Aarushhh/wikipedia-simple-splitted huggingface dataset:
Phi (uppercase/lowercase Φ φ), is the 21st letter of the Greek alphabet, used to represent the "ph" sound in Ancient Greek. This sound changed to "f" some time in the 1st century AD, and in Modern Greek the letter denotes the "f" sound. In the system of Greek numerals, it has a value of 500. The Cyrillic letter Ф came from Phi. In English, φ is pronounced like "f" but transliterated (re-written) as "ph" in words which originate in Ancient Greek. In those words which originate in Modern Greek, such as feta cheese, φ is transliterated as "f". The letter Phi is used to represent the golden ratio (which is about 1.618).

Related pages 
 Euler's totient function

References 

Greek alphabet
Chi (uppercase/lowercase Χ χ) is the 22nd letter of the Greek alphabet. It is used to represent the "ch" sound (as in Scottish "loch" or German "Bauch") in Ancient and Modern Greek. In the system of Greek numerals, it has a value of 600. Letters that came from it include the Roman X and Cyrillic Х.

In mathematics, the lowercase  is used to represent characteristic function, chi-square distribution in statistics and Euler characteristic in geometry.

Related pages 
 X (letter)

References 

Greek alphabet
Psi (uppercase/lowercase Ψ ψ) is the 23rd letter of the Greek alphabet. It is used to represent the "ps" sound in Ancient and Modern Greek. In the system of Greek numerals, it has a value of 700. Letters that came from it include Cyrillic Ѱ.

In mathematics, the uppercase  is used as a variable for sets of sentences (in logic), and the lowercase  is used to represent the sum of reciprocals of Fibonacci numbers. Other applications include the polygamma function, the gamma function and the super golden ratio.

Related pages 
 Phi

References 

Greek alphabet
Omega (uppercase/lowercase Ω ω) is the 24th and the last letter of the Greek alphabet. It stood for a long "o" sound in Ancient Greek. It still stands for "o" in Modern Greek, but there is no longer a difference between long and short vowels, so it sounds the same as Omicron. In the system of Greek numerals, it stands for the number 800. 

There was also once a letter "Omega" Ѡ in the Cyrillic alphabet. It was there so people could spell Greek names both in Cyrillic and in Greek in the same way. However, this letter is no longer used today.

In mathematics, the uppercase omega Ω is used in big-Omega notation (a variant of big-O notation). It is also used to represent the Omega constant. In electromagnetism and engineering, the uppercase Ω is used as the symbol for ohms, which are the units of electrical resistance. In physics and other sciences, the lowercase ω is often used to represent angular frequency. 

In modern English, the phrase "From alpha to omega" expresses the idea of "everything".
Related pages 
 Alpha

References 

Greek alphabet
Vowel letters
Sampi or Disigma is a mysterious Greek symbol. Its meaning is still debated today. Some believe it to be a replacement of 'san'. Before that, it was a letter that was used in the Greek alphabet in a few Greek cities in the 5th century BC. At that time, it looked like  or . It was probably pronounced like "ts" or "tch" in the dialect of those cities. Over time, it was changed from  to  or  and at last to . Eventually, the letter came out of use, while it was still used to denote "900" in the system of Greek numerals.

Greek alphabet
The starting-point for this is to realize that speech is a relative newcomer in human evolution. Recently evolved behaviours are almost always less reliable than long-existing functions. Speech is evolutionarily recent and is unique to humans. Reading is built on speech (presupposes it). If speech itself is an evolutionary novelty, how much more should we expect reading to be a difficult skill?

