alibayram/wikipedia-40-langs huggingface dataset:
Lyon

Lyon (Arpitan: Liyon) is a city in the southeast of France. It is the third-largest city in the country (behind Paris and Marseille), with about 513,000 people living there in 2015. It is the second largest metropolis, or metro area, in France (behind only that of Paris), with about 2.3 million people in 2014. 

In ancient history, the name of Lyon was Lugdunum. Someone who lives in Lyon is called a Lyonnais (male) or a Lyonnaise (female) in French.

Lyon has a humid subtropical climate (Cfa in the Koeppen climate classification). It is between the Rhône and the Saône. It is about  west of the Italian border. 

The central part of Lyon, located on the peninsula between the Rhône and the Saône, was named a World Heritage Site by UNESCO.

Famous people from Lyon 
 The Lumière Brothers who created cinema
 Paul Bocuse, a world renowned chef

Sports 
Famous sports clubs from Lyon are:

 Olympique Lyonnais: The local football team that plays in Ligue 1
 ASVEL: The local basketball team
 LOU: (Lyon Olympique Universitaire) The local rugby team

Education 
 École Centrale de Lyon
 École pour l'informatique et les nouvelles technologies
 École pour l'informatique et les techniques avancées
 École spéciale de mécanique et électricité
 EMLYON Business School
 E-Artsup
 Institut Polytechnique des Sciences Avancées
 Institut supérieur européen de gestion group
 Institut supérieur européen de formation par l'action
 Sup'Biotech
 Web@cademie

References

 
World Heritage Sites in France
Organic compound

Organic compounds are carbon-based compounds. Organic compounds contain carbon bonds in which at least one carbon atom is covalently linked to an atom of another type (usually hydrogen, oxygen or nitrogen). Most polymers are organic compounds.

History 
The name "organic" is a historical name from the 19th century.

People believed that only living things could make organic compounds and "dead" things (such as minerals) could make inorganic compounds. However, Friedrich Wöhler proved this wrong by synthesizing urea, a well-known organic compound.

Kinds of organic compounds 
There are natural organic compounds, and synthetic ones. Their structure may be described by using names, and making diagrams. 

One way of showing the molecule is by drawing its structural formula. Because molecules can have complicated structures, people have made ways to show them in simple language. One way is to use line diagrams. Each atom is shown by a letter, and connected by a line to each atom with which it is has a covalent bond. One line means a single bond, two lines means a double bond and so on. 

Because there is in an infinite number of possible organic compounds, language is needed to give a unique name to each one. The International Union of Pure and Applied Chemistry, or IUPAC, made a system for doing this. Although an IUPAC name makes every single possible molecule unique, the names are often long and complicated, so in everyday life, trivial names--unofficial but widely understood names--are used, such as the trivial names Paracetamol, Tylenol, and Acetaminophen, which are used for a compound whose IUPAC name is N-(4-hydroxyphenyl) acetamide. Some of these trivial names are trademarks.

Natural Compounds 
Natural compounds are compounds made by living beings. These could also be made in a lab, but many of these compounds are taken from nature because it is easier and less expensive to do it that way. For example, every year people grow and eat huge amounts of natural sugar and starch. Other common natural compounds are: amino acids, proteins, carbohydrates, many antibiotics like Penicillin and Amoxicillin.

Synthetic compounds 
Synthetic compounds are those made by people. Sometimes, this is done by taking something natural and changing the molecule in a small way, such as making glycerin from vegetable oils. Other compounds are synthesized in long, complicated reactions with many steps. Plastics are sometimes mostly natural, and other kinds are manufactured.

Structure 
Since a compound is often first discovered in nature instead of being made on purpose in a lab, people may know the compound exists, and even know what it does sometimes, but not know exactly what atoms it is made of and how it is arranged. There are several ways of taking an unknown compound and finding out this structure:
 Mass spectrometry
 X-ray diffraction
 Nuclear magnetic resonance spectroscopy
 Infrared spectroscopy

Related pages 
Acetone
Inorganic compound
Organic chemistry
Biochemistry

Other websites 
 Organic chemistry online
Natural gas

Natural gas is a mixture of gases. It consists mainly of hydrocarbons. The main component is methane, which is a greenhouse gas. Natural gas is a natural resource, often found in the ground, either alone or together with petroleum. Landfills and natural processes produce a little methane. Usually it is transported to users in a pipeline.

Most natural gas is burnt as a fuel to produce energy. It burns with a blue flame. Like other flames, this can cause pollution with nitrogen oxides.

Natural gas is burned to produce electricity, to cook and to heat buildings. It is also used as fuel for natural gas vehicles for transport. When natural gas is burned in a power station it boils water into steam that spins a steam turbine that turns a generator to make electricity. Some power stations use natural gas in a gas turbine. 

Natural gas is also converted into many different industrial chemicals. It is the most common feedstock for making pure hydrogen. Hydrogen is used as fuel in fuel cells, and to make ammonia. Ammonia is used as a fuel, as a fertilizer for crops, and for making many other things. Natural gas is also converted into monomers to make many plastic products.

Related pages

Fossil fuel
Coal
non-renewable resource

References

Other websites 
History of using natural gas from the U.S. Department of Energy

Fossil fuels
Hydrocarbons
Jewel

Jewels (or gems or gemstones) are rare minerals. They usually come in colours and sizes. They begin in a rough rock form, but can be cut and polished to turn into a jewellery.

However, some other non-mineral rocks (such as lapis lazuli) or organic materials can also be also used for jewelry and are called gemstones. These include amber or jet. Pearls and coral are sometimes also called gemstones.

Most gemstones are hard. Soft minerals are used in jewelry too, because of their luster that gives them value. 

Being rare or in short supply also makes a gemstone valuable.

