Aarushhh/wikipedia-simple-splitted huggingface dataset:
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”.

Churches through the ages 

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.

English churches 

In English churches there were several different periods of architecture:
The Saxon period (700–1050) was a time when churches were very simple. The end of the church (end of the sanctuary) was often rounded. Hardly any are left now because they were mostly made of wood.
 The Norman period (1050–1190) came from the style called Romanesque which was popular in Europe. The arches had ornaments which were called “mouldings”. The tops of the pillars looked like cushions, so they were called “cushion capitals”. The windows were narrow and rounded at the top.
 Early English or Gothic architecture (1190–1280) was not as solid and heavy as Norman architecture. Towers were elegant and tall, like the tower of Salisbury Cathedral.
 The Decorated style of architecture (1280–1360)was popular at a time when the plague (Black Death) was raging and a third of the people in England died. For that reason, not so much building was done then. There were lots of stone carvings were made in churches at that time.
The Perpendicular style (1360–1540) was very grand. It had lots of straight upward lines and fan vaulting. This can be seen in Westminster Abbey and King's College Chapel, Cambridge. Many churches that can be seen in England were built in this period.
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.

Related pages
Cathedral
Chapel
Choir (music)

References 

 Encyclopædia Britannica, 1973

Other websites 

 Virtual Church
A city is a place where many people live close together.

A city has many buildings and streets. It has houses, hotels, condominiums, and apartments for many people to live in, shops where they may buy things, places for people to work, and a government to run the city and keep law and order in the city. People live in cities because it is easy for them to find and do everything they want there. A city usually has a "city center" where government and business occur and suburbs where people live outside the center.

Definition

No rule is used worldwide to decide why some places are called "city," and other places are called "town."
Some things that make a city are :
 A long history. Although many cities today have only been around for tens or hundreds of years, there are a few which have been so for thousands of years. For example, Athens, Greece was founded in 1000 BC and Rome, Italy has existed since 700 BC.
 A large population. Cities can have millions of people living in and around them. Among them are Tokyo, Japan, and the Tokyo Metropolis around it, which includes Yokohama and Chiba.
 In Japan, the population of a city ( 市 ) is at least over 50,000 people. and among cities, there are various grades according to laws, which the central government of Japan governs.
A center where business and government takes place. The first case is often described as the financial capital, such as Frankfurt in Germany. The second case is true for different levels of government, whether they are local or part of a larger region (for example, Atlanta, Georgia, or the capital of the United States Washington, D.C.) Cities that contain the government of the region it is in are called capitals. Almost every country has its own capital.
 Special powers called town privileges which have been given by the government of the country or its ruler. Europe during the Middle Ages was a great example of having town privileges.
 Having a cathedral or a university. This rule is found in the United Kingdom. The smallest "cathedral cities" are St. David's and St. Asaph's which are both in Wales, Ripon and Wells which are in England.
In American English, people often call all places where many people live cities. (See below: Size of cities )

Size of cities

The sizes of cities can be very different. This depends on the type of city. Cities built hundreds of years ago and which have not changed much are 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 marketplace. 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 Sienna, a significant 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.

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 named " 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 include several small ancient towns and villages. The metropolis of London includes London, Westminster, and many old villages such as Notting Hill, Southwark, Richmond, Greenwich, 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. Automobiles, factories, and waste create a lot of pollution that makes people sick.

Urban history
Urban history 

Urban history is history of civilization. The first cities were made in ancient times, as soon as people began to create civilization . The oldest city on Earth is probably Catal Huyuk, which existed from 7500BCE to 6500bce, although mainstream historians consider Catal Huyuk to be a proto-city.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 than 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 privilege, 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.
Features

Infrastructure 

People in a city live close together, so they cannot grow all their own food or gather their own water or energy. People also create waste and need a place to put it. Modern cities have infrastructure to solve these problems. Pipes carry running water, and power lines carry electricity. Sewers take away the dirty water and human waste. Most cities collect garbage to take it to a landfill, burn it, or recycle it.