If that were not enough, the problem of aliteracy exists. This is the state of being able to read but being uninterested in doing so. Teachers and school librarians are trying to deal with this problem.
Stratford P. Sherman wrote, in a November 18, 1991 article in Fortune magazine, about the need for America to read more.  He began by saying that most Americans could not understand the article.  He referred to a study by John P. Robinson, a sociology professor at the University of Maryland, showing that the average American at that time spent only 24 minutes per day in reading.  He mentioned the continuing decline in newspaper sales, and referred to a guess by Leonard Riggio, CEO of Barnes & Noble, that 50% of books sold by his company were never read.  He quoted Samuel Robert Lichter, director of the Center for Media and Public Affairs, on his preference for the ease of turning on the TV instead of reading a book.  Sherman went on, in his article, to mention the growing need for skillful commmunication in American business but also the decreasing quality of the same activity.  He quoted Monsanto CEO Richard Mahoney on the importance of reading in helping a business manager to see connections between events
.  He described print media as being first among different media with respect to (1) the amount of information conveyed by so few widely understood symbols, (2) portability, (3) suitability for the user's own speed of use, and (4) economical distribution of broad and deep information which can be used immediately.
Sherman said that Motorola was making preparations to pay $5,000,000 to teach workers reading and other basic skills, and that, since 1982, Ford Motor Company had already sent 32,000 workers on a similar program. He said that Simon & Schuster  predicted a market of $500,000,000 per year in the sales of remedial programs to corporations.  He quoted a spokesman for the National Association of Broadcasters as saying that "the biggest predictor of scholastic success is the time parents spend reading to their children."  However, Sherman said that the amount of time thus spent meant that the outlook was "not bright".

Related pages
 Book
 Dyslexia
 Literacy

Other websites 
 Reducing "Alliteracy" in H.S. Students by Joanne Collison

Literature
L'Anse aux Meadows is a historical settlement on the island of Newfoundland in eastern Canada. It was settled by Vikings from Greenland, Iceland, and Norway around the year 1000, almost 500 years before Christopher Columbus came to the Americas. It is the only known Viking place in North America outside of Greenland. The remains of the settlement were discovered in 1960, and were declared a UNESCO World Heritage Site in 1978. 

World Heritage Sites in Canada
Settlements in Newfoundland and Labrador
An Inquiry into the Nature and Causes of the Wealth of Nations is better known simply as The Wealth of Nations. It was written by Adam Smith in 1776, who was a Scottish man. It looks at division of work, following self-interest, and freedom of trade.

The book was the beginning of classical economics, and market economics. Smith said that if everyone did what was best for themselves, the result would be best for society. Before that, economics was about the king's personal interests, and the wealth of a nation was measured by the king's treasury or by the gold and silver in the country. 

Smith said what's important is what's best for the whole nation, and that wealth should be measured by the yearly income of the nation. He wanted to discover how wealth can grow, and how people could do things to support that growth. Smith's book said land, labor, and capital were the three "factors of production" and the main contributors to a nation's wealth.
Smith said markets should be free. At the time, some big companies (like the East India Company) were controlled by the government. Sometimes the rulers made laws that were good for themselves but not for workers or customers. For example, in the American colonies, colonists could grow cotton but were not allowed to make clothing from it. They had to ship it to England to be made into clothing, then buy it back after it was finished. Smith said this was bad for individuals and for society. He thought it was better for money to flow freely and naturally between buyers and sellers without outside interference. Money would naturally go to the sellers who made the best product at the best price. This way if people did what was best for them, it would end up being best for society as a whole, almost like an "invisible hand" was guiding everything.

References

1770s books
British literature‎
Economics books
La Dessalinienne (, ; "The Dessalines Song") is the national anthem of Haiti, honoring Jean-Jacques Dessalines. The lyrics (words of the song) were written by Justin Lhérisson and its music composed by Nicolas Geffrard; it was adopted in 1904.

Lyrics

French version

Haitian Creole version

References

Other websites 
 La Dessalinienne (mp3)

1904 works
North American anthems
National symbols of Haiti
Aixinjueluo Yuhuan (; ) (October 1929 – 23 June 2003) was a recent Chinese traditional artist in both traditional Chinese paintings and traditional Chinese music. He is also one of the few descendants of the royal family of the Qing Dynasty. He is the great-great-grandson of the Daoguang Emperor. He was born in the Prince Gong Mansion in Beijing, China.

Art career
In 1957, he joined the China Artists' Association, and in 1981 he was added into The Chinese Great Artists' Dictionary. He has won many art prizes in China dealing with Chinese traditional art, his pieces are mostly landscapes, people, and close-up flowers and bamboo.
Early art career
YuHuan was an only son of Aixinjueluo Pu Shu Ming who has lived in the Prince Gong Mansion for some time after the Qing Dynasty was overruled. Good links to his uncle Pu Xin-Yu, who was a famous traditional artist of China, provided him with art lessons which set his appetite for painting Chinesetraditional art. In Junior High School, he has already started publishing his own comics on the newspapers, he became more and more interested in the arts, he eventually applied and was accepted by the Arts Department of the Beijing Normal University. The art he was taught at the Beijing Normal University was Western art although he was used to Chinese paintings.

