining Hubble Telescope imags on July 16, 2013. It is only 12 miles across, allowing it to evade detection even by the Voyager 2 spacecraft. 

Neptune cannot be seen with naked eye alone, since Neptune's normal brightness are between magnitudes +7.7 and +8.0, which can be out-shined by Jupiter's Galilean moons, the dwarf planet Ceres, and the asteroids 4 Vesta, 2 Pallas, 7 Iris, 3 Juno and 6 Hebe. A telescope or strong binoculars will show Neptune as a small blue dot, similar in appearance to Uranus. The blue color comes from the methane in its atmosphere. Its small obvious size has made it difficult to study visually; most telescopic data was quite limited until the arrival of the Hubble Space Telescope and large ground-based telescopes with adaptive optics.

With an orbital period (sidereal period) of 164.88 Julian years, Neptune will soon return (for discovery) to the same place in the sky where it was discovered in 1846. This will happen three different times, also with a fourth in which it will come very close to being at that position. These are April 11, 2009, when it will be in prograde motion; July 17, 2009, when it will be in retrograde motion; and February 7, 2010, when it will be in prograde motion. It will also come very close to being at the same point since the 1846 discovery in late October through early-mid November 2010, when Neptune will turn from retrograde to direct motion on the exact degree of Neptune's discovery and will then stop for a moment along the ecliptic within 2 arc minutes at that point (closest on November 7, 2010). This will be the last time for about the next 165 years that Neptune will be at its point of discovery.

This is explained by the idea of retrogradation. Like all planets and asteroids in the Solar System beyond Earth, Neptune goes through retrogradation at certain points during its synodic period. In addition to the start of retrogradation, other events inside the synodic period include astronomical opposition, the return to prograde motion, and conjunction to the Sun.

In its orbit around the Sun, Neptune returned to its original point of discovery in August 2011.

Currently, only one spacecraft has visited Neptune. NASA's Voyager 2 probe made a quick flyby of the planet with its closest encounter on August 25, 1989, and was the last planet to have been visited by at least one spacecraft.

Some of Voyager 2s important discoveries was its very close fly-by of Triton where took pictures of several parts of the moon. The probe also discovered the Great Dark Spot, although it has now disappeared after when the Hubble Space Telescope took pictures of Neptune in 1994. Originally thought to be a large cloud or cyclonic storm system, it was later guessed just to be a hole in the visible cloud deck.

Neptune turned out to have the strongest winds of all the solar system's gas giants. In the outer regions of the solar system, where the Sun shines over 1000 times fainter than on Earth (still very bright with a magnitude of -21), the last of the four giants did happen as what the scientists actually expected. One might think that the farther a planet is from the Sun, the less energy and heat there would be to create and run the very strong winds around. The winds on Jupiter were already hundreds of kilometres per hour. Rather than seeing slower winds, the scientists found faster winds (over 1600 km/h) on more distant Neptune.

One possible guess for the cause of the faster wind speeds is that if enough energy is produced, turbulence is created, which slows the winds down (like those of Jupiter). At Neptune however, there is so little solar energy that once winds are started they meet very little resistance, and are able to keep very high speeds. Anyhow, Neptune gives out more energy than it gets from the Sun, and the internal energy source of these winds remains undetermined.

The pictures sent back to Earth from Voyager 2 in 1989 became the basis of a PBS all-night program called Neptune All Night.

Future missions to Neptune




#Article 232: Now (245 words)


Now is the time span between the past and the future. It can be long (like an eon in geologic time) or short (like a picosecond) but it is almost always used to refer to the span between the present instant to some time horizon when a decision must be made. It can be used to ask or demand that someone make a decision even if they want to delay.

Mathematics and measurement assume that everything used in one equation equals the same quantities at the beginning of calculation or axiomatization as at the end. That means it is mathematically correct to say that the idea of equal means equal from the time the  starts to the time it ends. In General Semantics and E Prime the words equal, remain (for the past until now) and become (for now into the future) replace the verb to be for this reason.

Algebra is now often called snapshot algebra or algebra of seeing because of this dependence on time. If any action or event were possible between steps in algebraic analysis, then, in theory, one would have to start over as if one had no knowledge of the new state at all. For these reasons the idea of statistics and also knowledge and knowledge management are sometimes questioned, for instance, in the book Lies, Damn Lies, and Statistics. A major issue is the comparing of numbers gathered in the past, and now, after some key conditions change.




#Article 233: New York City (3972 words)


New York City (NYC) or simply New York (NY) is the largest city by population in the United States, located in the state of New York. New York’s population is similar to London in the United Kingdom with over 8 million people currently living in it, and over 22 million people live in the bigger New York metropolitan area. It is in the south end of the state of New York, which is in the northeastern United States.  It is the financial capital of the US since it is home to the nation's stock market, Wall Street, and the One World Trade Center. A leading global city; New York exerts culture, media and capital internationally, as well as attracting great numbers of international travelers. It is also the home of the United Nations Headquarters.

Being on one of the world's largest natural harbors, New York City is made up of five boroughs, each of which is a county of the State of New York. The five boroughs—Brooklyn, Queens, Manhattan, the Bronx, and Staten Island—were combined into one city in 1898. The city and its metropolitan area are an important place for legal immigration to the United States. As many as 800 languages are spoken in New York, making it the most linguistically diverse city in the world. New York has more than 3.2 million people born outside the United States, the biggest foreign-born population of any city in the world as of 2016.

New York City started as a trading post created by colonists from the Dutch Republic in 1624 on Lower Manhattan; the post was named New Amsterdam in 1626. In 1664, the English controlled the city and the areas around it, and were renamed New York after King Charles II of England gave the lands to his brother, the Duke of York. New York was the capital of the United States from 1785 until 1790, and has been the biggest U.S. city since 1790. The Statue of Liberty welcomed millions of immigrants as they came to the U.S. by ship in the late 19th and early 20th centuries, and it is a symbol of the U.S. and its ideals of liberty and peace. In the 21st century, New York has grew into a global hub of creativity and entrepreneurship and environmental sustainability, and as a symbol of freedom and cultural diversity. In 2019, New York was voted the best city in the world in a survey of over 30,000 people from 48 cities worldwide, because of its cultural diversity.

Many districts and landmarks in New York City are well known, including three of the world's ten most visited tourist places in 2013. A record 62.8 million tourists came to New York City in 2017. Times Square is the colorful area of the Broadway Theater District, one of the world's busiest pedestrian intersections, and a famous area for the world's entertainment industry. Many of the city's landmarks, skyscrapers, and parks are known around the world. Manhattan's real estate market is one of the most expensive in the world. New York has more ethnic Chinese people outside of Asia than anywhere else in the world, with many Chinatowns across the city. The New York City Subway is the biggest single-operator rapid transit system worldwide, with  rail stations. The city has over 120 colleges and universities, including Columbia University, New York University, Rockefeller University, and the City University of New York system, which is the biggest urban public university system in the United States. The world's two largest stock exchanges, the New York Stock Exchange, located on Wall Street in the Financial District of Lower Manhattan, and NASDAQ, headquartered in Midtown Manhattan, are both in Manhattan.

In 1664, the city was named after the Duke of York, who would become King James II of England. James's older brother, King Charles II, had chosen the Duke proprietor of the former territory of New Netherland, including the city of New Amsterdam, which England had recently taken from the Dutch.

The oldest part of the city, the island of Manhattan, still has its original Lenape name. Although Native people such as the Lenape and Canaries had lived there for many thousands of years, New York City was first explored by Europeans in the 1500s. Florentine explorer Giovanni da Verrazzano found the entrance to New York Harbor in the year 1524 he gived to this site the name of New Angoulême in the honor of Francois 1st. In 1609, the English explorer Henry Hudson rediscovered New York Harbor while looking for the Northwest Passage to the Orient for the Dutch East India Company. Hudson's first mate said it was a very good Harbour for all windes and the river was a mile broad and full of fish.

Juan Rodriguez (transliterated to Dutch as Jan Rodrigues) was one of the first people associated with Europe to live there. He was a merchant from Santo Domingo. He was born in Santo Domingo of Portuguese and African descent, and he came to Manhattan during the winter of 1613–14. He trapped for pelts and traded with the local people as a representative of the Dutch. Broadway, from 159th Street to 218th Street in Upper Manhattan, is named Juan Rodriguez Way in his honor.

New York City was settled by Europeans from The Netherlands in 1624. The Dutch called the whole area of New York Netherland (New Netherland) and they named a fort and town on the south end of Brooklyn.

In 1626, the Dutch colonial Director-General Peter Minuit, acting for the Dutch West India Company, bought the island of Manhattan from the Canarsie, a small Lenape band. He paid the value of 60 guilders (about $900 in 2018). A false story says that Manhattan was bought for $24 worth of glass beads. 1626 was also the year the Dutch began to bring black slaves there.

After the purchase, New Amsterdam grew slowly. In 1647, Peter Stuyvesant started his job as the last Director-General of New Netherland. During this time, the number of people of New Netherland grew from 2,000 to 8,000.

Island New Amsterdam (New Amsterdam), after the capital city of the Netherlands, which was to become present-day New York. The English took over the colony in 1664 during the second Anglo-Dutch War. They changed the name to New York, to honor the Duke of York, who later became King James II of England and James VII of Scotland. The Dutch surrendered Nieuw Amsterdam without fighting.

By the time the English took New York, there were many other Dutch towns in what would become New York City, including Breukelen (Brooklyn), Vlissingen (Flushing), and Nieuw Haarlem (Harlem). There were already some English towns in the area also, such as Gravesend in Brooklyn and Newtown in Queens. Dutch, English and other people had been living together in New York for a long time.

New York became more important as a trading port while under British rule in the early 1700s. It also became a center of slavery as the British increased the slave trade and built a slave market in the city. 42% of households owned slaves by 1730, the highest percentage outside Charleston, South Carolina.

The 1735 trial and acquittal in Manhattan of John Peter Zenger, who had been accused of seditious libel after criticizing colonial governor William Cosby, helped to create the freedom of the press in North America. In 1754, Columbia University was created under charter by King George II; it was called King's College, and it was in Lower Manhattan.

New York quickly grew to become a large and important port city. The Stamp Act Congress met in New York in October 1765, as the Sons of Liberty. It organized in the city, and they skirmished over the next ten years with British troops stationed there. The  important Battle of Long Island of the American Revolution was fought in Brooklyn in 1776; it was the biggest battle of the war. The Americans lost the battle. The British used the area as its headquarters for the war in North America.

New York was the capital of the United States under the Articles of Confederation from 1785 to 1788.  When the US Constitution was made, it stayed as the capital from 1789 until 1790. In 1789, the first President of the United States, George Washington, was inaugurated; the first United States Congress and the Supreme Court of the United States each met for the first time, and the United States Bill of Rights was written, all at Federal Hall on Wall Street. By 1790, New York grew bigger than Philadelphia, so it become the biggest city in the United States. By the end of 1790, because of the Residence Act, Philadelphia became the new capital.

During the nineteenth century, New York City's population grew from ~60,000 to ~3.43 million. The number of black people in New York City reached more than 16,000 in 1840. Even though slavery and the slave trade were abolished in New York, the slave trade continued illegally for many years.

The Great Irish Famine brought a many Irish immigrants; more than 200,000 were living in New York by 1860, more than a quarter of the city's population. There was also many people from German provinces, and Germans made up another 25% of New York's population by 1860.

During the American Civil War, many white people in the city supported the Confederate States of America, and July 1863 they killed many black New Yorkers in a riot.

In 1898, the cities of New York and Brooklyn came together with the Bronx, Staten Island, and the western towns in Queens County to make Greater New York. This is the total area of the City of New York today.  Around this time, many new immigrants came into New York City.  They came in at Ellis Island, an island in New York's harbor near the Statue of Liberty.  Many of them then moved to the Lower East Side neighborhood in Manhattan, which had over a million people living in just a few square miles.

Early in the twentieth century, with better transportation, more people moved to outer parts of the greater city, and many commuted to Manhattan. Many skyscrapers and other big buildings were put up to provide places to work.

In the 1970s, many jobs were lost due to industrial restructuring. This caused New York City to have economic problems and high crime rates. Though the financial industry grew, which greatly helped the city's economy in the 1980s, New York's crime rate continued to increase through that decade and into the beginning of the 1990s. By the mid 1990s, crime rates started to drop a lot due to different police strategies, better economic opportunities, gentrification, and new residents, both Americans and new immigrants from Asia and Latin America. Important new sectors, such as Silicon Alley, started in the city's economy. New York's population reached all-time highs in the 2000 census and then again in the 2010 census.

New York had most of the economic damage and biggest loss of human life from the September 11, 2001 attacks. Two of the four planes taken over that day were flown into the twin towers of the World Trade Center, destroying them and killing 2,192 civilians, 343 firefighters, and 71 police officers. The North Tower became the tallest building ever to be destroyed anywhere.

Hurricane Sandy brought a destructive storm surge to New York City on the evening of October 29, 2012, flooding numerous streets, tunnels and subway lines in Lower Manhattan and other areas of the city and cutting off electricity in many parts of the city and its suburbs.

During the Wisconsin glaciation, 75,000 to 11,000 years ago, the New York City area was at the edge of a big ice sheet over  deep. Erosion and the ice moving lead to the creation of what is now Long Island and Staten Island. It also left bedrock at a shallow depth, providing a solid foundation for most of Manhattan's skyscrapers.

New York City is located in the Northeastern United States, in southeastern New York State, approximately halfway between Washington, D.C. and Boston. The city includes all of Manhattan Island and Staten Island, and the western end of Long Island. There are also many smaller islands.

Water divides several parts of the city. The Hudson River flows through the Hudson Valley into New York Bay. Between New York City and Troy, New York, the river is an estuary. The Hudson River separates the city from the U.S. state of New Jersey. Part of the Hudson River forms the border between Manhattan and the Bronx on one side, and the State of New Jersey on the other side. The East River forms the border between Manhattan on one side, and Brooklyn and Queens on the other side. The Harlem River forms the border between Manhattan and the Bronx (except for a small part of Manhattan that is on the mainland). Part of Long Island Sound separates the Bronx and Queens. Newtown Creek is part of the border between Brooklyn and Queens. Some parts of the city are very separate from the others because of water, such as Rockaway in Queens and City Island in the Bronx. A small piece of land in Manhattan is international territory and belongs to the United Nations Headquarters. The country of Somalia is the only country whose national flag copied the colors of the UN. The Bronx River, which flows through the Bronx and Westchester County, is the only entirely fresh water river in the city.

The city's total area is , including  of land and  of this is water. The tallest place in the city is Todt Hill on Staten Island. It is at  above sea level, and it is the tallest place on the Eastern Seaboard that is south of Maine. The summit of the ridge is mostly woodland as part of the Staten Island Greenbelt.

The hallmark of New York city is its many skyscrapers, especially in Manhattan. In New York City there are about 5600 skyscrapers. 48 of them are over 200 metres tall, which is the highest number of skyscrapers in one area in the world.

New York City has five boroughs: Manhattan, Brooklyn, Queens, the Bronx, and Staten Island.

Manhattan (New York County) is the geographically smallest and most densely populated borough. It has Central Park and most of the city's skyscrapers. It is sometimes locally known as The City.

Brooklyn (Kings County), on the western end of Long Island, has the most people living in it than any other borough. Brooklyn is known for its cultural, social, and ethnic diversity, an independent art scene, unique neighborhoods, and unique architecture.

Queens (Queens County), on Long Island north and east of Brooklyn, is geographically the biggest borough and the most ethnically diverse county in the United States. It is also the most ethnically diverse urban area in the world.

The Bronx (Bronx County) is New York City's northernmost borough. It is the only New York City borough with most of the land being on the mainland United States. The Yankee Stadium, the baseball park of the New York Yankees, and the biggest cooperatively owned housing complex in the United States, Co-op City, are in the Bronx. The Bronx Zoo, the world's largest metropolitan zoo, is also in the Bronx. It is  big and has more than 6,000 animals. Rap and hip hop culture were created in the Bronx. Pelham Bay Park is the biggest park in New York City, at .

Staten Island (Richmond County) is the most suburban of the five boroughs. Staten Island is connected to Brooklyn by the Verrazano-Narrows Bridge. It is connected to Manhattan by way of the free Staten Island Ferry, a daily commuter ferry which has clear views of the Statue of Liberty, Ellis Island, and Lower Manhattan. In central Staten Island, the Staten Island Greenbelt is about  big, including  of walking trails and one of the last untouched forests in the city.

Under the Köppen climate classification, New York City experiences a humid subtropical climate (Cfa) that borders a humid continental climate (Dfa). The average temperature in January, the area's coldest month, is . However, temperatures in winter could for a few days be as low as  and as high as . Summers are typically hot and humid with a July average of . New York City gets some snow in winter.

New York City currently has over 9 million people. Over 20 million people live in the New York metropolitan area including the city. The majority of the people in New York City belong to ethnic groups that are minorities in the US.  New York City has had large numbers of immigrants for centuries. In the early 19th Century, they came from Ireland and Germany. Later in the 19th century, they came from Italy, Russia and Eastern Europe. Today, many are from Puerto Rico, Haiti, the Dominican Republic and Colombia.

New York City is a global hub of business and commerce, as a center for banking and finance, retailing, world trade, transportation, tourism, real estate, new media, traditional media, advertising, legal services, accountancy, insurance, theater, fashion, and the arts in the United States. The Port of New York and New Jersey is also a big part of the economy. It received a record cargo volume in 2017, over 6.7 million TEUs. New York City's unemployment rate fell to its record low of 4.0% in September 2018.

Many Fortune 500 companies are headquartered in New York City, as are many multinational corporations. One out of ten private sector jobs in the city is with a foreign company. New York City has been ranked first among cities around the world in getting capital, business, and tourists. New York City's role as the top global center for the advertising industry can be seen with Madison Avenue. The city's fashion industry has about 180,000 employees with $11 billion in annual wages.

Chocolate is New York City's biggest specialty-food export, with up to $234 million worth of exports each year. Entrepreneurs were creating a Chocolate District in Brooklyn , while Godiva, one of the world's biggest chocolatiers, continues to be headquartered in Manhattan.

New York City's most biggest economic part is the U.S. financial industry, also known as Wall Street. The city's securities industry, which has 163,400 jobs in August 2013, continues to be the biggest part of the city's financial sector and an important economic part. In 2012, Walls Street made 5.0 percent of the city's private sector jobs, 8.5 percent ($3.8 billion) of its tax revenue, and 22 percent of the city's total wages, including an average salary of $360,700.

In Lower Manhattan, there is the New York Stock Exchange, on Wall Street, and the NASDAQ, at 165 Broadway, representing the world's biggest and second biggest stock exchanges, respectively. Investment banking fees on Wall Street totaled about $40 billion in 2012, while in 2013, senior New York City bank officers who manage risk and compliance functions earned as much as $324,000 every year. In fiscal year 2013–14, Wall Street's securities industry made 19% of New York State's tax revenue.

Many of the world's biggest media conglomerates are also in the city. Manhattan had more than 500 million square feet (46.5 million m2) of office space in 2018, making it the biggest office market in the United States. Midtown Manhattan, with 400 million square feet (37.2 million m2) in 2018, is the biggest central business area in the world.

WNBC NBC

WCBS CBS

WABC American Broadcasting Company

USA Network

Showtime (TV channel)

New York is an important place for the American entertainment industry, with many movies, television series, books, and other media being set there. , New York City was the second biggest center for filmmaking and television production in the United States, making about 200 feature films every year, making about 130,000 jobs. The filmed entertainment industry has been growing in New York, providing nearly $9 billion to the New York City economy as of 2015. By amount, New York is the world leader in independent film production—one-third of all American independent films are created there. The Association of Independent Commercial Producers is also based in New York.

New York City is also an important place for the advertising, music, newspaper, digital media, and publishing industries, and it is the biggest media market in North America. Some of the city's media conglomerates and companies include Time Warner, the Thomson Reuters Corporation, the Associated Press, Bloomberg L.P., the News Corporation, The New York Times Company, NBCUniversal, the Hearst Corporation, AOL, and Viacom. Seven of the world's top eight global advertising agency networks have their headquarters in New York. Two of the top three record labels' headquarters are in New York: Sony Music Entertainment and Warner Music Group. Universal Music Group also has offices in New York.

More than 200 newspapers and 350 magazines have an office in the city, and the publishing industry has about 25,000 jobs. Two of the three national daily newspapers with the biggest circulations in the United States are published in New York: The Wall Street Journal and The New York Times, which has won the most Pulitzer Prizes for journalism. Big tabloid newspapers in the city include The New York Daily News, which was created in 1919 by Joseph Medill Patterson, and The New York Post, created in 1801 by Alexander Hamilton. The city also has a many ethnic presses, with 270 newspapers and magazines published in more than 40 languages. El Diario La Prensa is New York's biggest Spanish-language daily newspaper, and it is the oldest in the United States. The New York Amsterdam News, published in Harlem, is a big African American newspaper. The Village Voice, historically the biggest alternative newspaper in the United States, announced in 2017 that it would end publication of its print version, and it will only publish online.

New York is also an important place for non-commercial educational media. The oldest public-access television channel in the United States is the Manhattan Neighborhood Network, created in 1971.

The New York City Public Schools system, managed by the New York City Department of Education, is the biggest public school system in the United States. It serves about 1.1 million students in more than 1,700 different primary and secondary schools.

The New York City Charter School Center helps the creation of new charter schools. There are about 900 additional private secular and religious schools in the city.

More than 600,000 students are enrolled in New York City's more than 120 colleges and universities, which is the most of any city in the United States and more than other major global cities such as London, and Tokyo. More than half a million are just in the City University of New York (CUNY) system , including both degree and professional programs. New York City's colleges and universities had also higher average scores than those two cities in 2019, according to the Academic Ranking of World Universities. New York City has many famous private universities such as Barnard College, Columbia University, Cooper Union, Fordham University, New York University, New York Institute of Technology, Rockefeller University, and Yeshiva University; many of these universities are ranked as some of the best universities in the world.

The mayor of New York is Bill de Blasio, a Democrat. The city also has a City Council that makes some local laws. Most laws in New York City are set by the state government in Albany.

Subway transportation is provided by the New York City Subway system, one of the biggest in the world. Pennsylvania Station, the busiest train station in the United States, is here.

John F. Kennedy International Airport, which is in the Queens borough of New York, is one of the busiest airports in the United States.




#Article 234: October (459 words)


October (Oct.) is the tenth month of the year in the Gregorian calendar, coming between September and November. It has 31 days. The name comes from the Latin octo for eight. It was the eighth month of the year before January and February were added to the beginning of the year.

October begins on the same day of the week as January in common years, but doesn't begin on the same day of the week as any other month in leap years. October always ends on the same day of the week as February, and additionally, January in common years.

October is the tenth month of the year in the Gregorian calendar, coming after September and before November. It has 31 days. Its name comes from Latin octo, meaning eight, as it was the eighth month of the year in the Old Roman Calendar before January and February were added to the beginning of the year, though its name did not change. The tenth month at the time was December.

October is an Autumn (Fall) month in the Northern Hemisphere and a Spring month in the Southern Hemisphere. In each Hemisphere, it is the seasonal equivalent of April in the other.

October begins on the same day of week as January in common years, but doesn’t begin on the same day of the week as any other month in leap years. October ends on the same day of the week as January in common years and February every year, as each other's last days are 39 weeks (273 days) and 35 weeks (245 days) apart respectively.

In common years, October starts on the same day of the week as May of the previous year, and in leap years, August of the previous year. In common years, October finishes on the same day of the week as May of the previous year, and in leap years, August and November of the previous year.

In years immediately before common years, October starts on the same day of the week as April and July of the following year, and in years immediately before leap years, September and December of the following year. In years immediately before common years, October finishes on the same day of the week as July of the following year, and in years immediately before leap years, April and December of the following year.

October is the month of the Rosary devotion. 

October 31/November 1 is Samhain in old Pagan tradition. Several current observances at this time are believed to be related to it. They are: Halloween (October 31) in many western traditions, All Saints Day (November 1), All Souls Day (November 2), and the Day of the Dead (October 31 to November 2), which is celebrated in Mexico.




#Article 235: 1 (number) (118 words)


One (1) is a natural number after zero and before two.
It represents a single item.
A human typically has one head, nose, mouth, and navel (belly-button).
The Roman numeral for one is I.

In mathematics, 1 is the multiplicative identity of common numbers. It is sometimes called the unity. It is also the only number for which these special facts are true.

In mathematics, 0.999... is a repeating decimal that is mathematically equal to 1. Many proofs have been made to show this is correct.

The number one is important for computer science, because the binary numeral system uses only 1s and 0s. In machine code and many programming languages, one means true and zero means false.




#Article 236: O Canada (323 words)


O Canada is the national anthem of Canada. 

Calixa Lavallée wrote the music; Adolphe-Basile Routhier wrote the words in French. It was first sung in French in 1880. Robert Stanley Weir wrote English words for the song in 1908.

It was sung as the national anthem for many years before the government made it official on 1 July (Canada Day) in 1980. 

Here are the words, explained in Simple English:

 O Canada! Our home and native land, 
 True patriot love in all of us command! 
 With glowing hearts we see thee rise 
 The True North strong and free, 
 From far and wide, O Canada, 
 We stand on guard for thee. 
 God keep our land glorious and free! 
 O Canada, we stand on guard for thee; 
 O Canada, we stand on guard for thee.

(Canada, our home and the country where we were born, everything we do is for you! With joy we watch you get better and better. You are the True North, strong and free. Our citizens come from all over the earth and we watch over you to keep you safe. God, please keep our land good and free! O Canada, we watch over you to keep you safe.)

Here are the words in French. The words in French and English do not mean the same thing.

 Ô Canada! Terre de nos aïeux, 
 Ton front est ceint de fleurons glorieux! 
 Car ton bras sait porter l'épée, 
 Il sait porter la croix! 
 Ton histoire est une épopée 
 Des plus brillants exploits. 
 Et ta valeur de foi trempée 
 Protégera nos foyers et nos droits; 
 Protégera nos foyers et nos droits. 

(Canada, land of our parents and grandparents, you wear a crown of beautiful flowers! You can carry a sword, and you can carry a cross (for Christianity); your whole history is full of the great things you have done. You are brave and faithful, and this will protect our homes and our rights.)




#Article 237: Oahu (256 words)


Oahu (or Oʻahu) is the third largest of the Hawaiian Islands, in the United States. It means the gathering place (a place where people meet) in the Hawaiian language. Most of the people of Hawaii live there (1.2 million of the state's 1.7 million in the mid-1990s). The total land area is . Honolulu, the capital city of Hawaii, is on this island. Other well-known places on Oahu are Waikiki, Pearl Harbor, Diamond Head, Hanauma Bay, Kaneohe Bay, and both the North Shore and Makaha (which are famous for very big ocean waves). 

Kamehameha I made Oahu his capital when he became the first king of Hawaii. Iolani Palace was built later on by others of the royal family. It is the only royal palace on American soil. 

Oahu was perhaps the first of the Hawaiian Islands which the crew of HMS Resolution saw on 18 January 1778. This was during Captain James Cook's third Pacific Ocean trip. Europeans did not land on Oahu until 28 February 1779 when Captain Clerke of the HMS Resolution stepped ashore at Waimea Bay. Clerke took command of the ship after Captain Cook was killed at Kealakekua Bay on February 14.

Today, Oahu has become a tourism and shopping center. Almost 7 million visitors (mainly from the American mainland and Japan) go there every year to enjoy the special island holiday found only in Hawaii.

Oahu can be seen in hundreds of movies and TV shows. Some of them are Magnum, P.I., Lost, Hawaii Five-O and Jake and the Fatman.




#Article 238: Open content (298 words)


Open Content is when someone creates something and lets others  it or  it without having to ask for . Any media can be open content, from text and pictures to video and sound.

When someone creates something (like a picture or book), they can make that work open.  This means that other people are allowed to copy it and change it if they want.  Something that is open content may be  of charge, but it does not have to be. 

The Simple English Wikipedia is open content. So are other Wikipedias. If a person changes open content or makes new open content, everyone can give it to anyone else, or even sell it. It is never needed to ask permission to do this, because the people who wrote the text already gave their permission when they clicked the save button.

The rules that say how people can use, change and pass around open content are called a license. A license explains exactly what you are allowed to do with the content that falls under it. Licenses are often written in difficult lawyer language (legal jargon), but many licenses have summaries that are much easier to understand.

The makers of open content get to choose what license to use for their work, and everyone else has to follow it. Only the maker, who owns the copyright, can change it to another license.  Most open content licenses say that when others change the work, they must also declare it to be open and under the same license.  This is called share-alike and means that anything based on work will always be open content.

All the content in Wikipedia is open under the rules of the , a very well-known open content license. Another well-known open content license is the .




#Article 239: Orthography (1287 words)


Orthography is an official or correct way to write a particular language. It includes rules of spelling. Orthography may also include rules about punctuation, capitalization, and diacritics (e.g. accents). In English, spelling is a problem for all learners, and is the main issue in orthography.

Some languages have someone to decide the correct spelling, such as the Académie française. English does not. English orthography was the work of the early printers. They had to decide how particular words would be spelled in their books. Gradually the number of alternative spellings began to drop. The word which is merry today was spelled in about 30 ways in written sources from the 9th to the 16th century.p970

English orthography, or English spelling, is the way the 26 letters of the alphabet are used to write down the 36 (IPA) sounds of English. The first manuscripts in Old English were written using the Latin alphabet. It had 24 letters.p16

No alphabet fits its language exactly. One reason for this is that there are always more sounds than letters. In English there are far more vowel sounds than vowels. The ancient Greeks, who were the first to use letters for vowels, decided to use only a few letters for their vowel sounds. This choice influenced all later alphabets:

English would need about 20 vowels to represent the vowel phonemes (~sounds) in common use,p237 and some languages do have more letters for vowels. The Georgian language has a total of 41 letters. A shorter alphabet works by using two or three letters for a single sound, or one letter for several sounds.

The English alphabet has only three consonants which have one sound, cannot be produced by other combinations and are never silent: n, r and v. The English language uses 22 to 26 consonant phonemes.

The other reason that alphabets never exactly fit languages is dialect. A spoken language varies from place to place and from time to time. This is very obvious with English, as the pronunciation is so different in different parts of the world. A written language will always be less flexible than its spoken parent. It has a different function, and is produced mechanically. It must serve everyone who speaks the language, and it does this by keeping the spelling similar from one time to another.

Therefore, all alphabets have sounds which are difficult to represent with the letters in use. And English also has other problems: sounds that can be written in different ways, and spelling which can be pronounced in different ways. This all gives rise to problems of spelling.

Differences between American English and British English spelling came about mainly as the result of one man. Noah Webster (1758–1843) wrote a Grammar, a Spelling book, and finally an American dictionary of the English language. In the course of this, he proposed a number of simplifications in spelling. In his dictionary, he chose s over c in words like defense, he changed the re to er in words like center, he dropped one of the Ls in traveler. At first he kept the u in words like colour or favour but dropped it in later editions. He also changed tongue to tung: that did not stick. His main reason was to help children learn to read and write. Webster's dictionary contained seventy thousand words, of which twelve thousand had never appeared in a published dictionary before.

Webster did create a slightly different identity for American English. But, because his efforts did not address some of the most glaring problems, his variations make little difference to the way the language is used.  An example of the real problems in English orthography is the word ending -ough, which is pronounced several different ways: tough, bough, cough...  The root causes of spelling variation are historical.  Loan words come with their own (foreign) spelling.  Some French loan words are still spelled in the French way; others have been changed. 

English spelling reform has been proposed by many people since Webster, such as George Bernard Shaw, who proposed a new phonetic alphabet for English. In some cases Webster's changes have been widely adopted in Britain: the spelling programme came from the French; US program is clearly simpler, and more consistent with word endings in English. In our modern world, English orthography is still a problem. In some countries (notably, France) a national committee can give advice and direction as to spelling. English has long escaped from national custody.

Modern British spelling and use was greatly influenced by the two great English dictionaries, Samuel Johnson's A dictionary of the English language (1755), and James Murray's Oxford English Dictionary. Johnson's dictionary was hugely influential, abroad as well as at home. The dictionary was exported to America.

For American lexicographers, the dictionary was impossible to ignore:

Some people argue which language is the easiest to spell. People who learn a second language tend to think that their first (native) language is the easiest. However, for the learner, programmatic languages, with well-defined rules, are easier to start with than English. The spelling of the English language is by far the most irregular of all alphabetic spellings and thus the most difficult to learn. English is, in its origin, a Germanic language. From its early roots as Anglo-Saxon, it has borrowed words from many other languages: French (a Romance language) and Latin are the most frequent donors to English.

Languages that use phonetic spelling are easier to learn to spell than others. With phonetic spelling the words are spelled as they are pronounced. The Italian word orologio for instance is pronounced oh-ro-LO-jo (gi always making a j sound.) In English, one comes across the word knife. In knife, the k is not spoken, even though in English it's more common to pronounce Ks when they are in words.

One of the problems we have is that similar sounding words may be spelt quite differently. Rough and ruff; meet and meat; great and grate. Words with complicated spelling may be pronounced simply: Leicester is pronounced 'Lester'. Even what rules we do have are frequently broken. i before e except after c has over 100 exceptions.p272 Almost all these problems have come about for historical reasons. English has been changing for the last thousand years, and as the language changes, so parts of it get stuck with different spellings.

