open-index/open-wikipedia-markdown huggingface dataset:
Natural gas

.  It has been burning continuously since 1971, fed by the rich natural gas deposits in the area.]]

**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
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 and Ancient Egyptians 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
* Alexandrite
* 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.
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 losses.

## Examples
For instance, 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 when you "think you know" it was a different person.

## Related pages
* Holocaust denial
* Holodomor denial
* Historical revisionism
* Rwandan genocide denial
* Cambodian genocide denial
Xenon

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

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 
Like other Noble gases, Xenon is very unreactive.  However, in 1962, chemists 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

## References
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
Kuala Lumpur

**Kuala Lumpur** () is the capital city and the largest city of Malaysia and a Federal Territory. After Putrajaya was constructed in the late 1990s, the administrative capital has been moved there. Kuala Lumpur has one of the tallest buildings in the world, the Petronas Twin Towers.

## Climate 
Kuala Lumpur has a tropical rainforest climate (*Af* in the Koeppen climate classification).

The annual range of temperature in Kuala Lumpur is small, only 1°C. There is no distinct seasonal difference in temperature in the city. Kuala Lumpur is hot throughout the year. The annual mean temperature are 26.5&nbsp;°C (79.7&nbsp;°F).

The annual rainfall in Kuala Lumpur is high (2393mm). The rainfall distribution is even in the city, with heavy rainfall all the year. In April and November, the monthly rainfall is slightly higher.

## Mayors of Kuala Lumpur 
Since Kuala Lumpur became a Federal Territory of Malaysia on February 1, 1972, the city has been led by seven mayors. They are:

# Tan Sri Dato' Lokman Yusof (1972)
# Tan Sri Yaakob Latiff (1973 - 1983)
# Tan Sri Dato' Elyas Omar (1983 - 1992)
# Dato' Dr. Mazlan Ahmad (1992 - 1995)
# Tan Sri Dato’ Kamaruzzaman Shariff (1995 - 2001)
# Datuk Mohmad Shaid Mohd Taufek (2001 - 2004)
# Datuk Ruslin Hasan (since 2004) http://www.dbkl.gov.my/_profail/pengenalan.php 

## References
## Other websites 
* Kuala lumpu city location map
* Kuala lumpu City Hall 
* Maps of Kuala lumpu
* Kuala lumpu Travel Guide  - Comprehensive Travel Guide to Kuala lumpu | City Guide, hotels, attractions and vacations.
Alloy

of brass alloy (Copper and zinc).]]
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 .
* 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.
* Amalgams are alloys of mercury with another metal, and are used in dental fillings.
* Electrum is a natural mix of gold and silver.
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
## Related pages
*Materials science
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.

## Related pages 
*Artificial neural network
*Brain cell
*Neurotransmitter

## 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 .
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.

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". An astronomy object is a "celestial body".

## Related pages 
* Human body
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
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 draw a point as a small cross 'X' or a small **dot** (a small, round shape). Different points can be labelled using capital letters (A, B, C...X, Y, Z). The point is one of the most fundamental ideas in geometry.

Two points form a line segment. When part of a line segment, the points are called its vertices. All polytopes are made of vertices.

In general, **two points** can be:
* Coincident (they are one and the same, such as on coinciding lines)
* 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
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 the 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 

Image:Zamek królewski fasada saska 06.jpg|Royal Castle
Image:Poland-00741 - Palace Prezydencki (31071435322).jpg|Presidential Palace
Image:4 Warszawa 23.jpg|Old Town
Image:Warszawa Palac Branickich (dron).jpg|Branicki Palace
Image:Pałac Jabłonowskich na Placu Teatralnym (1862).jpg|Jablonski Palace
Image:4 Warszawa-Lazienki Krolewskie 126.jpg|Łazienki Palace
Image:4 Warszawa-Lazienki Krolewskie 151.jpg|Łazienki Palace
Image:5 Warszawa 083.jpg|Belweder
Image:4 Warszawa-Lazienki Krolewskie 107.jpg|Chopin
Image:4 Warszawa-Zamek Ujazdowski 03.jpg|Ujazdów Palace
Image:Pałac Króla Jana III Sobieskiego w Wilanowie 14.JPG|Wilanów
Image:AleksanderWarszawa.jpg|Aleksander's Church
Image:4 Warszawa 44.jpg|Seminar Church
Image:Warszawa - Plac Saski z lotu ptaka (1919).jpg|Saxon Garden 1900
Image:WarsawFilharmonia.jpg|Filharmonia
Image:OldWarsaw10.jpg|Politechnic
Image:ZOO_aleja_Kazimierza_Lisieckiego_„Dziadka”_2017.jpg|Zoo
Centrum Praskie Koneser 2019a.jpg|Praga District

## 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
Line

A **line** is the path of one point that is moving. A line is a type of geometric . 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  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 .