Transport is any way of getting from one place to another. Cities have roads which are used by automobiles (including trucks), buses, motorcycles, bicycles, and pedestrians (people walking). Some cities have trains and larger cities have airports. Many people in cities travel to work each day, which is called commuting.
Buildings and design 
Houses and apartments are common places to live in cities. Great numbers of people in developing countries (and developed countries, in the past) live in slums. A slum is poorly built housing, without clean water, where people live very close together. Buildings are usually taller in the city center, and some cities have skyscrapers.

City streets can be shaped like a grid, or as a "wheel and spokes": a set of rings and lines coming out from the center. Streets in some older cities like London are arranged at random, without a pattern. The design of cities is a subject called urban planning. One area of the city might have only shops, and another area might have only factories. Cities have parks, and other public areas like city squares.

United States politics
Atlanta, Georgia: 5 of the 16 delegates representing Georgia in the US Congress are Democrats. All hail from districts in Atlanta.
 New Orleans, Louisiana: the only Democratic delegate from Louisiana in the US Congress was elected from a New Orleans district.
 Kansas City, Kansas: the only Democratic congressman from Kansas was elected from a district in Kansas City.
 Las Vegas, Nevada: all of the Democrats in the US House who represent Nevada are from Las Vegas.
 Salt Lake City, Utah: the only Democrat representing Utah in the US Congress was elected from a Salt Lake City district.
 Chicago, Illinois: if it weren't for Chicago, the state of Illinois would be as conservative as Indiana.
 Louisville, Kentucky: the only Democrat representing Kentucky in the US Congress was elected from a Louisville district.

World's largest cities
These cities have more than 10 million people and can be called megacities:
 Tokyo, Japan - 37 million
 Delhi, India - 29 million
 Shanghai, China - 26 million
 São Paulo, Brazil - 22 million
 Mexico City, Mexico - 22 million
 Cairo, Egypt - 20 million
 Mumbai, India - 20 million
 Beijing, China - 20 million
 Dhaka, Bangladesh - 20 million
 Osaka, Japan - 19 million
 New York, United States - 19 million
 Karachi, Pakistan - 15 million
 Buenos Aires, Argentina - 15 million
 Chongqing, China - 15 million
 Istanbul, Turkey - 15 million
 Kolkata, India - 15 million
 Manila, Philippines - 13 million
 Lagos, Nigeria - 13 million
 Rio de Janeiro, Brazil - 13 million
 Tianjin, China - 13 million
 Kinshasa, DR Congo - 13 million
 Guangzhou, China - 13 million
 Los Angeles, United States - 12 million
 Moscow, Russia - 12 million
 Shenzhen, China - 12 million
 Lahore, Pakistan - 12 million
 Bangalore, India - 11 million
 Paris, France - 11 million
 Bogotá, Colombia - 11 million
 Jakarta, Indonesia - 11 million
Chennai, India - 10 million
 Lima, Peru - 10 million
 Bangkok, Thailand - 10 million
Gallery of cities

References
Cooking is a process to make food ready to eat by heating it.

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.

Methods
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.

Cooks 

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.

 
Basic English 850 words
To chat is to talk about ordinary things that are not very important. A person can chat with another person, or to many people. People also use this word now for parts of the Internet where we can talk with many different people at the same time. Usually, people chat on the Internet in a chat room or messaging service like AOL Instant Messenger (AIM), Yahoo Messenger Windows Live Messenger or Tencent QQ. There are also programs which let people use different messaging services from one program, such as Pidgin.

Related pages
 Internet Relay Chat (IRC)
 Conversation

Human communication
Internet communication
Messaging
A cup is any kind of container used for holding liquid and drinking. These include:

teacup
paper cup

Cup may also mean:

Measuring cup, a measuring instrument for liquids and powders, used primarily in cooking
Cup (unit), a customary unit of volume and measure
Cancer of unknown primary origin, form of cancer
The cup of a brassière, the part that covers the breasts
A cup-shaped trophy or award for winning in a sport

Basic English 850 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. The latter two often fall under the category of victimless crime

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.
Etymology 
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".