Music career
Artist YuHuan was also a sanxian musician, his lessons with traditional Chinese instruments started when he was a child, and still living in the Prince Gong Mansion. At his death, he had already mastered many difficult pieces and he played until his late 60s.
The Song of Qing Dynasty
At the age of eight, he started to learn the sanxian, a 500-year-old Chinese three-string, plucked instrument. The song he learned was a song from the Qing Dynasty(the dynasty of his great-great-grandfather), it consisted of 13 pieces, with each piece about 20–45 minutes long. He did not learn all of the pieces of the song because his tutor only knew 13 of them (there were more that his tutor did not know); even so, it took him 2 years to master it, with courses of one 2-hour lesson per week. He had already passed on the song to a lecturer in the Central Conservatoire of Music in Beijing, his student also took two years to master it.
Influences
The leaders of many countries and foreign ministers have met with Yuhuan and either bought or received his paintings as donations or presents, the countries include: Hungary, Germany, the US, Canada, Japan, and many more. He has also lectured in many universities Japan, Singapore and Indonesia. Galleries and exhibitions of his work were also presented to and hosted at many of the above countries.

Family
Mr. Aixinjueluo has three successful sons, whose names are Aixinjueluo Hengyue(writer), Aixinjuelo Hengkai(artist), and Aixinjueluo Hengjun(IT specialist).
References
 Zhang, Hu. "A Developed Era with a Beautiful Sound: Mr. YuHuan Discusses Music at Prince Gong Mansion". Beijing Morning News 16 July 1988.
 Xia, Jun. "The Knowledgeable and Talented Ai Xin Jue Luo YuHuan". Renmin Ribao of Hong Kong 13 July 1988.
 Xia, Jun. "Ai Xin Jue Luo YuHuan and the Music of Prince Gong Mansion". Renmin Ribao of China 24 February 1989.
 "Royal Painting". The Indonesia Times: an Independent Newspaper 16 September 1992.
 "The Last Emperor's Nephew: My two Grueling Years to Master Qing Song". The Strait Times 30 January 1992.

1929 births
2003 deaths
Chinese painters
Chinese musicians
New Castle is a city in Henry County, Indiana, 44 miles (71 km) east of Indianapolis, on the Big Blue River. In 1900, 3,406 people lived in the town; in 1910, 9,446; in 1920, 14,458; and in 1940, 16,620. The population was 17,780 in 2000. The city is the county seat of Henry County. New Castle is home to New Castle Fieldhouse, the largest high school gymnasium in the world.

References

Other websites
 City of New Castle

News & Media 
 The Courier-Times
 New Castle Online 

Cities in Indiana
County seats in Indiana
Pop art is a modern art movement that developed in the 1950s and 60s. It was created by the Scottish sculptor and artist Eduardo Paolozzi in London, 1952. Andy Warhol, Robert Indiana and Roy Lichtenstein are examples of pop artists.

Pop art has themes and techniques drawn from popular mass culture, such as advertising and comic books. Pop art employs images of popular as opposed to elitist culture in art..

Origin 
The Independent Group (IG), founded in London in 1951, is regarded as the starting point of the pop art movement. They were a gathering of young painters, sculptors, architects, writers and critics who were challenging modernist approaches to culture as well as traditional views of "fine art". The group discussions centered on popular culture implications from such elements as mass advertising, movies, product design, comic strips, science fiction and technology.
At the first Independent Group meeting in 1952, co-founding member, artist and sculptor Eduardo Paolozzi presented a lecture using a series of collages titled Bunk! that he had assembled during his time in Paris between 1947–1949. This material consisted of 'found objects' such as, advertising, comic book characters, magazine covers and various mass-produced graphics that mostly represented American popular culture. One of the images in that presentation was Paolozzi's 1947 collage, I was a Rich Man's Plaything, which includes the first use of the word "pop″, appearing in a cloud of smoke emerging from a revolver. After Paolozzi's seminal presentation in 1952, the IG focused on the imagery of American popular culture, particularly mass advertising.