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:

:::
::: _____ &nbsp; __
:::

## Naming lines 
Lines can get their names from any two points on the line. For example, if a line contains two different points, named A and B, then the line can be called either \overleftrightarrow{AB}, or \overleftrightarrow{BA}.

Sometimes, lines are named with just one symbol. A letter such as \ell 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
Plane (mathematics)

space]]
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 \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)
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
Hindu–Arabic numeral system

The **Hindu–Arabic numeral system**, sometimes known as the **Indo–Arabic numeral** or **Latin numeral system** or simply the **Hindu numeral system**, **Indo numeral system** or **Arabic numeral system**, is a system of numbers used all around the world. It is a base-ten place-value system. This system has ten basic lowercase-only symbols, which are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. The Hindu–Arabic numeral system was first created by the Indians in the 6th century and used by the Arabs in the 7th century and Romans in the 16th century. 

In Europe, Hindu-Arabic numeral system became very popular after the publication of *Liber Abaci,* a book written by Italian mathematician Fibonacci. They are very different from previous methods of counting, such as the abacus. The numbers allowed mathematics to develop. In the past, many other number systems had been used.
## References
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 (alpha), \beta (beta), \gamma (gamma) and \theta (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 2\pi\mbox{ rad} = 360^\circ (for example,  22.5^\circ = \tfrac{\pi}{8}\mbox{ rad}). Yet another unit of angle is gradian,

### 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 \tfrac{1}{4} turn, 90°, or \tfrac{\pi}{2} radians). Supplementary angles are also two angles, this time their combined measure is a straight angle (\tfrac{1}{2} turn, 180°, or \pi radians). Two angles that total to a full angle (1 turn, 360°, or 2\pi radians) are referred to as  or *conjugate* angles.

## Related pages 
* Sun angle

## References
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, 1941
* VOC ship *Batavia*
* *Bendigo*, North Carolina, United States
* *Bismarck* battleship, 1945
* *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, 11 miles of the coeast of Old Head of Kinsale, 1915
* *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, North Atlantic Sea, 1912
* *Uluburun*
* *Struma*, Black Sea
* HMS Wasa, Stockholm, Sweden
* *Vicar of Bray*
* SS Yongala, Townsville, Australia, 1911
* VOC *Zuytdorp*, Australia, 1712
* RMS Empress of Ireland, Saint Lawrence River, 1914
*The White Ship, 1120

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

The name "Middle East" does not always have the same meaning, and the size of the area is not always the same. 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 originated 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 from the Arabian Peninsula to most of the Middle East's lands in the 7th century AD, during the first Muslim conquests of the Sasanian Empire and parts of the Byzantine Empire. There are also significant historic Christian communities present in almost every Middle Eastern country. Other minority faiths include the Yazidis, Alevis, Druze and Alawites among others.

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.

## Countries 
### Full sovereign countries 
### Partially recognized countries / territories 
## Related pages 
* Western Asia
* Central Asia
* East Asia
* South Asia
* Southeast Asia
* Levant

## References
List of telescope types

Unit Telescopes Working as One]]

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
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
** Dane-zaa, 300 speakers
** Cayuga, 360 speakers
** Delaware (Munsee), fewer than 10 speakers
** Hare, 600 speakers
** Onandaga, fewer than 100 speakers
** Oneida, 200 speakers
** Potawatomi, 100 speakers
** Tsuut'ina, 10 speakers
** Seneca, 25 speakers
** Tlingit, 200 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
** Livonian, Estonia, 35 speakers
** South Italian Greek (Italy) very fast decline
** Istro-Romanian, Istria Croatia, 500 speakers
** Italkian (Judeo-Italian) (Italy) nearly extinct
** Molise Slavic (Italy) very fast decline
** Occitan (France) very fast decline
** Sami languages, (Scandinavia), some having fewer than 100 speakers
** 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
** Krimchak (Judeo-Crimean Tatar)
** Mordvin (Russia), steady decline
*** Erzya language
*** Moksha language
**Scottish Gaelic (United Kingdom) very fast decline
**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
List of languages

## A
## B
## C
## D
## E
## F
## G
## H
## I
## J
## K
## L
## M
## N
## O
* Oostfräisk or East Frisian Low Saxon (Germanic)

* Old Prussian (Balto-Slavic)
* Oshimbalantu (Oshiwanbo)
* Odia (Indian)

## P
* Palestinian Arabic (Dialect of Arabic - Semitic)
* Pascenda or Pashandah (Romance - Semitic mix, possible auxiliary language)
* Phat Thai (Thai Mainly)

## 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
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
List of mental disorders

The following is a list of mental disorders.