Definition
Definition

England and Wales 
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.

Scotland 
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.

Sociology 
A normative definition views crime as deviant behavior that violates prevailing norms – cultural standards prescribing how humans ought to behave normally.
Levels of crime 
There are various levels of crimes. In some jurisdictions they are:
 misdemeanor - a minor crime, typically punished by a fee or less than 1 year in jail.
 felony (or high crime) - a major crime, typically punished by 1 year or longer in prison.

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:
 Actus rea - the criminal did something against the law
 Mens rea - the criminal knew what they were doing was against the law and did it anyways, or they knew they were doing something that could accidentally end up being against the law and didn't care 

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

References
References

Basic English 850 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 in August 2015. It was last archived by the Wayback Machine on January 12, 2016.

Related pages 
 Conspiracy theory
 Pseudoscience

References 

Pseudoscience
American websites
1997 establishments in the United States
Conspiracy theories
The Census of Marine Life was a ten-year survey of life in the oceans, starting in 2000. Its head was Ron O'Dor of Dalhousie University in Halifax, Nova Scotia, Canada. It used data from researchers all over the world. More than 70 nations were involved and over a billion US dollars were spent on it.

It was a major work of marine ecology. It was founded by J. Frederick Grassle.

The purpose of the Census of Marine Life was to say what is alive in our seas and oceans.

Other websites 
 Census of Marine Life website

Biological oceanography
Marine life
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.

The genus Zea 
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.

References 

 
Model organisms
Civics is the study of government.  It most often refers to studying government in high school to prepare to be a good citizen.  In college, civics is usually called political science.  Since a city has the most unsimple government problems, the word for this study is like that for city.

Theories of civics can be grouped as:

Anarchist
Capitalist
Democrat
Green
Libertarian
Republican

It contains the rule and regulations of the citizen to make the country democratic
Political science
Calculus is a branch of mathematics that describes continuous change.

There are two different types of calculus. Differential calculus divides (differentiates) 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 sciences such as physics, astronomy, biology, engineering, economics, medicine and sociology.
History
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

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

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 writes 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: 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.
Differential calculus is also useful for graphing. A very similar problem is to find the slope (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 vertical) divided by how much it goes across (x or horizontal). 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.

In the real world, calculus 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.

Integral calculus

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
.

Main idea of calculus
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".

Applications of calculus
Calculus is used to describe things that change, like things in nature. It can be used for showing and learning all of these:

How waves move. Waves are very important in the natural world. For example, sound and light can be thought of as waves.
Where heat moves, like in a house. This is useful for architecture (building houses), so that the house can be as cheap to heat as possible.
How very small things like atoms act.
How fast something will fall, also known as gravity.
How machines work, also known as mechanics.
The path of the moon as it moves around the earth. Also, the path of the earth as it moves around the sun, and any planet or moon moving around anything in space.

Related pages 

 Calculus of variations
 Derivative (mathematics)
 Difference quotient
 Mathematical analysis
 Multivariable calculus
 Vector calculus

References
A coin is a piece of metal that is used as currency, or money. The earliest coins were in Lydia, in what is Turkey today, in 7th Century BC. They were made from electrum, an alloy found in riverbeds. 

Most people use coins as currency. They usually have lower value than banknotes. Most are made in government mints.

Appearance 
Many coins have unique or complicated decorations; one side often has the picture of a king or ither 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.

Collecting
Collecting 

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.

References
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:
Prices are rising.
I attacked every weak point in his argument. (Argument as war rather than enquiry or search for truth).
Life is a journey.
Love talked about as if it were war or competition.
Time talked about as if it were a path through space, or a quantity that can be saved or spent or wasted.