Methods 
The artists use mechanical means of reproduction or rendering techniques which downplay the expressive hand of the artist.
Pop artists went for absolute clarity. Most forms were bordered with black lines as in comic books. The objects are often plain like a poster, and without perspective. The colours are clear, achromatic and primitive colours.

Objects of the everyday life get isolated and modified or processed in collages. Pop art is a connection between reality and art, handled with abstract means. Some of their catchwords are: popular, consumable, cheap, funny and outstanding.
 
Much of pop art is rather academic, as the unconventional organizational practices used often make it difficult for some to understand. Pop art and minimalism are considered to be the last modern art movements and so the precursors to postmodern art, or some of the earliest examples of postmodern art themselves.

Famous pop artists 

 Peter Blake
 Jim Dine
 James Gill
 Red Grooms
 Richard Hamilton
 Keith Haring

 David Hockney
 Robert Indiana
 Jasper Johns
 Roy Lichtenstein
 John McHale
 Claes Oldenburg
Julian Opie
 Eduardo Paolozzi
 Peter Phillips
 Pietro Psaier
 Robert Rauschenberg
 Larry Rivers

 James Rizzi
 James Rosenquist
 George Segal
 Wayne Thiebaud 
 Andy Warhol
 John Wesley
 Tom Wesselmann

References
The Museum of Modern Art (MoMA) is a modern art museum in New York, New York, United States, on 53rd Street between Fifth and Sixth Avenues. It has been called the most important museum of modern art in the world. Some of the artists featured at the museum include Jackson Pollock, Vincent van Gogh, Andy Warhol and Robert Indiana.

References

Other websites 

 Museum of Modern Art official site
 Abby Aldrich Rockefeller: Patron of the modern 
 New York Times, 2007: Donors Sweetened Director's Pay At MoMA, Prompting Questions Controversy over the compensation package of MoMA's Director, Glenn D. Lowry.
 Taniguchi and the New MOMA
 Museum Conservation Lab Renovation 

Art museums in the United States
Museums in Manhattan
The Rankine scale is a thermodynamic (absolute) temperature scale. It is based around absolute zero. Rankine is similar to the Kelvin scale in that it starts at absolute zero and 0 °Ra is the same as 0 K but is different as a change of 1 °Ra is the same as a change of 1 °F (Fahrenheit) and not 1 °C (Celsius). Note that the abbreviation °R is ambiguous, as it can also refer to the Réaumur scale. 

The Kelvin and Rankine temperature scales are defined so that absolute zero is 0 kelvins (K) or 0 degrees Rankine (°R). The Celsius and Fahrenheit scales are defined so that absolute zero is −273.15 °C or −459.67 °F.

The Rankine scale was originally used in the United States and France.

Units of temperature
High fidelity or hi-fi is a way of describing a very good home music system. "High fidelity" means that the sound is as close to the original as possible with no changes or added noise. People who like hi-fi are sometimes called audiophiles. Hi-fi is often now called "high-end audio".

History 
In  the 1930s and 1940s, vacuum tubes were used to make radios and electronic amplifiers. Radio was becoming popular, and microphones, amplifiers and loudspeakers began to be sold. Manufacturers began to compete to produce the best product. A lot of research was done at Bell Laboratories and products were made by Western Electric.

Then a new kind of vinyl record with less noise and better sound was invented. Manufacturers began to call their equipment and records "high fidelity" to help sell them. In the 1950s, "hi-fi" became the popular term, replacing "phonograph" and "record player".  Rather than playing a record "on the phonograph," people would play it "on the hi-fi".
In the late 1950s and early 1960s, Westrex invented the stereo record that used two speakers. This led to more improvements in home audio. The word "stereo" replaced the word "hi-fi." Records were now played on "a stereo". 

Some people bought individual parts (separate speakers and amplifiers), and even built their own equipment. The term "high fidelity" is still used for very good music systems.

Other websites 
 
 A Dictionary of Home Entertainment Terms
 Renato Giussani: Optimal Stereo Soundstage and Imaging 
 The High Fidelity Museum

Sound
Derby is a city in the East Midlands region of England. It is on the banks of the River Derwent in the south of Derbyshire. In the 2001 census, 233,700 people lived there. At that time, Derby was the 18th largest place in England.

History

Origins
The city has Roman, Saxon and Viking origins.

The Roman camp of 'Derventio' was probably near to Derby. The site of the old Roman fort is at Chester Green. Later the town was one of the 'Five Boroughs' of the Danelaw.