Here are some of the causes of English orthography:

English has a huge number of words, but its spelling comes from many different sources. The large and varied lexicon of English has been bought at the expense of an increasingly deversified graphology.p275

Some languages have a high correspondence between phonemes and letters. That means they get close to one letter for each sound. If there was a perfect correspondence, that language would have phonemic orthography. English is highly non-phonemic. It has almost every kind of deviation known:

This field of study is called orthographic depth. The orthographic depth of an alphabetic script is the degree to which a written language deviates from simple one-to-one letter–phoneme correspondence. It shows how easy it is to predict the pronunciation of a word from its spelling. Shallow orthographies are easy to pronounce based on the written word, and deep orthographies are difficult to pronounce based on how they are written. In shallow orthographies, the spelling-sound correspondence is direct: given the rules of pronunciation, one is able to say the word correctly.

Most other international languages have similar problems: in French, Arabic or Hebrew, new readers have difficulty learning to decode words. As a result, children learn to read more slowly. In both Spanish and Italian there is a more direct connection between spelling and pronunciation. Those are languages with low orthographic depth.




#Article 240: Oil (198 words)


The word oil is used for many different kinds of liquids. Oil usually does not mix with water.

Vegetable oils are made from plants. Many are used in foods and for cooking. Some kinds of plant oils that people use are palm oil, maize (corn), olive, peanut, soy, and sunflower.

Other kinds of oil are made from crude oil (petroleum) which comes from under the ground. People use large oil wells to bring the oil up to the surface. The oil is sent in special ships called tankers or in pipelines to factories called refineries where it is distilled into LPG, gasoline (petrol), diesel fuel, and fuel oil. Plastics are among the Petrochemicals made from crude oil or natural gas. Oils from crude oil are also used as fuels for engines or as lubricants to make the parts of machines work together without sticking or stopping.

Different kinds of oils are also used for many other things, for example to make cosmetics, medicines, paints, and detergents, like washing up liquids. Soap(s) are similar to detergents, but they are generally made from animal fat(s) rather than oils.

Oil is also made for various purposes including synthetic fuel and lubricant.




#Article 241: OK (192 words)


OK (okay) is a word in the English language. It is used to mean that something is good or correct.

It can often be used instead of the word Yes.  It is not certain where the word OK originally comes from, but some experts say it came from a funny way of writing Ol Korrect (All correct). 

It is also the two-letter abbreviation for the state of Oklahoma in the United States of America.

You also find the phrase Ola kala in Greek, which means something like Everything fine.

The term appears to have achieved prominence in the United States in 1840, when supporters of the American Democratic political party claimed during the 1840 United States presidential election that it stood for Old Kinderhook, a nickname for a Democratic presidential candidate, Martin Van Buren, a native of Kinderhook, New York. 'Vote for OK' was snappier than using his Dutch name.  In response, Whig opponents attributed OK, in the sense of Oll Korrect, to Andrew Jackson's bad spelling. The country-wide publicity surrounding the election appears to have been a critical event in okays history, widely and suddenly popularizing it across the United States.




#Article 242: Oxymoron (191 words)


An oxymoron  is a term for a figure of speech.   It is made up of two or more words that seem to be opposite to each other, or actually are opposite.

For example, the words Wise fool, Warm freezer, Legal murder all have two words. In each one, the one word looks like the opposite of the other word.

You can have words that look opposite, but are right. For example, a warm freezer could be right. A freezer could be warm if it was turned off or left open.

The word oxymoron is an oxymoron; 'oxy' comes from the Greek word that means 'sharp', while 'moron' comes from the Greek word that means 'dull'.

Words that really are opposite to each other, would be words that just cannot be put together. For example, a round square could not happen because squares are not round.

Oxymorons sometimes appear in jokes. Sometimes, the joke is just to say that a pair of words are an oxymoron. For example, a joke that says that honest politician is an oxymoron. This means that politicians are dishonest, if the word 'politician' is opposite to 'honest'.




#Article 243: Operating system (588 words)


 

An operating system (or OS) is a group of computer programs, including device drivers, kernels, and other software that lets people interact with a computer. It manages computer hardware and software resources. It provides common services for computer programs. An OS can be small (like MenuetOS), or large (like Microsoft Windows). Different operating systems can be used for different purposes. Some are used for everyday things like on a personal computer. Others are mobile operating systems or are used for specialized work.

An operating system has many jobs. It makes sure that all the programs can use the CPU, system memory, displays, input devices, and other hardware. Some also give the user an interface to use a computer. An OS is also responsible for sending data to other computers or devices on a network. 

Some examples of commonly used operating systems are macOS, Linux, and Microsoft Windows.

The first operating system was used with the ENIAC (Electronic Numerical Integrator and Computer). It was very hard to make ENIAC do work. How the operating system worked was based on how the switches and cables were put together and depending on this factor punch cards would make a result. While this was an operating system of a kind, it is not what is thought of as one in modern times.

The first operating system that looked and felt like operating systems in the modern age was UNIX, made in 1969 by Bell Labs. It had a small kernel and many tiny programs that could be put together to work with user input and data. Many of its features were taken from Multics, an older operating system made in 1964.

A single-tasking system can only run one program at a time.  A multitasking operating system can run more than one program at the same time.  Multi-tasking is done by dividing processor time.  The processor gives a little bit of its time to each program.

Single-user operating systems cannot distinguish between users, but may allow multiple programs to run simultaneously. A multi-user operating system permits multiple users to interact with the system at the same time.

A distributed operating system manages a group of distinct computers and makes them appear to be a single computer. Distributed computations are carried out on more than one machine.

In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine as a guest operating system, then saving it as a tool for multiple running virtual machines. The technique is common in large server warehouses.

Embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDAs with less autonomy and are able to operate with a limited number of resources. Windows CE and Minix 3 are some examples of embedded operating systems.

A real-time operating system guarantees processing of events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.

A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments.




#Article 244: Philosophy (1218 words)


Philosophy is the study of  things. This means philosophy tries to understand the reasons or  for things. It also tries to understand how things should be.  is the Ancient Greek word for the love of wisdom. A person who does philosophy is called a philosopher. A philosopher is a kind of thinker or researcher. A philosophy can also mean a group of ideas by philosophers, or by a philosopher. Philosophy is a way of thinking about the world, the universe, and society. In the past, sciences were part of philosophy as well.

The ideas in philosophy are often general and . But this does not mean that philosophy is not about the real world. Ethics, for example, asks about how to be good in our day-to-day lives. Metaphysics asks about how the world works and what it is made of.
Sometimes people talk about how they have a ‘personal philosophy’, which means the way a person thinks about the world. This article is not about people's ’personal philosophies’. This article is about the ideas that have been discussed by philosophers (people who think and write about ways of thinking) for a long time.

One philosophical question is this: Is there any knowledge in the world which is so certain that no reasonable man could doubt it?. Other questions asked by philosophers are these:

The etymological meaning of the word 'Philosophy' is 'love of wisdom'. It comes from the Greek word 'Philosophia', with 'Philo' meaning 'beloved' and 'Sophia' meaning 'wisdom.

There are different types of philosophy from different times and places. Some philosophers came from Ancient Greece, such as Plato and Aristotle. Others came from Asia, such as Confucius or Buddha and . Some philosophers are from the Middle Ages in Europe, such as William of Ockham or Saint Thomas Aquinas.

Philosophers from the 1600s, 1700s, and 1800s included Thomas Hobbes, René Descartes, John Locke, David Hume, and Immanuel Kant. Philosophers from the 1900s included Søren Kierkegaard, Ludwig Wittgenstein, and Jean-Paul Sartre.

Philosophy is the study of humans and the world by thinking and asking questions. It is a science and an art. Philosophy tries to answer important questions by coming up with answers about real things and asking why?

Sometimes, philosophy tries to answer the same questions as religion and science. Philosophers do not all give the same answers to a question. Many types of philosophy criticize or even attack the beliefs of science and religion.

In his work Critique of Pure Reason,  Immanuel Kant asked the following questions:

The answers to these questions gives the different domains or categories of philosophy.

Philosophy can be divided into different groups, based on the types of questions that it asks. Below is a list of questions split into groups. One possible list of answers to these questions can be called a 'philosophy'. There are many different 'philosophies', because all of these questions have many different answers according to different people. Not all philosophies ask the same questions. These are the questions that are usually asked by philosophers from the Western world:

Metaphysics is sometimes split up into ontology (the philosophy of real life and living things), the philosophy of mind and the philosophy of religion; but these sub-branches are very close together.

The philosophy of mind:

The philosophy of religion:

In epistemology:

In ethics:

In aesthetics:

In logic:

In :

Other divisions include eschatology, teleology and theology. In past centuries natural science was included in philosophy, and called natural philosophy.

Does philosophy do any good? Very few people would dispute this. It is easy to argue that philosophy is a good thing, because it helps people to think more clearly. Philosophy helps people to understand the world and the way people act and think. Philosophers believe that asking philosophical questions is useful because it brings wisdom and helps people to learn about the world and each other. Some philosophers might even argue that the question Is philosophy good or bad? is a philosophical question itself.

However, some people think that philosophy is harmful, as philosophy encourages free-thinking and often questions the beliefs that others hold. For example, philosophies such as some existentialist views say that there is no meaning to life or human existence, except the meaning that we make up or invent. People from some religions do not agree with the beliefs of existentialism.

Every major science, including physics, biology, and chemistry, are disciplines that were once considered as philosophy. Medicine was always considered a practical art, however. As facts about nature became more understood, these subjects branched away. Psychology only split a century and a half ago. In our own time, subjects such as consciousness studies, decision theory, and applied ethics have increasingly found independence from philosophy as a whole. Because of this, philosophy seems useful because it spins off new kinds of science.

Philosophers ask questions about ideas (concepts). They try to find answers to those questions. Some thinkers find it very hard to find those words that best describe the ideas they have. When they find answers to some of these questions philosophers often have the same problem, that is how to best tell the answers they found to other people. Depending on the meaning of the words they use, the answers change.

Some philosophers are full-time thinkers (called academics), who work for universities or colleges. These philosophers write books and articles about philosophy and teach classes about philosophy to university or college students.

Other philosophers are just hobby thinkers who think about philosophy during their free time. A small number of hobby thinkers have thought so much about philosophy that they are able to write articles for philosophy magazines. Other people approach philosophy from another job. For example, monks, artists, and scientists may think about philosophical ideas and questions.

Most philosophers work by asking questions and looking for good definitions (meanings) of words to help them understand what a question means.

Some philosophers say the only thing needed to answer a question is to find out what it means. The only thing that makes philosophical questions (such as those above) difficult is that people do not really know what they mean. Ludwig Wittgenstein believed this.

Philosophers often use both real and imaginary examples to make a point. For example, they may write about a real or fictional person in order to show what they think a good person or a bad person is like.

Some philosophers look for the simplest way to answer a question and say that is probably the right answer. This is a process called Occam's razor. Others believe that complicated answers to questions can also be right. For an example of a philosophical problem, see the God paradox.

Philosophers use logic to solve problems and answer questions. Logical consistency is a cornerstone of any acceptable theory. Philosophers who disagree with a theory will often try to find a logical contradiction in a theory. If they find a contradiction, this gives them a reason to reject that theory. If they do not find an inconsistency, the philosopher might show that the theory leads to a conclusion which is either unacceptable or ridiculous. This second approach is usually called reductio ad absurdum.

People listed here should be genuine philosophers, rather than social or political campaigners. The lists are not meant to be complete.




#Article 245: Physics (2071 words)


Physics is a branch of science. It is one of the most fundamental scientific disciplines. The main goal of physics is to explain how things move in space and time and understand how the universe behaves. It studies matter, forces and their effects.

The word  physics comes from the Greek word ἡ φύσις, meaning nature. Physics can also be defined as that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events.

Astronomy, a part of physics, is the oldest natural science. In the past it was a part of 'natural philosophy' with other fields of science, such as chemistry and biology. During the scientific revolution, these fields became separate, and physics became a distinct field of knowledge.

Physics is very important in the development of new technologies, such as airplanes, televisions, computers and nuclear weapons. Mechanics, a branch of physics, helped develop the mathematical field of calculus.

Modern physics connects ideas about the four laws of symmetry and conservation of energy, momentum, charge, and parity. 

Astronomy is the oldest natural science. The Sumerians, and Ancient Egyptians studied the stars, mostly with a view to prediction and religion. The first Babylonian star maps date from about 1200 BC. That astronomical events are periodic also dates back to the Babylonians.  Their understanding was not scientific, but their observations influenced later astronomy. Much astronomy came from Mesopotamia, Babylonia, Ancient Egypt, and Ancient Greece. Astronomers from Egypt built monuments that showed how objects in the sky moved, and most of the names for the constellations in the Northern hemisphere came from Greek astronomers.

Natural philosophy started in Greece around 650 BC when a movement of philosophers replaced superstition with naturalism, which refuted the spiritual. Leucippus and his student Democritus suggested the idea of the atom around this period.

Islamic scholars continued to study Aristotelian physics during the Islamic Golden Age. One main contribution was to observational astronomy. Some, like Ibn Sahl, Al-Kindi, Ibn al-Haytham, Al-Farisi and Avicenna, worked  on optics and vision. In The Book of Optics, Ibn al-Haytham rejected previous Greek ideas concerning vision and proposed a new theory. He studied how light enters the eye, and  developed the camera obscura. European scientists later built eyeglasses, magnifying glasses, telescopes, and cameras from this book.

Physics became a separate field of study after the scientific revolution. Galileo's experiments helped to create classical physics. Although he did not invent the telescope, he used it when he looked into the night sky. He supported Copernicus' idea that the Earth moved around the Sun (heliocentrism). He also investigated gravity. Isaac Newton used Galileo's ideas to create his three laws of motion and his law of universal gravitation.  Together these laws explained the motion of falling bodies near the earth and the motion of earth and planets around the sun. 

In a couple centuries, the Industrial Revolution was in full swing and many more discoveries were made in many fields of science. The laws of classical physics are good enough to study objects that move much slower than the speed of light, and are not microscopic. When scientists first studied quantum mechanics, they had to create a new set of laws, which was the start of modern physics.

As scientists researched particles, they discovered what classical mechanics could not explain. Classical mechanics predicted that the speed of light varied, but experiments showed the speed of light stayed the same. This was predicted by Albert Einstein's theory of special relativity. Einstein predicted that the speed of electromagnetic radiation through empty space would always be the same. His view of space-time replaced the ancient idea that space and time were quite separate things.

Max Planck came up with quantum mechanics to explain why metal releases electrons when you shine a light at it, and why matter emits radiation. Quantum mechanics applies for very small things like the electrons, protons, and neutrons that make up an atom. People like Werner Heisenberg, Erwin Schrödinger, and Paul Dirac continued to work on quantum mechanics and eventually we got the Standard Model.

Physics is the study of energy and matter in space and time and how they are related to each other. Physicists assume the existence of mass, length, time and electric current and then define (give the meaning of) all other physical quantities in terms of these basic units. Mass, length, time, and electric current are never defined but the standard units used to measure them are always defined. In the International System of Units (abbreviated SI from the French Système International), the kilogram is the basic unit of mass, the metre is the basic unit of length, the second is the basic unit of time, and the ampere is the basic unit of electric current.
In addition to these four units, there are three other ones: the mole, which is the unit of the quantity of matter, the candela which measures the luminous intensity (the power of lighting) and the kelvin, the unit of temperature.

Physics studies how things move, and the forces that make them move. For example, velocity and acceleration are used by physics to show how things move. Also, physicists study the forces of gravity, electricity, magnetism and the forces that hold things together.

Physics studies very large things, and very small things. For instance, physicists can study stars, planets and galaxies but could also study small pieces of matter, such as atoms and electrons.They may also study sound, light and other waves. As well as that, they could examine energy, heat and radioactivity, and even space and time. 
Physics not only helps people understand how objects move, but how they change form, how they make noise, how hot or cold they will be, and what they are made of at the smallest level.

Physics is a quantitative science because it is based on measuring with numbers. Mathematics is used in physics to make models that try to predict what will happen in nature. These predictions are compared to the way the real world works. Physicists are always working to make their models of the world better.

Classical mechanics contains major topics such as Newton's laws of motion, Lagrangian mechanics, Hamiltonian mechanics, kinematics, statics, dynamics, chaos theory, acoustics, fluid dynamics, continuum mechanics.  Classical mechanics is all about forces acting on a body in nature, balancing forces, maintaining equlibrium state, etc . 

Electromagnetism is study of charges on a particular body.  It contains subtopics such as Electrostatics, electrodynamics, electricity, magnetism, magnetostatics, Maxwell's equations, optics . 

Thermodynamics and statistical mechanics are related with temperature.  It includes main topics such as Heat engine, kinetic theory.  It uses terms such as heat(Q), work(W), and internal energy (U).  First law of thermodynamics gives us the relation them by the following equation (ΔU = Q − W)

Quantum mechanics is the study of particle at the atomic level taking into consideration the atomic model.  It includes subtopics Path integral formulation, scattering theory, Schrödinger equation, quantum field theory, quantum statistical mechanics.

Physics is the science of matter and how matter interacts. Matter is any physical material in the universe. Everything is made of matter. Physics is used to describe the physical universe around us, and to predict how it will behave. 
Physics is the science concerned with the discovery and characterization of the universal laws which govern matter, movement and forces, and space and time, and other features of the natural world.

The sweep of physics is broad, from the smallest components of matter and the forces that hold it together, to galaxies and even larger things. There are only four forces that appear to operate over this whole range. However, even these four forces (gravity, electromagnetism, the weak force associated with radioactivity, and the strong force which holds protons and neutrons in an atom together) are believed to be different parts of a single force.

Physics is mainly focused on the goal of making ever simpler, more general, and more accurate rules that define the character and behavior of matter and space itself. 
One of the major goals of physics is making theories that apply to everything in the universe. In other words, physics can be viewed as the study of those universal laws which define, at the most basic level possible, the behavior of the physical universe.

Physics uses the scientific method. That is, data from experiments and observations are . Theories which attempt to explain these data are produced. Physics uses these theories to not only describe physical phenomena, but to model physical systems and predict how these physical systems will behave. Physicists then compare these predictions to observations or experimental evidence to show whether the theory is right or wrong.

The theories that are well supported by data and are especially simple and general are sometimes called scientific laws. Of course, all theories, including those known as laws, can be replaced by more accurate and more general laws, when a disagreement with data is found.

Physics is more quantitative than most other sciences. That is, many of the observations in physics may be represented in the form of numerical measurements. Most of the theories in physics use mathematics to express their principles. Most of the predictions from these theories are numerical. This is because of the areas which physics has addressed work better with quantitative approaches than other areas. Sciences also tend to become more quantitative with time as they become more highly developed, and physics is one of the oldest sciences.

Classical physics normally includes the fields of mechanics, optics, electricity, magnetism, acoustics and thermodynamics. Modern physics is a term normally used to cover fields which rely on quantum theory, including quantum mechanics, atomic physics, nuclear physics, particle physics and condensed matter physics, as well as the more modern fields of general and special relativity, but these last two are often considered fields of classical physics as they do not rely on quantum theory. Although this difference can be found in older writings, it is of little new interest as quantum effects are now understood to be of importance even in fields that before were called classical.

There are many ways to study physics, and many different kinds of activities in physics. The two main types of activities are the collection of data, and the development of theories.

Some subfields of physics can be studied by experiment. For example, Galileo Galilei invented kinematics by making experiments and studying the data. Experimental physics focuses mainly on an empirical approach. Some experiments are done to explore nature, and other experiments are performed to produce data to compare with the predictions of theories.

Some other fields in physics like astrophysics and geophysics are mostly observational sciences because most of their data has to be collected passively instead of through experimentation. Galileo, for example, could only look at Jupiter and discover that it has moons. However, observational programs in these fields use many of the same tools and technology that are used in the experimental subfields of physics. 
 
Theoretical physics often uses quantitative approaches to develop the theories that attempt to explain the data. In this way, theoretical physicists often use tools from mathematics. Theoretical physics often can involve creating quantitative predictions of physical theories, and comparing these predictions quantitatively with data. Theoretical physics sometimes creates models of physical systems before data is available to test and support these models.

These two main activities in physics, data collection, theory production and testing, use many different skills. This has led to a lot of specialization in physics, and the introduction, development and use of tools from other fields. For example, theoretical physicists use mathematics and numerical analysis and statistics and probability and computer software in their work. Experimental physicists develop instruments and techniques for collecting data, using engineering and computer technology and many other fields of technology. Often the tools from these other areas are not quite appropriate for the needs of physics, and need to be changed or more advanced versions have to be made.

It is frequent for new physics to be discovered if experimental physicists do an experiment that current theories cannot explain, or for theoretical physicists to generate theories which can then be put to the test by experimental physicists.

Experimental physics, engineering and technology are related. Experiments often need specialized tools such as particle accelerators, lasers, and important industrial applications such as transistors and magnetic resonance imaging have come from applied research.

Famous theoretical physicists include




#Article 246: Politics (581 words)


Politics is the way that people living in groups make decisions. 
Politics is about making agreements between people so that they can live together in groups such as tribes, cities, or countries. In large groups, such as countries, some people may spend a lot of their time making such agreements. These people are called politicians. Politicians, and sometimes other people, may get together to form a government. The study of politics in universities is called political science, political studies, or public administration.

In everyday life, the term politics refers to the way that countries are governed, and to the ways that governments make rules and laws. Politics can also be seen in other groups, such as in companies, clubs, schools, and churches.

The government  tries to lead the whole group. Governments do things such as:

One of the ways the government leads the group is by making laws and rules which tell everybody what they can and can not do. The government makes these laws so that society will be safe and well-ordered. The law that says you must not drink alcohol while driving a car stops people from drunk driving, which could kill people. The law that says you must wear a helmet on a motorcycle makes sure that people protect themselves when riding their motorcycles. 

The government can also control people and what happens in a country in other ways besides making laws.

Politics is often compared to ethics (ideas about right and wrong). Ethics is a more abstract study of right and wrong. Ethics is usually more concerned with principle than law or politics or diplomacy, so many people think ethics is not practical. But without some agreement on ethics, there is probably no way to even have a debate, laws or an election. There is always some agreement on ethics and personal conduct in a political system.

In most countries, people have formed political parties to put forward their ideas. There is usually some disagreement between people within a party, but they work together because they feel that they agree on enough things, and they will have more power if they join together. They agree to take the same position on many issues, and agree to support the same changes to law and the same leaders. An election is usually a competition between different parties. Some examples of parties are the Liberal party, the Labor party and the Greens.

The Greek philosopher Aristotle wrote that humans are a political animal and that ethics and politics are closely linked.
	
Niccolò Machiavelli wrote, in his 1532 book, The Prince, that politics was firstly about having and keeping power. He said that without power, a leader could do nothing.

In 1651, Thomas Hobbes wrote Leviathan, a book about politics. Hobbes wrote that people living in groups often give up some of their rights in exchange for some protections from a government.
	
In the 1800s, John Stuart Mill developed the liberal idea of politics. Mill said that democracy is the most important political development of the 1800s. He said that there should be more protection for individual rights against the government. 

Bernard Crick wrote a list of the political virtues, which were about best practices of politics itself.

There are also disagreements between different countries. Attempts to solve the problem with meetings are called diplomacy. This is politics between nations instead of politics within nations. If the problems are not resolved by diplomatic meetings they can lead to war or terrorism.




#Article 247: Value (personal and cultural) (112 words)


A value (or principle) usually means an abstract rule, one that can be seen to apply in many experiences, or can be applied by choice in a lot of situations. It can also mean a moral choice one makes often and consistently, for example, some Buddhists avoid eating meat as a matter of principle.

Many groups of people agree on lists of principles. They may also try to agree on the order in which they are to apply, that is, which principles should be violated before which other ones. They might also try to list best practices which reflect the principles in the right order, and provide more practical (less abstract) .




#Article 248: Profanity (479 words)


Profanity means swear words. The adjective is 'profane'. Profanities can also be called curse (cuss) words, dirty words, bad words, foul language, obscenity, obscene language, or expletives. It can be called swearing, although this also has a normal meaning of making a solemn promise. A profanity usually refers to religion, sex, or bodily functions. These are things that people feel very strongly about. In some languages, such as French, there is more profanity about religion than most other topics. This is the original meaning, from a Latin word meaning before the temple.  

Religious profanity is called blasphemy. The verb is to blaspheme and the adjective is 'blasphemous'. Saying “God!” or “Jesus Christ!” as an expression of surprise or annoyance is considered by many to be blasphemy, mostly because one of the Ten Commandments says not to use God's name in vain (without substance or without relevance). Swearing oaths can also be considered wrong by some who follow Jesus' teaching against swearing oaths in the Gospels (such as Matthew 5:34).

A profanity can be a word or gesture or some other form of behavior.

Different words can be profane to different people, and what words are thought of as profanity in English can change over time.

Whether a word is a profanity will always depend on the way people think. Some people will be offended by something, while others will not be. Words which should not be used are taboo words. Using such words is thought by some people to be a sin. For example, some Christians and some Muslims believe that swearing is a sin.  

Some people call profanity crude, but some say that it is no cruder to say damn or crap than it is to use hate (a word that is about a very strong emotion, but not a swear word). People who use profanity do not always mean to make anybody feel bad, and tolerance for different forms of profanity can vary widely, from person to person. Most often, using profanity is a verbal outlet for strong feelings (usually unpleasant ones), that might otherwise cause a physical reaction. At other times, some people may use profanity as humor.

Coprolalia is a mental condition that makes people use profanity constantly. It is different from Tourette syndrome. Tourette syndrome is actually a group of symptoms that only includes coprolalia 15% of the time. The condition can be made worse by stress.

Several of these words come from Anglo-Saxon or old Norse names for body parts, and bodily functions. They came to be thought of as profanity mostly after the Normans brought French and Latin words for them to England.  

 (or Arse)

 
 (or Arsehole)

 

 

 (or )

 (or Pussy)

 

 (or ) 

These are mostly performed while facing another person and can be meant toward them, or about them. These gestures are considered as strong as profane words in most cases.




#Article 249: People's Republic of China (2918 words)


The People's Republic of China (PRC) () is a one-party state in East Asia governed by the Chinese Communist Party (CCP). It was founded on 1 October 1949. It currently has more than 1.4 billion people (as of 2017), which is more than any other country in the world. It covers an area of 9.6 million square kilometers.

The capital city is Beijing and Shanghai is the city with the most people living in it. Along with the cities of Tianjin and Chongqing, these four cities are municipalities directly controlled by the national government. Two other cities are given the status of special administrative region (SAR). They are Hong Kong, which was once a colony of the United Kingdom and given back to China in 1997 and Macau, which Portugal gave back in 1999. These two cities remain highly autonomous or have much of their own power. Aside from the municipalities and the SAR's, there are 23 provinces and five autonomous regions or regions with more law-making rights than the provinces and with many people of a minority group population. They are the Xinjiang Uyghur Autonomous Region, the Tibet Autonomous Region or Xizang Autonomous Region, the Guangxi Zhuang Autonomous Region, the Inner Mongolia Autonomous Region or Nei Mongol Autonomous Region and the Ningxia Hui Autonomous Region.

In the SAR's, the central government is responsible for defense and foreign affairs but not the daily operations for 50 years. PRC claims Taiwan as one of its many provinces. However, PRC does not have control of Taiwan which has an entirely different political system and officially known as the Republic of China (Taiwan).

 
China has one of the world's oldest civilizations and has the oldest continuous civilization. It has archaeological evidence over 5,000 years old. It also has one of the world's oldest writing systems (and the oldest in use today), and is viewed as the source of many major inventions.

Ancient China was one of the first civilizations and was active since the 2nd millennium BC as a feudal society.

Chinese civilization was also one of the few to invent writing, with the others being Mesopotamia, the Indus Valley civilization, the Maya civilization, the Minoan civilization of ancient Greece, and Ancient Egypt. It reached its golden age during the Tang Dynasty (c. A.D. 10th century).  Home of  Confucianism and Daoism, it had great influence on nearby countries including Japan, Korea, and Vietnam in the areas of political system, philosophy, religion, art, and even writing and literature. China is home to some of the oldest artwork in the world. Statues and pottery, as well as decorations made of jade, are some classic examples.

Before the Qin Dynasty united China, there were hundreds of small states that fought each other for hundreds of years in a war to control China. This is known as the Warring States Period. Although the continuing wars made people suffer, it was at this time when many of the great philosophies of the East were born, including Confucianism and Daoism. Confucianism and Daoism alone have been the foundation of many social values seen in modern eastern-Asian cultures today.

Its geography mostly looked like that of modern China, except with northern and western edges that varied. It was often attacked by northern nomadic people such as the Turkic tribes and the Mongols lead by Genghis Khan and Kublai Khan. During the history of ancient China, the northern nomadic people and the Chinese people had been fighting each other and taking turns to rule the land and the people of China. However, when the northern people beat the Chinese people and came to rule the kingdom, they also Incorporated the Chinese way of living and became like the Chinese. Many of the strongest dynasties of China were ruled by the northern people, including the Qin, Tang, Yuan (Mongolian), and Qing (Manchu). Each time, they also brought new elements into the Chinese culture.

While China achieved many things in the First millennium and early 2nd millennium, it became an isolationist country in the 15th century C.E. This was because Spain found a lot of silver in the newly explored continents of North and South America. Silver was the main currency (money) in China and Europe at the time, and China did not want to be bought by the foreigners.

By the time of the Renaissance, European powers started to take over other countries in Asia. During this time the opium epidemic was growing in China. Foreign traders (primarily British) had been illegally exporting opium mainly from India to China since the 18th century, but that trade grew dramatically from about 1820. The resulting widespread addiction in China was causing serious social and economic disruption there. This led to what is now known as the first opium war. The first Opium War between China and Great Britain lasted from 1839 to 1842. The conflict was the result of years of attempts by the British to exploit China as a market for British goods. Britain eventually relied on its superior military capabilities to force open the lucrative Chinese market, while imposing an illicit trade in opium on the Chinese people.

While China was never actually taken over by Europeans, many European countries, such as Britain and France built spheres of influence in China.  Since China had cut itself off from the world over the previous few centuries, by the Qing Dynasty, it had fallen behind other countries in technology, and was helpless to stop this from happening.  This had become clear when it lost the Opium Wars to Britain in the 19th century.

In 1912, the Qing dynasty was overthrown by the Sun Yat-sen and the Kuomintang, a nationalist party, and the Republic of China established. Over time, Marxist ideas grew popular and the Communist party was formed.

The Chinese Civil War later started between the Kuomintang (Nationalists) of the Republic of China (ROC) and the Communists of the People's Republic of China (PRC). The Communists wanted to make China like the Soviet Union, whereas the other side wanted to keep China in its current state at the time. The Communists were led by Mao Zedong, Zhou Enlai, Liu Shaoqi and others. Later Liu lost influence with Mao and his death to this day remains unresolved. The Communists eventually won the war. The Nationalists (led by Chiang Kai-shek) fled to the island of Taiwan and set up their new capital city in Taipei. After the Chinese Civil War, the Communist leader Mao Zedong declared a new country, the People's Republic of China (PRC), in Beijing on October 1, 1949.

In 1927, the Chinese Civil War began as the Kuomintang, led by Chiang Kai-shek, and the Communists fought one another.

Amidst the turmoil brewing between the Nationalist and Communist parties who were vying for control of China at the time, Japan had launched an invasion of Manchuria in 1934 and began to creep steadily inland.  China, the Nationalist party in particular, owed Japan immense amounts of money, which they could not pay whilst infused in their own civil war. The Treaty of Versailles promised the Japanese government land in China in return for forgiveness of their debt. This ended up not being a popular sentiment and was rallied against all over the country, and most famously during the May 4th Movement in Beijing in 1919. When the Chinese did not readily give up their rights to their land, Japan tried to take it by force. This was the beginning of World War II in the Pacific Theater.

By 1949, the Red Army of the Chinese Communist Party had gained control over mainland China and Mao Zedong announced the creation of the People's Republic of China. Chiang Kai-shek and the other nationalists fled to Taiwan.

As the Chairman of the Chinese Communist Party, Mao began many social and economic reform projects with mixed results. The Great Leap Forward, from 1958 to 1961, tried to industrialize China and increase its food production, but resulted in one of the largest famines in history. It is estimated that 45 million people died as a result of this reform project. In 1966, Mao began the Cultural Revolution to remove capitalist influences from society and government. Major government officials and ordinary citizens were accused of being revisionists - people who disagreed with some parts of Marxism - or counter-revolutionaries and were persecuted. Many universities and schools were closed, and historical and religious sites were destroyed. Although the program officially ended in 1969, it continued until Mao's death in 1976.

During this time period, the People's Republic of China did not get along with the capitalist countries of the Western world. Beginning in the 1960s, relationships between the People's Republic of China and the Soviet Union also became increasingly unfriendly in the Sino-Soviet Split. In 1972, to counter the power of the Soviet Union, Chairman Mao and Chinese Premier Zhou Enlai met with US President Richard Nixon in Beijing. This began to improve relationships between China and the Western world.

After Mao's death, there was a power struggle between the Gang of Four and Chinese Premier Hua Guofeng, the man Mao had chosen to be the next leader of China. Eventually, Deng Xiaoping, one of the veterans of the revolution, took power. He began a Reform and Opening Up () campaign. These reforms tried to make the People's Republic of China a modern, industrial - but still socialist - nation by moving towards a market system. Deng's policies would be known as socialism with Chinese characteristics.

Although Deng's policy helped loosen restrictions on citizens, the People's Republic of China continues to have problems with the amount of control the government has over citizens' private lives. In 1979, the one-child policy, which limits most couples to one child, was created because of the overpopulation problem in the People's Republic of China. This policy is highly controversial and many Westerners have criticized it. News and Internet sites are also censored by the government.