History 
The Ancient Greeks began to decide which gems are precious and semi-precious. This continued in other cultures. 

In modern times, the precious stones are diamond, ruby, sapphire and emerald, with all other gemstones being semi-precious.

Types 
 Amethyst
 Aquamarine
 Diamond
 Emerald
 Jade
 Peridot
 Ruby
 Sapphire
 Topaz
 Turquoise
 Opal
 Spinel

References

Other websites
 "Book of Royal Gemstones" is a book from 1554 that talks about gemstones.
 "The Blossoms of Thoughts Regarding the Precious Stones" is an old book from the 1600s that is considered one of the most important books about precious stones. It is written in the Arabic language.

Basic English 850 words
Xenon

Xenon is a non-metal chemical element. It has the chemical symbol Xe and atomic number 54. It is one of the few elements that are a gas at the standard temperature and pressure.

History 
Sir William Ramsay and M. W. Travers discovered this element in 1898. The element's name came from the Greek word xenos, which means 'stranger'.

Chemistry 
Xenon belongs to the group of the noble gases. Noble gases are very unreactive. However, in 1962, chemists have found that xenon can react with fluorine under special conditions, such as high pressure and high temperature. It is not known why xenon behaves differently under these circumstances. There are also some compounds with oxygen. The gas is not very reactive, because if fulfills the octet rule. This means that a lot of energy is needed to remove an electron from xenon. This activation energy for xenon is 1172 kJ/mol. To remove a second electron from xenon, an energy of 2046.4 kJ/mol is needed.

Known oxidation states of xenon are 0, +1, +2, +4, +6 and +8. However, the most stable form is pure xenon, or the xenon's oxidation state of 0. Xenon has 8 stable isotopes and more than 30 unstable isotopes.

Uses 
Xenon gas is used in electron tubes, bactericidal lamps, trobe lamps, and lamps used to excite ruby lasers.
It has the atomic mass of 131.294 and is the 5th inert gas in the inner gas group.

Xenon is also a trace gas in the atmosphere, occurring at 87 ±1 nL/L (parts per billion) or approximately 1 in 11.5 million. It is also emitted from some mineral springs.

Related pages
 Periodic table
 List of common elements

Noble gases
Denial

Denial is a word used in psychology on defense mechanism. It  means that someone denies that something has happened or is happening although he really knows it is true. Usually this happens because admitting it would cause a lot of pain.

Denial is usually the first state of coping with loss. For example, if someone close to a person dies, the survivor's first feeling might be denial, or refusal to accept the fact that the person is really dead.

Denial, is also when you think that a team (like in football) will win a football match before its even started and refuse to accept the fact thet they could lose

Denial, is also when you refuse to accept the fact that someone else did something (like change something) when you 'think you know' it was a different person

Psychology
List of physicists

This is a list of physicists.

Chile
Nicanor Parra

France
René Descartes

German
Albert Einstein

 Werner Heisenberg

Heinrich Rudolf Hertz

Georg Ohm

Great Britain
 Ernest Rutherford

England
 Michael Faraday

Thomas Young

Stephen Hawking

Robert Hooke

 James Prescott Joule

Isaac Newton

North Ireland
John Stewart Bell

Scotland
 James Clerk Maxwell

Holland
René Descartes

Italy
Galileo Galilei

Alessandro Volta

New Zealand
 Ernest Rutherford

Serbia
Nikola Tesla

United States

Gerard K. O'Neill
Nikola Tesla

Related pages
Physicist
Physics

Lists of scientists
Brass

Brass is an alloy of copper and zinc. Some types of brass are called bronzes.

Brass has a golden appearance. It is harder than pure metals and resists corrosion. It costs more than zinc.

There are some common brasses:
 Alpha brasses - with less than 40% zinc
 Beta brasses - 
 White brasses - with more than 45% zinc

Things brass are used to make include:
 Brass instruments
 Ornaments
 Electrical fittings
 Buttons
 Screws
 Taps
 Hinges
 Door knobs

Properties
Brass is more malleable than bronze or zinc. The melting point of brass can be 900 to 940 °C or 1,650 to 1,720 °F, depending on what it is made of. The density of brass is 8.4 to 8.73 g/cm3 (0.303 to 0.315 lb/cu in). 

Today, almost 90% of all brass alloys are recycled. Brass is not ferromagnetic. Brass scrap is collected and transported to the foundry. In the foundry, it is melted and recast into billets. The billets are heated and stretched into the form and size that is wanted.

Brass will corrode when it is exposed to moisture, chlorides, acetates, ammonia, and some acids.

Brass alloys 
There are many brass alloys. They include:

 Abyssinian gold
 Admiralty brass
 Aich's alloy
 Aluminum brass
 Arsenical brass
 Cartridge brass
 Common brass
 DZR brass
 Delta metal
 Free machining brass
 Gilding metal
 High brass
 Leaded brass
 Lead-free brass
 Low brass
 Manganese brass
 Muntz metal
 Naval brass
 Nickel brass
 Nordic gold
 Orichalcum
 Prince's metal
 Red brass
 Tombac
 Silicon tombac
 Tonval brass
 Yellow brass

References 

Alloys
Basic English 850 words
Body

A body is the physical material of a person or organism. It is only used for organisms which are in one part or whole. There are organisms which change from single cells to whole organisms: for example, slime moulds. For them the term 'body' would mean the multicellular stage. Other uses:
Plant body
Cell body: here it may be used for cells like neurons which have long axons (nerve fibres). The cell body is the part with the nucleus in it.

The body of a dead person is also called a corpse or cadaver. The dead bodies of vertebrate animals and insects are sometimes called carcasses.

The human body has a head, neck, torso, two arms, two legs and the genitals of the groin, which differ between males and females.