The town name is seen as 'Darby' or 'Darbye' on early modern maps, such as that of Speed (1610).

Modern research into the history and archaeology of Derby has shown that the Vikings and Anglo-Saxons probably co-existed, occupying two areas of land surrounded by water. The Anglo-Saxon Chronicle (c. 900) says that "Derby is divided by water". These areas of land were known as Norþworþig and Deoraby, and were at the "Irongate" (north) side of Derby.
Modern History
In World War I, Derby was targeted by German Zeppelin air bombers. They killed five people in a 1916 raid on the town.

All Saints Church was designated as a cathedral in 1927. That showed that the town was ready for city status.

In the 1920s and 1930s, slums were cleared out and people were moved to new council estates in the suburbs. There were also houses for sale there. Rehousing, council house building and private housing developments continued on a large scale for some 30 years after the end of World War II in 1945.
Derby became a high profile town internationally in sport following the appointment of Brian Clough as manager of Derby County F.C. in 1967. Promotion to the Football League First Division was achieved in 1969, and County won of the English league three years later. Following the Clough's resignation in 1973, his successor guided County to another league title in 1975, but this is the club's last major trophy to date; relegation followed in 1980 and top flight status was not regained until 1987, since when Derby have spent a total of 10 seasons (across two spells) in the top flight. The club moved from its century-old Baseball Ground in 1997 to the new Pride Park Stadium.

Derby was awarded city status on 7 June 1977 by Queen Elizabeth II. Until then, Derby had been one of the few towns in England with a cathedral but not city status.
Despite its strategic industries (rail and aero-engine), Derby suffered comparatively little damage in both world wars (contrast Bristol and Filton). This may in part have been due to the jamming of the German radio-beam navigations systems (X-Verfahren and Knickebein), camouflage and decoy techniques ('Starfish sites') were built, mainly south of the town, e.g. out in fields near Foremark.

Places of interest 

 Cathedral Quarter
 Darley Abbey
 Derby Arboretum
 Derby Canal
 Derby Cathedral
 Derby Industrial Museum (Silk Mill)
 St Mary's Church, Derby
 Derby Friargate Station (of which all that remains is Handyside's bridge across Friargate)
 Markeaton Park Light Railway, a heritage railway
 Pride Park Stadium (Derby County F.C.) and its predecessor the Baseball Ground (now demolished)
 River Derwent
 St Helen's House, Derby

Sport and Culture

Sport 

Derby has several sports clubs.
Derby's main football club is Derby County who've won the FA Cup and the Football League. There are also three senior non-league football clubs based in the city. Derby also had a short lived baseball team, which played at Derby's former ground.

Arthur Keily the marathon runner and Olympian was born in Derbyshire in 1921 and has lived his whole life in Derby. In Rome in 1960 he broke the English Olympic record, recording a time of 2hours 27mins.

Recreation 
Derby has the first public park in the country to have an arboretum, which is south of the city centre. The arboretum was set up by the philanthropic landowner and industrialist Joseph Strutt in 1840. The arboretum's website states that the arboretum's design was the inspiration for the vision of great urban parks in the USA, notably Central Park in New York City.

There are four museums: Derby Museum and Art Gallery; Pickford's House Museum; The Silk Mill and The Royal Crown Derby Museum.

References

 
Unitary authorities
Stereophonic sound, also simply called stereo, is the reproduction of sound using two or more audio  loudspeakers. This creates a pleasant and natural sound heard from various directions, as in natural hearing. 

The word "stereophonic" comes from Greek stereos = "solid" and phōnē = "sound". It was coined by Western Electric.

In popular usage, stereo usually means two-channel sound recording and sound reproduction using data from two speakers. The electronic device for playing back stereo sound is often called "a stereo".

Sound
Ely (; IPA , rhyming with "freely") is a cathedral city in the East Cambridgeshire district of Cambridgeshire in the east of England and  north north-east of Cambridge.

Ely has been called a city for a long time because it has a cathedral. However, the Royal Charter making it a city was only issued in 1974. Ely's population was 15,102 in 2001. This means Ely is the third smallest city in England. Only after Wells in Somerset and the City of London which are smaller.

The University of Cambridge rowing team has a boathouse on the bank of the river and train there for the annual Boat Race against the University of Oxford.