In 1989, the Chinese Communist Party used soldiers and tanks to stop a protest in Beijing's Tiananmen Square organized by students seeking political reform. This action received worldwide criticism and led to economic sanctions being placed on the Chinese government.

In August 2008, China hosted the Summer Olympics for the first time.

The People's Republic of China is the third- or fourth-largest country in the world after Russia, Canada, and (in some sources) the United States and the second-largest by land area. China has every kind of climate in the northern hemisphere except the polar climate. It is also the largest country without any land north of the Arctic Circle. China borders 14 nations, which is more than any other country in the world. It borders Vietnam, Laos, and Burma in Southeast Asia; India, Bhutan, Nepal and Pakistan in South Asia; Afghanistan, Tajikistan, Kyrgyzstan and Kazakhstan in Central Asia; a small section of Russian Altai and Mongolia in Inner Asia; and the Russian Far East and North Korea in Northeast Asia.

China has two major rivers, the Yellow River and the Yangtze River. There is also the Taklamakan and the Gobi Desert.

The world's highest point, Mt. Everest (8848m), is on the border between China and Nepal. The country's lowest point, and the world's fourth-lowest, is the dried lake bed of Ayding Lake (−154m).

China is one of 17 megadiverse countries. It is in two of the world's major ecozones: the Palearctic and the Indomalaya. In the Palearctic zone, mammals such as the horse, camel, tapir, and jerboa can be found. Among the species in the Indomalaya region are the Leopard Cat, bamboo rat, treeshrew, and various monkey and ape species. Some overlap is between the two regions; deer, antelope, bears, wolves, pigs, and many rodent species can all be found in China's environments. The famous giant panda is found only in a limited area along the Yangtze River. China has a continuing problem with trade in endangered species. There are now laws to stop such activities.

China also has a variety of forest types. Cold coniferous forests cover most of the north of the country. The forest have animal species such as moose and the Asian black bear, along with over 120 bird species. Moist conifer forests can have thickets of bamboo. It is replaced by rhododendrons in higher montane stands of juniper and yew. Subtropical forests, which are mostly in central and southern China. These support as many as 146,000 species of flora. Tropical and seasonal rainforests, though confined to Yunnan and Hainan Island, have a quarter of all the plant and animal species found in China.

China is a one-party state wherein the General Secretary of the Chinese Communist Party (CCP) holds ultimate power and authority over state and government and serves as the paramount leader. The current General Secretary is Xi Jinping, who took office on 15 November 2012 and was re-elected on 25 October 2017.

The President is the titular head of state, elected by the National People's Congress. The current president is Xi Jinping, who is also the General Secretary of the Communist Party of China and the Chairman of the Central Military Commission, making him China's Paramount leader. The Premier is the head of government, heading the State Council alongside with four vice premiers and the heads of ministries and commissions. The current premier is Li Keqiang, who is also a senior member of the CCP Politburo Standing Committee, China's de facto top decision-making body.

The PRC Armed Forces, also known as the People's Liberation Army (PLA), is one of the most powerful armies in the world. Nowadays PRC is among the atomic powers in the world. It also has the largest standing army in the world of over 2 million soldiers on active duty.

There are 56 recognized ethnic minority groups in China. Han is the largest ethnic group in China. Mandarin Chinese is the main spoken language.

China is the origin of Eastern martial arts, called Kung Fu or Wushu. China is also the home of the well-respected Spa Monastery and Wudang Mountains. Martial art started more for the purpose of survival, defense, and warfare than art. Over time some art forms have branched off, while others have retained their distinct Chinese characteristics.

China has had renowned artists including Wong Fei Hung and many others. Art has also co-existed with a variety of paints including the more standard 18 colors. Legendary and controversial moves like Big Mak are also praised and talked about within the culture.

China has many traditional festivals, such as the Chinese New Year, Dragon Boat Festival, Mid-Autumn Festival and so on. The most significant is Chinese New Year. Another important holiday is the National Day celebration around October.  Weekends are moved around to make sure everyone has a week-long holiday for it, just like during the lunar new year.

Chinese New Year lasts fifteen days, including one week as a national holiday. It starts with the first day of the Chinese lunar year and ends with the full moon fifteen days later. It is always in the middle of winter, but is called the Spring Festival in Chinese because Chinese seasons are a little different from English ones. On the first day of the Chinese New Year, people call on friends and relatives. Because most people watch the special performances on CCTV all the night on New Year's Eve and don't go to bed until 12:00 AM, they usually get up later in the next day. The fifth day of the Chinese New Year is the day to welcome the god of Wealth (Chinese:财神爷), many people make and eat dumplings (Chinese:饺子.  Pinyin: Jaozi). They believe that dumplings can hold the god of Wealth and bring luck.  The last day of the Chinese New Year is the Lantern Festival. On this day, the moon becomes the full moon. People go out and watch the lantern festivals everywhere. After that, they eat sweet dumpling (Chinese:汤圆,元宵), a kind of dumpling which is round and looks like the full moon.

Dragon Boat Festival is celebrated to commemorate the death of Qu Yuan, a patriotic poet of the State of Chu during the Warring States period. He persuaded his emperor not to accept Qin's diplomats's offers several times but his emperor did not listen to him. He was very sad and ended up jumping into the river to end his life. The people loved him so much that they did not want the fish to eat his corpse. They made and threw rice dumplings into the river. They hope the fish eat these dumplings instead of the poet's corpse. They also rowed dragon boats in the river to get rid of the fish.  Eating rice dumplings and holding dragon boat races, became what the Chinese do in this festival nowadays.

Held on the fifteenth day of the eighth lunar month, the Mid-Autumn Festival is a festival for families. Now when the festival sets in, people sit together to eat moon cakes, appreciate the moon and the moon itself, celebrate the bumper harvest, and enjoy the family love and happiness. To the Chinese people, the full moon symbolizes family reunion, as do the moon cakes. Hence why the Mid-Autumn Festival is also called the Family Reunion Festival.

Trains are commonly used for moving from one place to another, mainly for long distances. Bullet trains are faster and more common in the cities. China has more high-speed trains than any other country in the world. Buses and air transport are also very common.




#Article 250: Psychoneuroimmunology (483 words)


Psychoneuroimmunology (PNI) is the study of the interaction between psychological processes and the nervous and immune systems of the human body. PNI takes an interdisciplinary approach.

The main interests of PNI are the interactions between the nervous and immune systems and the relationships between mental processes and health. 

Interest in the relationship between psychiatric syndromes or symptoms and immune function has been a consistent theme since the beginning of modern medicine.

Claude Bernard, a French physiologist, founded the concept milieu interieur in the mid 1800s. In 1865, Bernard described the perturbation of this internal state “… there are protective functions of organic elements holding living materials in reserve and maintaining without interruption humidity, heat and other conditions indispensable to vital activity. Sickness and death are only a dislocation or perturbation of that mechanism. (Bernard, 1865) 

Walter Cannon, a professor of physiology at Harvard University coined the term homeostasis in his book The Wisdom of the Body in 1932. In his work with animals Cannon observed that any change of emotional state in the beast, such as anxiety, distress, or rage was accompanied by total cessation of movements of the stomach (Bodily Changes in Pain, Hunger, Fear and Rage, 1915). These studies into the relationship between the effects of emotions and perceptions on the autonomic nervous system, the  responses that led to the freeze, fight or flight response.  

In 1975 Robert Ader and Nicholas Cohen advanced PNI with a demonstration of classic conditioning of the immune function, and coined the term psychoneuroimmunology. Ader was investigating how long conditioned responses  might last in laboratory rats. The highly reproducible results showed that conditioned rats exposed to the conditioned stimulus were immuno suppressed. In other words, a signal via the nervous system (taste) was affecting immune function. This was one of the first scientific experiments that demonstrated that the nervous system can affect the immune system.

In 1981 David Felten, then working at the Indiana University of Medicine, discovered a network of nerves leading to blood vessels as well as cells of the immune system. The researchers also found nerves in the thymus and spleen terminating near clusters of lymphocytes, macrophages and mast cells, all of which help control immune function. This discovery provided one of the first indications of how neuro-immune interaction occurs.

Ader, Cohen and Felten went on to edit the groundbreaking book Psychoneuroimmunology in 1981, which laid out the underlying premise that the brain and immune system represent a single, integrated system of defense.

Stressors can produce profound health consequences. In one epidemiological study, for example, all-cause mortality increased in the month following a severe stressor – the death of a spouse. Theorists propose that stressful events trigger cognitive and affective responses which, in turn, induce sympathetic nervous system and endocrine changes. These ultimately impair immune function. Potential health consequences are broad, but include rates of infection, HIV progression, and cancer incidence and progression.




#Article 251: Political party (470 words)


A political party is an organized group of people or bodies who seek to capture political power through an election in order to run the affairs of a country. It often puts forward candidates for public office. In a democracy, leaders must run for office in an election. In a dictatorship, there is generally only one party allowed, that can approve a new leader without non-members having a choice.

A political party is similar to a faction, and can be the same thing. In some systems, members of one party in the legislature are all expected to vote the same way. The laws written by the party or faction with the majority of votes become adopted by the country, so this means whatever party is elected to over half the seats, gets to run the government. The next largest party is often called the opposition. Sometimes when there are more than two parties with seats, no one party has over half of the seats. Then two or more parties might join together to form what is called a coalition.

Some parties are formed around a single issue or interest group. Others form policies to address all matters of government, known as a platform.

Many political parties have a set of ideas and beliefs (called its ideology). People often describe these ideologies using words such as conservative and liberal. 

Common ideologies include environmentalism, socialism (ranging from social democracy to Marxism and Communism), conservatism, democracy, liberalism, and nationalism.

Political parties can be against the law in some places. When some parties get a lot of power, they can make all other political parties illegal. For example, the Nazi Party did this in Germany, and the Communist Party did it in several countries. Some countries make extreme-right parties illegal (such as Vlaams Blok in Belgium). At other times, countries have outlawed far-left parties. For example, West Germany banned the Communist Party in 1956.

A handful of countries like China, North Korea and Cuba still have one-party dictatorships. In a few other dictatorships, such as Saudi Arabia, all political parties are banned and there is no parliament at all.

In all big democratic countries, parties are very important. But there are a few very small countries, such as the island of Jersey, where most politicians do not belong to any party and where parties do not matter much.

In some democracies, there are only two big political parties. For example, in the United States, there is the Democratic Party and the Republican Party. Some other parties exist but are very small and do not hold seats in Congress.

In other countries there are larger numbers of parties. In the German federal Parliament (or Bundestag), six parties have seats. In the United Kingdom, there are two big parties, one medium-sized party, and many small ones.




#Article 252: Pet (170 words)


A pet is a domesticated animal that lives with people, but is not forced to work and is not eaten, in most instances. In most cases, a pet is kept to entertain people or for companionship. Some pets such as dogs and cats are placed in an animal shelter if there is no one willing to take care of it. If no one adopts it or the pet is too old/sick, the pet may be euthanized.

Dogs, cats, fish, rodents, lagomorphs, ferrets, birds, certain reptiles and amphibians, and a wide variety of arthropods such as tarantulas and hermit crabs are the most common pets in North America.  Horses, elephants, oxen, and donkeys are usually made to work, so they are not usually called pets.  Some dogs also do work for people, and it was once common for some birds (like falcons and carrier pigeons) to work for humans.

Rodents are also very popular pets. The most common are guinea pigs, rabbits, hamsters (especially Syrian and dwarf hamsters), mice and rats.




#Article 253: Platonic realism (561 words)


Platonic realism is the theory of reality developed by Plato, and explained in his theory of Forms.  Platonic realism states that the visible world of particular things is a shifting exhibition, like shadows cast on a wall by the activities of their corresponding universal Ideas or Forms.  Whereas the visible world of particulars is unreal, the Forms occupy the unobservable yet true reality and are real.

Platonism is a similar, yet sometimes modified, view of reality. 

Among the natural philosophers in ancient Greece, the problem of universals was the mystery of where particular things derive their traits that we perceive as universals—for instance red or apple or good or woman or truth.

Plato explained that the particular things of the visible world are imperfect, transient copies of the universal Ideas that are the perfect, lasting Forms.  Existing exist outside space and time, the Forms are the universals and act as templates from which particulars manifest.

In his Metaphysics, Aristotle, a student of Plato, explained that Socrates and his own student Plato held it significant that the world is in flux, much as Heraclitus had commented, You cannot step into the same river twice, a theme of the Eleatics, a group of pre-socratic philosophers.

Plato considered that only the mind could access the timeless reality of truths, the realm of the Forms casting the visible world.  Plato's metaphorical allegory of the cave—whereby humans only know reality as shadows of the real things they see interacting on a wall—suggests the practical consequences of Platonic realism as to natural philosophy in its endeavor to explain the natural world and as to values in human society.  (Value theory comprises ethics, aesthetics, and political philosophy.)

Plato had led the focused application of geometry, developed by Euclid, to explain the natural world.  Yet by his view of nature, Plato regarded astronomy as similar to seeking a theoretical proof in geometry—abstract and not the real world—whereupon the mind's insights derived from a quest to hold other truths through the mind's probing of ethics and aesthetics would yield discovery of truths within the realm of Forms, outside space and time.

Aristotle, a student of Plato, answered the problem of universals differently.  Aristotle explained that universals are concepts corresponding to traits borne and shared by the particular things themselves.  Aristotle did not regard all reality as visible, as he recognized existence of souls, yet regarded souls as unobserved parts of the visible world, real in itself.   largely shaped the course of Western thought.

Aristotle developed a more or less full description and explanation of the natural world and developed logic—syllogistic logic—to derive conclusions of the relations among things.  Aristotle's grounding in the visible world was a metaphysical approach that suggested what evolved by some 2 000 years later into empirical science.

 
Some mathematicians and physicists are Platonists, for instance Max Tegmark and Roger Penrose.  Yet today's Platonists usually view entities within the visible world as real, and simply regard universal abstractions like numbers, sets, propositions, and geometry as corresponding to real and timeless entities that also exist, though pure Platonists regard only the Forms or their realm as real.

By way of string theory and the holographic principle, some physicists conjecture that Plato's allegory of the cave approximates the natural world's structure.  Tegmark, who regards only the mathematical structure of the universe as real, has been called a radical Platonist.




#Article 254: Paradox (345 words)


A paradox is a sentence in logic that cannot be true but also cannot be false.  Many famous problems of this kind exist.

A famous paradox is called the liar's paradox. It is the simple sentence This sentence is a lie, or equivalently, This statement is false.

If the sentence is true, then it is a lie as it says.  But if it is a lie, it cannot be true. A lie cannot also be a truth. So the sentence being true makes it a lie.

On the other hand, if the sentence is a lie, then it is not as it says: it is true.  But that is just what the sentence says, which makes the content of the sentence true.  So the sentence being a lie makes it true.

This paradox is not just true in English, but in any language powerful enough for a sentence to make a claim about itself. This is true of mathematics as well.  Paradox can never be removed from any symbol system that makes claims about itself.

Another example is the statement that there is no cabal.  Only a cabal can know if there is no cabal, so this is either a guess, or, it is a cabal trying to pretend it does not exist.

Not all paradoxes are true logical paradoxes, since they can also be common-sense-defying statements that appear true. Some famous examples of this kind of paradox include:

A paradox can also arise in ethics. Assuming power over others may sometimes be required to protect them while diminishing their right to autonomy. This is defined as an , which means a paradox arising in ethics. Similarly, an ethical dilemma may be resolved by re-framing of the problem to reveal the false contradiction. 

Because a paradox forces one to think out of the box about possibilities other than true or false in logic, right or wrong in morality, it is often brought up for educational purposes. People who do not see a paradox where others do are likely to be too  that they are right.




#Article 255: Potato (313 words)


A potato is a root vegetable, the Solanum tuberosum. It is a small plant with large leaves. The part of the potato that people eat is a tuber that grows under the ground.

A potato contains a lot of starch and other carbohydrates. Potato usually has a light-brown or yellowish skin and is white or yellow inside. If the potato gets light on it, the tuber turns green and will be poisonous.

The potato is originally from the high and cool areas of the Andes mountains.  It was grown as a food crop thousands of years ago.  When Spanish conquistadores came to South America in the 1500s they took potatoes back to Europe. 

It took nearly 200 years for the potato to become a widely grown crop.  In the 1780s the farmers in Ireland began growing potatoes because they grew well in the poor soils.  They also have most of the vitamins that people need to live.  When a potato plague destroyed the crop in 1845 the Irish Potato Famine killed many people.

The potato plant is now grown in many different parts of the world. Captain William Bligh planted potatoes on Bruny Island, Tasmania in 1792.  In Australia they are now the largest vegetable crop.

The English word potato comes from the Spanish word patata.

Scientists in Germany have used genetic engineering to make a potato called the Amflora, which could be grown to make starch for making other things in factories.

Potatoes are almost always eaten cooked. People cook potatoes by boiling, baking, roasting, or frying them. French fries or chips are potatoes cut into long pieces and fried until they are soft. Potato chips, often called crisps, are potatoes cut into very thin round pieces and fried until they are hard. 

William Shakespeare wrote that the potato was an aphrodisiac, but there is no evidence to show this is true.




#Article 256: Plant (1068 words)


Plants are one of six big groups (kingdoms) of living things. They are autotrophic eukaryotes, which means they have complex cells, and make their own food. Usually they cannot move (not counting growth).

Plants include familiar types such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants, known as botany, has identified about 350,000 extant (living) species of plants. Fungi and non-green algae are not classified as plants.

Most plants grow in the ground, with stems in the air and roots below the surface. Some float on water. The root part absorbs water and some nutrients the plant needs to live and grow. These climb the stem and reach the leaves. The evaporation of water from pores in the leaves pulls water through the plant. This is called transpiration.

A plant needs sunlight, carbon dioxide, minerals and water to make food by photosynthesis. A green substance in plants called chlorophyll traps the energy from the Sun needed to make food. Chlorophyll is mostly found in leaves, inside plastids, which are inside the leaf cells. The leaf can be thought of as a food factory. Leaves of plants vary in shape and size, but they are always the plant organ best suited to capture solar energy. Once the food is made in the leaf, it is transported to the other parts of the plant such as stems and roots.

The word plant can also mean the action of putting something in the ground. For example, farmers plant seeds in the field.

Photosynthesis is a process that is taken place by the leaves on the plant. The leaves are the only parts of a plant that can do this process (as they adapted). This is also known as how the plant gets its food.You can make the process quicker by adding more CO2, light and chlorophyll.

Green algae:

Land plants (embryophyte)

At least some plant cells contain photosynthetic organelles (plastids) which enable them to make food for themselves. With sunlight, water, and carbon dioxide, the plastids make sugars, the basic molecules needed by the plant. Free oxygen (O2) is produced as a by-product of photosynthesis.

Later, in the cell cytoplasm, the sugars may be turned into amino acids for proteins, nucleotides for DNA and RNA, and carbohydrates such as starch. This process needs certain minerals: nitrogen, potassium, phosphorus, iron and magnesium.

Plant nutrition is the study of the chemical elements that are necessary for plant growth.

Micronutrients (trace elements) include:

The roots of plants perform two main functions. First, they anchor the plant to the ground. Second, they absorb water and various nutrients dissolved in water from the soil. Plants use the water to make food. The water also provides the plant with support. Plants that lack water become very limp and their stems cannot support their leaves. Plants which specialise in desert areas are called xerophytes or phreatophytes, depending on the type of root growth.

Water is transported from the roots to the rest of the plant through special vessels in the plant. When the water reaches the leaves, some of it evaporates into the air. Many plants need the help of fungi to make their roots work properly. This plant/fungi symbiosis is called mycorrhiza. Rhizobia bacteria in root nodules help some plants get nitrogen.

Flowers are the reproductive organ only of flowering plants (Angiosperms). The petals of a flower are often brightly colored and scented to attract insects and other pollinators. The stamen is the male part of the plant. It is composed of the filament (a stalk) that holds the anther, which produces the pollen. Pollen is needed for plants to produce seeds. The carpel is the female part of the flower. The top part of the carpel contains the stigma. The style is the neck of the carpel. The ovary is the swollen area at the bottom of the carpel. The ovary produces the seeds. The sepal is a leaf that protects a flower as a bud.

The process by which pollen gets transferred from one flower to another flower is called pollination. This transfer can happen in different ways. Insects such as bees are attracted to bright, scented flowers. When bees go into the flower to gather nectar, the spiky pollen sticks to their back legs. The sticky stigma on another flower catches the pollen when the bee lands or flies nearby it.

Some flowers use the wind to carry pollen. Their dangling stamens produce lots of pollen that is light enough to be carried by the wind. Their flowers are usually small and not highly coloured. The stigmas of these flowers are feathery and hang outside the flower to catch the pollen as it falls.

A plant produces many spores or seeds. Lower plants such as moss and ferns produce spores. The seed plants are the Gymnosperms and Angiosperms. If all the seeds fell to the ground besides the plant, the area might become overcrowded. There might not be enough water and minerals for all the seeds. Seeds usually have some way to get to new places. Some seeds can be dispersed by the wind or by water. Seeds inside juicy fruits are dispersed after being eaten. Sometimes, seeds stick to animals and are dispersed that way.

 plant tree, showing the major clades and traditional groups. Monophyletic groups are in black and paraphyletics in blue. Diagram according to symbiogenetic origin of plant cells,  and phylogeny of algae, bryophytes, vascular plants, and flowering plants.

The question of the earliest plant fossils depends on what is meant by the word plant.

By the Silurian, fossils of whole plants are preserved, including the lycophyte Baragwanathia. From the Devonian, detailed fossils of rhyniophytes have been found. Early fossils of these ancient plants show the individual cells within the plant tissue. The Devonian period also saw the evolution of the first tree in the fossil record, Wattezia. This fern-like tree had a trunk with  fronds, and produced spores.

The coal measures are a major source of Palaeozoic plant fossils, with many groups of plants in existence at this time. The spoil heaps of coal mines are the best places to collect; coal itself is the remains of fossilised plants, though structural detail of the plant fossils is rarely visible in coal. In the Fossil Forest at Victoria Park in Glasgow the stumps of Lepidodendron trees are found in their original growth positions.




#Article 257: Prediction (139 words)


A prediction is a statement that someone makes about what they think is going to happen. It is often very helpful to know what is going to happen to help prepare for these future events. Predictions are based on the idea that two beginning positions that are like each other will have similar results. By watching something happen, it is possible to predict what will happen if something similar happens. Predictions are given by science or fortune tellers or horoscopes. 

The most common example of a prediction is the weather forecast. Studying how weather happens lets people predict what the weather will be by looking at what is currently happening. This is helpful because by knowing that it is going to rain, a person can wear the right clothes for it.

Nostradamus has made many predictions about the future.




#Article 258: Probability (393 words)


Probability is a part of applied mathematics. It has to do with chance, the study of things that might happen or might not happen. 

For example, using probability, one can show that by throwing a coin up in the air and letting it land, half of the time it will land with one side facing up, and half of the time with the other side facing up. Many coins have a picture of the face of a famous person on one side, and something else on the other side. Often people call the side with the face heads, and the other side tails.

The probability (p) of an event E, written , is always between zero (impossible) and one (certain).

If we roll a die (plural: dice), then the chance that it will land on 1 is 1/6 (because there are 6 numbers on a die). Similarly, the chance it will land on 2 is also 1/6. The chance it will land on any number between 1 and 6 is 1, because every time we roll the die, it will always land on a number between 1 and 6.

Probability can be figured out using mathematics. For example, if one rolls six dice, the chance of them getting a number more than ten is not obvious, but can be figured out using math and science.

One of the most interesting things about chance is that to figure out the probability that two things will both happen, one usually multiply their two probabilities together. For example, suppose that one wants to know the probability of rolling two dice and getting a certain combination (it could be two 6s or a 3 then a 5, just any two). The possibility of getting a 3 is one in six (⅙), and the possibility of getting a 5 is also one in six, so the chances of getting a 3 then a 5 is ⅙×⅙=⅟36. If that number is expressed as somewhere between 0 and 1, it equals 0.027...7, which is fairly low. The possibility of getting a 3, then a 5, and then a 2 would be ⅙×⅙×⅙=⅟216 or 0.00463, which is a much lower probability.

People like Jacob Bernoulli, Pierre-Simon Laplace, or Christiaan Huygens used the word probability, as described above. Other people thought about frequencies; the notion of probability is usually called frequency probability.




#Article 259: Protein (419 words)


Proteins are long-chain molecules built from small units known as amino acids. They are joined together with peptide bonds.

They are biochemical compounds consisting of one or more polypeptides folded into a round or fibrous shape.

A polypeptide is a single linear polymer chain of amino acids. The sequence of amino acids in a polypeptide comes from the DNA sequence of a gene. The genetic code specifies 20 standard amino acids. Shortly after synthesis, some amino acids are chemically modified. This alters the folding, stability, activity, and function of the protein. Sometimes proteins have non-peptide groups attached, as cofactors.

Proteins are essential to all cells. Like other biological macromolecules (polysaccharides and nucleic acids), proteins take part in virtually every process in cells: 

Proteins have different functions depending on their shape. They can be found in meat or muscle. They are used for growth and repair, as well as for strengthening the bones. They help to make tissue and cells. They are in animals, plants, fungi, bacteria, and also in the human body.

Muscles contain a lot of protein. When protein is digested, it is broken down into amino acids. These amino acids can then be used to build new protein. Proteins form an important part in foods like milk, eggs, meat, fish, beans, spinach, and nuts. There are four factors that determine what a protein will do. The first is the order of the amino acids. There are 20 different types of amino acids. The second is the little twists in the chain. The third is how the entire structure is folded up. The fourth is whether it is made up of different sub-units. Haemoglobin molecules, for example, are made of four sub-units.

Most proteins are enzymes, and mutations may slow them or stop them working. 50% of human cancers are caused by mutations in the tumour suppressor p53. p53 is a protein which regulates cell division.

Proteins are necessary in an animal's diets, since animals cannot make all the amino acids they need (they can make most of them). They must get certain amino acids from food. These are called the essential amino acids. Through digestion, animals break down ingested protein into free amino acids. The amino acids are then used in metabolism to make the enzymes and structures the body needs.

There are nine essential amino acids for humans, which are obtained from food. The nine essential amino acids are:  histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.  but many other scientists have studied proteins.




#Article 260: Periodic table (375 words)


The table of chemical elements is a list of known chemical elements. In the table, the elements are placed in the order of their atomic numbers starting with the lowest number of one, hydrogen. The atomic number of an element is the same as the number of  protons in that particular nucleus of an atom. In the periodic table the elements are arranged into periods and groups. A row of elements across the table is called a period. Each period has a number; from 1 to 8. Period 1 has only 2 elements in it: hydrogen and helium. Period 2 and Period 3 both have 8 elements. Other periods are longer. Elements in a period have consecutive atomic numbers.

A column of elements down the table is called a group. There are 18 groups in the standard periodic table.  Each group has a number: from 1 to 18. Elements in a group have electrons arranged in similar ways, according to the number of valency electrons, which gives them similar chemical properties (they behave in similar ways).  For example, group 18 is known as the noble gases because they are all gases and they do not combine with other atoms.

There are two systems of group numbers; one using Arabic numerals (1,2,3) and the other using Roman numerals (I, II, III). The Roman numeral names were used in most of the 20th century.  In 1990 the International Union of Pure and Applied Chemistry (IUPAC) decided to use the new system with Arabic numerals, to replace the two old group systems that used Roman numerals.

The periodic table has been used by chemists to observe patterns and relationships between elements. There are 3 main groups in the Periodic Table; metals, metalloids, and nonmetals. For example, elements to the bottom and far left of the table are the most metallic, and elements on the top right are the least metallic. (e.g. cesium is much more metallic than helium). There are also many other patterns and relationships.

The periodic table was invented by the Russian chemist Dmitry Ivanovich Mendeleyev (18341907). In his honor, element 101 was named after him, mendelevium.

The version of the periodic table shown above is the one most used.  Other widespread versions are shown below:




#Article 261: Physiology (131 words)


Physiology is the study of how living things work. Physiologists can study how organs of an organism work together to make things happen. In human beings, for example, the digestion of food hormones and other chemicals are made by the stomach, liver, and pancreas. Muscle contraction happens because of chemical messages made by nerves of that muscle. By learning how the body functions normally, physiologists and physicians can better understand what happens when organs do not function normally. For example, an understanding of how the thyroid gland functions has helped in treating goitre. Studies of the circulatory system and the nervous system have helped physicians understand and treat such illnesses like heart disease, stroke, and high blood pressure.

The field is usually divided into human physiology, animal physiology, and plant physiology.




#Article 262: Planet (529 words)


A planet is a large object such as Jupiter or Earth that orbits a star. Planets are smaller than stars, and they do not produce light. Jupiter is the biggest planet in the Solar System. 

Planets are shaped like a slightly squashed ball (called a spheroid). Objects that orbit planets are called satellites. A star and everything which orbits it are called a star system. 

There are eight planets in the Solar System. Pluto used to be called a planet, but in August 2006, the International Astronomical Union decided it was a dwarf planet instead. There are four more known dwarf planets in the Solar System, Ceres, Makemake, Eris and Haumea.

The name planet is from the Greek word πλανήτης (planetes), meaning wanderers, or things that move. Until the 1990s, people only knew of those in the Solar System.  As of June 2017, we know of 3,610 other planets.  These newly found planets are orbiting other stars: they are extrasolar planets. Sometimes people call them exoplanets.

The planets are composed of material quite different from the Sun. The Sun is almost entirely composed of hydrogen, and some helium. Its energy comes from the conversion of hydrogen to helium. In contrast, the terrestrial planets are composed almost entirely of larger atoms and molecules which cannot have come from the Sun. It follows, therefore, that the material which forms those planets must have come from another source or sources. Those sources were the atoms formed in supernovae explosions by much larger and much shorter-lived stars in the Sun's neighbourhood as it moved in the galaxy. This material was captured by the Sun's gravity and pulled along to become the basic material out of which the planets condensed. The same considerations apply to other planetary systems in the galaxy.

The gas giants are composed of hydrogen gas from the same source as the Sun, plus (at their centres) higher metallic elements like the terrestrial planets. This is known from the drive-by data gathered by satellites, and by drive-into probes like the Galileo (spacecraft). There is a huge amount of data collected about each planet. The data is stored on computer files, and there are summary volumes in print.

The planets in the Solar System have names of Greek or Roman gods, apart from Earth, because people did not think Earth was a planet in old times. However, Earth is occasionally referred by the name of a Roman god: Terra. Other languages, for example Chinese, use different names. Moons also have names of gods and people from classical mythology. The names of the moons of Uranus are from the plays written by Shakespeare. 

Here is a list of planets in the Solar System. They are ordered by how close they are to the Sun, nearest first. 

Astronomers speak about major (or true) planets, and minor planets, which are smaller objects that go around the Sun. Some examples of minor planets are asteroids, comets, and trans-Neptunian objects.

Planets in the Solar System are of three sorts:

Many objects in the Solar System that are not planets are also icy. Examples are the icy moons of the outer planets of the Solar System (like Triton).




#Article 263: Police (806 words)


Police are a group of people whose job is to  laws, help with emergencies, solve crimes and protect property. A person who carries out this duty is known as a police officer. They work out of a police station. Police are trained in first aid and , because police officers are often one of the first people to get to a place where people are sick or injured, such as a car accident, or a fire.

A police agency may be called a police force, police department, police service, constabulary, civil guard or protective service. A gendarmerie is a police force that is part of the military, although its members rarely do actual military work.

Most police forces in the United States name themselves as [Place] Police Department, such as New York City Police Department. State police forces are usually known as either [State] Highway Patrol or [State] State Police. In the United Kingdom, most are [Place] Police or [Place] Constabulary. In Canada and other English-speaking countries, [Place] Police Service is common. Ireland's police are called the Garda Síochána.

A law enforcement agency is any agency that enforces the law. In the United States, there are some law enforcement agencies that are not called police forces but carry out similar work, such as the Federal Bureau of Investigations. One common type is a sheriff's office (also sheriff's department), an agency that is led by a sheriff.

Those who carry out policing duties are known as police officers. They may also be known as policemen (men only), policewomen (women only), peace officers, constables, rangers or civil guards. In a sheriff's office, they are known as sheriff's deputies or deputies for short. In Ireland they are known by the Irish language word gardaí (garda if singular) or as guards.

The police have different powers to help them do their job. These powers are different in different countries. Most police officers have the power to arrest people, search people, and search houses/properties. They sometimes carry  such as guns, batons, tasers, or pepper spray. The area where police officers can use these powers is called their jurisdiction. If officers are outside of their jurisdiction, another police force with jurisdiction can then use their powers.

The police deal with:

Most police departments have officers in two main groups: a patrol group with officers who wear uniforms, and a detective group with officers who wear normal clothing. 

Not all countries use the same words to describe these groups. In the United Kingdom, for example, patrol officers form the uniform branch, while detectives work within the CID (Criminal Investigation Department). Also in the United Kingdom, not all police officers are armed, these police officers form an Armed Response Unit which comes under other names in different constabularies, in the Metropolitan Police Service, it falls under SFC (Specialist Firearms Command) which all MET Armed Police fall under  

Police uniforms, equipment and methods vary depending on the country. In some places, groups of police train for special jobs such as dealing with riots or dealing with highly dangerous criminals. 

Different countries have different ways of organizing their police. Some countries like South Africa, Ireland and New Zealand have just one police force. Other countries have more than one. France has two police forces, one for cities and another for rural areas. Chile also has two, one for patrol and another for investigations.