The study of the body is anatomy.                                                                                                                                                                                            

The study of the workings of the body is physiology.

Here are the names of the body parts of a woman and a man. 

The word body is sometimes used in other ways.  For example, a lake is a body of water. The laws on a topic are a "body of law".

Related pages 
 Human body

Body parts
Basic English 850 words
Alloy

An alloy is a uniform mixture. It is made up of two or more chemical elements, of which at least one is a metal. An alloy has properties different from the metals it is made of.

Most alloys are made by melting the metals, mixing them while they are liquid to form a solution, then leaving them to cool and turn solid again.

Theory 
Combining a pure metal with one or more other metals or non-metals often makes it better. For example, steel is an alloy made from iron but it is stronger than iron. Physical properties like density, reactivity and electrical and thermal (heat) conductivity may not be much different than the elements (substances) which make the alloy. But, properties like strength can be very much different.

The first alloy to be discovered was Bronze. Bronze is made from copper and tin. Bronze was discovered a very long time ago in  the prehistoric period. Then, bronze was being used for making tools and weapons. This period was known as Bronze Age. But, later better alloys were discovered which replaced bronze for making tools and weapons. Now, bronze is used for making ornaments, statues, and bells. Brass is another alloy made from copper and zinc.

Melting point is the temperature at which a solid changes to liquid. Most alloys do not have a single melting point. They have a melting range in which the alloy is a mixture of solid and liquid stages. The temperature at which melting just starts is called solidus and the temperature at which the melting is just finished is called liquidus.

Terms related to alloys 
The term alloy means a mixture of atoms in which the main substance or the primary constituent is a metal. This primary metal is called the base or matrix.

If an alloy has only two types of atoms, like copper-nickel alloy, then such an alloy is called binary alloy. If an alloy has three types of atoms, like iron, nickel and chromium, then it is called a ternary alloy. An alloy with four types of atoms is called a quaternary alloy and an alloy with five types of atoms is called a quinary alloy.

Different varieties or forms of alloys can be made from the same constituent materials (substances from which the alloy is formed). These different forms or varieties can be formed by using different amounts of the constituents.

Some common alloys 
There are some common alloys:

 Brass is made of 35% zinc and 65% copper and is used for musical instruments, jewellery, faucets and decorative hardware.
 Stainless steel is mostly iron, plus more than 11% chromium, and various amounts of nickel and carbon and is used for tableware, cookware and surgical tools.
 Steel is made of 99% iron and 1% carbon and is used for tools, car bodies, machinery, girders and rails.
 Bronze is made of mostly copper and some tin and is used for boat hardware, screws and grill work.
 Alnico is a mix of aluminium, nickel and cobalt, and it is used to make permanent magnets.

 
Metallurgy
Material

Material is what everything that you can touch is made of. Even material that is too small to touch, is called material. We use materials to make things. We can also call material "physical substances."

Raw material is materials such as ores which we can clean and mix with other materials to make another material like steel, for example. Cotton is a raw material used to make textiles, which are used to make clothes. Material is not matter, though. Matter is everything in existence. Material is used for things that have use. Refined materials are materials that have been refined, like metal, reduced or converted into better, more useful materials like clothes and tools. Refined materials are usually mixes of other materials, like glue or steel.

Some important materials

 Metals
 Steel
 Aluminum
 Copper
 Gold
 Polymers
 Rubber
 Plastic
 Ceramics
 Glass
 Cement
 Stone
 Textiles
 Cotton fabric
 Wool fabric
 organic materials
 Leather
 Bone
 Paper
 Lumber/wood
 Glue
 Composites
 Fiberglass
 Concrete

Table of material properties

References
Neuron

A neuron (or neurone) is a nerve cell that carries electrical impulses. Neurons are the basic units of our nervous system.

Neurons have a cell body (soma or cyton), dendrites and an axon. Dendrites and axons are nerve fibers. There are about 86 billion neurons in the human brain. Almost all brain cells are neurons. The human brain has about 16 billion neurons in the cerebral cortex. The neurons are supported by glial cells and astrocytes.

Neurons are connected to one another, but they do not actually touch each other. Instead they have tiny gaps called synapses. These gaps are chemical synapses or electrical synapses which pass the signal from one neuron to the next.

Neuron ( link )

Types of neurons

By connection 
There are three classes of neurons: motor neurons, sensory neurons and inter neurons.
 Sensory neurons carry information from tissues and organs into the central nervous system.
 Motor neurons transport signals from the central nervous system to the effector cells.
 Interneurons connect neurons within the central nervous system.

By function 
Sensory neurons carry signals from sense organs to the spinal cord and brain.
Relay neurons carry messages between sensory or motor neurons and the central nervous system
Motor neurons carry signals from the CNS to muscles, motor neurons are connected to the relay neurons. The signal passes between the neurons via synapses. Synapses are microscopic voids between cells where chemicals are released from the axon terminal of one cell to specialized chemical receptors on the dendrite of the receiving cell.

Cell division 
Mature neurons never divide: that is the general rule. They do not undergo cell division. In most cases, neurons are generated by special types of stem cells. A type of glial cell, called astrocytes, have also been seen to turn into neurons. In humans, neurogenesis (the origin of new nerve cells) largely ceases during adulthood  but in two brain areas, the hippocampus and the olfactory bulb, there is strong evidence for substantial numbers of new neurons..

Related pages 
Artificial neural network
Brain cell

References

Other websites 
 Fibrinogen found to inhibit EGFR in neuronal cells Blood clotting protein may inhibit spinal cord regeneration 
 Cell Centered Database  UC San Diego images of neurons.
 High resolution neuroanatomical images of primate and non-primate brains .