## Types of depression 
* Major depressive disorder, also known as clinical depression
* Minor depressive disorder
* Depressive personality disorder
* Bipolar disorder, also known as manic depression
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 &times; 2)
*Finger bones or phalanges:
**proximal phalanges (5 &times; 2)
**intermediate phalanges (4 &times; 2)
**distal phalanges (5 &times; 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 &times; 2)
*Toe bones:
**proximal phalanges (5 &times; 2)
**intermediate phalanges (4 &times; 2)
**distal phalanges (5 &times; 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
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
List of nearest stars

This **list of the nearest stars to Earth** is by distance in light years (ly). These distances are taken from parallax data determined by the Research Consortium on Nearby Stars (or Recons). 
The sources for this information were the Yale Parallax Catalog [Y], Hipparcos [H], Soderhjelm 1999 [S], Tinney 1996 [T]. Stars move, and so distances are as at present only.

Some 52 star systems beyond our own, the Solar System,  lie within  of the Sun. These systems contain 63 stars. 50 of these are red dwarfs, by far the most common type of star in the Milky Way. Much more massive stars, such as our own, make up the remaining 13. In addition to these "true" stars, scientists have identified 11 brown dwarfs (objects not quite massive enough to fuse hydrogen), and four white dwarfs. White dwarfs are extremely dense collapsed cores that remain after stars such as our Sun have exhausted all fusible hydrogen in their core and have slowly shed their outer layers. Despite the relative proximity of these 78 objects to Earth, only nine are bright enough in visible light to be visible to the naked eye from Earth, at or brighter than 6.5 apparent magnitude. All of these objects are currently moving in the Local Bubble (simple wiki link) Local Bubble (wiki link), a region within the Orion–Cygnus Arm of the Milky Way.

## List 
# Sun – about 8.2 light minutes from Earth
# Alpha Centauri star system – 4.24 to 4.36 ly
#* Proxima Centauri – 4.24 ly [YH]
#* Alpha Centauri A – 4.36 ly [YS]
#* Alpha Centauri B – 4.36 ly [YS]
# Barnard's Star – 5.96 ly [YH]
# WISE 1049-5319 – 6.5 ly, also known as Luhman 16, a binary of two brown dwarf stars
# Wolf 359 – 7.78 ly [Y]
# Lalande 21185 – 8.3 ly [YH]
# Sirius star system
#* Sirius A – 8.58 ly [YH]
#* Sirius B – 8.58 ly [YH]
# Luyten 726-8 – 8.73 ly 
#* UV Ceti – 8.73 ly [Y]
#* Gl 65 B – 8.73 ly [Y]
# Ross 154 – 9.68 ly [YH]
# Ross 248 – 10.32 ly [Y]
# Epsilon Eridani – 10.52 ly [YH]
# Lacaille 9352 – 10.74 ly [YH]
# Ross 128 – 10.92 ly [YH]
# EZ Aquarii star system
#* EZ Aquarii – 11.26 ly [Y]
#* Gl 866 B – 11.26 ly [Y]
#* Gl 866 C – 11.26 ly [Y]
# Procyon star system
#* Procyon A – 11.4 ly [YH]
#* Procyon B – 11.4 ly [YH]
# 61 Cygni star system
#* 61 Cygni A – 11.4 ly [YH]
#* 61 Cygni B – 11.4 ly [YH]
# Struve 2398 (Gliese 725) star system
#* Struve 2398 A – 11.52 ly [YH]
#* Struve 2398 B – 11.52 ly [YH]
# Groombridge 34 (Gliese 15) star system
#* Groombridge 34 A – 11.62 ly [YH]
#* Groombridge 34 B – 11.62 ly [YH]
# Epsilon Indi – 11.82 ly [YH]
# DX Cancri – 11.82 ly [Y]
# Tau Ceti – 11.88 ly [YH]
# GJ 1061 – 11.92 ly [RECONS]
# YZ Ceti – 12.13 ly [YH]
# Luyten's Star – 12.36 ly [YH]
# Teegarden's Star – 12 ly (discovered 2003)
# Kapteyn's Star – 12.77 ly [YH]
# AX Microscopium – 12.86 ly [YH]
# Kruger 60 star system
#* Kruger 60 A – 13.14 ly [YS]
#* Kruger 60 B – 13.14 ly [YS]
# Ross 614 star system
#* Ross 614 – 13.34 ly [YS]
#* Gl 234 B – 13.34 ly [YS]
# Gl 628 – 13.81 ly [YH]
# Gl 35 – 14.06 ly [YH]
# Gl 1 – 14.22 ly [YH]
# Wolf 424 star system
#* Wolf 424 – 14.30 ly [Y]
#* Gl 473 B – 14.30 ly [Y]