Some countries have two or more levels of police forces. For example, most policing in Australia is carried out by the six state police forces, but there is also the Australian Federal Police who police the whole country. Germany has a similar system. The United Kingdom and Switzerland have many local police forces and several national agencies, but no actual national police force. In Canada, local governments can choose to either run their own police force or give the job to a bigger one. So most Canadian cities have their own police, while most rural areas are policed by the Royal Canadian Mounted Police, which is also the national police.

The United States has over 17,000 law enforcement agencies. Many areas have four levels of law enforcement agencies. For example, Los Angeles has the Los Angeles Police Department but there are many other agencies that can work in the city. This includes the county-level Los Angeles Sheriff's Department, the state-level California Highway Patrol and over 100 federal (or national) law enforcement agencies.

Worldwide, police are a small percentage of the number of people they serve. On average there are 303.3 police officers per 100,000 people. 

In most countries, police officers carry guns during their normal duties. In the United Kingdom, New Zealand, Ireland and a few other countries, most police officers do not carry guns.

Officers communicate using radio devices. The radios can be on both the uniform and in the patrol vehicle. 




#Article 264: Pi (878 words)


The number  () is a mathematical constant that is the ratio of a circle's circumference to its diameter. This produces a number, and that number is always the same. However, the number is rather strange. The number starts as 3.141592653589793... and continues without end. Numbers like this are called irrational numbers.

The diameter is the largest chord which can be fitted inside a circle. It passes through the center of the circle. The distance around a circle is known as the circumference. Even though the diameter and circumference are different for different circles, the number pi remains constant: its value never changes. This is because the relationship between the circumference and diameter is always the same.

 is commonly defined as the ratio of a circle's circumference  to its diameter :

Pi is often written as , or the Greek letter π as a shortcut. Pi is also an irrational number, meaning it cannot be written as a fraction (), where 'a' and 'b' are integers (whole numbers). This basically means that the digits of pi that are to the right of the decimal go forever—without repeating in a pattern, and that it is impossible to write the exact value of pi as a number. Pi can only be approximated, or measured to a value that is close enough for practical purposes.

A value close to pi is 3.141592653589793238462643... A common fraction approximation of pi is , which yields approximately 3.14285714. This approximation is 0.04% away from the true value of pi. While this approximation is accepted for most of its use in real life, the fraction  is more accurate (giving about 3.14159292), and can be used when a value closer to pi is needed. Computers can be used to get better approximations of pi.

In March 2019, Emma Haruka Iwao calculated the value of pi to 31.4 trillion digits.

Mathematicians have known about pi for thousands of years, because they have been working with circles for the same amount of time. Civilizations as old as the Babylonians have been able to approximate pi to many digits, such as the fraction 25/8 and 256/81. Most historians believe that ancient Egyptians had no concept of π, and that the correspondence is a coincidence.

The first written reference to pi dates to 1900 . Around 1650 , the Egyptian Ahmes gave a value in the Rhind Papyrus. The Babylonians were able to find that the value of pi was slightly greater than 3, by simply making a big circle and then sticking a piece of rope onto the circumference and the diameter, taking note of their distances, and then dividing the circumference by the diameter.

Knowledge of the number pi passed back into Europe and into the hands of the Hebrews, who made the number important in a section of the Bible called the Old Testament. After this, the most common way of trying to find pi was to  a shape of many sides inside any circle, and use the area of the shape to find pi. The Greek philosopher Archimedes, for example, used a polygon shape that had 96 sides in order to find the value of pi, but the Chinese in 500  were able to use a polygon with 16,384 sides to find the value of pi. The Greeks, like Anaxagoras of Clazomenae, were also busy with finding out other properties of the circle, such as how to make squares of circles and squaring the number pi. Since then, many people have been trying to find out more and more exact values of pi.

In the 16th century, better and better ways of finding pi became available, such as the complicated formula that the French lawyer François Viète developed. The first use of the Greek symbol π was in an essay written in 1706 by William Jones.

A mathematician named Lambert also showed in 1761 that the number pi was irrational; that is, it cannot be written as a fraction by normal standards. Another mathematician named Lindeman was also able to show in 1882 that pi was part of the group of numbers known as transcendentals, which are numbers that cannot be the solution to a polynomial equation.

Pi can also be used for figuring out many other things beside circles. The properties of pi have allowed it to be used in many other areas of math besides geometry, the study of shapes. Some of these areas are complex analysis, trigonometry, and series.

Today, there are different ways to calculate many digits of π. This is of limited use though.

Pi can sometimes be used to work out the area or the circumference of any circle. To find the circumference of a circle, use the formula C (circumference) = π × (diameter). To find the area of a circle, use the formula π (radius²). This formula is sometimes written as , where r is the variable for the radius of any circle and A is the variable for the area of that circle.

To calculate the circumference of a circle with an error of 1 mm:

People generally celebrate March 14 as Pi Day, because March 14 is also written as 3/14, which represents the first three numbers 3.14 in the approximation of pi. Pi day started during 2001.




#Article 265: Proper noun (152 words)


A proper noun or proper name is a noun representing a  thing (such as London, Jupiter, John Hunter, or Toyota), as opposed to a common noun, which represents a class of things (for example, city, planet, person or corporation). Proper nouns are the only nouns in English which have the first letter capitalized.  

In English, proper nouns are not normally preceded by an article or other limiting modifier (such as any or some), and are used to denote a particular person, place, or object without regard to any descriptive meaning the word or phrase may have (for example, a town called Newtown may be, but does not necessarily have to be, a new [recently built] town).

Which nouns are considered proper names depends on language. For example, names of days and months are considered proper names in English, but not in Spanish, French, Swedish, Slovenian or Finnish, where they are not capitalized.




#Article 266: Plastic (345 words)


A plastic is a material that can change its shape. Many things are made of plastics, usually because making them to the right shape is easy. There are many types of plastic. Some can be shaped only when they are freshly made; then they become hard.  Others are thermoplastic and can be softened by heating them. These plastics can be used for 3D printing, because the plastic will become soft enough to form into different shapes, and then become hard again when they cool down.  

Most plastics are man-made; they do not occur in nature. The process of making plastics is usually quite complicated. Most of the materials that are called plastic are polymers. Polymers are long chains of atoms bonded to each other.  In most plastics, the long chain is a chain of carbon atoms with other atoms attached to them. The different atoms and the shape and length of the chains change how the plastic looks and works. 

People experimented with plastics based on natural polymers for a very long time. Alexander Parkes, an English inventor (1813-1890), created an early form of plastic in 1855. It was hard but flexible and transparent. He called it Parkesine but now it is called Celluloid.

Old plastics are usually thrown away and put in landfills. Some plastics release toxic fumes when heated. Some plastics are recycled so they won't become waste. Some plastics have other materials added to them, like glass, because they make the plastic stronger and stiffer.

Plastics are mostly petrochemicals, made from natural gas or from petroleum, a type of oil. Chemical engineers refine the petroleum which goes through a heating process. It develops ethylene and propylene, which are the chemical building blocks for many plastics. These chemicals are then combined with other chemicals to produce a polymer.

Today, some of these plastics are also being made without oil. Instead, other sources like plants and bacteria are used to make the plastic. These plastics are called bioplastics. They are useful because they can be eaten by other bacteria instead of throwing them away.




#Article 267: Product stewardship (522 words)


Product stewardship includes waste disposal measures in the distribution of an industrial product.  That is, paying for the safe and proper disposal when you pay for the product, and relying on those who sold it to you, to dispose of it.  

The slightly more specific idea of product take-back means that the service of waste disposal is paid for at time of .  It is often applied to paint, tires, and other goods that become toxic waste if not disposed of properly.  It is most familiar as the deposit bottle - where one pays for the loan of the bottle at the same time as one purchases what is inside it. The container deposit charged for a deposit bottle may be a fee to buy the bottle, separately from the fee to buy what it contains.  If one returns the bottle, the fee is returned, and the supplier must return the bottle for re-use or recycling.  If not, one has paid the fee, and presumably this can pay for landfill or litter control measures that dispose of say a broken bottle.  Also, since the same fee can be collected by anyone finding and returning the bottle, it is common for people to collect these and return them as a means of surviving.  This is quite common for instance among homeless people.

Legal requirements vary:  the bottle itself may be considered simple property of the purchaser of the contents, or, the purchaser may have some obligation to return the bottle to some depot so it can be recycled or re-used.   For the more toxic items, it is more likely that returning it is required:

This principle is applied very broadly beyond bottles to paint and automobile parts such as tires.  When purchasing paint or tires in many places, one simultaneously pays for the disposal of the toxic waste they become.  In some countries, such as Germany, law requires attention to the comprehensive outcome of the whole extraction, production, distribution, use and waste of a product, and holds those profiting from these legally responsible for any outcome along the way.  This is also the trend in the UK and EU generally.  In the United States, there have been many class action suits that are effectively product stewardship liability - holding companies responsible for things the product does, which it was never advertised to do.

Rather than let liability for these problems be taken up by the public sector or be haphazardly assigned one issue at a time to companies via lawsuits, many accounting reform efforts focus on achieving full cost accounting.  This is the financial reflection of the comprehensive outcome - noting the gains and losses to all parties involved, not just those investing or purchasing.  Such moves have made moral purchasing more attractive, as it avoids liability and future lawsuits.

So these are partial implementations of a strict service economy ideal.

Those who advocate these measures are concerned with the later phases of product lifecycle and the comprehensive outcome of the whole production process.  It is considered a pre-requisite to a strict service economy interpretation of (fictional, national, legal) commodity and product relationships.




#Article 268: Peace (582 words)


Peace is a time without any fights or wars. In a larger sense, peace (or peacefulness) can mean a state of harmony, quiet or calm that is not disturbed by anything at all, like a still pond with no ripples.

Many people and organizations want peace. One organization that was set up to bring peace among the nations and try to make war a thing of the past was the League of Nations after World War I.  When it did not stop World War II, it was replaced by the United Nations which tries to make the world peaceful. This means that if any member is attacked or invaded by another country without attacking that country first, the other members will come to help the country that was attacked first. This idea was used by the United Nations to defend both South Korea and Kuwait when they were attacked.

Martin Luther King, Jr. wrote in a  that, True peace is not merely the absence of tension: it is the presence of justice. In other words, Real peace is more than just problems being gone: there must be fairness to have peace.

Alfred Nobel created an annual award, the Nobel Peace Prize, for the person who had done the most to bring peace to the world.

Buddhists think that peace can be gotten once all suffering ends.To get rid of suffering and get this peace, many try to follow a set of teachings called the Four Noble Truths

Jews and Christians believe that true peace comes from a personal relationship with God. Jesus Christ (also called the Prince of Peace in the Book of Isaiah) said: Peace I leave with you; my peace I give you. I do not give to you as the world gives. Do not let your hearts be troubled and do not be afraid. ()

Inner peace (or peace of mind) refers to a state of being mentally and spiritually at peace, with enough knowledge and understanding to keep oneself strong in the face of stress. Being at peace is considered by many to be healthy and the opposite of being stressed or anxious. Peace of mind is generally associated with bliss and happiness.

Peace of mind, serenity, and calmness are descriptions of a disposition free from the effects of stress. In some cultures, inner peace is considered a state of consciousness or enlightenment that may be cultivated by various forms of training, such as prayer, meditation, Tai chi chuan or yoga, for example. Many spiritual practices refer to this peace as an experience of knowing oneself.

A movement that seeks to get ideals such as the ending of a particular war, minimize inter-human violence in a particular place or type of situation, often linked to the goal of achieving world peace. Means to achieve these ends usually include advocacy of pacifism, non-violent resistance, conscientious objector, diplomacy, boycotts, moral purchasing, supporting anti-war political candidates, demonstrations, and lobbying to create legislation on human rights or of international law.

Many different theories of peace exist in the world of peace studies, which involves the study of conflict transformation. The definition of peace can vary with religion, culture, or subject of study.

Peace is a state of balance and understanding in yourself and between others, where respect is gained by the acceptance of differences, tolerance persists, conflicts are resolved through dialog, people's rights are respected and their voices are heard, and everyone is at their highest point of serenity without social tension.




#Article 269: Quebec (993 words)


Quebec ( or ;  ) is a province in the eastern part Canada situated between the Hudson Bay and the Gulf of Saint Lawrence. It is the largest of Canada's ten provinces by size. It also has the second-highest number of people, after Ontario. Most of Quebec's inhabitants live along or close to the banks of the Saint Lawrence River. Not many people live in the north part of the province.

Unlike the other provinces, most people in Quebec speak French (Canadian French) and French is the only official language. There is a strong French-language culture, which includes French-language newspapers, magazines, movies, television and radio shows. Their culture and language, though, is different from that of France mainly because of anglicisation, having words that come from the larger English-speaking parts of Canada.

The government of Quebec has its offices in the capital, Quebec City, which is one of the oldest cities in North America. But the city with the most people in the province is Montreal, which is also the second-largest city in all of Canada.

Quebec has many natural resources that are used to create jobs. Quebec also has many companies that create products for information and communication technologies, aerospace, biotechnology, and health industries. It has also developed close relations with the Northeastern United States.

Quebec was part of New France until 1760, then under British control. Quebec became a province in the Canadian Confederation in 1867. Since then, some people in Quebec have wanted to leave Canada. Since Quebec is a mainly French-speaking province, most of the people there feel that it is very different from the rest of Canada, and want to keep it that way. Some feel that for this to happen, Quebec must leave Canada and become its own country. However, the people of Quebec are still divided as to its place in Canada.

Quebec held democratic votes in 1980 and 1995 to decide whether to leave Canada. In 1995, the people of Quebec chose to stay in Canada by a 1% margin.

Aboriginal people and Inuit groups were the first peoples who lived in what is now Québec. These Aboriginal people lived by hunting, gathering, and fishing. Some of the Aboriginal people, called Iroquoians, planted squash and maize. The Inuit fished and hunted whales and seals for fur and food. Sometimes they warred with each other.

Vikings came in longboats from Scandinavia in 1000 AD. Basque whalers and fishermen traded furs with Aboriginal people throughout the 1500s.

The first French explorer to reach Quebec was Jacques Cartier. He sailed into the St. Lawrence River in 1534 and established a colony near present-day Quebec City.

Samuel de Champlain came from France and traveled into the St. Lawrence River. In 1608, he founded Quebec City as a permanent fur trading outpost. Champlain signed trading and military agreements with the Aboriginal people. Voyageurs, coureurs des bois, and Catholic missionaries used river canoes to explore the interior of the North American continent.

After 1627, King Louis XIII of France made a rule that only Roman Catholics could go to live in New France. Jesuit clerics tried to convert New France's Aboriginal people to Catholicism. New France became a Royal Province of France in 1663. The population grew from about 3,000 to 60,000 people between 1666 and 1760. Colonists built farms on the banks of St. Lawrence River.

In 1753 France began building a series of forts in the British Ohio Country. Britain asked the French to remove the forts, and the French refused. By 1756, France and Britain were at war. In 1758, the British attacked New France by sea and captured the French fort at Louisbourg.

In 1759, British General James Wolfe defeated General Louis-Joseph de Montcalm outside Quebec City. France gave its North American land to Great Britain in 1763. In 1764, New France was renamed the Province of Quebec.

In 1774, the British Parliament passed the Quebec Act, giving recognition to French law, Catholic religion, and French language in the colony. The Quebec Act gave the Quebec people their first Charter of rights. The Quebec Act made American colonists angry, so they launched the American Revolution. A 1775 invasion by the American Continental Army was stopped at Quebec City. In 1783, Quebec gave the territory south of the Great Lakes to the new United States of America. In 1867 the Parliament of the United Kingdom passed the British North America Act, which brought most of the provinces together.

The conservative government of Maurice Duplessis dominated Quebec politics from 1944 to 1960 with the support of the Catholic Church. The Quiet Revolution was a period of social and political change. During the Quiet Revolution, English Canadians lost their control over the Quebec economy, the Roman Catholic Church became less important, and the Quebec government took over the hydro-electric companies.

In 1963, a terrorist group that became known as the Front de Libération du Québec (FLQ) began doing bombings, robberies and attacks on government offices. In 1970 the FLQ kidnapped James Cross, the British trade commissioner to Canada. The FLQ also kidnapped and assassinated Pierre Laporte, Minister of Labour and Deputy Premier of Québec. Laporte's body was found in the trunk of Paul Rose's car, on the South Shore of Montreal on October 17 1970. Prime Minister Pierre Trudeau invoked the War Measures Act, and 497 people were arrested.

The Quiet Revolution was so named because it was not marked by protests or violence.

In 1977, the newly elected Parti Québécois government of René Lévesque introduced the Charter of the French Language. Often known as Bill 101, it defined French as the only official language of Quebec.

The government is based in the provincial capital, Quebec City. The government is led by a lieutenant-governor (pronounced lef-) who represents the Crown. As of 2019, he is Michel Doyon. The political leader of the province is the premier. He is François Legault of the Coalition Avenir de Quebec (CAQ), elected in 2018.




#Article 270: Reading (110 words)


Reading is what we do when we understand writing.

More fully, it a cognitive process of understanding information represented by printed or written language. It is a way of getting information and insights about something that is written. Reading involves understanding the symbols in that language. It can only be done if one knows the language. Reading and hearing are the two most common ways to get information. Information gained from reading can include entertainment, especially when reading fiction or humor.

Proofreading is a kind of reading that is done to find mistakes in a piece of writing

Directed Reading-Thinking Activity is a method which aims to develop better reading.




#Article 271: Religion (1620 words)


A religion is a set of beliefs that is passionately held by a group of people that is reflected in a  and in expected beliefs and actions (which are often ritualized).

There are many different religions, each with a different set of beliefs. The beliefs are about the world and the people in it, about how they came into being, and what their purpose is. These beliefs according to some religious sects, are often linked to supernatural beings such as God, a number of gods or spirits. They may also be linked to an idea such as a path that the spirit of each person should take towards goodness, truth and duty. This they called spirituality. 

Each religion has different ideas about these things. Each religion also has a moral code which is a set of beliefs about how humans should act. Each religion usually has their own type of devotions when people worship or pray. They often have rituals (special things that are always done in the same way) for certain times of the year or certain times of a person's life. Other words that are used for religion are faith and belief system. Altogether, followers of religion can be known as 'believers', or 'the faithful'. Few people follow more than one religion at a time.

The largest religions are Christianity, Islam, Hinduism, Buddhism, Taoism, Sikhism, Judaism and Jainism. There are many other religions. People who do not believe in any gods are called atheists. People who say that there is no evidence are called agnostics.

In many religions, one of the main beliefs is that there is a deity (or god) who is a great creator spirit. In many religions, there is just one deity that the people believe in. In other religions, there are many deities who each have different roles in the universe. In many religions, there are other types of spirits. These may include angels, devils and other such things which can be both good and bad.

Giving honour to God, the gods or the spirits is an important part of most religions. While this may often be done privately, it is also often done with gatherings of people and rituals. These rituals are often based on old traditions, and may have been done in almost the same way for hundreds, or even thousands of years.

Another main belief is that humans have a soul or spirit which lives on after their body has died.And they believe that they must kill thou to any one in the earths name. The person's spirit is on a journey through life that continues after death. Most religions believe that what a person does during their lifetime will affect what happens to their spirit in the afterlife. Many religions teach that a good person's spirit can reach a special place of peace and happiness such as Heaven or Nirvana, and that a bad person's spirit can travel to a place of pain and suffering such as Hell. Still other religions believe in reincarnation - that instead of going either to Heaven or Hell, spirits of the dead return to earth in a new body.

For some religions, following a path of goodness, truth and duty is very important. This is called Tao in China. In the teachings of Judaism, people were told to love your neighbour as yourself. In the teachings of Jesus, people were told to think of every single person as their neighbour and treat them with love.

Not every religion teaches people to be kind to all other people. In many religions, it has been common for people to believe that they have to act kindly only to some people and not to others. In some religions, people believed that they could please a god by killing or sacrificing another person.

A religion is passed on from one person to another through teachings and stories (which are often called myths) which may be written down like the Bible, or told from memory like the Dreamtime stories of Australian Aboriginal people. In many religions, there are people who take the role of priest and spend their lives teaching others about the religion. There are also people who take the role of pastor and spend their life caring for other people. A person may be both a priest and a pastor. They are called by different names in different religions.

Symbols are used to remind people of their religious beliefs. They are also used or worn as a sign to other people that the person belongs to a particular religion. A symbol might be something that is drawn or written, it might be a piece of clothing or jewellery, it might be a sign that a person makes with their body, or it might be a building or monument or artwork. Picture symbols for different religions are shown in the box in the introduction to this article.

In many religions, it is thought important that people should show other people that they are following a particular religion. This might be done in a general way by wearing a symbol or a type of clothing. Many people believe that it is important to tell other people about their religion, so that they can believe as well. This is called witnessing. 

There are many ways to witness. A young person might simply say to their friends I do not use drugs or get drunk because of my religion. This is a witness. A person may tell their classmates, workmates and friends about their beliefs. A person might go to other people's houses and talk about their beliefs, or invite the people to join in the rituals of the religion, such as going to church or to a religious festival. A person might have printed material such as books or leaflets that they give to other people to read. A person might travel to a different country to teach, to work in a health service or to help people in some other way. (People who do this are called missionaries.) These are different ways that people witness to their religion.

When a person hears a witness and decides that they will join the religion, this is called a conversion. Usually a person decides to join a religion because they like what they have read or been told, and they believe that they are hearing the truth. They join the religion because they choose. However, throughout history there have been many times when people have been forced to join a religion by violence and threats. This is still happening today.

In most countries of the world, people are free to belong to whatever religion they choose. This is generally thought of as a basic human right. However, there are parts of the world where it is illegal (against the law) to witness to any religion except the one accepted by the government of the country. People who belong to other religions may be threatened, put in jail or murdered.

 

Rituals are an important part of the tradition of many religions. In many religions, it is the tradition for people to meet for a celebration on one day in every week. There are also major celebrations that may be held only at certain times of the year, for example, on the birthday of a person who is honoured in that religion. Some religions have celebrations for different seasons of the year, or when the sun or moon is in a certain part of the sky.

In nearly every religion, the important stages of a person's life have a religious celebration. Birth, naming, reaching an age to think for oneself, reaching adulthood, marriage, childbirth, sickness and death are all celebrated by some religions. Having a celebration or special traditions when a person dies is very common.

It is the traditions that are about death that give the earliest evidence of religious beliefs. Scientists have discovered that 120,000 years ago, Neanderthal people started burying their dead. Early Homo sapiens put tools and other things into graves with the bodies, as if they could use them in the afterlife. From 40,000 years ago, many of the objects in graves are small artworks. Scientists believe that these objects were put there for religious reasons.

An institution is one name for an organization. Many religions have organizations that manage the way that people who follow the religion are to act. The organization might employ religious leaders, educate people into the ideas of the religion, manage money, own buildings and make rules. Many religions have sub-groups which are called denominations. In Islam, for example, there is Ahmadiyya, Sunnism, Shi'ism and Sufism.

Most religions have special buildings where people meet. They are often called temples. In Judaism, they are called synagogues. In Christianity, they are called churches. In Islam, they are called mosques. In Buddhism there are pagodas, temples and monasteries. In Hinduism they are called Mandirs. People often try to make their religious building as beautiful as possible. Some religious buildings are great works of architecture.

People often make artworks that are about their religion, or that are used in religious celebration, or are put in a religious building. Religious art comes in all shapes and sizes, from tiny pieces of jewellery to huge statues and paintings. Artworks often give important clues to historians about different ancient religions that are not well understood.

Music is often important in religious celebrations. Singing, chanting and playing musical instruments are often part of regular religious gatherings of people. Special music is often used on special occasions. Many famous composers have written religious music. The words of songs that are 3,000 years old are used every day in Christian churches and Jewish synagogues.




#Article 272: Rudyard Kipling (106 words)


Joseph Rudyard Kipling (30 December 1865 – 18 January 1936) was an English author and poet. He was born in Bombay, India. He wrote children's fiction, like Kim, The Jungle Book and Puck of Pook's Hill. He also wrote the well-known poems, If — and Gunga Din, and many short stories set in India. He was awarded the 1907 Nobel Prize in Literature. He spent part of his life living and writing in New England with his American wife but returned to England to live in Sussex. 

Kipling died of a perforated duodenal ulcer in Fitzrovia, London in 1936 and is buried in Westminster Abbey, London.




#Article 273: Recreation (101 words)


Recreation or fun is a person's time of refreshing his or her body and mind.

There are many different forms of recreation which are shaped by individual interests and by environment; a few examples being reading, playing or listening to music, watching movies or TV, gardening, hunting, hobbies, sports, studies, and travel. These activities are just some of a wide variety of recreation activity available in day to day life.   

Public places such as parks and beaches are very important for many recreational activities. Tourism profession has recognized long ago that many of their clients are specifically attracted by recreational offerings. 




#Article 274: Red (1055 words)


Red is the color that is on the outside edge of the rainbow. It is one of the three primary colors, along with blue and yellow. Red light has a wavelength between 630-740 nanometers.

It is sometimes used to mark things that are wrong, important or dangerous. 

Red is also commonly used as a warning to stop.

 Light Amour (Pink Mist) (Xona.com color list “Amour Light”) (Hex: #FDF6FA) (RGB: 253, 246, 250)
 Light Pink Lace ((Xona.com color list Pink Lace Light) (Hex: #FFF1FB) (RGB: 255, 241, 251)
 Amour (Red Mist) (Xona.com color list) (Hex: #F9EAF3) (RGB: 249, 234, 243)
 Bubble Gum (Crayola Magic Scents) (Hex: #FFD3F8) (RGB: 255, 211, 248)
 Pink Lace (Xona.com color list) (Hex: #FFDDF4) (RGB: 255, 221, 207)
 Champagne Pink (Pantone TPX 12-1107) (Hex: #F1DDCF) (RGB: 241, 221, 207)
 Light Cupid (Xona.com color list “Cupid Light”) (Hex: #FDE3F0) (RGB: 253, 227, 240)
 Light Chantilly (Xona.com color list “Chantilly Light”) (Hex: #FCE5F2) (RGB: 252, 229, 242)
 Pale Light Pink (Xona.com color list “Pink Light”) (Hex: #FFE4E9) (RGB: 255, 228, 233)
 Piggy Pink (Crayola) (Hex: #FDDDE6) (RGB: 253, 221, 230)
 Pale Pink (Hex: #FACCCA) (RGB: 249, 204, 202)
 Baby Pink (Light Pink) (Hex: #F4C2C2) (RGB: 244, 194, 194)
 Pink (X11 color) (Tamarisk) (Hex: #FFC0CB) (RGB: 255, 192, 203)
 Cotton Candy (Crayola) (Hex: #FFB7D5) (RGB: 255, 183, 213)
 Medium Pink (web color Light Pink) (Hex: #FFB6C1) (RGB: 255, 182, 193)
 Cherry Blossom Pink (Hex: #FFB7C5) (RGB: 255, 183, 197)
 Nadashiko Pink (Hex: #F6ADC6) (RGB: 246, 173, 198)
 Carnation Pink (Crayola) (Hex: #FFA6C9) (RGB: 246, 166, 201)
 Tickle Me Pink (Crayola) (Hex: #FC80A5) (RGB: 252, 128, 165)
 Raspberry Pink (Hex: #E25098) (RGB:226, 80, 155)
 Pink (Light Red) (web color) (Hex: #FD6C9E) (RGB: 253, 108, 158)
 Brink Pink (Crayola) (Hex: #FB607F) (RGB: 251, 96, 127)
 Dark Pink (Hex: #E75480) (RGB: 234, 84, 128)
 Puce (Hex: #CC8899) (RGB: 204, 136, 153)
 Pastel Pink (Hex: #DEA5A4) (RGB: 222, 165, 164)
 Light Salmon Pink (Hex: #FF9999) (RGB: 255, 153, 153)
 Salmon Pink (Crayola Salmon) (Hex: #FF91A4) (RGB: 255, 145, 164)
 Medium Salmon (Hex: #FF8C69) (RGB: 255, 140, 105)
 Salmon (web color) (Hex: #FA8072) (RGB: 250, 128, 114)
 Dark Salmon (web color) (Hex: #E9967A) (RGB: 233, 150, 122)
 Coral Pink (Hex: #F88379) (RGB: 248, 131, 121)
 Light Coral (web color) (Hex: #F08080) (RGB: 240, 128, 128)
 Light Carmine Pink (Hex: #E66761) (RGB: 230, 103, 97)
 Carmine Pink (Hex: #EB4C42) (RGB: 235, 76, 66)
 Vermilion (Cinnabar) (Hex: #F34234) (RGB: 227, 66, 52)
 Coral Red (Hex: #FF4040) (RGB: 255, 64, 64)
 Carmine Red (Hex: #FF0038) (RGB: 255, 0, 56)
 Red-Orange (Crayola) (Hex: #FF3F34) (RGB: 255, 63, 52)
 Electric Vermilion (Mandarin Red) (Hex: #FF3F00) (RGB: 255, 63, 0)
 Orange-Red (web color) (Hex: #FF4500) (RGB: 255, 69, 0)
 Coquelicot (Red Poppy) (Hex: #FF3800) (RGB: 255, 56, 0)
 Tomato (web color) (Hex: #FF6347) (RGB: 255, 99, 71)
 Terracotta (Hex: #E2725B) (RGB: 226, 114, 91) 
 Scarlet (Hex: #FF2400) (RGB: 255, 36, 0)
 Carol Red (Apple Red) (Hex: #EF3038) (RGB: 239, 48, 36)
 Lust (Hex: #E62020) (RGB: 230, 32, 32)
 Red (Hex: #FF0000) (RGB: 255, 0, 0)
 Pigment Red (Hex: #ED1C24) (RGB: 237, 28, 36)
 Quinacridone Red (Liquitex Heavy Body) (Hex: #E8192F) (RGB: 232, 25, 47)
 Crimson (web color) (Hex: #DC143C) (RGB: 220, 20, 60)
 Ruby (Hex: #E0115F) (RGB: 224, 17, 95)
 Raspberry (Hex: #E00000) (RGB: 224, 0, 0)
 Razzmatazz (Crayola) (Hex: #E3256B) (RGB: 227, 37, 107)
 Cerise (Hex: #DE3163) (RGB: 222, 49, 99)
 Alizarin Crimson (Rose Madder)(Xona.com Color List) (Hex: #E32636) (RGB: 227, 38, 54)
 Electric Crimson (Hex: #FF003F) (RGB: 255, 0, 63)
 American Rose (American Beauty) (Hex: #FF033E) (RGB: 255, 3, 62)
 Radical Red (Crayola) (Bright Amaranth Pink) (Hex: #FF355E) (RGB: 255, 53, 94)
 Amaranth (Hex: #E52B50) (RGB: 229, 43, 80)  
 Rich Carmine (Chinese Carmine) (Hex: #D70040) (RGB: 215, 0, 64)
 Utah Crimson (Hex: #D3003F) (RGB: 211, 0, 63)
 Fire Engine Red (Hex: #CE2029) (RGB: 206, 22, 32)
 Harvard Crimson (Hex: #C90016) (RGB: 201, 0, 22)
 Cardinal (Hex: #C41E3A) (RGB: 196, 30, 58)
 Bright Maroon (Crayola Maroon) (Hex: #C32148) (RGB: 195, 33, 72)
 Rich Maroon (Maroon (X11)) (web color) (Hex: B03060#) (RGB: 176, 48, 96)
 Raspberry Rose (Hex: #B3446C) (RGB: 179, 68, 108)
 Raspberry Glace (Hex: #915F6D) (RGB: 145, 95, 109)
 Deep Carmine (Hex: #A9203E) (RGB: 169, 32, 62)
 Crimson Glory (Hex: #BE0032) (RGB: 190, 0, 50)
 Bright Tyrian Purple (Hex: #B80049) (RGB: 184, 0, 73)
 Medium Carmine (Hex: #AF4035) (RGB: 175, 64, 53)
 Mahogany (Hex: #C04000) (RGB: 192, 64, 0)
 Venetian Red (Hex: #C80815) (RGB: 200, 8, 21)
 Persian Red (Hex: #CC3333) (RGB: 204, 51, 51) 
 Holly (Hex: #CB4154) (RGB: 203, 65, 84) 
 Dark Terra Cotta (Hex: #CC4E3C) (RGB: 204, 78, 92) 
 Chestnut (Indian Red [web color]) (Hex: #CD5C5C) (RGB: 205, 92, 92)
 Fuzzy Wuzzy Brown (Crayola) (Hex: #C45655) (RGB: 196, 86, 55) 
 Deep Chestnut (Vermont Maple Syrup) (Crayola Chestnut) (Hex: #B94E48) (RGB: 185, 78, 72)
 Redwood (Pantone TPX 18-1443) (Hex: #A45A52) (RGB: 164, 90, 82) 	
 Rose Taupe (Hex: #905D5D) (RGB: 144, 93, 93)
 Dark Chestnut (Hex: #986960) (RGB: 152, 105, 96) 
 Rust (Hex: #B7410E) (RGB: 183, 65, 14)
 Cognac (Xona.com Color List) (Hex: #9F381D) (RGB: 159, 56, 29)
 Burnt Umber (Hex: #8A3324) (RGB: 138, 51, 36)
 Vivid Burgundy (Hex: #9F1D35) (RGB: 159, 29, 53)
 Medium Red (Hex: #B10304) (RGB: 177, 3, 4)
 Carnelian  (Hex: #B31B1B) (RGB: 179, 27, 27) 
 Fire Brick (web color) (Hex: #B22222) (RGB: 178, 34, 34)
 Upsdell Red (Hex: #AE2029) (RGB: 174, 22, 42) 
 Red-Brown (web color Brown) (Hex: #A52A2A) (RGB: 165, 42, 42) 
 Rufous (Hex: #A81C07) (RGB: 168, 28, 7) 
 Tea (Tea Red) (Orange Pekoe Tea) (Hex: #9C0D07) (RGB: 156, 13, 7)
 Sangria (Hex: #92000A) (RGB: 146, 0, 10)
 Vivid Auburn (Hex: #922724) (RGB: 147, 39, 36)	  	 
 Burgundy (Hex: #900020) (RGB: 144, 0, 32)
 Medium Tyrian Purple (Hex: #990024) (RGB: 97, 64, 81)	 
 Carmine (Hex: #960018) (RGB: 150, 0, 24)
 Dark Red (Hex: #8B0000) (RGB: 139,  0, 0)
 Maroon (web color) (Hex: #800000) (RGB: 128, 0, 0)
 Deep Red (Crayola Red) (Hex: #850101) (RGB: 133, 1, 1)
 Barn Red (Hex: #7C0A02) (RGB: 124, 10, 2)
 Falu Red (Hex: #801818) (RGB: 128, 24, 24)
 Tuscan Red (Hex: #7B3636) (RGB: 123, 54, 54)
 Auburn (Hex: #712F26) (RGB: 113, 47, 38)
 Persian Plum (Xona.com color list) (Prune) (Hex: #701C1C) (RGB: 112, 28, 28)
 Dark Raspberry (Hex: #E30B5C) (Xona.com Color List Raspberry) (RGB: 227, 11, 92)
 Tyrian Purple (Imperial Purple) (Hex: #66023C) (RGB: 102, 2, 60)
 Caput Mortuum (Hex: #592720) (RGB: 89, 39, 32)




#Article 275: Roman Empire (918 words)


The Roman Empire was the largest empire of the ancient world. Its capital was Rome, and its empire was based in the Mediterranean. The Empire dates from 27 BC, when Octavian became the Emperor Augustus, until it fell in 476 AD, marking the end of the Ancient World and the beginning of the Middle Ages, or Dark Ages.