Anatomy of the nervous system
Cells
Middle East

The Middle East is a large area of land in the eastern hemisphere. The lands of the Arabian Peninsula and some of the lands of the eastern Mediterranean are part of the Middle East. The Middle East's population is mostly Muslim. The name of the Middle East comes from its position to the east of Europe and to the west of the Far East. 

It is normal for the modern countries of Arabia (Saudi Arabia, Oman, Yemen, Bahrain, Jordan, Kuwait, and the United Arab Emirates) to be counted with the modern countries of  Iraq, Syria, Lebanon, and Palestine (the State of Palestine and Israel) as part of the Middle East.

The name "Middle East" does not always have the same meaning, and the size of the area is not always the same. When the name Middle East started to be common, it was the name for the lands in between the Near East and the Far East. The Indian subcontinent was part of the Middle East at that time. Now, parts of south-west Asia and northern Africa can count as the Middle East. The land between Egypt and Iran is a common definition. Many countries in the Middle East today are also part of the Near East. Sometimes, people name countries that are far away from these countries as countries in the Middle East. These countries can be in North Africa (like Morocco) and the Indian subcontinent (like Pakistan). This area also has the name Greater Middle East.

Many ancient civilizations began in the Fertile Crescent in the Middle East. These were Sumer, Babylonia and Assyria in the area called Mesopotamia. The Abrahamic religions that believe in one God also started in the Middle East. (Judaism and Christianity began in ancient Palestine and Islam began in Arabia.) Today, the Middle East is the homeland of Arabs, Turks, Persians, Kurds, and Jews, among many other ethnic groups. Islam is the most common religion in the Middle East. Islam came to most of the Middle East's lands in the 7th century AD, during the first Muslim conquests of the Sasanian Empire and of the Roman Empire's lands.

Today, the Middle East is very important because much of the petroleum that other countries use comes from here. There are also many arguments and wars, such as the conflict between Sunni and Shia, the Israeli–Palestinian conflict, and the Syrian civil war.

Related pages 

 Western Asia
 Central Asia
 East Asia
 South Asia
 Southeast Asia

References
Warsaw

Warsaw (In Polish: Warszawa) is the capital of Poland in Masovian Voivodeship. It is also the biggest city in that country. There are about 2,000,000 people living there (1,726,581 as of 31 March 2014). People from Warsaw are called "Varsovians".

There are other names for Warsaw. For example,  (Latin, Spanish) and Varsóvia (Portuguese),  (French),  (Italian),  (German, Dutch),  /Varshe (Yiddish),  (Lithuanian),  (Hungarian) and Varšava (Czech)

Geography 
Warsaw is near the middle of Poland on both sides of the Vistula river, and about 350 km (225 miles) from the Baltic Sea. It is about 100 m (325 ft) above sea level. Warsaw has a humid continental climate (Dfb in the Koeppen climate classification).

Warsaw is home to four universities and 62 colleges, and many theatres and art galleries.

History 
People began living here in the 13th century. By the 15th century, Warsaw had grown enough to be called a city. It became the capital of Poland in 1596.

The city was destroyed several times in its history, but every time it was rebuilt. The most important of these times was during the Second World War. Poland had been occupied by Germany between 1939 and 1944. On 1 August 1944, the people of Warsaw started fighting to free their city.

Tourist attractions 
There are lot of attractions in the capital of Poland. The most famous monument of Warsaw is Palace of Culture and Science. There is a palace in Wilanów. The king of Poland John III Sobieski lived there. Many people like going to the Museum of Warsaw Uprising. The uprising started in 1944 during World War II

Partner cities 
-Athens, Greece

-Chicago, USA

- Rio de Janerio, Brazil

- The Hague, The Netherlands

Pictures of Warsaw

References

Other websites 

 Official web page of Warsaw 
 Official tourist web page of Warsaw 
 Interactive city map 
 Modern architecture in Warsaw 
 Historic images of Warsaw
Hindu–Arabic numeral system

The Hindu–Arabic numeral system, sometimes known as Arabic number system, is the system of Latin-script numbers used by almost all the world today. It is a positional notation system. This system has ten basic symbols, they are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. It represents numbers in the decimal numeral system. The Hindu–Arabic numeral system was first developed by the Hindu and Arabs. Later in the 16th century in Germany, it was changed and introduced to the rest of the western world by Albrecht Dürer. The Hindu–Arabic numeral system is one of the few numeral systems that use a place value system. This system is now commonly used all over the world.

They originated in India in the 6th or 7th century and were introduced to Europe through the writings of Middle Eastern mathematicians, especially al-Khwarizmi and al-Kindi, about the 12th century.  They are very different from previous methods of counting, such as the abacus, and paved the way for the development of algebra.  In the past many other systems were used. Fibonacci popularized the Hindu–Arabic numeral system to the western world.

References 

Numbering systems
Point (geometry)

A point is a position in space which has no size, but which does have position.

In geometry, a point has no size, but has a position. This means it has no volume, area or length. We usually represent a point by a small cross 'X' or by a small dot (a small, round shape). Points are always labelled by capital letters (A, B, C...X, Y, Z). It is one of the most fundamental but undefined terms in geometry.

In general, two points can be:
 Coincident (they are one and the same)
 Not coincident (they are not one and the same)
and are always:
 Coplanar (on the same plane)
 Colinear (on the same line)
 Concyclic (on the same circle)

Three points can be:
 Colinear
 Coincident
 Not coincident
 Not colinear
and are always:
 Coplanar
 Concyclic

Four points can be: 
 Coplanar
 Colinear
 Coincident
 Not coincident
 Not colinear
 Not coplanar

Related pages 

 Line
 Plane

References 

Geometry
Line (geometry)

A line is the path of one point that is moving. A line is a type of geometric figure. A line has length, but no width. A line is made up of an endless number of points.