## Related pages 
* Astronomy
* Star
* List of stars

## References
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 nearest galaxies

This **list of the nearest galaxies to Earth** is ordered by increasing distance. Many of the distances are only estimates, and some may be incorrect by 50% or more. The distance ranking in this list should be seen only as a guess. Distances are given in light years (ly).

## The nearest galaxies (ranked) 
#Milky Way – home galaxy of Earth
#Canis Major dwarf  25,000 ly (satellite of Milky Way)
#Segue 1 – 75,000 ly (satellite of Milky Way)
#Sag Deg – 70,000 ly (satellite or part of Milky Way)
#Large Magellanic Cloud – 160,000 ly (satellite of Milky Way)
#Small Magellanic Cloud – 190,000 ly (satellite of Milky Way)
#Ursa Minor dwarf – 205,500 ly (satellite of Milky Way)
#Draco dwarf – 248,000 ly (satellite of Milky Way)
#Sculptor dwarf – 254,000 ly (satellite of Milky Way)
#Sextans dwarf – 257,500 ly (satellite of Milky Way)
#Carina dwarf – 283,500 ly (satellite of Milky Way)
#Fornax dwarf – 427,000 ly (satellite of Milky Way)
#Leo II – 701,000 ly
#Leo I – 890,000 ly
#Phoenix dwarf – 1,271,000 ly
#Barnard's galaxy (NGC 6822) – 1,760,000 ly
#NGC185 – 2,021,000 ly (satellite of Andromeda)
#NGC147 – 2,152,000 ly (satellite of Andromeda)
#Andromeda galaxy (M31) – 2,363,000 ly
#Messier 32 (NGS 221) – 2,650,000 ly (satellite of Andromeda)
#M110 (NGC 205) – 2,363,500 ly (satellite of Andromeda)
#Andromeda I – 2,363,500 ly (satellite of Andromeda)
#Andromeda II – 2,363,500 ly (satellite of Andromeda)
#Andromeda III – 2,363,500 ly (satellite of Andromeda)
#LGS 3 – 2,477,500 ly (satellite of Triangulum)
#IC 1613 – 2,494,000 ly
#Triangulum galaxy (M33) – 2,592,000 ly
#Aquarius dwarf – 2,608,000 ly
#Tucana dwarf – 2,836,000 ly
#Wolf-Lundmark-Melotte (WLM) – 3,064,500 ly

## Related pages 
*Galaxy
*List of galaxies
*Local Group
*Most distant things
*IC 1101: the largest known galaxy, with about 100 trillion stars.

## References
List of satellites of the Milky Way

**List of satellites of Milky Way:**
* Canis Major dwarf galaxy - 25,000 ly (satellite of Milky Way)
* Sagittarius dwarf - 81,000 ly (satellite of Milky Way)
* Large Magellanic Cloud - 160,000 ly (satellite of Milky Way)
* Small Magellanic Cloud - 190,000 ly (satellite of Milky Way)
* Ursa Minor dwarf - 205,500 ly (satellite of Milky Way)
* Draco dwarf - 248,000 ly (satellite of Milky Way)
* Sculptor dwarf - 254,000 ly (satellite of Milky Way)
* Sextans dwarf - 257,500 ly (satellite of Milky Way)
* Carina dwarf - 283,500 ly (satellite of Milky Way)
* Fornax dwarf - 427,000 ly (satellite of Milky Way)

*Note: ly means light years*

## Related pages
* List of galaxies
* List of nearest galaxies