The 1944 Boat Race was raced on the River Great Ouse near Ely, the only time it has not been held on the River Thames. The race was won by Oxford despite Cambridge being ahead early in the contest.
Landscape 
Ely is built on an clay which is one of the highest points in the Fens. This is very different to the West of Cambridgeshire which is made up of limestone. The river Great Ouse runs through the city, and is one of the longest rivers in the UK with many others flowing into it. The drainage area of the rivers that form the Great Ouse is around 6000 square miles (16,000 square kilometres). This is five times larger than the Fens itself The landscape was a large marsh until the 18th century, when much of the Fens was drained, making Ely no longer an island. Because of this, the ground around the city is very fertile and most of the region is used for farming. The marshes also had many different animals in them such as the Eel, which the city is named after.
Climate 
Cambridgeshire is one of the driest counties in Britain. It is protected from coastal wind from the east. It gets an average of 24 inches (600mm) of rain per year. Because of this, Cambridgeshire is warm in summer and cold and frosty in winter.

References 

Settlements in Cambridgeshire
Cities in England
Tube sound (or valve sound) is the sound produced by a vacuum tube-based audio amplifier.  All amplifiers distort to some degree; some audiophiles prefer the sound produced by tube amplifiers.  The reasons for the difference in sound between tube and solid state electronic devices is a continuing debate among audiophiles.

References 
Hamm, Russell O. Tubes Vs. Transistors: Is There An Audible Difference? in Journal of The Audio Engineering Society, presented September 14, 1972, at the 43rd Convention of the Audio Engineering Society, New York.
Rosenberg, Harvey (2004). Understanding Tube Electronics II .
Santo, Brian. Volume cranked up in amp debate in Electronic Engineering Times, Issue 817, October 3, 1994.

Sound
Audio technology
Derby is the county town of Derbyshire. It may also refer to:

Places 
In Australia:
 Derby, Tasmania
 Derby, Western Australia

In South Africa:
 Derby, South Africa

In the United Kingdom:
 Derby Road railway station, Ipswich, England
 West Derby, Liverpool, England

In the United States:
 Derby, Colorado
 Derby, Connecticut
 Derby, Iowa
 Derby, Kansas
 Derby, New York
 Derby, Vermont
 Derby Line, Vermont

Sport 
 Derby County F.C., a football club currently playing in the Premier League
 Derby (horse race), a race usually restricted to three year old horses
 Epsom Derby
 German Derby
 Kentucky Derby
 New Zealand Derby
 Victoria Derby

 Local derby, a game between two neighbouring teams
 Demolition derby
 Roller derby
 Soap Box Derby
 Bike derby
 Fishing derby
 Home Run Derby
Other meanings 
 Apache Derby, a Java relational database management system from Apache Software Foundation (ASF)
 Earl of Derby, a title in the peerage of England
 Derby hat, another name for a bowler hat
 Derby shoe
 Derby cigarettes, a brand of cigarettes sold in some parts of Latin America
 Royal Crown Derby, a pottery factory in Derby, England
 Derby Missile, a beyond-visual-range (BVR) air-to-air missile developed by RAFAEL Armament Development Authority.
 Derby Records, a record label.
 Sage Derby cheese, a kind of cheese.
Gamma is a Greek letter. Used as a symbol or name it may refer to:

Language
 Latin gamma, used as an IPA symbol for voiced velar fricative, and in the alphabets of African languages.

Science and Mathematics
The Greek letter gamma is used in both science and mathematics very often.

Unspecified
 Gamma wave, a type of brain wave
 Lapse rate, the temperature change with height in an atmosphere
 linewidth, relating to uncertainty of mass energy in short-lived particles
 Gamma is an old non-SI name for either a microgram or for a nanotesla, SI units
 Gamma quadra, in Socionics
Lower case, γ
 Gamma correction, a property of images and video displays
 Gamma ray, also Gamma radiation, an electromagnetic ray
 Adiabatic index, also known as the Heat capacity ratio, the ratio of the heat capacity at constant pressure to that at constant volume.
 Bayer designation, the third brightest star
 Euler-Mascheroni constant, a mathematical constant
 photon, seen as an elementary particle in physics
 Lorentz factor in relativity theory and astronomy
 propagation constant of an electromagnetic wave
 voiced velar fricative in phonetics