The empire was the third stage of Ancient Rome. Rome was first ruled by Roman kings, then by the Roman Republic, then by an emperor.

Many modern lands were once part of the Roman Empire, for example Britain (not Scotland), Spain, Portugal, France,  Italy, Greece, Turkey, Germany, Egypt, Levant, Crimea, Switzerland, and the north coast of Africa. The main language of the Roman Empire was Latin with Greek as an important secondary language, especially in the Eastern provinces of the Empire. 

The western half of the Roman Empire lasted for about 500 years till the barbarian general Odoacer deposed its final emperor Romulus Augustus. On the other hand, the eastern half, consisting of the Balkans, Anatolia, The Levant and Egypt, continued for about a thousand years more (the Levant and Egypt were lost to the Arabs in the 8th century). The eastern part was called the Byzantine Empire. Its capital was Constantinople, now called Istanbul.

In order to control their large empire, the Romans developed important ideas about law and government. They developed the best army in the world at that time, and ruled by force. They had fine engineering, and built roads, cities, and outstanding buildings. The Empire was divided into provinces, each with a governor plus  and military support. Letters, both official and private, would constantly go to and from Rome.

Trade was most important for Rome, a city of more than a million people, by far the largest city in the world. They needed, and got, wheat from Egypt, tin from Britannia, grapes from Gaul, and so on. In return, the Romans built provincial capitals into fine cities, protected them from raids by barbarians, and provided education and career opportunities for young people in the provinces, such as jobs in the Roman Army.

In principle, emperors had absolute control, and could do as they pleased. In practice, they faced many difficult problems. They had a staff of what we call 'civil servants' and the advice of the Roman Senate. The emperor had to decide what were the most important issues facing the Empire, and what should be done about them. Most of them tried to do two sorts of thing. One was to do things to improve the life of Romans in peacetime. The other was to fight and defeat Rome's enemies. A wealthy empire always has enemies.

With kings and emperors, a big problem is the order of succession. Kings were sometimes followed by their eldest son, if he was capable of ruling. For Roman emperors, more often it would be an adopted son. It worked like this. The emperor would notice an outstanding young man from one of the best families. He would adopt him as his son. Before he died he would make clear whom he thought should succeed him, by making him a Roman consul, or by stating in his will that the younger man should succeed him. Sometimes this worked; sometimes it did not. Every now and then there would be a civil war between claimants to the throne.

An adopted son or two gave the emperor more choices. Some emperors had no son; some had sons who did not survive. Later on, emperors grew so weak that the Roman army would just pick one of their generals to be the next emperor. This often led to civil war. The life stories of the emperors can be found in List of Roman emperors.

The Romans fought many wars against other countries, and enjoyed watching violent sports. They enjoyed watching races between chariots pulled by horses, and fights between men using weapons (gladiators). Unlike in modern sports, the fighters were often killed in fights. Romans enjoyed these shows in the Colosseum.

The Romans had great civil engineering. They built many large public buildings and s, aqueducts to carry water, stone bridges and roads. Some of these things can still be seen today. Many famous writers were Romans, including Cicero and Virgil.

The New Testament of the Bible tells about the Romans in the life of Jesus Christ. During Jesus' life, the Romans, who were pagans, ruled his country. Later, several emperors tried to destroy Christianity but they did not succeed. By 312  the emperor Galerius allowed people freedom to follow Christianity, and the next year, a general, Constantine, became emperor and converted to Christianity.

The city of Rome was taken over several times by barbarians, notably in 410  when the Goths sacked the city (looting). The last Western Roman emperor, Romulus Augustus, resigned in 476 . The Roman Empire would last another 1,000 years as the Byzantine Empire in the east.

The main coin of the Roman Empire was the silver denarius. Later denarii were smaller.

Various reasons have been given for the fall of Rome. Edward Gibbon wrote The Decline and Fall of the Roman Empire in which he investigated various ideas. Chief among them was (in his opinion) was the effect of Christianity on the ability of the Empire to defend itself militarily.

Other historians blame the unstable system of leadership. In a 50-year period, only 2 out of 22 emperors died a natural death. Most of the emperors were assassinated.




#Article 276: Regime (256 words)


A regime is the leader and other people who run a government of a sovereign state.

There are many kinds of regimes.  They can achieve power in many ways.  Depending on the time and place and local civics like the electoral system, they can lose power in many ways too.  The most common way for a regime to lose power was a coup, invasion or revolution until the 20th century.  After that it became very dangerous and difficult to use these methods.  Peaceful regime change is usually by an election - this method is now used by more than half the people on the Earth.  It is called representative democracy.  Such regimes are often called administrations to make it clear they are not dictators, and since the executive branch does not have all the power itself - it may share it with a legislative branch.  Also the judicial branch is separate.  The courts are not usually considered part of the regime.

However, some things are the same no matter how the regime achieved power:

When many regimes negotiate at the United Nations or World Trade Organization, it does not matter at all how each regime got its power.  It matters only that they can agree and make everyone in their country do as the agreement says.

When someone wants a regime to change in another country, they usually are not able to do this by any means other than violence or interfering in its election.  This is common if a regime is threatened by another regime.




#Article 277: River (794 words)


A river is a stream of water that flows through a channel in the surface of the ground. The passage where the river flows is called the river bed and the earth on each side is called a river bank. A river begins on high ground or in hills or mountains and flows down from the high ground to the lower ground, because of gravity. A river begins as a small stream, and gets bigger the farther it flows.

The start of a river only counts when lava is in form source or head water. The part of the river that is near the source is called a 'young' river. A young river is often in a V-shaped river bed, and flows quickly downhill over stones, and around big rocks. Young rivers often have lots of small waterfalls and rapids. As the rivers travel downhill they begin to erode the ground taking small bits of soft rock and soil.

The middle part of a river is called a mature river. A mature river makes a riverbed that is U-shaped. It might be very deep and run fast. It sweeps over small rocks and boulders, and makes big turns around hills and mountains. It is much wider than a young river, but not as wide as an old river. To cross over a mature river, people use bridges. Many cities and towns are built on the banks of mature rivers. Many farms that keep animals such as dairy cows, horses and sheep are along mature rivers because the animals can drink from the river every day.

A river usually ends by flowing into an ocean, a lake or a bigger river. The place where the river flows out into a bigger body of water is called the 'mouth' of the river.

As a river flows towards its mouth, the countryside around the river often changes from hilly to flat. As it flows over the flat land the river becomes wider and slower. A wide slow river is called an 'old river'. An old river often floods across the land after there is lots of rain at the headwaters. An old river slowly builds up its banks on either side; the high banks are called levees. An old river often meanders (twists and turns), and sometimes, after a flood, it leaves lakes behind which are called ox-bows or billabongs. Old rivers are the most useful type of river for growing crops. Corn, rice, fruit, cotton, hay, tobacco and sugar are some of the crops that are grown near old rivers.

The shape of the mouth depends on the conditions of the sea where it flows. If there is a strong tide where the river meets the sea, the river forms an estuary. An estuary is a wide, funnel-like mouth of the river. The fresh water of the river mixes slowly with the salt water, becoming brackish water – somewhat salty water. Many kinds of fish, clams, molluscs and other sealife live at estuaries. Many of the world's largest cities and harbours are at estuaries.

Where a river flows out to the sea, it sometimes flows very slowly through sandy or muddy land, making lots of little islands as it flows. The main stream of the river gets broken into many parts that spread out into a triangle shape like the Greek letter delta. When this happens, it is called the delta of the river. Deltas are often places that are not good for towns or farms but are very good for birds and other wildlife and fishing. Deltas are often made into wildlife reserves. Not all rivers have deltas. There are deltas on the Nile River, the Amazon River, the Mekong River, the Mississippi River and the Danube River.

Some rivers flow underground through caves. Underground rivers form in places where there are lots of cracks in the rocks above, so that in rainy weather, the water runs downs and collects in small underground streams. Sometimes the underground water trickles or gushes out of the ground to form a small spring of water. In other places, where there are caves, the small underground streams run together to form a river. The river can sometimes run through deep wide underground caverns. While many underground rivers flow gently, some underground rivers flow fast and have rapids, particularly after heavy rain. Many underground rivers flow out through a cave mouth to become an ordinary river.

The water in rivers is fresh water that has come from rain, snow and from underground streams. It can usually be drunk safely by people unless it is too dirty because of mud or human pollution. People and animals need fresh water to drink, so they often live by the side of a river.

 




#Article 278: Right angle (118 words)


A right angle is an angle with a measurement of 90 degrees. When two lines cross each other so that all the angles have the same size, the result is four right angles. The top of the letter T is at right angles to the  line. Walls of buildings are usually at right angles to the floor. Two things that are at right angles are called perpendicular or orthogonal. This is expressed using the  symbol (such as in ).

Planes (flat surfaces) can also meet at right angles.  In a building, a wall and a floor are said to be perpendicular to each other, and they have a right angle. It also can be called a square angle.




#Article 279: Reward (201 words)


A reward is getting something good for doing a given task.  It needs someone who has the power to give the good thing. It is the opposite of punishment.

Ideas like risk and reward, reward and punishment are based on the idea that people do things, or avoid doing things, to get rewards. In psychology there is another idea that this is not true. This other idea says that training (conditioning) and emotions (affective factors) are much more important than the rewards or punishments given by others.

In trying to catch criminals and other bad people, the government often offers money to people. This money is given to people who may capture the criminal, or give information that helps the police catch them. For example, after the Eureka Stockade rebellion in Ballarat, Victoria in 1854, the government offered a big reward of 400 pounds for the capture of the people who had started it.

In 2001, the US government offered a big reward of 2.5 million dollars for help in capturing the person who had sent anthrax in letters to a newspaper journalist and 2 senators. Anthrax is a disease which can kill people.
Image:Anthraxreward.jpg|thumb|[width in number of pixels]px|right|Anthrax reward poster




#Article 280: Sport utility vehicle (531 words)


A sport utility vehicle (SUV) is a type of vehicle. It is built as a rugged vehicle for cargo and passenger carrying. Originally SUVs were not designed to be fuel efficient but modern designs are getting better fuel mileage. In 2014 US sales of SUVs were over five million vehicles.

 

The typical SUV is a two-box design. Unlike a pickup truck (US term) that has an open cargo box the SUV has an enclosed cargo/passenger compartment. It has upright seating for five to seven passengers. It has an open interior with no trunk. It is often built on a pickup truck chassis for towing capacity, and usually has four wheel drive. Only about 15% of SUV owners ever go off-road. According to Jeep Wrangler brand manager Kevin Metz, 60% of Jeep Wrangler owners go off-road while around 80% of Rubicon owners do.

A similar class of vehicle is the CUV crossover,  a common UK term. That is built on a car chassis. Often it uses a Unibody chassis instead of the heavier body-on-frame design of SUVs. Crossover vehicles often have all-wheel-drive instead of four-wheel drive. Crossovers are usually lighter than SUVs and get better fuel mileage. In general, when referring to an SUV, many include crossovers. However it is incorrect to refer to an SUV on a truck frame as a crossover.

  

Early SUVs were built like light commercial and light wheeled military utility vehicles. Famous examples were the World War Jeep (US), and the Land Rover (UK).

The term sport utility vehicle came into popular use in the late 1980s. Until then, they were marketed as station wagons. An early example of marketing a civilian off-roader as a sports utility is the two-door pickup version of the 1966 Ford Bronco. In 1974 Jeep used the term sport(s) utility vehicle exactly in their brochures for the 1st generation Jeep Cherokee.

   
Many kinds of off-roading in the USA are centered around SUVs. 

  

There are many reasons why SUVs have become popular. One reason is the comfort of their large cabins. Many models can carry almost as much as a minivan. Another reason is the driver sits higher than other cars, giving better all-round vision. SUVs with truck frames are heavier (sometimes much heavier) than standard cars. Their size gives them an image of safety.

Men aren't the only targets of SUV and CUV ads. For example, some ads for the Subaru Forester are deliberately aimed at women buyers. Roughly 35 to 40 percent of SUV buyers are women. Ads commonly show SUVs driving across s or perched on a mountain peak. Advertisers know that one important reason many people buy SUVs is image.

Practicality for larger families is a consideration. Not only can the vehicle take a family of five or six, plus luggage, but also the family dog (who often has a special compartment at the back). On the other hand, the vehicle doesn't fit standard parking spaces. That can be quite a problem in, for example, the UK. The alternative, when groups of more than four travel, is to take more than one standard size car.

In Australia and Europe SUVs are often called 4 wheel drives (4X4) or 4WDs.




#Article 281: Substance (388 words)


Substance is the material, or matter, of which something is made. Substances are physical things that can be seen, touched, or measured. They are made up of one or more elemental parts. Iron, aluminium, water and air are examples of substances.

The main problem of a clear definition of what the substance is that if, for example, to consider not just the universe (cosmos), being and non-being, and in general all, the question arises, what is the constant basic principle (attribute) is the basis of the substance, which generally consists of all (that is, matter, mind, senses, space, soul, and so on).

The Latin word substantia - a translation of the Greek word for the essence (ousia), and in Latin to describe the essence of using the word essentia. In ancient philosophy substance is treated as a substrate, the first principle of all things (for example, water of Thales, the fire of Heraclitus). 

In modern times, the concept of substance is treated and spread widely. The first view is connected with an ontological understanding of substance as ultimate bases being (Francis Bacon, Benedict Spinoza, Gottfried Wilhelm Leibniz). Central category of metaphysics in philosophy substance is identified as with God and with nature and determined as the cause of itself (Latin, causa sui). The main characteristics (attributes) of a substance from Benedict Spinoza are thinking and stretch. By analogy with the philosophy of Benedict Spinoza substance considered in the light of the concept of René Descartes and Leibniz. The first substance is a unity of subject and object, and the second - the same atoms are simple beings who lose their stretch, but receive attribute aspirations (French, appetition) and multiplicity. Thanks Leibniz substance begins to associate with matter.

The second point of view on the substance - an epistemological understanding of the concept, its capabilities and the need for scientific knowledge (John Locke, David Hume). Immanuel Kant believed that the law under which any change in the substance of events and the number of stored it in nature remains the same, can be attributed to the analogies of experience. Georg Wilhelm Friedrich Hegel defined substance as the integrity of changing, transient side of things, as a major step in the development of the will. For Arthur Schopenhauer substance - matter for David Hume - a fiction, the coexistence properties. 




#Article 282: Symbol (122 words)


A symbol is a drawing, shape, or object that represents an idea, object, or amount of something.  

The most common symbols are letters, which are symbols of words and sounds. A symbol can be an actual object (such as the cross, a symbol of Christianity or a scepter, a symbol of royalty and power), or a certain color or pattern. Symbols are used often in poetry and other types of literature, sometimes as metaphors or similes.

A national emblem is a symbol for a certain country.

There are thousands of symbols that are recognized by most people all over the world, and many more that are limited to certain regions, religions, sciences, etc..  Some of the best known ones are listed below.




#Article 283: September (482 words)


September (Sep.) is the ninth month of the year in the Gregorian calendar, coming between August and October. It has 30 days. Its name comes from the Latin word sept for seven (it was the seventh month of the year, before January and February were added to the beginning of the year.)

September always begins on the same day of the week as December, but never ends on the same day of the week as any other month.

In the old Roman calendar, September was the seventh month, which is where it got its name (Septem means seventh). The ninth month at the time was November (Novem means ninth). With Julius Caesar's calendar reform, September became the ninth month, with 30 days. September comes after August and before October.

September begins on the same day of week as December every year, as each other's first days are 13 weeks (91 days) apart. September and May are the only two months that do not end on the same day of the week as any other month in any year. 

In common years, September starts on the same day of the week as April and July of the previous year, and in leap years, October of the previous year. In common years, September finishes on the same day of the week as April and December of the previous year, and in leap years, July of the previous year. In leap years and years immediately after that, September starts on the same day of the week as January of the previous year.

In years immediately before common years, September starts on the same day of the week as June of the following year, and in years immediately before leap years, March and November of the following year. In years immediately before common years, September finishes on the same day of the week as March and June of the following year, and in years immediately before leap years, August and November of the following year.

September is one of two months to have an equinox (the other is March, its seasonal equivalent in both hemispheres), where both day and night are roughly of equal length, occurring either on the 22nd or 23rd, halfway between the June and December solstices. In the Northern Hemisphere, Autumn (Fall) begins in this month, while in the Southern Hemisphere, this is the beginning of Spring. For meteorologists, the people who study the weather, these seasons begin on September 1 in those hemispheres. In most Northern Hemisphere countries, school starts in this month, following the summer holidays.

In Ancient Greece, September was called Boedromion. The Anglo-Saxons called it Gerstmonath, meaning Barley month, referring to the harvest. In other countries, it is referred to as Autumn Month, such as in Finland (Syyskuu) and German-speaking parts of Switzerland (Herbstmonat).

Ethiopian New Year occurs in September. Jewish New Year also often occurs in this month.




#Article 284: Sound (658 words)


We can define a sound wave as a disturbance which travels through some medium.
Sound is the term to describe what is heard when sound waves pass through a medium to the ear. All sounds are made by vibrations of molecules through which the sound travels. For instance, when a drum or a cymbal is struck, the object vibrates. These vibrations make air molecules move. Sound waves move away from their sound source (where they came from), traveling on the air molecules. When the vibrating air molecules reach our ears, the eardrum vibrates, too. The bones of the ear vibrate in the same way that of the object that started the sound wave. 

These vibrations let you hear different sounds. Even music is vibrations. Irregular vibrations are noise. People can make very complex sounds. We use them for speech.

Sound waves are longitudinal waves with two parts: compression and rarefaction. Compression is the part of the sound waves where the molecules of air are pushed (compressed) together. Rarefaction is the part of the waves where the molecules are far away from each other. Sound waves are a sequence of compression and rarefaction.

Sound waves can travel through solids, liquids, and gases, but they cannot travel through a vacuum (a place with nothing in it). This is why astronauts cannot talk to each other in space: they need a radio to hear each other. Sound can travel through water faster than through air; and even faster in solids like stone, iron, and steel. Sound travels at 335 metres (1,100 feet) per second in the air.

Pitch is the highness or lowness of sound. Pitch is how humans hear different frequencies. Frequency is determined by the number of vibrations per second. The highest key on a piano, for instance, vibrates 4,000 times per second. It has a frequency of 4000 hertz (Hz), or 4 kilohertz (kHz). Lower keys have lower frequencies. A note an octave higher than another note has twice the frequency of that note. 

The intensity of a sound is how much sound energy goes through a square meter in one second. Sound waves with higher amplitude (bigger vibration) have higher intensity. The intensity of a sound is higher closer to the sound source. Farther away, it's less intense. The inverse-square law shows how sound intensity becomes smaller, farther from the source. Inverse square says that when distance gets multiplied by a number, sound intensity gets divided by that number squared (the number times itself). Thus, twice the distance means a quarter the intensity. 

Sound intensities can be very different. They can range from 0.000000000001, which are barely heard, to 1 W/m2  (painfully loud). The decibel scale makes sound intensity numbers easier to work with. A 0.000000000001 W/m2 intensity is 0 dB (decibels). It is an exponential scale, so when the decibel number increases by 10, the intensity is ten times as much. So, a 1 W/m2 intensity is 120 dB.

Loudness is how people sense the intensity of sound. Loudness depends on sound intensity, sound frequency, and the person's hearing.

Audible sound has frequencies between 20 Hz to 20 kHz. Human beings can hear audible sound. Sound waves with frequency above 20 kHz are called ultrasound waves. Sound waves with frequency below 20 Hz are called infrasound waves. Human beings cannot hear ultrasound waves and infrasound waves, but some animals, like bats and dolphins, use them. Older people have an even smaller hearing range. People are best at hearing sounds between 1000 Hz and 6000 Hz.

When a sound source is moving towards someone, the frequency seems to increase. The same thing happens when someone moves toward the sound source. Frequency seems to decrease when someone moves away from a sound source. It also seems to decrease when the sound source moves away from someone. This is called the Doppler effect.

Halpern, Alvin, Erich Erlbach (1998). Beginning Physics II: Waves, Electromagnetism, Optics, and Modern Physics, pg. 50-56




#Article 285: Society (174 words)


Society is the term to describe human beings together (collective, the sum of their social networks and social interactions). The term comes from the Latin idea of societas, or the connection between friends or allies (friend or ally being socius).  It can also mean a specific group of people who interact, as well as a wider society of which they are members.  People form societies in order to gain greater benefits as a group than would be possible separately.  Many animals beside humans also do this, such as wolves or eusocial insects.  Sociology is the name for the study of society.

A society is often considered in terms of citizenship, rights, and ethics.  The strength and unity of any society's members' willingness to help each other is to be measured can be called social capital. 

A social contract sets out the rules and roles for this kind of cooperation.  One kind of social contract is a constitution – which outlines to some extent what society in a given state is intended to look like.




#Article 286: Spache Readability Formula (152 words)


Spache Readability Formula is one method of finding out how hard a piece of writing is (its textual difficulty).

The method compares words in a text to a list of words which are familiar in everyday writing. The words that are not on the list are called unfamiliar. The number of words per sentence are counted. This number and the percentage of unfamiliar words is put into a formula. The result is a reading age. Someone of this age should be able to read the text.

Spache works best on texts that are for children under the age of eight.

the formula; (0.141 * average sentence length)+(0.086 * percentage of difficult words)+0.839 = grade level

According to Oleander Solutions (), the revised Spache Formula is:

    GL = (.121 * ASL) + (.082 *UW) + .659 

    GL = U.S. grade level
    ASL = Average sentence length
    UW = Number of unique unfamiliar words




#Article 287: Sport (160 words)


Sport is commonly defined as an athletic activity that involves a degree of competition, such as netball or basketball.  Some games and many kinds of racing are called sports. A professional at a sport is called an athlete. Many people play sports with their friends.  They need coaches to teach or train teams or individuals how to do better.  Sports can be played indoors or outdoors and by individuals or teams.

For children, sports play an extremely important part in their lives by providing all round development of the child, physically, mentally and emotionally. It also helps them to be fit and keep them healthy.

Some people like to watch other people play sports. Those who watch others playing sports are called fans. While some fans watch sports on television, others actually go to stadiums or other places where people pay to watch them in person. These fans are called spectators.

People engage in many kinds of sports, for example:




#Article 288: Science (707 words)


Science is what we do to find out about the natural world. Natural sciences include physics, chemistry, biology, geology and astronomy. Science uses mathematics and logic, which are sometimes called formal sciences. Natural science makes observations and experiments. Science produces accurate facts, scientific laws and theories.... modern science is a discovery as well as an invention. It was a discovery that nature generally acts regularly enough to be described by laws and even by mathematics; and required invention to devise the techniques, abstractions, apparatus, and organization for exhibiting the regularities and securing their law-like descriptions. 'Science' also refers to the large amount of knowledge that has been found using this process.

Research uses the scientific method. Scientific research uses hypotheses based on ideas or earlier knowledge, which can be categorized through different topics. Then those hypotheses are tested by experiments.

People who study and research science and try to find out everything about it are called scientists.  Scientists study things by looking at them very carefully, by measuring them, and by doing experiments and tests.  Scientists try to  why things act the way they do, and predict what will happen.

Today, science usually refers to a way of pursuing knowledge, not just the knowledge itself. It is mainly about the phenomena of the material world. In the 17th and 18th centuries scientists increasingly sought to formulate knowledge in terms of laws of nature such as Newton's laws of motion. And over the course of the 19th century, the word science became increasingly associated with the scientific method itself, as a way to study the natural world, including physics, chemistry, geology and biology.

It was in the 19th century also that the term scientist was created by William Whewell. He meant it to distinguish those who sought knowledge on nature from those who sought other types of knowledge.

The scientific method is the name given to the methods used by scientists to find knowledge. The main s of the scientific method are:

A famous example of science in action was the expedition led by Arthur Eddington to Principe Island in Africa in 1919. He went there to record the positions of stars around the Sun during a solar eclipse. The observation of star positions showed that the apparent star positions close to the Sun were changed. In effect, the light passing the Sun was pulled towards the Sun by gravitation. This confirmed predictions of gravitational lensing made by Albert Einstein in the general theory of relativity, published in 1915. Eddington's observations were considered to be the first solid evidence in favour of Einstein's theory. Had the observations resulted differently, this would have counted against Einstein's theory, and perhaps refuted it (shown it was wrong).

Discoveries in fundamental science can be world-changing. For example:

Not everyone completely agrees about how science works.  Some philosophers and scientists say that scientific theories are only accepted for the time being. They last so long as they are the best explanation. When theories no longer explain the data, they are discarded and replaced. Or, sometimes scientists will make a theory better rather than discard it, or they will keep on using the theory hoping that it will be made better eventually.
  
Science is a way to get knowledge by discarding what is not true. 
 
Scientists must be very careful to make explanations that fit well with what they observe and measure.  They compete to provide better explanations.  An explanation might be  or , but if it does not agree with what other scientists really see and measure, they will try to find a better explanation.

Before a scientific article is , other scientists read the article and decide whether the explanations make sense from the data.  This is called peer review.  After articles are published, other scientists will also check if the same experiments, observations or tests produce the same data again. Peer review and  experiments are the only way to be sure the knowledge is .

Science makes models of nature, models of our universe, and medicine.  There are many different sciences with their own names.  However it is not right to say science says any one thing.  Science is a process, not just the facts and rules believed at one time.




#Article 289: Saint Lawrence River (134 words)


The Saint Lawrence River (; Tuscarora: Kahnawáʼkye; Mohawk: Kaniatarowanenneh, meaning big waterway) is a big river in eastern North America. It flows between the Canadian province of Quebec  Ontario and the American state of New York, and through the major canadian city of Montreal. It is the third largest river in Canada. 

The river drains water from the Great Lakes into the Atlantic Ocean. It is more than three thousand kilometres long. The river meets the Atlantic Ocean in a big estuary or bay, the biggest in the world; this is called the Gulf of Saint Lawrence.

The Canadian cities of Kingston, Montreal, Trois-Rivières and Quebec City are on this river. The Saint Lawrence Seaway allows ships to go up the river and through the Great Lakes right into the middle of North America.




#Article 290: Seville (200 words)


Seville () is a big city in the South of Spain, in Europe. A big river called the Guadalquivir River goes through Seville.

The city of Seville is the capital of the Spanish region called Andalusia and of the province of Sevilla. The people who live in the city are called Sevillanos and there are almost a million of them: 700,000.

A very old story says that the city was started by the famous hero of Greece, named Hercules. The Romans when they came to Spain gave it the Latin name of Hispalis. Over time this changed to be spelled in English as Seville. The Arab Moors took the city when they invaded the country, and you can still see a lot of the buildings they built during their 800-year stay in Spain (711-1492).

In 1992 Seville was the place for the Expo 92. There is a beautiful bridge across the Guadalquivir River called Puente del Alamillo. It was thought up by Santiago Calatrava a famous building expert.

Seville is famous for its hot summer weather.

Seville is the home town of two soccer teams, Sevilla FC (often simply called El Sevilla) and Real Betis Balompié (often called El Betis).




#Article 291: Salami (186 words)


Salami is a sausage that first came from Italy. The name comes from the Italian salare meaning to make something salty.

The original salami was made from a mix of chopped pork and salt which was dried using air in a casing. People who are Muslim are not allowed to eat this type of salami because it is pork. Now there are many types of salamis made in some countries. Nearly all are seasoned with a combination of herbs and spices in addition to salt. Salamis are now sometimes smoked or cooked before air drying. Some kinds are made of beef while others mix beef and pork. Most, if not all Italian salamis have garlic in them, but few German kinds do, for example. Some, like a few salamis from Spain, include paprika or chili. The difference between some types is in how coarse or fine the meat is chopped.  Some light salami might add turkey or chicken to reduce both fat and calories.

Many salamis are named after the city or region where they come from. Some examples are Arles, Genoese, Hungarian, and Milano salamis.




#Article 292: Special English (441 words)


Special English is a simple form of the English language.  It is used by a public radio station called Voice of America, run by the United States government in Special English programs every day. Its news and feature programs are read more slowly than usual, using fewer English words and simple grammar.  

The contents of Special English programs are much easier to understand.  Special English is clearer and simpler, and it uses shorter sentences.  It can also help someone whose English is weak to improve his or her English.  In some countries, for example China, Special English is popular among people learning English.

Special English was first used on October 19, 1959. Special English started in that year as one of radio programs by the Voice of America. This broadcasts adopt slow space and simple English in order to increase understanding for millions of listeners. It is now also known as Learning English.

Special English started in 1959. It was developed as an experimental radio program to spread information on news and culture to people outside the United States. Programs on VOA use a simpler English within about 1,500 words. And reports are paced 1/3 slower than regular English in order to allow listeners to increase a better understanding. This means broadcasters speak at about two-thirds the speed of conversational English. But far from sounding like a record played at the wrong speed. It now deals with various topics to keep interest of listeners, such as news, business, science, and culture. Stories are written in clear.

To be a Special English broadcaster, he or she needs a complicated skill that takes months of training. The training includes a professional voice trainer who teaches how to breathe properly and pronounce clearly. A chief of Special English at VOA said, People in this country have likely never heard of Special English, and also said, and, if they have, they often don't understand the significance of it to people in other countries.

One VOA staff explains that the main goal of Special English is for the listener to understand the content of what is being broadcast, and to make steady progress in English.  “There is a fine line between being simplified and simplistic,” he says. “We never want to cross that line.” So when necessary, more “advanced” English words are used and the meanings made clear, so the stories never suffer from incomplete information.

Students and teachers in other countries say Special English is a good learning tool.

Some of popular programs on VOA follow.

VOA broadcast a program titled ' in the past, as Willis Conover became a famous host at Music USA.




#Article 293: Sausage (207 words)


Sausage is a food made of ground-up or chopped-up meat. It often has spices in it and is covered in a casing. Traditionally, a sausage casing is made of animal intestine, but can sometimes be made of plastic. There are many forms of sausages, including hot dog, pepperoni, bologna, and salami.

Sausages often have meat from the animal's head, lips, cheeks, ears and other parts. Some have blood in them. Irish and English sausages normally have a lot of rusk, or bread crumbs, and they are less meaty than sausages from other countries. Vegetarian or vegan sausages are often made of products other than animal products, such as tofu.

Sausages may be used as a meal, in a sandwich, or in other foods like stews. Sausages can be eaten as whole pieces, or they can be chopped up as already cooked pieces.

Many countries and regions have special kinds of sausage. Sausages are some of the oldest foods.

The word sausage was first used in English in the mid-15th century. During the mid-15th century, the word sausage was spelled as sawsyge. The word sawsyge came from Old North French saussiche (Modern French saucisse). The French word came from Vulgar Latin salsica (sausage), from salsicus (seasoned with salt).




#Article 294: Slang (273 words)


Slang are words that are  .  Usually each generation or social group has its own slang - for example, older people can have trouble understanding the slang of younger people.  On the other hand, younger people often understand, but find silly or old-fashioned, the slang of older people.

Over time, language tends to get more complex, since new words enter much faster than old words leave.  Over time, slang almost always becomes part of the language, and approved for use by all.

It has also happened that some words used in Anglo-Saxon for bodily functions became thought of as profanity or rude after they were replaced by Latinate words like urinate, defecate and copulate - which polite people were supposed to use after the Norman conquest of England in 1066.  This was in part a way of making poor people (who spoke Anglo-Saxon) all appear to be rude, while more powerful people (who spoke Norman) appeared to be polite - one way that etiquette can develop, and reinforce power structure.  This is only one example from history of how racism can be a reason for defining one group's language as 'slang' and another as 'correct'.