Straight and curved lines 

A line can be straight or curved. In geometry, the word line means a straight line. A straight line is the shortest distance between two points. A straight line is traced by a point moving in a direction that does not change.

A curved line is sometimes called a curve. The edge of a circle is not straight. It is an example of a curve.

Line segments 
A line segment is part of a line. Here are examples of straight line segments:

 _   __

Naming lines 
Lines can get their names from any two points on the line. For example, if a line contains two different points, named  and , then the line can be called either , or .

Sometimes, lines are named with just one symbol. A letter such as  might be used.

Two lines 
Two lines can be:
 Parallel: Two lines are parallel if they are on the same plane and they never touch.
 Concurrent: Two lines are concurrent if they touch on one point.
 Coincident: Two lines are coincident if they are made of the same points.
 Perpendicular: Two lines are perpendicular if they make four right angles where they touch.
 Skew: In Euclidean space, two lines are skew if they are not parallel but they never touch.

Related pages
 Linear function
 Point (geometry)
 Plane (mathematics)

References 

Basic English 850 words
Geometry
Plane (mathematics)

A plane is a perfectly flat surface extending in all directions. It can be thought of as the ceiling of a room, only extended into all directions infinitely. A plane has two dimensions: length and width. All planes are flat surfaces. If a surface is not flat, it is called a curved surface. 

The tool plane can be used to create a flat, level surface like the mathematical plane—hence the name.

In geometry, a plane is made up of an infinite number of lines (or points). It has no depth. It is absolutely flat and infinitely large.

A plane figure is part of a plane. It is named by the capital letters (such as A, B, C, ...X, Y, Z) that are put at its corners. Sometimes, a single capital pi  is also used to refer to a plane. A plane can also be named after three points that are not all on the same line.

In general, two planes can be:
 Parallel (they never meet)
 Concurrent (they meet forming a line)
 Coincident (they are one and the same)

Plane in mathematics 

In mathematics, a plane is a fundamental two-dimensional object. Intuitively, it looks like a flat infinite sheet of paper. There are several definitions of the plane. They are equivalent in the sense of Euclidean geometry, but they can be extended in different ways to define objects in other areas of mathematics. The only two-dimensional figure in our three-dimensional world is a shadow.

In some areas of mathematics, such as plane geometry or 2D computer graphics, the whole space in which the work is carried out is a single plane. In such situations, the definite article is used: the plane. Many fundamental tasks in geometry, trigonometry and graphing are performed in the two dimensional space, or in other words, in the plane.

Euclidean geometry 
 	
A plane is a surface such that, given any three distinct points on the surface, the surface also contains all of the straight lines that pass through any two of them.
One can introduce a Cartesian coordinate system on a given plane in order to label every point on it with a unique ordered pair, which is composed of two numbers and is the coordinate of the point.

Within any Euclidean space, a plane is uniquely determined by any of the following combinations:

 Three points which are not lying on the same line
 A line and a point not on the line
 Two different lines which intersect
 Two different lines which are parallel
 A vector normal to the plane and a distance from the origin

Related pages
 Point (geometry)
 Line

References

Other websites 
 Mathworld: Plane
 Easing the Difficulty of Arithmetic and Planar Geometry (work in Arabic, description in English)

Shapes
Geometry
Angle

When two straight lines come together, they make an angle. The two lines are called the sides of the angle, and they meet at a point. A flat surface (called a plane) also forms an angle when it meets another.

To represent an angle, Greek letters such as  (alpha),  (beta),  (gamma) and  (theta) are sometimes used. An angle indicates the space between its sides, or the amount of rotation needed to make one side coincide the other.

To measure the size of an angle, we use units called degrees. A degree is a standard unit and we use the symbol ° after a number to show that it is a number of degrees. We can use a decimal number or a fraction for part of a degree, but a degree can also be divided into 60 minutes (1° = 60'), and a minute can be divided into 60 seconds (1' = 60"). So 22.5°, 22° and 22° 30' are all the same angle.  

In mathematics, angles can also be (and often are) measured in radians instead of degrees, by using the conversion factor  (for example, ). Yet another unit of angle is gradian, with  . 

Angles are studied in geometry, where an angle where edges meet is often called a vertex. For example, the three sides of a triangle are its edges and two of the edges meet at each vertex. Similarly, two of the six sides (or faces) of a cube meet at each of its twelve edges, and three edges meet at each of its eight corners (or vertices, which is the plural version of vertex).

Types of angles

Individual angles 
 In a zero angle the lines lie one upon the other thus creating a 0° angle aka the zero angle.

 An angle measuring greater (wider) than 0° but less (narrower) than 90° is called an acute angle.

 An angle 90° wide is called a right angle.

 An angle more than 90° but less than 180° is called an obtuse angle.

 An angle that measures 180° is called a straight angle.
 An angle wider than 180° and narrower than 360° is called a reflex angle.
 An angle that has a made or full circle/completed 360° is called a full or complete angle.

Special angle pairs 
In geometry, there are pairs angles having a special relationship with each other, making them interesting and convenient.There is a pair of angles called complementary angles to which the sum of their measure (wideness) is equal to one right angle (which is equal to  turn, 90°, or  radians). Supplementary angles are also two angles, this time their combined measure is a straight angle ( turn, 180°, or  radians). Two angles that total to a full angle ( turn, 360°, or  radians) are referred to as explementary or conjugate angles.

Related pages 

 Sun angle

References

 
Basic English 850 words
List of astrophysicists

An astrophysicist is a person whose profession is astrophysics.

Canada
 Hubert Reeves, is known for  explaining science to the general public (or popularizing science).