The idea of a conceptual metaphor came from a book by George Lakoff and Mark Johnson in 1980: Metaphors we live by.
"The most recent linguistic approach to literature is that of cognitive metaphor, which claims that metaphor is not a mode of language, but a mode of thought". Donald Freeman.
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.
Political metaphors 
 eminence grise: literally, "grey man," from French. Colloquially, the power-behind-the-throne. An official close to the president or monarch who has so much power behind the scenes that he or she may double or serve as the monarch.
 figurehead: a leader whose powers are entirely symbolic, such as a constitutional monarch.
 puppet government: a government that is manipulated by a foreign power for its own interests.
 star chamber: a secretive council or other group within a government that possesses the actual power, regardless of the government's overt form.
 character assassination: spreading (usually) manufactured stories about a candidate with the intent to destroy his or her reputation in the eyes of the public.
 landslide victory: a huge victory for one side.
 riding coattails: victories by local or state politicians because of the popularity of more powerful politicians.
 grassroots: a political movement driven by the constituents of a community.
astroturfing: public relations campaigns in politics and advertising that try to create the impression of being spontaneous, grassroots behavior.
 straw man: the practice of refuting an argument that is weaker than one's opponent actually offers, or which he simply has not put forth at all. A type of logical fallacy.
 spin (public relations): a heavily biased portrayal of an event or situation.
 witch-hunt: the hysterical pursuit of political enemies
 bread and circuses: satisfaction of shallow or immediate desires of the populace at the expense of good policy; also, the erosion of civic duty and the public life in a populace.
There are many more, enough to prove the importance of the metaphor in our lives.

Notes 

Metaphors
Crust is a piece of bread where the edge where it is harder and darker.

Crust can also mean:
Crust (geology) - the outer solid layer of a planet such as the Earth but other planets also.
On Earth the crust can be divided into: 
continental crust on which the land of the planet Earth sits 
oceanic crust which forms most of the ocean floor
Comedy (from ), in modern times, is an 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.

History

Satire 
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.

Satyr plays 
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 
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.

Types

Slapstick 
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.

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.

Parody/Spoof 
A parody or spoof movie imitates or exaggerates another person or movie to make them seem silly, dumb, or just plain out of it.
Different types of comedy movies 
Some types of comedy movies mix comedy with other types of movies. 
There is a type of movie called a dramedy, which is a mix of a drama movie and a comedy movie. 
There is also a type of movie called a romantic comedy (sometimes called a "rom-com"). In romantic comedies, there is a love story about a couple who fall in love, along with silly or funny comedy parts.

Comedy television shows 
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.

Related pages
Comedian
Opera buffa

 
Genres
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 night.  

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.

Famous comets 

Halley's
Hale-Bopp
Shoemaker-Levy 9
Ikeya seki
History of comets 
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.

Related pages
List of comets

Other websites 
Are Comets Made of Antimatter?
Cytology is the study of the cells, especially their appearance and structure. Cells are the small parts that make up all living things, and their effects on each other and their environment.

There are two types of cells. Prokaryotic cells do not have a clear and easy-to-see nucleus, and do not have a membrane, or wall, around them. Eukaryotic cells have an easy-to-see nucleus where all of the cell's functions take place, and a membrane around them. The main organelles of a cell and their uses are: 
 Mitochondria: produces energy for the cell
 Endoplasmic reticulum: makes proteins and carbohydrates for the cell to use
 Golgi bodies: store and package products that the cell uses
 Plastid (present in plant cells only): contains chemicals needed to photosynthesize (create energy from sunlight); in plants only.
 Nucleus: directs the actions of the cell
 Centrosomes: guides the cell in mitosis and meiosis, the processes for cell division.
Related pages
Cell biology is mostly about how cells work, and about cell division and molecular biology.
Histology deals with techniques for looking at tissues under a microscope.
Cytopathology is a medical discipline that deals with techniques for looking at cells under a microscope.

 
Molecular biology
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 or prophesied in the Hebrew Bible/Old Testament.  Christianity is the world's largest religion, with 2.1 billion followers around the world.

Views of the Bible 
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.
Who is a Christian? 
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 formally 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.

Church life 
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.
Related pages
 Christianity
 Religion
 Salvation
 Meitei Christians

References 

Christians