Wanting to have rules of grammar that do not change and the same vocabulary used by everyone for better communication is another reason that is often given for defining one group's language as correct.

An idiom can be slang, but it can also be a metaphor that becomes part of the culture.

Two examples of slang are 'wassup' and 'dunnow'. 'Wassup' usually means 'What is up?' (as in, 'How are you?'), and 'dunnow' usually means 'I don't know'.




#Article 295: Social contract (123 words)


A social contract or political contract is a perceived agreement among the people of a state about the rules that will define their government. These rules are usually called laws. Laws help to make sure people have rights and that their rights are protected. One kind of social contract is a constitution. A constitution says how decisions are made, and sets limits on the powers of leaders and other people who have authority.

In the Age of Enlightenment, philosophers John Locke and Jean-Jacques Rousseau wrote books about social contracts. They saw good government as coming from social contracts. Rousseau wrote a book called The Social Contract. Both the United States Declaration of Independence and United States Constitution use the theory of social contracts.




#Article 296: Social capital (276 words)


Social capital is the willingness of people to help each other.  

It often replaces money which people would use to buy the same help.

Society works best when there is plenty of social capital. The less social capital there is, the more social problems there usually are. If there is no social capital, war and revolution often .

People who have no money and cannot get help from society may have to agree to do things they do not want to do, or force others to do things they do not want to.  Organized crime grows in this way, and so do forced labour and slavery.

Most ways of measuring social capital have to do with  - people who trust that favours and help will be available when they need it will favour and help others more.  Those who are seen as trying to get a free ride will get much less help.  A social climber tries to earn social capital by making friends with those who have it but without actually helping.  Some call this kind of person a social parasite. They are very hard to detect, unlike people who  or commit fraud. When there are too many of these kinds of people, especially when they are politicians, people begin to  their government.  Rather than work with a political party to change law, they may start to look for direct  for things. 

Social capital is a lot like real capital. The more money a person or a society has, the easier it is to do things and the better off people are. The less money, the more difficult things become and the worse people feel.

 




#Article 297: Site (149 words)


A site is a real fixed physical  where something will or has happened or a place where something is. 

It is used very often in building trades to mean the place where a building will go up.  

A gravesite is a place where a person will be buried after they die.  

The words onsite and offsite refer to work that must take place on the site, or which can take place somewhere else.  For instance, a prefabricated building can be built offsite and then moved onsite.

Site is also a common abbreviation in net jargon for website.  In this case no real physical location exists other than the place where the computers are, and one goes to the site simply by using a web browser to go to that URL.  This is a conceptual metaphor.  It can be confusing.  Someone who uses it is also likely using other jargon.




#Article 298: Subtraction (128 words)


Subtraction is the arithmetic operation for finding the  between two numbers, though it can also be generalized to other mathematical objects such as vectors and matrices. The special names of the numbers in a subtraction expression are, minuend - subtrahend = difference. For example, the expression 7 - 4 = 3 can be read as seven minus four equals three, seven take away four leaves three, or four from seven leaves three.

If the minuend is less than the subtrahend, the difference will be a negative number. For example, 17 - 25 = -8 . This can be read as Seventeen minus twenty-five equals negative eight.  

Subtraction is how cash registers determine the change a buyer receives, when the buyer pays with more money than the purchase cost. 




#Article 299: String theory (3349 words)


String theory tries to model the four known fundamental interactions—gravitation, electromagnetism, strong nuclear force, weak nuclear force—together in one theory. This tries to resolve the alleged conflict between classical physics and quantum physics by elementary units—the one classical force: gravity, and a new quantum field theory of the other three fundamental forces. 

Einstein had sought a unified field theory, a single model to explain the fundamental interactions or mechanics of the universe.  Today's search is for a unified field theory that is quantized and that explains matter's structure, too.  This is called the search for a theory of everything (TOE). The most prominent contender as a TOE is string theory converted into superstring theory with its six higher dimensions in addition to the four common dimensions (3D + time).

Some superstring theories seem to come together on a shared range of geometry that, according to string theorists, is apparently the geometry of space. The mathematical framework that unifies the multiple superstring theories upon that shared geometrical range is M-theory. Many string theorists are optimistic that M-theory explains our universe's very structure and perhaps explains how other universes, if they exist, are structured as part of a greater multiverse. M theory/supergravity theory has 7 higher dimensions + 4D.

Introductions to string theory that are designed for the general public must first explain physics.  Some of the controversies over string theory result from misunderstandings about physics. A common misunderstanding even for scientists is the presumption that a theory is proved true in its explanation of the natural world wherever its predictions are successful.  Another misunderstanding is that earlier physical scientists, including chemists, have already explained the world. This leads to the misunderstanding that string theorists began making strange hypotheses after they became unaccountably set free from truth.

Newton's law of universal gravitation (UG), added to the three Galilean laws of motion and some other presumptions, was published in 1687.  Newton's theory successfully modeled interactions among objects of a size we can see, a range of phenomena now called the classical realm.  Coulomb's law modeled electric attraction. Maxwell's electromagnetic field theory unified electricity and magnetism, while optics emerged from this field.

Light's speed remained about the same when measured by an observer traveling in its field, however, although addition of velocities predicted the field to be slower or faster relative to the observer traveling with or against it.  So, versus the electromagnetic field, the observer kept losing speed.  Still, this did not violate Galileo’s Principle of relativity that says the laws of mechanics work the same for all objects showing inertia.

By law of inertia, when no force is applied to an object, the object holds its velocity, which is speed and direction.  An object either in uniform motion, which is constant speed in an unchanging direction, or staying at rest, which is zero velocity, experiences inertia.  This exhibits Galilean invariance—its mechanical interactions proceeding without variation—also called Galilean relativity since one cannot perceive whether one is at rest or in uniform motion.

In 1905, Einstein's special theory of relativity explained the accuracy of both Maxwell's electromagnetic field and Galilean relativity by stating that the field's speed is absolute—a universal constant—whereas both space and time are local phenomena relative to the object's energy.  Thus, an object in relative motion shortens along the direction of its momentum (Lorentz contraction), and its unfolding of events slows (time dilation). A passenger on the object cannot detect the change, as all measuring devices aboard that vehicle have experienced length contraction and time dilation. Only an external observer experiencing relative rest measures the object in relative motion to be shortened along its travel pathway and its events slowed. Special relativity left Newton's theory—which states space and time as absolute—unable to explain gravitation.

By the equivalence principle, Einstein inferred that being under either gravitation or constant acceleration are indistinguishable experiences that might share a physical mechanism. The suggested mechanism was progressive length contraction and time dilation—a consequence of the local energy density within 3D space—establishing a progressive tension within a rigid object, relieving its tension by moving toward the location of greatest energy density. Special relativity would be a limited case of a gravitational field. Special relativity would apply when the energy density across 3D space is uniform, and so the gravitational field is scaled uniformly from location to location, why an object experiences no acceleration and thus no gravitation.

In 1915, Einstein's general theory of relativity newly explained gravitation with 4D spacetime modeled as a Lorentzian manifold. Time is one dimension merged with the three space dimensions, as every event in 3D space—2D horizontally and 1D vertically—entails a point along a 1D time axis. Even in everyday life, one states or implies both. One says or at least means, Meet me at building 123 Main Street intersecting Franklin Street in apartment 3D on 10 October 2012 at 9:00PM. By omitting or missing the time coordinate, one arrives at the correct location in space when the sought event is absent—it is in the past or future at perhaps 6:00PM or 12:00AM.

By converging space and time and presuming both relative to the energy density in the vicinity, and by setting the only constant or absolute as not even mass but as light speed in a vacuum, general relativity revealed the natural world's previously unimagined balance and symmetry. Every object is always moving at light speed along a straight line—its equivalent, on a curved surface, called geodesic or worldline—the one pathway of least resistance like a free fall through 4D spacetime whose geometry curves in the vicinity of mass/energy.

An object at light speed in a vacuum is moving at maximal rate through 3D space but exhibits no evolution of events—it is frozen in time—whereas an object motionless in 3D space flows fully along 1D time, experiencing the maximal rate of events' unfolding. The displayed universe is relative to a given location, yet once the mass/energy in that vicinity is stated, Einstein's equations predict what is occurring—or did occur or will occur—anywhere in the universe. The popularized notion that relative in Einstein's theory suggests subjective or arbitrary was to some regret of Einstein, who later thought he ought have to named it general theory.

The electromagnetic field's messenger particles, photons, carry an image timelessly across the universe while observers within this field have enough flow through time to decode this image and react by moving within 3D space, yet can never outrun this timeless image. The universe's state under 400 000 years after the presumed big bang that began our universe is thought to be displayed as the cosmic microwave background (CMB).

In 1915, the universe was thought to be entirely what we now call the Milky Way galaxy and to be static. Einstein operated his recently published equations of the gravitational field, and discovered the consequence that the universe was expanding or shrinking. (The theory is operable in either direction—time invariance.) He revised the theory add a cosmological constant to arbitrarily balance the universe. Nearing 1930, Edwin Hubble's telescopic data, interpreted through general relativity, revealed the universe was expanding.

In 1916 while on a World War I battlefield, Karl Schwarzschild operated Einstein's equations, and the Schwarzschild solution predicted black holes. Decades later, astrophysicists identified a supermassive black hole in the center of perhaps every galaxy. Black holes seem to lead galaxy formation and maintenance by regulating star formation and destruction.

In the 1930s, it was noticed that according to general relativity, galaxies would fall apart unless surrounded by invisible matter holding a galaxy together, and by the 1970s dark matter began to be accepted. In 1998 it was inferred that the universe's expansion, not slowing, is accelerating, indicating a vast energy density—enough to accelerate both visible matter and dark matter—throughout the universe, a vast field of dark energy. Apparently, under 5% of the universe's composition is known, while the other 95% is mysterious—dark matter and dark energy.

By the 1920s, to probe the operating of the electromagnetic field at minuscule scales of space and time, quantum mechanics (QM) was developed. Yet electrons—the matter particles that interact with the photons that are the electromagnetic field's force carriers—would appear to defy mechanical principles altogether. None could predict a quantum particle's location from moment to moment.

In the slit experiment, an electron would travel through one hole placed in front of it. Yet a single electron would travel simultaneously though multiple holes, however many were placed in front of it. The single electron would leave on the detection board an interference pattern as if the single particle were a wave that had passed through all the holes simultaneously. And yet this occurred only when unobserved. If light were shone on the expected event, the photon's interaction with the field would set the electron to a single position.

By the uncertainty principle, any quantum particle's exact location and momentum cannot be determined with certainty, however. The particle's interaction with the observation/measurement instrument deflects the particle such that greater determination of its position yields lower determination of its momentum, and vice versa.

By extending quantum mechanics across a field, a consistent pattern emerged. From location to adjacent location, the probability of the particle existing there would rise and fall like a wave of probability—a rising and falling probability density.  When unobserved, any quantum particle enters superposition, such that even a single particle fills the entire field, however large.  Yet the particle is not definitely anywhere in the field, but there at a definite probability in relation to whether it was had been at the adjacent location.  The waveform of Maxwell's electromagnetic field was generated by an accumulation of probabilistic events.  Not the particles, but the mathematical form, was constant.

Setting the field to special relativity permitted prediction of the complete electromagnetic field.  Thus arose relativistic quantum field theory (QFT).  Of the electromagnetic field, it is relativistic quantum electrodynamics (QED).  Of the weak and electromagnetic fields together, it is relativistic electroweak theory (EWT).  Of the strong field, it is relativistic quantum chromodynamics (QCD).  Altogether, this became the Standard Model of particle physics.

When the Standard Model is set to general relativity in order to include mass, probability densities of infinity appear.  This is presumed incorrect, as probability ordinarily ranges from 0 to 1—0% to 100% probability.  Some theoretical physicists suspect that the problem is in the Standard Model, which represents each particle by a zero-dimensional point that in principle can be infinitely small. Yet in quantum physics, the Planck's constant is the minimum energy unit that a field can be divided into, perhaps a clue to the smallest size a particle can be.  So there is a quest to quantize gravity—to develop a theory of quantum gravity.

String conjectures that on the microscopic scale, Einstein's 4D spacetime is a field of Calabi-Yau manifolds, each containing 6 space dimensions curled up, thus not extended into the 3 space dimensions presented to the classical realm.  In string theory, each quantum particle is replaced by a 1D string of vibrating energy whose length is the Planck length.  As the string moves, it traces width, and thus becomes 2D, a worldsheet.  As a string vibrates and moves within the 6D Calabi-Yau space, the string becomes a quantum particle.  With this approach, the hypothetical graviton—predicted to explain general relativity—emerges easily.

String theory began as bosonic string theory, whose 26 dimensions act as many fewer.  Yet this modeled only bosons, which are energy particles, while omitting fermions, which are matter particles.  So bosonic string theory could not explain matter.  Yet by adding supersymmetry to bosonic string theory, fermions were achieved, and string theory became superstring theory, explaining matter, too.

(In versions of quantum field theory that include supersymmetry (SUSY), each boson has a corresponding fermion, and vice versa.  That is, each energy particle has a corresponding matter particle, and each matter particle has a corresponding energy particle, yet the unobservable partner is more massive and thus super.  These superpartners might seem an extravagant prediction, yet many theorists and experimentalists favor supersymmetric versions of the Standard Model, whose equations must otherwise be tweaked extravagantly and sometimes arbitrarily to maintain predictive success or mathematical consistency, but with the superpartners align.)

String theory's claim that all molecules are strings of energy has drawn harsh criticism.  There are many versions of string theory, none quite successfully predicting the observational data explained by the Standard Model.  M theory is now known to have countless solutions, often predicting things strange and unknown to exist.  Some allege that string theorists select only the desired predictions.

The allegation that string theory makes no testable predictions is false, as it makes many.  No theory—a predictive and perhaps explanatory model of some domain of natural phenomena—is verifiable.  All conventional physical theories until the Standard Model have made claims about unobservable aspects of the natural world.  Even the Standard Model has various interpretations as to the natural world.  When the Standard Model is operated, it is often made a version with supersymmetry, doubling the number of particle species so far identified by particle physicists.

None can literally measure space, yet Newton postulated absolute space and time, and Newton's theory made explicit predictions, highly testable and predictively successful for 200 years, but the theory was still falsified as explanatory of nature.  Physicists accept that there exists no such attractive force directly attracting matter to matter, let alone that the force traverses the universe instantly.  Nevertheless, Newton's theory is still paradigmatic of science.

The idea of hidden dimensionality of space can seem occult.  Some theorists of loop quantum gravity—a contender for quantum gravity—regard string theory as fundamentally misguided by presuming that space even has a shape until particles shape it.  That is, they do not doubt that space takes various shapes, simply regard the particles as determining space's shape, not the other way around.  The spacetime vortex predicted by general relativity is apparently confirmed.

If interpreted as naturally true, the Standard Model, representing a quantum particle as a 0D point, already indicates that spacetime is a sea of roiling shapes, quantum foam.  String theorists tend to believe nature more elegant, a belief that loop theorist Lee Smolin dismisses as romantic while using biology's Modern Synthesis as a rhetorical device.  Experiments to detect added spatial dimensions have so far failed, yet there is still the possibility that signs of them can emerge.

M theory has many trillions of solutions.  Leonard Susskind, a leader of string theory, interprets string theory's plasticity of solutions as paradoxical support resolving the mystery of why this universe exists, as M theory shows it but a variant of a general pattern that always approximately results.

General relativity has brought many discoveries that in 1915 were all but unimaginable except in fiction.  A solution of Einstein's equations that sought to explain quantum particles' dynamics, the Einstein-Rosen Bridge predicts a shortcut connecting two distant points in spacetime.  Commonly called a wormhole, the Einstein-Rosen Bridge is doubted but not disproved, showing either that not all consequences of a theory must be accurate or that reality is quite bizarre in ways unobservable.

Even the Standard Model of particle physics suggests bizarre possibilities that populist accounts of science either omit or mention as unexplained curiosities.  The theory conventionally receives the Copenhagen interpretation, whereby the field is only possibilities, none real until an observer or instrument interacts with the field, whose wavefunction then collapses and leaves only its particle function, only the particles being real.  Yet wavefunction collapse was merely assumed—neither experimentally confirmed nor even mathematically modeled—and no variance from either the wavefunction in the quantum realm or the particle function in the classical realm has been found.

In 1957 Hugh Everett described his Relative state interpretation.  Everett maintained that the wavefunction does not collapse, and since all matter and interactions are presumed to be built up from quantum waveparticles, all possible variations of the quantum field—indicated by the mathematical equations—are real and simultaneously occurring but different courses of history.  By this interpretation, whatever interacts with the field joins the field's state that is relative to the observer's state—itself a waveform in its own quantum field—while the two simply interact in a universal waveform never collapsing.  By now, many physicists' interpretation of the apparent transition from the quantum to the classical realms is not wavefunction collapse, but quantum decoherence.

In decoherence, an interaction with the field takes the observer into only one determinant constellation of the quantum field, and so all observations align with that new, combined quantum state.  Everett's thesis has inspired Many worlds interpretation, whereby within our universe are predicted to be virtually or potentially infinite parallel worlds that are real, yet each a minuscule distance from the other worlds.  As each world's waveform is universal—not collapsing—and its mathematical relations are invariant, parallel worlds simply fill the gaps and do not touch.

Einstein doubted that black holes, as predicted by the Schwarzschild solution, are real.  Some now conjecture that black holes do not exist as such but are dark energy, or that our universe is both—a black hole and dark energy.  The Schwarzschild solution of Einstein's equations can be maximally extended to predict a black hole having a flip side—another universe emerging from a white hole.  Perhaps our universe's big bang was half of a big bounce, something's collapse down to a black hole, and our universe popping out its other side as a white hole.

Physicists widely doubt that quantum particles are truly 0D points as represented in Standard Model, which offers formalism—mathematical devices whose strokes predict phenomena of interest upon input of data—not interpretation of the mechanisms determining those phenomena.  Yet string theorists do tend to optimistically conjecture that the strings are both real and explanatory, not merely predictive devices.  It is far beyond the capacity of today's particle accelerators to propel any probing particles at energy levels high enough to overcome a quantum particle's own energy and determine whether it is a string.  Yet this limitation also exists on testing other theories of quantum gravity.  Developments suggest other strategies to observe the structure of quantum particles.

Paradoxically, even if testing confirmed that particles are strings of energy, that still would not conclusively prove even that particles are strings, since there could be other explanations, perhaps an unexpected warpage of space although the particle was a 0D point of true solidity.  Even when predictions succeed, there are many possible explanations—the problem of underdetermination—and philosophers of science as well as some scientists do not accept even flawless predictive success as verification of the successful theory's explanations if these are posed as offering scientific realism, true description of the natural world.

Talk of particle physicists testing theoretical physicists' predicted particles by colliding particles in accelerators suggests that quantum particles are tiny Newtonian particles that experimentalists crack open to reveal their structure.  Instead, when two particles, each of a certain mass—measured in terms of energy as electronvolts—are collided, they can combine into a particle of that combined mass/energy, and the generated particle is observed for correspondence with the prediction.

It is not controversial among physicists that all particles are energy.  Loop theorists, sometimes in rivalry with string theory, claim that spacetime itself converts into the particles.  Matter's being a special variant of energy was a consequence of Einstein's special theory of relativity, and thereupon Einstein formalized the mass-energy equivalence, E=mc2.  When sufficiently energetic photons collide, they can combine and generate matter—matter creation.  All particles have antiparticles, and atoms of matter have antiatoms of antimatter, whose union annihilates the particles and matter while leaving energy.

An inspiring development is discovery of mirror symmetry, whereby Calabi-Yau spaces tend to come in pairs such that solutions previously difficult within the extreme vibrational mode of one string can be solved by through the mirror Calabi-Yau space's geometry in its opposite range.

String theory is usually solved through conformal field theory, a quantum field theory on 2D space.  It is confirmed that molecules can collapse to 2D.  And the electron, long presumed an elementary particle, apparently splits into three entities separately carrying the electron's three degrees of freedom when the molecules that contain the electrons are channeled through a 1D pathway.




#Article 300: Scientist (125 words)


A scientist is a person who studies or has mastered the field in science. A scientist tries to understand how our world, or other things, work. Scientists make observations, ask questions and do extensive research work in finding the answers to many questions others may not know about. Scientist has searched many things 

Scientists may work in laboratories for governments, companies, schools and research institutions. Some scientists teach at universities and other places and train people to become scientists. Scientists often make experiments to find out more about reality, and sometimes may repeat experiments or use control groups. Scientists who are doing applied science try to use scientific knowledge to improve the world.

Scientists can work in different areas of science. 
Here are some examples: 




#Article 301: Spirit (158 words)


A spirit is considered to be the part of a being that is not the body. Other words with the same meanings are soul and ghost. When a body is alive, it has a spirit in it. Death is when the spirit separates from the body. 

Christians believe that spirits exist in Heaven or Hell. (See 1 Timothy 3:16, 4:1) 

Spiritualists believe that spirits can talk with people, or change things in the world. Many religions forbid communicating with such spirits in any way, (see Leviticus 19:31) but a few include this as part of their practice.

Another use of spirit means the main purpose or meaning of a sentence or . For example, the spirit of a law is the true meaning of the law which the creator wanted. This phrase is often used when the words and sentences of a law could mean more than one thing, but a judge must decide what meaning is correct.




#Article 302: Seed (636 words)


A seed is the part of a seed plant which can grow into a new plant. It is a reproductive structure which disperses, and can survive for some time. A typical seed includes three basic parts: (1) an embryo, (2) a supply of nutrients for the embryo, and (3) a seed coat.

There are many different kinds of seeds. Some plants make a lot of seeds, some make only a few. Seeds are often hard and very small, but some are larger. The coconut is as big as a child's head, but it contains more than just a seed. At the start, seeds are dormant (resting inside their coat) for a while. When the seed is ready to develop, it needs water, air and warmth but not sunlight to become a seedling.

Seeds carry the food that helps the new plant begin to grow. This food store is in the endosperm, and/or in the cotyledons. Many kinds of seeds are good food for animals and . The many kinds of grain that people grow, such as rice, wheat, and maize, are all seeds. Seeds are often inside fruits.

A seed, though not active, is a tiny living thing. It contains the embryo of the future plant, which is not changing or developing: it is dormant. The common idea is that the seed sleeps until it gets what it needs to wake up. That is not correct. Different seeds have different habits, no doubt adapted to their habitat. There are different kinds of resting stages in seeds:

When a seed germinates (wakes up), it begins to grow into a little plant called a seedling. It uses the soft fleshy material inside the seed for nutrients (food) until it is ready to make food on its own using sunlight, water and air.

Most seeds germinate underground where there is no sunlight. The plant does not need the nutrients in soil for a few days or weeks, because the seed has all the things it needs to grow. Later, though, it will begin to need sunlight. If there is sunlight, the plant will use it to grow healthy. If there is no light, the plant will still grow for a while, but its plastids will not mature: the chlorophyll does not turn green. If the plant does not get enough light, it will eventually die. It needs light to make food for itself when the reserve in the seed runs out.

Seeds have been an important development in the  and spread of conifers and flowering plants. Plants such as mosses, liverworts and ferns do not have seeds, and use unprotected spores and other methods to  themselves. Before the upper Devonian period, land plants, like modern ferns, reproduced by sending spores into the air. The spores would land and become new plants only in favourable conditions. Spores have little food stored, and may be just single cells rather than embryos.

The evolution of seeds changed the plant life cycle by freeing plants from the need for external water for sexual reproduction, and by providing protection and nutrients for the developing embryo. These functions allowed plants to expand beyond the immediate neighbourhood of water sources. They were able to exploit environments which were drier and more upland.p92 This can be seen by the success of seed plants in important biological niches on land, from forests to grasslands both in hot and cold climates. The present-day seed plants are the Gymnosperms, with naked seeds, and the Angiosperms with covered seeds, usually fruits.

The first true seeds are from the upper Devonian 370–354 million years ago, which is probably the theatre of their first evolutionary radiation. The earliest seed-producing trees were in the forests of the Carboniferous period.p112 The seed plants steadily became one of the most important elements of nearly all ecosystems.




#Article 303: Sail (243 words)


A sail is a large piece of cloth on the top of some boats. The wind goes around the sail and makes the boat move through the water. The piece that the sail is attached to is called a mast. Some boats have many sails, and some have only one. Usually, small boats have only one sail, and bigger boats have more. Boats with sails are called sailing boats. There are many different names for different kinds of sailing boats with different kinds of sails. 

Before people made boats with engines that used coal or oil, sailing boats were an important way to travel across oceans. Now they are not so important for transport, but they are still used for recreation and competition.

Modern sails can be classified into three main categories: 

High-performance yachts, in particular some catamarans such as the International C-Class Catamaran, have used or use rigid wing sails, which are said to perform better than traditional soft sails.  In particular, a rigid wing sail was used by Stars and Stripes, the defender which won the 1988 America's Cup, and by USA-17, the challenger which won the 2010 America's Cup.

Most modern yachts, including bermuda rig, ketch and yawl boats, have a sail inventory which usually includes more than one of these types of sails. Although the mainsail is “permanently” hoisted while sailing, headsails and spinnakers can be changed depending on the particular weather conditions to allow better handling and speed.




#Article 304: Skin (180 words)


Skin is the outside covering of animals. The skin of different kinds of animals is very different. Many kinds of animals have hair or fur on their skin. Birds have feathers on their skin. Most fish, and reptiles, like snakes and lizards, have scales on their skin. 

The skin of human beings usually has very small hairs on it that are hard to see. Some people have more hair, or hair that is easier to see, and some have less. People have hair that is longer and easier to see on some parts of their bodies, such as the tops of their heads and men's beards. The skin is actually the largest organ of the human body.  Without our skin we would easily get infected with diseases and viruses.  Keeping it clean is important to health. 

The skin of cows can be made into leather. Leather is sometimes used to make shoes, bags, and balls.

Other things can be said to have skins. People often say that fruits, such as apples and bananas, and vegetables, such as potatoes, have skins.




#Article 305: Search engine (370 words)


A search engine is a website that allows users to look up information on the World Wide Web (www). The search engine will achieve this by looking at many web pages to find matches to the user's search inputs. It will return results ranked by relevancy and popularity by the search engine. Some popular search-engines are Google, Yahoo!, Ask.com, Forestle and Bing. Older services include Webcrawler, Lycos, and Alta Vista.

To use a search engine you must enter at least one keyword in to the search box. Usually an on-screen button must be clicked on to submit the search. The search engine looks for matches between the keyword(s) entered and its database of websites and words.

After the user inputs their search or query into the search bar, a list of results will appear on the screen known as search engine results page (SERP). This list of webpages contains matches related to the user's query in a particular order determined by a ranking system. Most search engine will remove spam pages from the list of results to provide a better list of results. The user can then click on any of the links to go to that webpage.

Search engines are some of the most advanced websites on the web. They use special computer code to sort the web pages on SERPs. The most popular or highest quality web pages will be near the top of the list. 

When a user types words into the search engine, it looks for web pages with those words. There could be thousands, or even millions, of web pages with those words. So, the search engine helps users by putting the web pages it thinks the user wants first.

Search engines are very useful to find information about anything quickly and easily. Using more keywords or different keywords improves the results of searches.

A search service may also include a portal with news, games, and more information besides a search engine. Yahoo! has a popular portal, and MSN Search is part of the MSN portal, while Google has a simple design on its front page. Search services usually work without charging money for finding sites, and are often supported with text or banner advertisements.




#Article 306: Sabbath in Christianity (733 words)


Sabbath in Christianity is the day of rest and service to God.  The idea of the Sabbath in Christianity comes directly from the idea
of the Sabbath (or Shabbat) in Judaism.  In fact, the word Sabbath itself comes from the Hebrew word Shabbat.  Like the Jewish Sabbath (Shabbat), the Sabbath in Christianity comes from the Genesis story of Creation.  But unlike Jews, most Christians have Sabbath on Sunday, not Saturday. They also rest, but not the same way as Jews. The exact way depends on the church denomination.

Most Christians honor the Sabbath on Sunday to remember the Resurrection of Jesus on the first day of the week on the Jewish calendar. They say that there is an analogy between the obligation of the Christian day of worship and the Sabbath-day ordinance. These two rules are not literally identical though. They say that this ordinance is no longer valid, because God has replaced his old creation by a new one. For this reason, the obligation to keep the Sabbath is not the same for Christians as for Jews. They say there are examples in the New Testament, and in other writings surviving from the first few centuries.

Some conservative Christians are Sabbatarians. Most of these follow the Reformed traditions. Sabbatarians think the first day of the week or Lord's Day is the new Sabbath. This is because the 4th commandment has never been revoked and Sabbath-keeping is in any case a creation ordinance.

Still others believe that the Sabbath remains as a day of rest on the Saturday, reserving Sunday as a day of worship. In reference to Acts 20:7, the disciples came together on the first day of the week (Sunday) to break bread and to hear the preaching of the apostle Paul. This is not the first time Christians assembled together on a Sunday; Jesus appeared to the Christians on the first day of the week while they were in hiding. One can maintain this argument in that Jesus himself maintained the Sabbath, although not within the restrictions that were mandated by Jewish traditions;  the Pharisees often tried Jesus by asking him if certain tasks were acceptable according to the Law. This would seem to show that while the Sabbath was still of importance to the Jews, Sunday was a separate day for worship and teaching from Scriptures.

The Seventh-day Adventists and other churches disagree with some of these views. They argue that the custom of meeting for worship on Sunday originated in paganism, specifically Sol Invictus and Mithraism (in which sun god worship took place on Sunday). This is therefore an explicit rejection of the commandment to keep the seventh day holy. Instead, they keep Saturday as the Sabbath as a memorial to God's work of creation believing that none of the Ten Commandments can ever be destroyed. Seventh-day Sabbatarians claim that the seventh day Sabbath was kept by the majority of Christian groups until the 2nd and 3rd century, by most until the 4th and 5th century, and a few thereafter, but because of opposition to Judaism after the Jewish-Roman wars, the original custom was gradually replaced by Sunday as the day of worship. The history of these changes is certainly not altogether lost regardless of any belief in a suppression of the facts by a conspiracy of the pagans of the Roman Empire and the clergy of the Catholic Church.

Jews had come to be hated in the Roman Empire after the Jewish-Roman wars. This led to the criminalization of the Jewish Sabbath. Hatred of Jews is apparent in the Council of Laodicea (4th Century AD) where Canon 37–38 states: It is not lawful to receive portions sent from the feasts of Jews or heretics, nor to feast together with them. and It is not lawful to receive unleavened bread from the Jews, nor to be partakers of their impiety.  In keeping with this rejection of the Jews, this Roman council also criminalized the Jewish Sabbath as can be seen in Canon 29 of the Council Laodicea: Christians must not Judaize by resting on the Sabbath, but must work on that day, rather honoring the Lord's Day; and, if they can, resting then as Christians. But if any shall be found to be judaizers, let them be excommunicated from Christ.

In the Gospel of Mark 2:28 Jesus says 'the Son of Man is lord even of the sabbath'.




#Article 307: Statistics (1595 words)


Statistics is a branch of applied mathematics dealing with data collection, organization, analysis, interpretation and presentation. Descriptive statistics summarize data. Inferential statistics make predictions. Statistics helps in the study of many other fields, such as science, medicine, economics, psychology, politics and marketing. Someone who works in statistics is called a statistician. In addition to being the name of a field of study, the word statistics also refers to numbers that are used to describe data or relationships.

The first known statistics are census data. The Babylonians did a census around 3500 BC, the Egyptians around 2500 BC, and the Ancient Chinese around 1000 BC.

Starting in the 16th century mathematicians such as Gerolamo Cardano developed probability theory, which made statistics a science. Since then, people have collected and studied statistics on many things. Trees, starfish, stars, rocks, words, almost anything that can be counted has been a subject of statistics.

Before we can describe the world with statistics, we must collect data. The data that we collect in statistics are called measurements. After we collect data, we use one or more numbers to describe each observation or measurement. For example, suppose that we want to find out how popular a certain TV show is. We can pick a group of people (called a sample) out of the total population of viewers. Then we ask each viewer in the sample how often they watch the show. The sample is data that one can see, and the population is data that one cannot see (assuming that not every viewer in the population are asked). For another example, if we want to know whether a certain drug can help lower blood pressure, we could give the drug to people for some time and measure their blood pressure before and after.

Numbers that describe the data one can see are called descriptive statistics. Numbers that make predictions about the data one cannot see are called inferential statistics.

Descriptive statistics involves using numbers to describe features of data. For example, the average height of women in the United States is a descriptive statistic: it describes a feature (average height) of a population (women in the United States).

Once the results have been summarized and described, they can be used for prediction. This is called inferential statistics. As an example, the size of an animal is dependent on many factors. Some of these factors are controlled by the environment, but others are by inheritance. A biologist might therefore make a model that says that there is a high probability that the offspring will be small in size—if the parents were small in size. This model probably allows to predict the size in better ways than by just guessing at random. Testing whether a certain drug can be used to cure a certain condition or disease is usually done by comparing the results of people who are given the drug against those who are given a placebo.

Most often, we collect statistical data by doing surveys or experiments. For example, an opinion poll is one kind of survey. We pick a small number of people and ask them questions. Then, we use their answers as the data.

The choice of which individuals to take for a survey or data collection is important, as it directly  the statistics. When the statistics are done, it can no longer be determined which individuals are taken. Suppose we want to measure the water quality of a big lake. If we take samples next to the waste drain, we will get different results than if the samples are taken in a far-away and hard-to-reach spot of the lake.