Great Britain

England
 Stephen Hawking, is known for Hawking radiation, Penrose–Hawking theorems, Bekenstein–Hawking formula, Hawking energy, Gibbons–Hawking ansatz, Gibbons–Hawking effect, Gibbons–Hawking space, Gibbons–Hawking–York boundary term, Thorne–Hawking–Preskill bet

United States

 Frank Drake, is known for developing the Drake equation, and as the creator of the Arecibo Message, a digital encoding of an astronomical and biological description of the Earth and its lifeforms, for transmission into the cosmos.

 Freeman John Dyson, is known for Dyson sphere, Dyson operator, Dyson series, Schwinger–Dyson equation, Circular ensemble,  Random matrix theory, Advocacy against nuclear weapons, Dyson conjecture, Dyson's eternal intelligence, Dyson number, Dyson tree, Dyson's transform

 Neil deGrasse Tyson, is known for being on a 2001 government commission on the future of the U.S. aerospace industry, and on the 2004 Moon, Mars and Beyond commission; got the NASA Distinguished Public Service Medal; host of television show NOVA ScienceNow on PBS

Related pages
List of astronomers

Lists of scientists
List of vegetables

Some vegetables which are botanically fruits (such as tomatoes) are considered to be vegetables in the culinary (eating) sense. This is why they appear in this article. For sources, see individual pages. See also List of fruits.

References

Food-related lists
List of telescope types

Astronomical telescopes are divided into subgroups. All telescopes work by collecting electromagnetic radiation and focussing it into an image which may be seen or photographed. The purpose is to see things which are far away in the universe.

The traditional types all work to collect visible light from the sky. Recent types may work outside the visible spectrum. They all have their different advantages and disadvantages and they are used in different areas of astronomy.

Optical

Refractors 
Dioptrics.
Telescopes which create their image with an objective that is a convex lens (refractors) are said to be "dioptric" telescopes.
 Achromatic: uses convex and concave lenses together, to correct for chromatic aberration.
 Apochromatic: a more complex arrangement, for even less chromatic aberration.
 Non-achromatic
 Binoculars

Reflectors 
Catoptrics.
Optical systems using mirrors: uses reflected light to form the image.
 Newtonian
 Gregorian
 Cassegrain
 Herschelian telescope

Combined Lens-Mirror Systems 
Catadioptric telescopes use corrector lenses to fix problems in a reflector.
 Schmidt telescope
 Maksutov telescope

Outside the optical spectrum 

 Čerenkov radiation telescope used to detect gamma rays
 Infrared telescope
 Radio telescope
 Submillimeter telescope
 Ultraviolet light telescope (for Ultraviolet astronomy)
 X-ray telescope (for X-ray astronomy)
Wolter telescope

!
Astronomy lists
List of shipwrecks

This list of shipwrecks is of those sunken ships whose remains have been found.

 Aarhus Historic Shipwreck
 Admiral Graf Spee
 VOC ship Amsterdam
 SS Andrea Doria, 1956
 USS Arizona, Pearl Harbor
 VOC ship Batavia
 Bendigo, North Carolina, United States
 Bismarck battleship
 Breadalbane, 1853
 Carnatic shipwreck, Red Sea
 USS California (later San Diego), Long Island
 USS Eagle, Lake Champlain, New York
 Elingamite, New Zealand, 1902
 SS Edmund Fitzgerald, Lake Superior, 1975
 Cape Gelidonya
 Giglio Island, Etruscan wreck
 HMS Hampshire
 HMS Hood
 HMS Hussar
 Iria
 I-18tou midget submarine
 I-52
 Russian submarine Kursk
 Lady Elgin, Chicago, Illinois
 HMT Lancastria
 RMS Lusitania
 Mahdia
 Mary Celestia
 Mary Rose
 Medusa, French passenger ship of west Africa in 1816.
HMS Montague, Lundy Island, England
 USS Monitor
 CSS Muscogee', Georgia, United States
 Nola
 SS Richard Montgomery
 wreck of Rochelongue, France
 Scharnhorst, Norway
Nuestra Senora de Atocha -  Spanish galleon which sank in 1622 and was found on July 20, 1985 40 miles off the coast of Key West, Florida by treasure hunters who soon began to raise $400 million in coins and silver.   
H.M.T. Rohna American troop carrier in WWII
 USS Scorpion
 Seattle, Norway
 Snow Squall
 USS Thresher
 USS Ticonderoga, Lake Champlain, New York
 RMS Titanic
 Uluburun
 Struma, Black Sea
 HMS Wasa, Stockholm, Sweden
 Vicar of Bray
 SS Yongala, Townsville, Australia
 VOC Zuytdorp, Australia, 1712
 RMS Empress of Ireland, Saint Lawrence River
The White Ship, 1120

Further reading
 A. J. Parker, Ancient shipwrecks of the Mediterranean and the Roman provinces (Oxford 1992).

Transport lists
Shipwrecks
List of languages

This is a partial list of natural languages, arranged alphabetically.

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

Related pages
 Language (for information about language in general)
 Constructed language
 List of fictional languages
 List of programming languages
 Sign language
 Languages on the Internet
List of endangered languages

A list of endangered languages (with fewer than 1000 speakers or with very fast decline).

In order to judge if a language is actually endangered, the number of speakers is less important than the distribution among age cohorts. There may be 200,000 mother tongue speakers of the Breton language over 50 years of age, but fewer than 2,000 under 25 years of age - thus it is likely Breton will die out in the next half century. On the other hand, while there are 30,000 Ladin language speakers left, almost all children still learn it as their mother tongue - thus Ladin is not endangered in the 21st century.