There are two kinds of problems which are commonly found when taking samples:

We can reduce chance errors by taking a larger sample, and we can avoid some bias by choosing randomly. However, sometimes large random samples are hard to take. And bias can happen if different people are not asked, or refuse to answer our questions, or if they know they are getting a fake treatment. These problems can be hard to fix. See standard error for more.

The middle of the data is called an average. The average tells us about a typical individual in the population. There are three kinds of average that are often used: the mean, the median and the mode.

The examples below use this sample data:

  Name | A   B   C   D   E   F   G   H   I   J
 ---------------------------------------------
  score| 23  26  49  49  57  64  66  78  82  92

The formula for the mean is

Where  are the data and  is the population size (see also Sigma Notation).

This means that one calculates the mean by adding up all the values, and then divide by the number of values. For the example above, the mean is:

The problem with the mean is that it does not tell anything about how the values are . Values that are very large or very small change the mean a lot. In statistics, these extreme values might be errors of measurement, but sometimes the population really does contain these values. For example, if there are 10 people in a room who make $10 per day and 1 who makes $1,000,000 per day. The mean of the data is $90,918 per day. Even though it is the average amount, the mean in this case is not the amount any single person makes, and thus is not very useful for some purposes. 

The mean described above is the arithmetic mean. Other kinds are useful for some purposes.

The median is the middle item of the data. For a given data , this is sometimes written as . To find the median, we sort the data from the smallest number to the largest number, and then choose the number in the middle. If there is an even number of data, there will not be a number right in the middle, so we choose the two middle ones and calculate their mean. In our example above, there are 10 items of data, the two middle ones are 57 and 64, so the median is (57+64)/2 = 60.5.  

As another example, like the income example presented for the mean, consider a room with 10 people who have incomes of $10, $20, $20, $40, $50, $60, $90, $90, $100, and $1,000,000. Here, the median is $55, because $55 is the average of the two middle numbers, $50 and $60.  If the extreme value of $1,000,000 is ignored, the mean is $53.  In this case, the median is close to the value obtained when the extreme value is thrown out.  The median solves the problem of extreme values as described in the definition of mean above.

The mode is the most frequent item of data. For example, the most common letter in English is the letter e. We would say that e is the mode of the distribution of the letters.

As another example, if there are 10 people in a room with incomes of $10, $20, $20, $40, $50, $60, $90, $90, $90, $100, and $1,000,000, then the mode is $90, because $90 occurs three times and all other values occur fewer than three times.

There can be more than one mode. For example, if there are 10 people in a room with incomes of $10, $20, $20, $20, $50, $60, $90, $90, $90, $100, and $1,000,000, the modes are $20 and $90. This is bi-modal, or has two modes. Bi-modality is very common, and it often indicates that the data is the combination of two different groups.  For instance, the average height of all adults in the U.S. has a bi-modal distribution.  This is because males and females have separate average heights of 1.763 m (5 ft 9 + 1⁄2 in) for men and 1.622 m (5 ft 4 in) for women.  These peaks are apparent when both groups are combined.

The mode is the only form of average that can be used for data that can not be put in order.

Another thing we can say about a set of data is how spread out it is. A common way to describe the spread of a set of data is the standard deviation. If the standard deviation of a set of data is small, then most of the data is very close to the average. If the standard deviation is large, though, then a lot of the data is very different from the average.

The standard deviation of a sample is generally different from the standard deviation of its originating population . Because of that, we write  for population standard deviation, and  for sample standard deviation.

If the data follows the common pattern called the normal distribution, then it is very useful to know the standard deviation. If the data follows this pattern (we would say the data is normally distributed), about 68 of every 100 pieces of data will be off the average by less than the standard deviation. Not only that, but about 95 of every 100 measurements will be off the average by less than two times the standard deviation, and about 997 in 1000 will be closer to the average by less than three standard deviations.

We also can use statistics to find out that some percent, percentile, number, or fraction of people or things in a group do something or fit in a certain category.

For example, social scientists used statistics to find out that 49% of people in the world are males.

In order to support statisticians, many statistical software have been developed:




#Article 308: Speed (125 words)


Speed is the distance of a moving  in a given amount of time. Speed is a measure of how fast something is moving. The average speed of an object in a certain time is the distance the object travelled divided by the time. Speed is also the distance covered by an object per unit time.

To find speed ,

where  is the distance and  is the time that has gone by.

There are many units of measurement for speed. For example, an object's speed can be measured in 

When an object changes speed, it gets faster or slower. If the speed of the object increases, it is called acceleration. If the object gets slower, and the speed , it is called deceleration, or negative acceleration.




#Article 309: Server (478 words)


In net jargon, a server is a computer that serves many kinds of information to a  or client machine. Usually a server will only do a few things for many clients. Every type of thing a server does is called a service. Services are used by other computers that are called clients. The relationship between client and server is called a client-server relationship. For example, Wikipedia has web servers which have a service for sending web pages over the Internet. Your client computer talks to Wikipedia's web page service to get web pages for you. A server can also host internet games, share files, and give access to peripheral equipment such as printers. In simple words, the individual computers are connected to some powerful computers called servers. These store files and information in the form of website. With an Internet connection, different users anywhere in the world can access these files.

For servers and clients to talk to each other, they need to be connected to a network.  They need to use the same communication protocol, a set way for machines to talk to other machines.  It is like a language.  For example, the Wikipedia server runs the HTTP to send web sites to your computer, and your computer uses the HTTP Protocol to ask Wikipedia for pages.

Usually, servers are specially made to be more powerful and reliable.  They are usually more expensive than normal computers.  Sometimes, servers can be clustered, which means many servers are working together to do one service.

The server might slow down if there are too many people accessing the server at the same time, resulting in a high load.  An overloaded server might also shut itself down automatically.

In a peer-to-peer system, every computer is both a client and a server to the others. This is commonly put into file sharing and VOIP.  However, this can help in attempts at piracy.

Typical server operating systems are Linux, FreeBSD, NetBSD, and OpenBSD.  Unlike other computers, a server often has no monitor, keyboard, or mouse.  When a server doesn't have to do very much, server software can run on a computer that is also doing other things.

A web server is a type of server that is used to host websites.
Examples of web server software include Apache or IIS. A web server can host one, or many, websites. The default port for a web server to listen to is port 80 (HTTP) or 443 (HTTPS).

Some web servers do other things than just serving a web page.  For example, they may have something called SSI that makes building a website easier.

Web servers use services like CGI to let software on the server make web pages. Some of the programming languages that can use CGI are scripting languages like Perl, Python, PHP, or ASP. Some are compiled languages like C++ or Java.




#Article 310: State (769 words)


In modern politics, a state is an association which has control over a geographic area or territory. States are seen as having three main pieces:

There are different forms of government a state can have, for example a republic or a monarchy. Sometimes states form their own countries. At other times many states work together to form a country (like the United States). Most states also have armed forces, civil service, law and police.

The earliest states were just human settlements. A group of farmers and merchants working together could be 'states' since people can control them and protect them.

More organized states could be monarchies such as early Egypt under the Pharaoh. Following this were larger more military-based states such as the Babylonian Empire or Roman Empire. The most famous early states, however, were the Ancient Greek states which had freedom, writing and a democracy.

When the military-based state, the Roman Empire,and  fell, lots of little states were made and each was also military-based and controlled by a king. These states did not often work together and war raged. However, once people within the state itself started fighting (what's called a Civil war), the kings had to make peace and start parliaments.

Modern states soon started in the late 15th century. The main states in Europe were:

These states all tried to improve their politics and economy and became more and more like the states today. They formed proper boundaries for their lands and worked with power within the state itself more, such as the Church or the nobility. They made armies, tax systems and embassies all to help make them more powerful and stable.

Types of state can be separated into two categories: democracy and dictatorship. However, just because a group of states are all democratic does not mean that they follow the same rules. Iran, Pakistan, France, Germany and the United States of America are all states. Each of them sees itself as a democracy. Each of them however has a different idea of what democracy really means.

Different states of the same 'category' can also function differently. For example, two democratic states may be quite different if one has a well-trained police or army while the other does not. Therefore, the word 'state' only tells us what type of government that state follows (democratic or dictatorship) and does not tell us about the country itself.

There are lots of sub-types of state branching off from democracy and dictatorship. The main ones are Pluralism, Marxism and Institutionalism.

Pluralism has been very popular in the United States. It shows the state as a neutral place for settling arguments between other states. Pluralism tells us that all people are not equal, but still allows each group of people to tell the state what to do. This type of state is called a polyarchy.

Also in a pluralist state, politics, the military and the economy are all united and work together. This means that all power in the state is 'diffused' across the people who live there.

Marxism was an ideologie advoctaing for the rights of workers and labourers of society. It was started by Karl Marx and Friedrich Engels. Marxism rejects the idea that a state is there to protect business interest, and is definitely not a neutral place for settling arguments.

The main job of a Marxist state is to protect the labour and financial situation of the peasant classes. With such reforms, a Marxist state focusses on collectivising resources and creating a planned economie to ensure the wellbeing of the workers. 

Both Marxism and Pluralism states have to react to the activities of groups of people in the state itself. Institutionalist states do not see themselves as 'instruments' to be controlled, they are more just geographical areas. In this area, the people just form groups themselves. An Institutionalist state can be made up of both Marxist and Pluralist people, both which have the power to control themselves and not influence the other parties of the state.

Anarchism is when a group of people have complete freedom and do not believe in having a state at all. Anarchists are a lot like Marxists, since they do not believe that all people are equal, but they believe (opposite to Marxists) that a country can work without any organizations in it. Law and order are not necessary.

Anarchists (such as Bakunin and Kropotkin in the 19th century), often want a form of Marxism but ignoring some of their rules. They want workers to manage themselves and simply get paid for what they do, rather than getting paid in wages.




#Article 311: Stream (836 words)


A stream is a natural flow of water moving across country between banks.  It is smaller than a river. 

The primary meaning of stream is a body of water, confined within a bed and banks, and detectably flowing.  Synonyms or related words include river, creek, tributary, run, branch, brook, bourne, wash, and fork. Navigable streams are sometimes called waterways, though the term may apply to any size of permanent and natural water feature except oceans.

In the United States, an intermittent stream is one that only flows for part of the year and is marked on topographic maps with a line of blue dashes and dots.  In desert areas of the American Southwest, this also includes washes, which only flow after thunderstorms or other significant rains.  A blue-line stream is one which flows for most or all of the year and is marked on topographic maps with a solid blue line. In Australia, an intermittent stream is usually called a creek, and marked on topographic maps with a solid blue line.

Generally, streams that form only during and immediately after precipitation are termed ephemeral streams.

Streams in geographic terms are awarded order designations.  A stream of the first order is a blue-line stream which does not have any other blue-line stream feeding into it.  A stream of the second order is one which is formed by the joining of two or more blue-line streams.  A third-order stream is one below the confluence of two or more second-order streams; a fourth-order stream is formed by the confluence of at least two third-order streams, and so forth.

Typically, streams are said to have a particular profile, beginning with steep gradients, no flood plain, and little shifting of channels, eventually evolving into streams with low gradients, wide flood plains, and extensive meanders.  The initial stage is sometimes termed a young stream, and the later state a mature or old stream.  However, a stream may meander for some distance before falling into a young stream condition.

The gradient of a stream is a critical factor in determining its character, and is entirely determined by its base level of erosion.  The base level of erosion is the point at which the stream either enters the ocean, a lake or pond, or enters a stretch in which it has a much lower gradient, and may be specifically applied to any particular stretch of a stream.  In geologic terms, the stream will erode down through its bed to achieve the base level of erosion throughout its course.  If this base level is low, then the stream will rapidly cut through underlying strata and have a steep gradient, and if the base level is relatively high, then the stream will form a flood plain and meanders.

When a stream flows over an especially resistant stratum and forms a waterfall or cascade, or the same results because for some reason the base level of erosion suddenly drops, perhaps as a result of a fault, the resulting sudden change in stream elevation is called a nickpoint.  The stream, of course, expends kinetic energy in trying to eliminate the nickpoint.

Meanders are looping changes of direction of a stream.  These may be somewhat sine-wave in form.  Typically, over time, the meanders don't disappear but gradually migrate downstream.  However, if some resistant material slows or stops the downstream movement of a meander, a stream may erode through the neck between two legs of a meander to become temporarily straighter, leaving behind an arc-shaped body of water termed an oxbow lake or bayou.  A flood may also result in a meander being cut through in this way.

The point of origin of a stream is often called the headwaters or source.  The entire basin drained by the stream is termed the watershed.  Every watershed is made up of smaller watersheds, while most watersheds are parts of larger watersheds.  For instance, the Continental Divide in North America divides the Atlantic Ocean watershed from the Pacific Ocean watershed, but the Atlantic Ocean watershed may be first divided into the Atlantic Ocean drainage and the Gulf of Mexico drainage.  This delineation within the United States is termed the Eastern Divide.  The Gulf of Mexico watershed may be divided into Mississippi River basin and a number of smaller watersheds, such as the Tombigbee River watershed.

The Mississippi River watershed includes the Ohio River watershed, which in turn includes the Kentucky River watershed, and so forth.

The point at which a stream empties into an ocean or other large body of relatively level water is termed the mouth.  There may often be an estuary or delta at the mouth.

Some streams flow underground through unconsolidated sediments or through caves.  Especially with caves, a stream may flow aboveground for part of its course, and underground for part of its course.  When a stream emerges from an underground course, it is termed a spring.

The study of streams and waterways in general is known as surface hydrology and is important in environmental geography or environmental geology.




#Article 312: Solar System (1061 words)


The Solar System is the Sun and all the objects that orbit around it. The Sun is orbited by planets, asteroids, comets and other things. 

The Solar System is about 4.6 billion years old. It formed by gravity in a large molecular cloud. Most of this matter gathered in the center, and the rest flattened into an orbiting disk that became the Solar System. It is thought that almost all stars form by this process.

The Sun is a star. It contains 99.9% of the Solar System's mass. This means that it has strong gravity. The other objects are pulled into orbit around the Sun. The Sun is mostly made out of hydrogen, and some helium.

There are eight planets in the Solar System. From closest to farthest from the Sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The first four planets are called terrestrial planets. They are mostly made of rock and metal, and they are mostly solid.  The last four planets are called gas giants.  This is because they are much larger than other planets and are mostly made of gas.

The Solar System also contains other things. There are asteroid belts, mostly between Mars and Jupiter.  Further out than Neptune, there is the Kuiper belt and the scattered disc. These areas have dwarf planets, including Pluto, MakeMake,Haumea,Ceres and Eris. There are thousands of very small objects in these areas. There are also comets, centaurs, and there is interplanetary dust.

Six of the planets and three of the dwarf planets are orbited by moons.  Furthermore, planetary dust orbits the gas giants.  Many other systems like the Solar System have been found.  Each of the billions of stars in the Milky Way galaxy might have a planetary system.

The formation and  of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud.

Most of the collapsing mass collected in the centre, forming the Sun, while the rest flattened into a protoplanetary disk of loose dust, out of which the planets, moons, asteroids, and other Solar System bodies formed.

This model, known as the nebular hypothesis, was developed in the 18th (1700s) century by Emanuel Swedenborg, Immanuel Kant, and Pierre-Simon Laplace. It has been adjusted by scientific disciplines such as astronomy, physics, geology, and planetary science. As our knowledge of space has grown, the models have been changed to account for the new observations.

The Solar System has evolved considerably since its initial formation. Many moons have formed from circling discs of gas and dust around their parent planets, while other moons are believed to have formed and were later captured by their planets. Still others, as the Earth's Moon, may be the result of giant collisions.

Many collisions between bodies have occurred, and have been important to the evolution of the Solar System. In the early stages, the positions of the planets sometimes shifted, and planets have switched places. This planetary migration is thought to have been responsible for much of the Solar System's early evolution.

The Earth's orbit around the Sun is nearly a perfect circle, but when mapped it is found that the Earth moves around the Sun in a very slightly oval shaped orbit, called an elliptical orbit. The other planets in the Solar System also orbits the Sun in slightly elliptical orbits. Mercury has a more elliptical orbit than the others, and some of the smaller objects orbit the Sun in very eccentric orbits.

For thousands of years, people had no need for a name for the Solar System. They thought the Earth stayed still at the center of everything (geocentrism). Although the Greek philosopher Aristarchus of Samos suggested that there was a special order in the sky, Nicolaus Copernicus was the first to develop a mathematical system that described what we now call the solar system. This was called a new system of the world. In the 17th century, Galileo Galilei, Johannes Kepler and Isaac Newton began helping people understand physics more clearly. People began to accept the idea that the Earth is a planet and moves around the Sun, and that the planets are worlds with the same physical laws that control Earth. More recently, telescopes and space probes have led to discoveries of mountains and craters, and seasonal meteorological phenomena such as clouds, dust storms and ice caps on the other planets.

In their order from the Sun:

The planets are the biggest objects that go around the Sun.  It took people many years of using telescopes to find the objects that were farthest away.  New planets might still be found, and more small objects are found every year.  Most of the planets have moons that orbit around them just as the planets orbit the Sun. There are at least 173 of these moons in the solar system.

Pluto had been called a planet since it was discovered in 1930, but in 2006 astronomers meeting at the International Astronomical Union decided on the definition of a planet, and Pluto did not fit. Instead they defined a new category of dwarf planet, into which Pluto did fit, along with some others. These small planets are sometimes called plutinos.

There are a few main parts of the Solar System. Here they are in order from the Sun, with the planets numbered, and the dwarf planets marked with the letters a - e.

The first four planets closest to the Sun are called the inner planets. They are small and dense terrestrial planets, with solid surfaces. They are made up of mostly rock and metal with a distinct internal structure and a similar size. Three also have an atmosphere. The study of the four planets gives information about geology outside the Earth. Most asteroids are also often counted with the inner planets

The Oort cloud is separate from the trans-Neptune region, and much farther out. It contains the long-period comets.

The plane of the ecliptic is defined by the Earth's orbit around the Sun. All of the planets orbit the Sun roughly around this same orbital plane. The farther away from this plane a planet orbits, the more inclined is its orbit to the ecliptic. If you could look at the solar system edge on then all the planets would be orbiting more or less in the plane of the ecliptic.




#Article 313: Saturn (2387 words)


Saturn is the sixth planet from the Sun in the Solar System. It is the second largest planet in the Solar System, after Jupiter. Saturn is one of the four gas giant planets, along with Jupiter, Uranus, and Neptune.

Inside Saturn is probably a core of iron, nickel, silicon and oxygen compounds, surrounded by a deep layer of metallic hydrogen, then a layer of liquid hydrogen and liquid helium and finally, an outer gaseous layer.

Saturn has 67 known moons orbiting the planet. 38 are officially named and 29 are waiting to be named. The largest moon is Titan, which is larger in volume than the planet Mercury. Titan is the second-largest moon in the Solar System. The largest moon is Jupiter's moon, Ganymede. There is also a very large system of rings around Saturn. These rings are made of ice with smaller amounts of rocks and dust. Some people believe that the rings were caused from a moon impact or other event. Saturn is about 1,433,000,000 km (869,000,000 mi) on average from the Sun. Saturn takes 29.6 Earth years to revolve around the Sun.

Saturn was named after the Roman god Saturnus (called Kronos in Greek mythology). Saturn's symbol is ♄ which is the symbol of Saturnus' sickle.

Saturn is an oblate spheroid, meaning that it is flattened at the poles, and it swells out around its equator. The planet's equatorial diameter is , while its polar diameter (the distance from the north pole to the south pole) is ; a 9% difference. Saturn has a flattened shape due to its very fast rotation, once every 10.8 hours.

Saturn is the only planet in the Solar System that is less dense than water. Even though the planet's core is very dense, it has a gaseous atmosphere, so the average specific density of the planet is 0.69 g/cm3. This means if Saturn could be placed in a large pool of water, it would float.

The outer part of Saturn's atmosphere is made up of about 96% hydrogen, 3% helium, 0.4% methane and 0.01% ammonia. There are also very small amounts of acetylene, ethane and phosphine.

Saturn's clouds show a banded pattern, like the cloud bands seen on Jupiter. Saturn's clouds are much fainter and the bands are wider at the equator. Saturn's lowest cloud layer is made up of water ice, and is about  thick. The temperature here is quite low, at 250 K (-10°F, -23°C). However scientists do not agree about this. The layer above, about  thick, is made up of ammonium hydrosulfide ice, and above that is a layer of ammonia ice clouds  thick. The highest layer is made up of hydrogen and helium gases, which extends between  and  above the water cloud tops. Auroras are also known to form in Saturn in the mesosphere. The temperature at Saturn's cloud tops is extremely low, at 98 K (-283 °F, -175 °C). The temperatures in the inner layers are much higher than the outside layers because of the heat produced by Saturn's interior.
Saturn's winds are some of the fastest in the Solar System, reaching 1,800 km/h (1,118 mph), ten times faster than winds on Earth.

Saturn's atmosphere is also known to form oval shaped clouds, similar to the clearer spots seen in Jupiter. These oval spots are cyclonic storms, the same as cyclones seen on Earth. In 1990, the Hubble Space Telescope found a very large white cloud near Saturn's equator. Storms like the one in 1990 were known as Great White Spots. These unique storms only exist for a short time and only happen about every 30 Earth years, at the time of the summer solstice in the Northern Hemisphere.
Great White Spots were also found in 1876, 1903, 1933, and 1960. If this cycle continues, another storm will form in about 2020.

The Voyager 1 spacecraft found a hexagonal cloud pattern near Saturn's north pole at about 78°N. The Cassini−Huygens probe later confirmed it in 2006. Unlike the north pole, the south pole does not show any hexagonal cloud feature. The probe also discovered a hurricane-like storm locked to the south pole that clearly showed an eyewall. Until this discovery, eyewalls had only been seen on Earth.

Saturn's interior is similar to Jupiter's interior. It has a small rocky core about the size of the Earth at its center. It is very hot; its temperature reaches 15,000 K (). Saturn is so hot that it gives out more heat energy into space than it receives from the Sun. Above it is a thicker layer of metallic hydrogen, about  deep. Above that layer is a region of liquid hydrogen and helium. The core is heavy, with about 9 to 22 times more mass than the Earth's core.

Saturn has a natural magnetic field that is weaker than Jupiter's. Like the Earth's, Saturn's field is a magnetic dipole. Saturn's field is unique in that it is perfectly symmetrical, unlike any other known planet. This means the field is exactly in line with the planet's axis. Saturn generates radio waves, but they are too weak to be detected from Earth. The moon Titan orbits in the outer part of Saturn's magnetic field and gives out plasma to the field from the ionised particles in Titan's atmosphere.

Saturn's average distance from the Sun is over 1,400,000,000 km (869,000,000 mi), about nine times the distance from the Earth to the Sun. It takes 10,759 days, or about 29.8 years, for Saturn to orbit around the Sun. This is known as Saturn's orbital period.

Voyager 1 measured Saturn's rotation as being 10 hours 14 minutes at the equator, 10 hours 40 minutes closer to the poles, and 10 hours 39 minutes 24 seconds for the planet's interior. This is known as its rotational period.

Cassini measured the rotation of Saturn as being 10 hours 45 minutes 45 seconds ± 36 seconds. That is about six minutes, or one percent, longer than the radio rotational period measured by the Voyager 1 and Voyager 2 spacecraft, which flew by Saturn in 1980 and 1981.

Saturn's rotational period is calculated by the rotation speed of radio waves released by the planet. The Cassini−Huygens spacecraft discovered that the radio waves slowed down, suggesting that the rotational period increased. Since the scientists do not think Saturn's rotation is actually slowing down, the explanation may lie in the magnetic field that causes the radio waves.

Saturn is best known for its planetary rings which are easy to see with a telescope. There are seven named rings; A, B, C, D, E, F, and G rings. They were named in the order they were discovered, which is different to their order from the planet. From the planet the rings are: D, C, B, A, F, G and E.

Scientists believe that the rings are material left after a moon broke apart. A new idea says that it was a very large moon, most of which crashed into the planet. This left a large amount of ice to form the rings, and also some of the moons, like Enceladus, which are thought to be made of ice.

The rings were first discovered by Galileo Galilei in 1610, using his telescope. They did not look like rings to Galileo, so he called them handles. He thought that Saturn was three separate planets that almost touched one another. In 1612, when the rings were facing edge on with the Earth, the rings disappeared, then reappeared again in 1613, further confusing Galileo. In 1655, Christiaan Huygens was the first person to recognise Saturn was surrounded by rings. Using a much more powerful telescope than Galilei's, he noted Saturn is surrounded by a thin, flat, ring, nowhere touching.... In 1675, Giovanni Domenico Cassini discovered that the planet's rings were in fact made of smaller ringlets with gaps. The largest ring gap was later named the Cassini Division. In 1859, James Clerk Maxwell showed that the rings cannot be solid, but are made of small particles, each orbiting Saturn on their own, otherwise, it would become unstable or break apart. James Keeler studied the rings using a spectroscope in 1895 which proved Maxwell's theory.

The rings range from  to  above the planet's equator. As proved by Maxwell, even though the rings appear to be solid and unbroken when viewed from above, the rings are made of small particles of rock and ice. They are only about  thick; made of silica rock, iron oxide and ice particles. The smallest particles are only specks of dust while the largest are the size of a house. The C and D rings also seem to have a wave in them, like waves in water. These large waves are  high, but only moving slowly at about  each day. Some scientists believe that the wave is caused by Saturn's moons. Another idea is the waves were made by a comet hitting Saturn in 1983 or 1984.

The largest gaps in the rings are the Cassini Division and the Encke Division, both visible from the Earth. The Cassini Division is the largest, measuring  wide. However, when the Voyager spacecrafts visited Saturn in 1980, they discovered that the rings are a complex structure, made out of thousands of thin gaps and ringlets. Scientists believe this is caused by the gravitational force of some of Saturn's moons. The tiny moon Pan orbits inside Saturn's rings, creating a gap within the rings. Other ringlets keep their structure due to the gravitational force of shepherd satellites, such as Prometheus and Pandora. Other gaps form due to the gravitational force of a large moon farther away. The moon Mimas is responsible for clearing away the Cassini gap.

Recent data from the Cassini spacecraft has shown that the rings have their own atmosphere, free from the planet's atmosphere. The rings' atmosphere is made of oxygen gas, and it is produced when the Sun's ultraviolet light breaks up the water ice in the rings. Chemical reaction also occurs between the ultraviolet light and the water molecules, creating hydrogen gas. The oxygen and hydrogen atmospheres around the rings are very widely spaced. As well as oxygen and hydrogen gas, the rings have a thin atmosphere made of hydroxide. This anion was discovered by the Hubble Space Telescope.

The Voyager space probe discovered features shaped like rays, called spokes. These were also seen later by the Hubble telescope. The Cassini probe photographed the spokes in 2005. They are seen as dark when under sunlight, and appear light when against the unlit side. At first it was thought the spokes were made of microscopic dust particles but new evidence shows that they are made of ice.
They rotate at the same time with the planet's magnetosphere, therefore, it is believed that they have a connection with electromagnetism. However, what causes the spokes to form is still unknown. They appear to be seasonal, disappearing during solstice and appearing again during equinox.

Saturn has 53 named moons, and another nine which are still being studied. Many of the moons are very small: 33 are less than  in diameter and 13 moons are less than . Seven moons are large enough to be a near perfect sphere caused by their own gravitation. These moons are Titan, Rhea, Iapetus, Dione, Tethys, Enceladus and Mimas. Titan is the largest moon, larger than the planet Mercury, and it is the only moon in the Solar System to have a thick, dense atmosphere. Hyperion and Phoebe are the next largest moons, larger than  in diameter.

In December 2004 and January 2005 a man-made satellite called the Cassini−Huygens probe took lots of close photos of Titan. One part of this satellite, known as the Huygens probe, then landed on Titan. Named after the Dutch astronomer Christiaan Huygens, it was the first spacecraft to land in the outer Solar System. The probe was designed to float in case it landed in liquid.
Enceladus, the sixth largest moon, is about  in diameter. It is one of the few outer solar system objects that shows volcanic activity. In 2011, scientists discovered an electric link between Saturn and Enceladus. This is caused by ionised particles from volcanos on the small moon interacting with Saturn's magnetic fields. Similar interactions cause the northern lights on Earth.

Saturn was first explored by the Pioneer 11 spacecraft in September 1979. It flew as close as  above the planet's cloud tops. It took photographs of the planet and a few of its moons, but were low in . It discovered a new, thin ring called the F ring. It also discovered that the dark ring gaps appear bright when viewed towards the Sun, which shows the gaps are not empty of material. The spacecraft measured the temperature of the moon Titan.

In November 1980, Voyager 1 visited Saturn, and took higher resolution photographs of the planet, rings and moons. These photos were able to show the surface features of the moons. Voyager 1 went close to Titan, and gained much information about its atmosphere. In August, 1981, Voyager 2 continued to study the planet. Photos taken by the space probe showed that changes were happening to the rings and atmosphere. The Voyager spacecrafts discovered a number of moons orbiting close to Saturn's rings, as well as discovering new ring gaps.

On July 1, 2004, the Cassini−Huygens probe entered into orbit around Saturn. Before then, it flew close to Phoebe, taking very high resolution photos of its surface and collecting data. On December 25, 2004, the Huygens probe separated from the Cassini probe before moving down towards Titan's surface and landed there on January 14, 2005. It landed on a dry surface, but it found that large bodies of liquid exist on the moon. The Cassini probe continued to collect data from Titan and a number of the icy moons. It found evidence that the moon Enceladus had water erupting from its geysers. Cassini also proved, in July 2006, that Titan had hydrocarbon lakes, located near its north pole. In March 2007, it discovered a large hydrocarbon lake the size of the Caspian Sea near its north pole.

Cassini observed lightning occurring in Saturn since early 2005. The power of the lightning was measured to be 1,000 times more powerful than lightning on Earth. Astronomers believe that the lightning observed in Saturn is the strongest ever seen.




#Article 314: Slavery (1814 words)


Slavery is when a person is treated as the property of another person. This person is usually called a slave, with the owner being called a slavemaster. It often means that slaves are forced to work, or else they will be punished by the law (if slavery is legal in that place) or by their master.

There is evidence that even before there was writing, there was slavery. There have been different types of slavery, and they have been in almost all cultures and continents. Some societies had laws about slavery, or they had an economy that was built on it. Ancient Greece and Ancient Rome had many slaves.

During the 20th century almost all countries made laws forbidding slavery. The Universal Declaration of Human Rights says that slavery is wrong. Slavery is now banned by international law. Nevertheless, there are still different forms of slavery in some countries.

The English word slave comes from the medieval word for the Slavic peoples of Central Europe and Eastern Europe, because these were the last ethnic group to be captured and enslaved in Central Europe.  According to Adam Smith and Auguste Comte, a slave was mainly defined as a captive or prisoner of war.  Slave-holders used to buy slaves at slave auctions. In many cases slaves are not allowed rights.

Slavery has existed for a long time. Early hunter-gatherers had no use for slaves. They did everything for themselves. Having another pair of hands to help them meant another mouth to feed. Slavery or owning another person made no sense to these people. Once men gathered in cities and towns and there was more than enough food, having a cheap supply of labor made sense. This is when the earliest forms of slavery appeared. Slavery can be traced back to the earliest records, such as the Code of Hammurabi (c. 1760 BC). This refers to it as an established institution.

In the Ancient Near East, captives obtained through warfare often became slaves. This was seen by the laws in the Bible book of  Deuteronomy as a legal form of slavery. But the Israelites were not allowed to enslave other Israelites. The Deuteronomic Code calls for the death penalty for the crime of kidnapping Israelites to enslave them.

In Ancient Egypt, slaves were mainly prisoners of war. Other ways people could become slaves was by inheriting the status from their parents who were slaves. Someone could become a slave if he could not pay his debts. People also sold themselves into slavery because they were poor peasants and needed food and shelter. The lives of slaves were normally better than that of peasants. Young slaves could not be put to hard work, and had to be brought up by the mistress of the household. Not all slaves went to houses. Some also sold themselves to temples, or were assigned to temples by the king. Slave trading was not very popular until later in Ancient Egypt. Afterwards, slave trades sprang up all over Egypt.

In many places, citizens were partly or fully protected from being enslaved, so most slaves were foreigners.

Slaves were important in society and the economy of ancient Rome. They did simple manual labor and domestic services, but also could have complex jobs and professions. Teachers, accountants, and physicians were often slaves. Greek slaves were often highly educated. Most slaves, like those sentenced to slavery as punishment, worked on farms, in mines, and at mills. Their living conditions were brutal, and their lives short.

Slaves were considered property under Roman law and had no legal personhood. Unlike Roman citizens, they could suffer corporal punishment, sexual exploitation (sex workers were often slaves), torture, and summary execution legally. Slave's words could not be accepted in a court of law unless the slave was tortured—a practice based on the belief that slaves would be too loyal to their masters reveal damaging evidence unless coerced. Over time, however, slaves gained some legal protection, including the right to file complaints against their masters. Attitudes changed in part because of the influence among the educated elite of the Stoics, whose egalitarian views of humanity extended to slaves, and because of slave rebellions.

Roman slaves could hold property which, even though it belonged to their s, they were allowed to use as if it were their own. Upper class slaves were allowed to earn their own money. With enough money they could buy their freedom.

After the Roman Empire broke up, slavery gradually changed into serfdom.