 This page should include a link to the language's page, geographical localization and an approximate number of speakers

Americas 
 Michif, spoken by fewer than 1,000 people in western Canada
 indigenous languages of Canada:
 Abenaki, 10 speakers
 Beaver, 300 speakers
 Cayuga, 360 speakers
 Delaware (Munsee), fewer than 10 speakers
 Han, few speakers
 Hare, 600 speakers
 Onandaga, fewer than 100 speakers
 Oneida, 200 speakers
 Potawatomi, 100 speakers
 Sarcee, 10 speakers
 Seneca, 25 speakers
 indigenous languages of the USA:
 Hawaiian language, Hawaii

Asia 
 Ainu, Northern Japan, 15 speakers
 Aramaic, Lebanon, Kurdistan
 Chukchi, Siberia, circa 10,400 speakers (2001)
 Udmurt, various parts of Russia
 Northern indigenous peoples of Russia
 Beechistani ,Somewhere in Northern India(Beechistaan), 6 speakers
Sanskrit, Nepal-India, Less than 500 speakers, According to Indian history, Sanskrit is the mother of all Indo-European languages.
Athpahariya language, Athpahariya
Bahing language, Bahing
Barām language, Barām
Chepang language
Kumāle language, Kumāle
Kusunda language, Kusunda
Surel language, Surel

Australia 
 all aboriginal languages

Europe 
 European Union
Alsatian (France) very fast decline
 Aragonese (Spain) very fast decline
 Aromanian (Greece) very fast decline
 Basque (Spain and France) very fast decline
 Breton (France) very fast decline
 Catalan (France) very fast decline
 Corsican (France) very fast decline
 Catalan (Italy) very fast decline
 South Italian Greek (Italy) very fast decline
 Italkian (Judeo-Italian) (Italy) probably extinct
 Molise Slavic (Italy) very fast decline
 Occitan (France) very fast decline
 Sami languages, (Scandinavia), some having fewer than 100 speakers
 Scottish Gaelic (United Kingdom) very fast decline
 Lower Sorbian, (Germany) very fast decline
 West Flemish (France) very fast decline
 Yevanic (Judeo-Greek) (Greece) probably extinct
 Outside of the European Union
 Belarusian, very low usage in Belarus
 Istro-Romanian, Istria Croatia, 500 speakers
 Krimchak (Judeo-Crimean Tatar)
 Livonian, Estonia, 35 speakers
 Mordvin (Russia), steady decline
 Erzya language
 Moksha language
 Votian, Russia, 50 speakers

Related pages
 endangered language
 list of extinct languages
 Language families and languages
 Language policy

References

Other websites 
 UNESCO Red Book of Endangered Languages

Language-related lists
Endangered languages
List of earthquakes

The following is a list of major earthquakes:

The Richter scale was adopted in 1935, and was used in the above table also about earlier earthquakes at a merely indicative title. Earthquakes' effects were once measured after the Mercalli scale, which regards the practical damages that a seismic event causes to infrastructures and houses, and a sort of comparison between the two scale is now in use, especially for ancient events.

Other websites 
USGS list of current earthquakes 
Earthquakes Canada
Recent New Zealand earthquakes 

Science-related lists
List of bridges

List of bridges is a work in progress.

Afghanistan
Afghanistan–Uzbekistan Friendship Bridge
Tajik-Afghan Friendship Bridge

Argentina

Armenia 
Haghtanak bridge

Austria

Australia

Azerbaijan

Bahrain 
King Fahd Causeway
Qatar–Bahrain Friendship Bridge

Bangladesh

Bermuda 
Somerset Bridge, Bermuda

Bosnia and Herzegovina
Latin bridge in Sarajevo
Mehmed Paša Sokolović Bridge
Stari Most

Brazil

Bulgaria

Cambodia 
Monivong Bridge

Canada

Chile

Colombia 
César Gaviria Trujillo Viaduct
Puente de Boyacá

Costa Rica 
Puente de la Amistad Costa Rica-Taiwan

Croatia

Czech Republic

Denmark

Dominican Republic

Egypt
Boulak Bridge
El Ferdan Railway Bridge
Suez Canal Bridge

Estonia

Faroe Islands
Brúgvin um Streymin, bridge connecting the islands of Streymoy and Eysturoy

Finland

France

Germany

Greece
Lake Polyfytos Bridge
Rio-Antirio bridge, longest cable-stayed bridge in the world
Tatarna Bridge

Hungary

India

Indonesia

Iran

Iraq 
Al-Aaimmah bridge
Al-Sarafiya bridge

Ireland

Israel 
Ad Halom
Allenby Bridge
Chords Bridge

Italy

Japan

Korea, North
 Bridge of No Return
Sino-Korea Friendship Bridge (Sinŭiju)

Korea, South

Laos 
 Second Thai–Lao Friendship Bridge
 Thai–Lao Friendship Bridge

Lithuania

Luxembourg 
 Adolphe Bridge
 Grand Duchess Charlotte Bridge
 Passerelle

Malaysia

Mexico
Coatzacoalcos bridge
Tampico bridge
Mezcala bridge

Montenegro
Millennium Bridge in Podgorica.  	 
Đurđevica Tara Bridge, Tara river in Montenegro

Netherlands

New Zealand

Panama 
 Bridge of the Americas, Panama City.
 Centennial Bridge, Panama City.
 Corredor Sur, Panama City

Philippines

Portugal

Romania
Trajan's bridge, Drobeta-Turnu Severin, ancient Roman bridge over the river Danube,(destroyed)
King Carol I Bridge, a railway bridge over Danube, in Cernavodă
Podul Grant, Bucharest

Russia

Moscow

St Petersburg

Others

Serbia

Slovakia

South Africa

Spain

Sweden

Switzerland
Chapel Bridge, Lucerne
Teufelsbrücke, Schöllenen Gorge, Uri

Tajikistan
Tajik-Afghan Friendship Bridge

Thailand

Turkey

United Kingdom

United States

Uzbekistan
 Afghanistan–Uzbekistan Friendship Bridge
 Amu Daria River Bridge

Venezuela
 Angostura Bridge
 General Rafael Urdaneta Bridge
 Orinoquia Bridge

Zimbabwe and Zambia
 Victoria Falls Bridge - connecting Zimbabwe to Zambia, built in 1905 as part of the projected Cape-Cairo railway.
List of bones of the human skeleton

A typical adult human skeleton consists of the following 206 bones. Some people have slightly more or fewer. Some bones are called "proximal" meaning nearer the torso, some as "intermediate" and some as "distal" meaning farther.

In the skull (22): 
Cranial bones:
frontal bones
Parietal bone (2)
temporal bones (2)
occipital bone
sphenoid bone
ethmoid bone
Facial bones:
mandible
maxilla (2)
palatine bone (2)
zygomatic bone (2)
nasal bone (2)
lacrimal bone (2)
vomer bone
inferior nasal conchae (2)
In the middle ears (6):
malleus (2)
incus (2)
stapes (2)
In the throat (1):
hyoid bone
In the shoulder girdle (4):
scapula or shoulder blade (2)
clavicle or collarbone (2)
In the thorax (25): 
sternum
ribs (2 x 12)
In the vertebral column (24): 
cervical vertebrae (7) incl. atlas & axis
thoracic vertebrae (12)
lumbar vertebrae (5)
In the arms (6): 
humerus (2)
radius (2)
ulna (2)
In the hands (54): 
Wrist (carpal) bones:
scaphoid bone (2)
lunate bone (2)
triquetral bone (2)
pisiform bone (2)
trapezium (2)
trapezoid bone (2)
capitate bone (2)
hamate bone (2)
Palm or metacarpal bones:
metacarpal bones (5 × 2)
Finger bones or phalanges:
proximal phalanges (5 × 2)
intermediate phalanges (4 × 2)
distal phalanges (5 × 2)
In the pelvis (4):
coccyx
sacrum
ossa coxae (hip bones or innominate bones) (2)
In the legs (8): 
femur (2)
patella (2)
tibia (2)
fibula (2)
In the feet (52): 
Ankle (tarsal) bones:
calcaneus (heel bone) (2)
talus (2)
navicular bone (2)
medial cuneiform bone (2)
intermediate cuneiform bone (2)
lateral cuneiform bone (2)
cuboid bone (2)
Instep bones:
metatarsal bone (5 × 2)
Toe bones:
proximal phalanges (5 × 2)
intermediate phalanges (4 × 2)
distal phalanges (5 × 2)

The infant skeleton has the following bones in addition to those above:
sacral vertebrae (4 or 5), which fuse in adults to form the sacrum
coccygeal vertebrae (3 to 5), which fuse in adults to form the coccyx
ilium, ischium and pubis, which fuse in adults to form the pelvic girdle

Science-related lists
Lists of astronomical objects

This is a partial list of the various lists of astronomical objects which either exist, or should exist, in Wikipedia.

 List of planets
 List of planetary moons
 List of exoplanets
 Minor planets:
 List of asteroids
 List of comets
 List of trans-Neptunian objects
 List of trans-Neptunian objects by number
 List of stars
 List of nearest stars
 List of brightest stars
 List of largest stars
 List of smallest stars
 List of stars with confirmed extrasolar planets
 List of variable stars
 List of semiregular variable stars
 special objects:
 List of pulsars
 List of quasars
 List of blazars
 List of gamma-ray bursters
 List of black holes
 List of largest black holes
 List of galaxies
 List of nearest galaxies
 List of farthest galaxies
 List of galaxy clusters
 List of cosmic structures
List of largest cosmic structures(en)
 List of satellites of the Milky Way
 List of traditional star names
 List of globular clusters
List of stars

The following is a small list of stars. On this list, stars should be placed by their English wiki title, unless a common name is clearly more used.

40 Eridani
51 Pegasi
61 Cygni
70 Virginis

A
Achernar
Acrux
Albireo
Aldebaran
Algol
Alioth
Alniyat
Alpha Arietis (Hamal)
Alpha Centauri (Rigil Kentaurus)
Alpha Herculis ( Ras Algethi)
Altair
Aludra
Antares
Arcturus
Arrakis
Avior

B
Barnard's star
Becrux (Mimosa)
Beta Arietis (Sharatan)
Beta Aurigae (Menkalinan)
Beta Centauri (Hadar) 
Beta Columbae
Beta Tauri (Elnath)
Betelgeuse

C
Canopus
Capella
Castor
Cygnus X-1
Deneb

D 
Delta Cephei

E
Epsilon Eridani
Epsilon Indi
Eta Carinae

F

Fomalhaut

G
GJ 1061
GRB 970228

H
HE0107-5240

K
Kapteyn's Star
Kruger 60 A
Kruger 60 B

L
Lacaille 9352
Lalande 21185

M
Meissa
Miaplacidus
Mintaka
Mira
Mirach
Mizar

N
Nemesis (hypothetical)

P
Pistol Star
Polaris
Pollux
Procyon
Proxima Centauri

R
Regulus
Rigel
Ross 128
Ross 154
Ross 248
RR Lyrae

S
Saiph
Sirius
Spica
Sun (Sol)
Stephenson 2-18

T
Tau Ceti
Thuban

U
Upsilon Andromedae
UY Scuti

V
V886 Centauri (BPM 37093)
Vega
VY Canis Majoris

W
Wolf 359
Wolf 489

Related pages 
List of nearest stars
Star formation
Star
Stellar evolution
Stellar classification