Historians estimate that between 650 AD and the 1960s, 10 to 18 million people were enslaved by Arab slave traders. They were taken from Europe, Asia and Africa across the Red Sea, Indian Ocean, and Sahara desert. Male slaves were often employed as servants, soldiers, or workers by their owners. Many male slaves were castrated. It is estimated that as many as 6 out of every 10 boys bled to death during the process. But the high price of Eunuchs made it worthwhile. According to Ronald Segal, author of Islam’s Black Slaves: The Other Black Diaspora (2002), The calipha in Baghdad at the beginning of the 10th Century had 7,000 black eunuchs and 4,000 white eunuchs in his palace”. Women and children taken as slaves were mainly used as servants and concubines. While the later Atlantic slave trade concentrated on men for labor, the Arab slave trade started with men and boys, but shifted over time to concentrate more on woman and young girls for sexual purposes. By the 1900s, Arab slave traders had taken between 10 and 20 million slaves out of Africa.

For four centuries, beginning in the late 15th century, millions of Africans were taken as slaves by Europeans. Europeans began exporting Africans to the New World as a source of cheap labor on colonial plantations.

Between 1452 and 1455, Pope Nicolas V issued a series of papal bulls authorizing the Portuguese to take African slaves. At first slave traders raided coastal areas and carried black people off. But the mines and fields of the colonies needed more and more slaves. In the early 16th century Spain began to issue licenses and contracts to supply slaves. By the 1750s large slaving companies were established. Most of Europe at the time was involved in the slave trade.

Many Europeans who arrived in North America during the 17th and 18th centuries came under contract as indentured servants. The change from indentured servitude to slavery was a gradual process in Virginia. The earliest legal documentation of such a shift was in 1640. This is where an African, John Punch, was sentenced to lifetime slavery for attempting to run away. This case also marked the disparate treatment of Africans as held by the Virginia County Court, where two white runaways received far lesser sentences. After 1640, planters started to ignore the expiration of indentured contracts. They kept their servants as slaves for life. This was demonstrated by the case Johnson v. Parker. The court ruled that John Casor, an indentured servant, be returned to Johnson who claimed that Casor belonged to him for his life. According to the 1860 U. S. census, 393,975 individuals, representing 8% of all US families, owned 3,950,528 slaves. One-third of Southern families owned slaves. Slavery in United States was legally abolished by Thirteenth Amendment to the United States Constitution in 1865.

Millions of people are still slaves in some parts of the world, mostly in South Asia and Africa. It is less common in the developed world because of better law enforcement, but it still happens there as well. The ways in which it is done have changed. Today, slaves may work because of things like a high debt (for example, slaves have to work to pay off a debt). Many victims are told that their families will be harmed if they report the slave owners. Many slaves are forced to be domestic servants. In some cases, their families sell them to the slave owners. Some slaves have been trafficked from one part of the world to another. These people are illegally in their host country, and therefore do not report the abuse. Forced prostitution is a type of slavery. Another form of slavery still happening today is forced child labor. Some children have to work in mines or in plantations, or they have to fight wars as child soldiers, for no pay.

One study says that there are 27 million people (but others say there could be as many as 200 million) in slavery today.

Other terms that describe the recruitement of laborers, and that may have similarities to slavery are Blackbirding, Impressment and Shanghaiing.

Some of the countries where there is still slavery are in Africa, the Middle East, and South Asia.  In summer 2007, 570 people were found to be slaves for brick makers in China. They included 69 children. The Chinese government made a force of 35,000 police check northern Chinese brick kilns for slaves, and sent lots of kiln supervisors and officials to prison and sentenced one kiln foreman to death for killing a worker who was a slave.

In Mauritania, it is thought that up to 600,000 men, women and children, or 20% of the population, are slaves, and that many of them are used as bonded labour. Slavery in Mauritania was made illegal in August 2007. In Niger, there is also much slavery. A Nigerian study has found that more than 800,000 people are slaves, almost 8% of the population. Child slavery has commonly been used when making cash crops and mining.  According to the United States Department of State, more than 109,000 children were working on cocoa farms alone in Côte d'Ivoire (Ivory Coast) in 'the worst forms of child labour' in 2002.
In November 2006, the International Labour Organization said that it would prosecute members of the junta that rules Myanmar (also called Burma) at the International Court of Justice for Crimes against Humanity. This is because the military makes some citizens do forced labour. The International Labour Organisation says that it thinks that about 800,000 people are forced to work this way.

Scholars of Islamic law have condemned the revival of the slave trade of non-Muslim women by the Islamic State of Iraq and the Levant.

An agitation called Abolitionism against slavery began in Christian countries in the 18th century. First they abolished the slave trade so more people wouldn't become slaves. In 1833, the British Empire stopped slavery. Several other countries followed. In the United States, disagreement over slavery led to the American Civil War and the Emancipation Proclamation. In 1865, when the North won, all slaves were made free. Still more countries abolished slavery afterwards. Pedro II of Brazil abolished it in 1888. Forced labor however continued, either against the law or by debt peonage or other methods which the laws of the various countries did not count as slavery.




#Article 315: Soul (515 words)


Many philosophies and religions say that a soul is the part of a living human being which is supernatural and lives after death. It is usually said to be immortal. It cannot be discovered by science, because it cannot be tested in any controlled way. Many different opinions exist as to what happens to personal experience after death. 

Reincarnation is a belief that after the body dies, the soul will be born again in another body. It is important to Hinduism. Buddhists understand the idea of an eternal soul, and the idea of simple annihilation as delusion; they say that there is no unchanging, permanent self, soul or essence in phenomena.  Buddhists believe in transmigration, or rebirth in samsara or other planes of existence, based on how they understand kamma (Pāli; karma in Sanskrit), and nibbana (nirvana in Sanskrit) for Enlightened ones.

Resurrection is the Christian belief that a soul returns in the same body. In most Christian denomination this was realized in Jesus Christ but is also the promise for all souls; see heaven, hell, and Final Judgement.

Most atheists say that there is no such thing as a soul, and that the body is the only part of a person.

In popular culture, soul usually means deep feeling and commitment. It is in this sense that the word appears in the term soul music. However that music was also influenced by gospel music which was religious.

One popular idea about souls that is easy to express, is that a person is a soul, and has a body. The soul is the I in I exist that feels and lives life. What people call the mind could be part of the soul: one soul started this article, other souls have edited it, and another soul is reading it. This view, however, implies that the human body is a possession, and seems to devalue bodies that do not have souls as defined or understood by the speaker (some people say that animals, heretics, and people of another religion do not have souls). Like most uses of the verb to be, there is an ideology in these simple words.

Christianity teaches that all humans have an immortal soul. This means that it is a part of them which does not die when their physical body dies, but lives on with them to heaven or to hell. Christians believe that the soul is the 'breath of life' which God gave to Adam.

In Japan the soul is believed to weigh 21 grams. This belief may have been influenced by the observations of  in the early 1900s. 

One distinction often made is between soul, which is distinct from other souls, and spirit which may be combined with that of other beings. The idea of the Holy Spirit in Christianity, for example, is a universal and shared spirit many souls are part of, and which is expressed on Earth in that faith by the Church meaning the body of Christ meaning all bodies that follow Jesus. This could be more inclusive than the is/has view of souls and bodies.




#Article 316: Soap (322 words)


Soap is a chemical compound resulting from the reaction of an alkali (commonly sodium or potassium hydroxide) with a fatty acid. Soaps are the metallic salts of long chain fatty acids. When mixed with water during bathing or washing, they help people and clothes get clean by lowering the chance of dirt and oil to get to the skin or fabric. Soaps are made from animal fats or vegetable oils. There are two basic steps in making soap. They are called Saponification and Salting-out of soap. Some people like to make their own soap.

Soap cleans very well in soft water. It is not toxic to water life. It can be broken down by bacteria. However, it is slightly soluble in water, so it is not often used in washing machines. It does not work well in hard water. It cannot be used in strongly acidic solutions. Mild hand soaps are only basic enough to remove unwanted skin oils. For other forms of oil, dishwashing soap is strong enough to remove almost all forms of oil without damaging petroleum products such as plastics. It does not damage skin either.

Soap has been made in many ways. Humanity has used soap-like things for thousands of years. The earliest recorded evidence of the making of soap-like materials dates back to around 2800 BC in Ancient Babylon and Sumeria. They were soap solutions, or soapy water.  People made them by mixing ashes with water and fat and boiling them. The Babylonians used water, alkali and cassia to make soap.

A recipe for solid soap appeared in about 800 c.e.  Gauls added salt to the soap solution to make the solid soap fall out.

The Ebers papyrus (Egypt, 1550 BC) suggests that ancient Egyptians bathed often and had animal and vegetable oils with alkaline salts to make a soap-like substance. Egyptian documents say that a soap-like substance was used in the preparation of wool for weaving.




#Article 317: Summary (145 words)


A summary is a condensed explanation of an event, story, document, etc.. i.e. summing up the facts. They are not constrained to any medium or topics. Not to be confused with abstract, which is a summary of a document. There are many different levels of summarization that can be done. The summarizer may choose any length, but the sumarees may not appreciate anything more than absolutely necessary to get the required facts.

Summaries help to spread information fast. They also help people make decisions on if it is something worth looking further into.

A quick good/bad can suffice in some situations. In other situations, the summary may rival the length of the original.

Many scientific journals publish a summary for every large article so people who do not have much time can read the main information quickly without spending too much time reading the article.




#Article 318: Sense (207 words)


There are several meanings of the word sense.  This page is for  - there are more detailed articles on each meaning:

When a word has several meanings, one can refer to it as being used in the sense of... some context or other.  In Simple English for instance we avoid using words in unusual senses.

The human sensory system is usually said to have six senses:

Other animals may have other senses. Fish have lateral lines which detect changes in the water pressure around them, and some can detect changes in electric fields around them.

Sense in this context is the  conveyed by language. 

Another use is to flag whether an argument or statement is correct and understood.  That makes no sense or That is nonsense are examples from everyday speech.  

A variation of this is to say that something does not make economic sense.  Usually these words signal a political dispute or some failure to define terms correctly.

The term common sense is thinking based on a wide experience of life. It used to mean practical . It has a long history of being used in politics, often to mean that some idea will be accepted or rejected because of human nature (what people are like).




#Article 319: Synagogue (365 words)


A synagogue is a place where Jews meet to worship and pray to God.

In Hebrew, a synagogue is called beit knesset, which means, a house of gathering. The word synagogue comes from sunagoge, which is a Greek word. In a synagogue, Jews carry out the Jewish services, which consist of prayers, sometimes with special actions.

A synagogue will usually have a large room for prayers. There might be some smaller rooms for studying. There will be some offices. There will also usually be a big room for special events. 

The front of a synagogue faces towards Jerusalem in Israel.  In the front is the holiest part of the synagogue, the Ark. This is a closet which has the Torah scrolls inside.  The Torah scrolls have the holy writings of Judaism on them.  The Ark usually has a curtain in front of it.

On top of the Ark is light which is always lit, called the “Eternal Lamp”. It is a symbol which means that God is always there.
Every synagogue has a raised platform called the “Bimah”. The person who reads the Torah scroll stands there when he reads. The Bimah is either in the middle of the hall, or in front of the Ark.

In some synagogues men and women sit in different places. Some synagogues even have a short wall so that they can not see each other. This is so that the people will think about the prayers better.

Jews may call synagogues by different names. Many Orthodox and Conservative Jews living in English-speaking countries use the name synagogue or the word shul, which is Yiddish. Jews who speak Spanish or Portuguese call synagogues esnoga. Some Jews call the synagogue a temple. 

Jewish worship does not have to be carried out in a synagogue.  It can be wherever a minyan of ten Jews are. It could be in someone's home or anywhere such as a cruise liner or an airplane. Some synagogues have a separate room or torah study, this is called the beth midrash meaning house of study. Some kinds of Jewish worship can be done alone or with fewer than ten people.
Synagogues are places were Jews can worship.




#Article 320: Scarcity (150 words)


Scarcity in economics is used to describe the lack of various forms of capital.  Scarcity can be used to describe an economic situation in economics, or it can be used to describe more general situations.

In economics, scarcity is the result of  having Unlimited Wants and Needs, or always wanting something new, and having Limited Resources. Limited Resources means that there are never enough resources, or materials, to satisfy, or fulfill, the wants and needs that every person have. Scarcity is called the basic economic problem, meaning that always exists.

Scarcity exists due to the effects of nature such as drought, floods, storms, pest infestation, fire and other things.  Real scarcity can also exist by over use of non-renewable resources.  Goods (things) and services are also scarce because there are only a limited number of things in the world and due to the limits of technology and our own priorities.




#Article 321: Textual difficulty (767 words)


Textual difficulty means how easy or hard a text is to read. Research has shown that two main factors affect the ease with which texts are read.

A readability test is a way to measure a text for how easy it is to read. Readability tests give a prediction as to how difficult readers will find a particular text. They do this by measuring one or both of the two main causes, as follows:

Word difficulty is usually measured by vocabulary lists or word length. 
In 1923, Bertha A. Lively and Sidney L. Pressey published the first reading ease  formula. They had been concerned that science textbooks in junior high school had so many technical words. They felt that teachers spent all class time explaining their meaning. They argued that their formula would help to measure and reduce the “vocabulary burden” of textbooks. Their formula used the Thorndike word list as a basis. Manually, it took three hours to apply the formula to a book.

Several vocabulary lists have been published by researchers. These lists are based on samples of published texts in English, and (less often) samples of recorded spoken language. The lists differ slightly according to the sources chosen, but they are very reliable. The items listed may represent more than one actual word; they are lemmas. For instance the entry be contains within it the occurrences of is, was, be and are. The top 100 lemmas account for 50% of all the words in the Oxford English Corpus.

The Reading Teachers Book of Lists claims that the first 25 words make up about one-third of all printed material in English, and that the first 100 make up about one-half of all written material.

One of the first readability tests, the Dale–Chall formula, used a vocabulary list. It counted the number of listed words in a passage, and applied a formula which gave a grade level. It was used to rate textbooks for grade levels in US school districts.

It is easy, in principle, to use a vocabulary list as part of a computer-based readability measure. The list is organised as a look-up table. The percentage of listed words in a passage gives the data for the formula, and the user is presented with a grade level.

This is called an index, or a proxy. This is because word length is correlated with word frequency, and word frequency is correlated with word difficulty. Longer words are, on average, harder than short words. 

Word length is measured by counting the letters in each word, or by counting syllables. Since most syllables have one vowel, some computer programs count vowels per average word. A few tests measure the percentage of words on a list; the list is based on the known frequency of words in a language.

Sentence difficulty is usually measured by sentence length. This again is an index, because longer sentences are, on average, harder than short sentences. Computers count the number of words between full stops, but this is a second-best method. Humans can judge whether a semi-colon or colon should count as the end of a sentence for testing purposes.

Since both factors may vary independently of each other, the best prediction is gained by devising a formula with makes use of both indices. What this means is that a single score is produced for a text, and that score is looked up on a table or graph. That tells you how difficult the text is in terms of either a) an American school grade level, or b) an artificial scale of 0% to 100%. Either way is effective. What really makes a difference is:

It is possible to get a good prediction by getting a group of subjects to read through a passage, followed by multiple-choice questions. Even better is a method called cloze, where subjects fill in blanks on a text they have not seen before. The percentage of correctly completed blanks is an outstandingly good predictor of text difficulty.

Naturally, this kind of direct measure requires subjects and a skilled experimenter. It also requires the prior preparation of texts suitable for the chosen sample of subjects. The method is therefore too expensive for widespread use.

A person can perform readability tests himself by counting and doing some math, or by using word-processing software. 

Wikipedia Signposts 2015-06-24 surveyed recent studies of web information on medical topics, including articles in English wiki.

Their summary was:

That shows these articles, and presumably many other medical articles on English wiki, are written in prose far too difficult for the average member of the public. 




#Article 322: Theatre (853 words)


Theatre (British English and also American English), or Theater (mostly American English), has several meanings.

The word comes originally from the Greek Theatron, meaning roughly, 'a place to behold'. In American English, the word 'theater' can mean either a place where films are shown (this is also called a cinema) or a place where live stage plays are performed. In British English, 'theatre' means a place where live plays are performed.  Some people, both English and American, use the spelling 'theatre' to mean a place where live plays are performed, and the spelling 'theater' to mean a cinema.

'Theatre' can also mean the business of putting on plays. An actor might say I am in the theatre business, or a writer might say I write for the theatre, meaning that they write plays, rather than writing for movies or television shows.

The first people we know created plays were the Ancient Greeks, about the year 500 B.C. They divided plays into two kinds: tragedy and comedy. This division is still used today. The best known Ancient Greek writers of plays are Aeschylus, Sophocles, Euripides and Aristophanes. Some of their plays survived, and are still performed today.

These ancient Greek plays were performed outdoors in large amphitheatres, so that many people could see them. There were contests among the playwrights (people who write plays are called playwrights) and the winner would get a prize.

The Greeks had many brilliant ideas. They used mechanical devices like trap doors and the machina: a crane for winching gods on and off the stage (hence 'Deus ex machina'). They had a Greek chorus that offered information to help the audience follow the performance. The chorus comments on themes, and shows how an audience might react to the drama. The players wore masks. Illustrations on vases show helmet-like masks, covering the entire face and head, with holes for the eyes and a small aperture for the mouth, plus a wig. The mask was to ‘melt’ into the face and allow the actor to vanish into the role. Therefore, onlookers did not think about the actor, but thought about the character.

In the Middle Ages, the Catholic Church began to use theatre as a way of telling the stories from the Bible to people who did not know how to read.  They wrote Mystery Plays, where each part of the Bible story would be a play put on by a different group of people.  They wrote miracle plays which were about the lives of the saints.  They wrote morality plays which taught the audiences how to live a good Christian life.

In the 1500s, groups of actors toured around Italy performing comic plays to entertain townspeople.  These plays were called Commedia dell'arte, and different stories would be created around the same group of characters.  Often the spoken lines would be made up by the actors for each performance.

Other kinds of plays called Neoclassical Dramas and Neoclassical Comedies were also popular in Italy and in France at this time. These plays were written to copy the style of the plays from Ancient Greece and Rome.

At the end of the sixteenth century (before 1600), the traveling actors began to perform in fixed theatre buildings. This was the period when William Shakespeare wrote. He lived from 1564 to 1616. At that time, in England, women were not allowed to perform, so male actors would play female characters.

His theatre was in London, England. It was called The Globe Theatre.  It was an outdoor theatre and plays were performed in the daytime for large audiences. His plays were very popular and many are still performed today. Many people believe Shakespeare was one of the best playwrights (a writer of plays).

Plays including Shakespeare's were banned during the Protectorate'. After that, many more were written and acted.

After World War II, playwrights in Europe and the United States began doing plays in a new style called Theatre of the Absurd. After seeing the horrors of war, these playwrights felt that all their old values had been destroyed. Playwrights such as Samuel Beckett, Eugène Ionesco, Harold Pinter, and Jean Genet wrote plays that are considered to be Theatre of the Absurd.

The Theatre of the Absurd plays have some of the same ideas that are found in the philosophy (a way of thinking) called existentialism. Existentialism is very different from many other philosophies. Most religions and philosopies say that human life has a meaning (or a purpose). The philosophy of existentialism is that human life does not have a meaning (or a purpose). When something has no meaning, it is absurd. (absurd means means silly and meaningless.)

The plays written in this style make people think about questions like what is it like to be a person in the world? and what does it mean for a person to be free? They are often filled with sad emotions, such as worry, fear, and thoughts about death.

Theatre breaks are a form of short holiday, based around viewing a theatrical convention show. Theatre breaks tend to include a nights hotel accommodation included in the price.




#Article 323: Test (357 words)


A test is a way of checking something to see if it is true, or false, or if it is edible or not. If something can be tested, or finishes the tests correctly, it is testable. The Concise Oxford English Dictionary defines a test as: a procedure intended to establish the quality, performance, or reliability of something.

A test is different from an experiment: Before a test is done, there is an expected result. The test is performed, to show this result. In an experiment, the outcome is open. Very often, tests are performed as part of an experiment.

Products are usually tested for quality, so customers will get good products.

In software engineering, a test is used to see if the software system can do what it should. Software is tested before it is released. Alpha testing is where software developers check the software for bugs. Software can also be checked for quality and usability. Beta testing is done by groups of users.

Tests of cars and other vehicles include a crash test. The car is put under severe conditions to see what will make it fail, or deliberately crashed to measure the damage. Other machines can also be crash tested. Crash test dummies can be used instead of humans. They are placed in the car seat to see if a human in the crash would have been injured or killed.

 are tested to see what they have learned. This is often called an  or examination. In learning, a test item is a question, or set of questions.

Many people think tests are valuable. They believe tests:

However, academic tests are not perfect measures. Tests could only partly measure a student’s memory and maybe their understanding. The test would only be about a small part of the subject, and only at that moment in time. Measurement can vary considerably and randomly based on questions being asked.

 and animals can also be tested for illnesses. For example, a blood test can be used to check for disease.

In science, tests can done to check for a presence of a substance, or to check the quality of something.




#Article 324: Time limit (189 words)


A time limit is a time horizon that is imposed on everyone at once. 

It may be used to try to achieve fairness in some system of ethics.  For instance, if poor people and rich people are debating something, a time limit may be imposed so that the rich people cannot keep debating until the poor people have to go to work, and lose.

Time limits are very important in accounting so that everyone can report their results (for tax and investment ) at the same time.  This in turn creates deadlines for the accountant and those reporting.

However, the deadline is imposed by an authority, whereas the time limit is imposed by a system.  So there can be slack in a deadline, so that results do not have to be reported always very fast.

For example, in the United States of America, the end of the calendar year on December 31 is the time limit for taxes, but the deadline for reporting is April 15.  Sometimes the government allows more time, as it did for the families of those who were killed in the September 11, 2001 attacks.




#Article 325: Taiwan (397 words)


Taiwan, officially the Republic of China (ROC; Chinese: 中華民國; pinyin: Zhōnghuá Mínguó), is a region and country in East Asia. It is the nationalist government of China since its settlement in 1949. It is called the  Republic of China (ROC) (also called Taiwan) which is a special region comprising the island of Taiwan and nearby islands (Pescadores islands and parts of Fujian). The ROC government led by Chinese Nationalist (Kuomintang abbreviated as KMT) moved to Taiwan after the Communist army took over the capital of Beijing. Currently, the ROC government governs Taipei, the capital of Taiwan. Taiwan is southeast of the People's Republic of China's mainland, south of Japan, and north of the Philippines.

Taiwan has also been called Formosa, a Portuguese name which means beautiful in Portuguese.

The largest cities in Taiwan are the capital, Taipei, and the port city of Kaohsiung.

Most people living in Taiwan (sometimes called Taiwanese) are Han. Taiwan has three large Han groups. They speak different dialects of Chinese and their ancestors came from different places: the Southern Fujianese (from China's Fujian Province), the Hakka (from China), and Mainlanders (from Mainland China after 1948).

There are also Taiwanese Aborigines who have lived in Taiwan before the Han came to live there.

In March 2004, China's government passed a law called the Anti-Secession Law. The law requires the Chinese military to invade Taiwan immediately if they declare independence. The law shows China's  over a growing move towards independence by the government of Taiwan.

The island of Taiwan is about 180 kilometers off the southeastern coast of China. It is across the Taiwan Strait. It has an area of . The East China Sea is to the north, the Philippine Sea to the east, the Luzon Strait directly to the south and the South China Sea to the southwest.

Taiwan's highest point is Yu Shan (Jade Mountain). It is 3,952 meters high (12,966 ft).  There are five other peaks over 3,500 meters.

The Penghu Islands are  west of the main island. They have an area of . More distant islands controlled by the Republic of China are the Kinmen, Wuchiu and Matsu Islands off the coast of Fujian. They have a total area of . The Pratas Islands and Taiping Island in the South China Sea have a total area of . They have no permanent inhabitants.

The largest cities in Taiwan are:




#Article 326: Trademark (543 words)


A trademark (or trade mark) is a way for a business to help people to identify the products that the business makes from products made by another business. A trademark can be a name, word, phrase, symbol, logo, design, or picture. It can only be used on things made by the business that owns the trademark. 

For example, Coca-Cola and Coke are trademark names for a certain drink made by the Coca-Cola Company. No other business can use these names or any names similar to them. Other businesses can make a drink that is similar, like colas soft drinks, but they have to use a different name for their drink, such as Pepsi.

Another example is the Nike company which makes sporting goods like shoes and clothes. The swoosh symbol used on their products is a trademark.

Famous trademarks like Coca-Cola and Nike are used for branding whole families of products.

Trademarks are protected by law. In some countries, a person or company can get a trademark simply by using the name, word, phrase, symbol, logo, design, or picture on its products.

Trademarks can also be registered. In that case, the business tells the government of its country that it wants to use a certain name, word, phrase, symbol, logo, design or picture as a trademark for the products it sells. If no other person or business is using the trademark to sell those products, then the government will list that trademark. Once it is listed, no one else can use that trademark for those products. This is called ing the trademark.

If someone uses the trademark in a wrong way, the trademark owner can sue the other person. If a court decides that the other person was not allowed to use the trademark, they might have to pay damages to the trademark owner. 

If another person wants to use a trademark that they do not own, they can ask the trademark owner for permission.  The trademark owner can grant the other person a license.  The other person usually must pay some money to the trademark owner for the license.  This can be in the form of a percentage of the cost of the product that the other person sells called a royalty. For example, a person might pay Nike ten percent (10%) of the cost of each pair of shoes it sells for the right to include the Swoosh.

When people write a word that is a trademark or show a picture or symbol that is a trademark, they should say that it is a trademark. If a trademark is not registered, they can write the word Trademark, use the abbreviation TM, or use the symbol ™ on their products. 

If a trademark is registered, they can use the letter R in a circle symbol: ®. People can also say it is a registered trademark or use the abbreviation Reg.

Trademarks are used for products.  Businesses that do things for people instead of making things are called service providers. They can get a service mark instead of a trademark. When people write or show a service mark, they can use the service mark symbol: ℠.

In the United States, the governing law for trademarks is the Lanham Act, in Germany the Markengesetz.




#Article 327: Ten Commandments (1611 words)


The Ten Commandments are a set of rules or laws. God gave them to the people of Israel.  The commandments exist in different versions. One version can be found in the Book of Exodus of the Bible. Another version can be found in the Book of Deuteronomy . In the Book of Exodus, the mountain where they were given is called Mount Sinai, the Book of Deuteronomy talks about Mount Horeb. Both are probably different names for the same mountain. The rules were written on stone tablets. These rules are important for Judaism and Christianity. Countries which follow those religions have some of the commandments as part of their Civil laws.

Sometimes these rules are also called Decalogue (from Greek, can be translated as ten statements). The name decalogue first occurs in the Septuagint. The Israelites  received the commandments after they had left Egypt during the reign of Pharaoh Thutmose. There are different texts talking about the commandments. Most of them are in the Bible: The Book of Exodus, Chapter 20 and the book of Deuteronomy, Chapter 5. The Qu'ran mentions the tablets but does not list exactly the same commandments. For instance Quran 17:23-39 starts with worshipping God alone and honouring your parents.

The Exodus version (from the ESV BIBLE)

The Ten Commandments in Deuteronomy Chapter 5: verses 1-22 NKJV

These commandments are translated from ancient Hebrew to Basic English, so the exact words chosen may not mean to us exactly what they meant to the Hebrews. There are a variety of interpretations of these commandments:

The  Roman Catholics understanding of the commandment to not make any image, or any likeness of any thing that is in heaven above means that likenesses may be built and used, as long as the object is not worshipped as an idol. 

The Eastern Orthodox Church has a very similar position. Eastern Orthodoxy teaches that the incarnation of an invisible God as a visible human, Jesus, makes it alright to use flat images in worship (see Iconoclasm). 

Most other Christians allow statues of religious figures, provided there is no veneration of them.  They are not commonly found in Protestant Churches, but may be found nearby or in Museums.  Historical figures or busts may be used for educational purposes. Stained glass windows may contain depictions of honored historical or Biblical persons. 

Judaism in its various forms usually takes a position somewhere between the Protestant view and that of Islam. Synagogues would not have any statues in them. Images of God are forbidden anywhere. 

Islam forbids any images whatsoever of Allah (God) or persons, including Mohammad. That is why their buildings are generally decorated with calligraphy but never depictions of living beings.

Jehovah's Witnesses criticize the use of all of the above, as well as the use of the cross. 

The Amish forbid any sort of image, such as photos.

This can be understood to mean cursing or using profanity which includes the name of God.
Many languages have expressions of anger or dismay that include the word God.  In addition, many times people swear to God to try to convince others they are telling the truth. Another offense might be to say that God told me to do something when He didn't.  The actual name of God in the Old Testament was YHWH, sometimes pronounced Yahweh or Jehovah.  Pious Jews refrain from using this name or even the word God, for which they substitute G_d.  This is to avoid using God's name in a way that might break this commandment.

Jews honor the Sabbath (Shabbat) from sundown on Friday until the appearance of three stars in the sky on Saturday night, the seventh day of the week on the Jewish calendar. 

In the New Testament Jesus did things that made the Sabbath command different from the other nine. Jesus seemed to reduce its demands, unlike some other commandments where he made them stronger. Jesus was often criticized for healing on the Sabbath or doing other things.  He said that the Sabbath was made for man, and not man for the Sabbath.  Doing good on the Sabbath seemed to be praised and practiced by Jesus.  In that way he disobeyed some of the strict interpretations that had become common in His day.  

Most Christians honor the Sabbath on Sunday to remember the Resurrection of Jesus on the first day of the week on the Jewish calendar.

Some conservative Christians are Sabbatarians (most of these follow the Reformed traditions). Sabbatarians think the first day of the week or Lord's Day is the new Sabbath, because the 4th commandment has never been removed. They also say that the Sabbath law was given when the world was made. It came before the ten commandments were given. 

Others believe that the Sabbath remains as a day of rest on Saturday, while Sunday as a day of worship, in reference to Acts 20:7: the disciples came together on the first day of the week to break bread and to hear the preaching of the apostle Paul. Also, Jesus appeared to his followers on the first day of the week while they were in hiding. 

The Seventh-day Adventist Church, and some others, believe that the custom of meeting for worship on Sunday originated in paganism, specifically Sol Invictus and Mithraism (in which sun god worship took place on Sunday). Instead, Adventists keep Saturday as the Sabbath as a memorial to God's work of creation believing that none of the Ten Commandments can ever be destroyed. Seventh-day Sabbatarians claim that the seventh day Sabbath was kept by the majority of Christian groups until the 2nd and 3rd century, but because of opposition to Judaism after the Jewish-Roman wars, the original custom was gradually replaced by Sunday as the day of worship.

To be false to the married relation, called adultery, is when a married person has sexual relations with a person other than his or her spouse. Having sex outside of  marriage is fornication and is also sin. It is condemned in other places in the Bible, but not specifically in the Ten Commandments.  Jesus taught his audience that the outward act of adultery does not happen apart from sins of the heart: From within people, from their hearts, come evil thoughts, unchastity, theft, murder, adultery, greed, malice, deceit, licentiousness, envy, blasphemy, arrogance, folly. All these evils come from within and they defile.” In The New Testament Jesus says But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.

There are different translations of this commandment; the Hebrew words  are translated either as thou shalt not kill or thou shalt not murder. Older Protestant translations of the Bible, those based on the Vulgate and Roman Catholic translations usually translate it Thou shalt not kill.  The Catholic Church believes that endangerment of human life or safety  is a mortal sin that breaks The Fifth Commandment.  Furthermore, the Catholic Church does not believe in a difference between murder and manslaughter the way the law does.  With the exceptions of killing in self-defense (a form of manslaughter in many nations' laws) and killing in war, the Catholic Church believes all other forms of killing or attempting to kill violate The Fifth Commandment. Unsafe driving could also lead to unintentional killing. Jewish and newer Protestant versions tend to use You shall not murder. There are different opinions as to which translation is more faithful to the original.

The many examples in the Old Testament of killing sanctioned by God, are quoted in defense of the view that murder is more accurate.  Furthermore, the Hebrew word for kill is  - harog, while the Hebrew word for murder is  - retzach, which is found in the Ten Commandments  - lo tirtzach.

Many theologians (such as German Old Testament scholar A. Alt: Das Verbot des Diebstahls im Dekalog (1953)) suggest that commandment you shall not steal was originally intended against stealing people—abductions and slavery. This would be the same as the Jewish interpretation of the statement as you shall not kidnap (e.g. as stated by Rashi). Civil laws in most countries list many types of stealing. These include burglary, embezzlement, looting, robbery, shoplifting or fraud. The penalties depend on the value of the thing stolen, and if violence was used to take it. 

In some places stealing horses brought a death penalty.  That is because it could cause danger or even death to the horse's owner who could no longer do necessary travel.  Poaching is the illegal killing of wild animals. Especially in modern times, money is often stolen by trickery or keeping false bank or debt records. In the 21st century this can be done using computers. This is called White-collar crime.

Some societies have attempted to say that no property is private but everything belongs to the whole society. If this were ever put in practice, it would make stealing impossible, but it has not been fully practiced anywhere.

To give false witness would include lying in court which is called perjury. Telling false gossip which harms someone is similar. Some think this commandment includes all lying. It is to knowingly give any false statement.  Others allow a white lie. Some Jewish teachers said that not all lying is false witness (perjury). They say that lying is sometimes permissible or even commendable. This would include changing the truth to be modest or to avoid harm to someone.  Saint Augustine believed that some lies could be pardoned, and that there were in fact occasions when lying would be the right thing to do. Various religions divide the commandments differently.  The table below shows those differences.




#Total Article count: 326
#Total Word count: 198871