Upper case, Γ
 Gamma distribution, a probability distribution function
 Gamma function, a mathematical function
 Christoffel symbol in General Relativity
 reflection coefficient in electrical engineering
 mathematical finance, where it is a risk measure, or Greek
 center of the Brillouin zone
 The Feferman-Schütte_ordinal Γ0
Technology
 Gamma software, in computer software and video game development
 GM Gamma platform - a subcompact automobile platform by General Motors
 Gamma correction, in video, graphics, color spaces, and photographic imaging
 Elias gamma coding, in computer science, encoding, compression

Things and places
 Tropical Storm Gamma, an Atlantic tropical storm

Popular culture
 Brave New World, where it is the third caste
 E-102 Gamma, a video game character
 Gamma (band), a rock band
Chile, the long and narrow South American nation between the Andes and the Pacific Ocean.
Chicago, the IATA city code for a major US city (sometimes informally written "Chi" or "Chi-town"). Additionally, most Chicago sports teams can be called "CHI" or "Chi" when citing scores, etc.
 Chicago Bears, a National Football League team
 Chicago Blackhawks, a National Hockey League team
 Chicago Bulls, a National Basketball Association team 
 Chicago Cubs, a Major League Baseball team
 Chicago White Sox, a Major League Baseball team
 Child Health International, a UK based charity for children's health (especially Cystic Fibrosis) in poor countries
 Human-Computer Interaction, otherwise known as Computer-Human Interaction (CHI) 
 CHI, an annual, international academic conference on the topic of Computer-Human Interaction
 Chromosomal crossover, in homologous recombination, a viral DNA sequence called a "crossover hotspot instigator" (CHI)
CHI, Longwood University's, secret honorary society formed in 1900 in Farmville, Virginia
 Closed Head Injury, meaning the skull is not broken.
 Columbia Helicopters, Inc of Aurora, Oregon.  Manufacturer and Operator of heavy lift helicopters
 Chingford railway station, London; National Rail station code CHI
Chi 
Chi could mean:
 Chi, the Greek letter, Χ
 The Chi distribution, which is denoted by 
 The Chi-square distribution, which is denoted by 
Chi (kana), a letter used in the Japanese script Hiragana
 Chi (magazine), an Italian magazine based in Milan
 Chi Cheng (musician), Bassist for Deftones
 Chi McBride, actor
 Chi River in North-East Thailand
 Chi, a fictional character in the anime/manga series Chobits
 In Igbo mythology in Nigeria, Chi is a god or personification of an individual's fate
 Chi is an alleged life force in every thing
Mu, Μ or μ, a letter in the Greek alphabet.
μ is used as a symbol for:
The SI prefix micro, meaning a factor of 10-6 (one millionth).
μ by itself is often used as the "unit" of strain, though in this context it retains its SI prefix meaning, which is interchangeable with "x 10-6" or "ppm" (parts per million).
μ by itself is an abbreviation for the unit micron. Both the term and the abbreviation should not be used. The preferred terms are µm and micrometre
In mathematics,
The arithmetic mean of a statistical population
The Möbius function
The least-fixed-point-operator
A degree of membership from a fuzzy set.
In chemistry,
The chemical potential
In physics, 
The coefficient of friction
The mobility coefficient
The permeability (electromagnetism) coefficient
The muon, an elementary particle
The standard gravitational parameter
The magnetic dipole moment
The linear density
Viscosity
Reduced mass
µTorrent, a freeware BitTorrent client for Microsoft Windows written in C++.
μZiq, An alias of Mike Paradinas.
In Asian languages:
Mù, (穆), a Chinese surname
Mu (unit of area) (亩/畝), a Chinese unit of area
Mu (kana), represented by the Japanese kana む or ム
Mu (negative) (無), a Japanese word important in Zen koan practice

Mu may also refer to:
Muonium's atomic symbol 
Mu-metal, an alloy used for screening magnetic fields
Mu (lost continent), a mythical continent in the Pacific Ocean subsequently appearing in several books, films, and games
Mu (rocket), a Japanese rocket
Mu Dan, Chinese poet and translator
Mu Online, an online role-playing game
Mu La Flaga, a character from the anime Mobile Suit Gundam SEED
Aries Mu, a character from the cartoon Saint Seiya
Groupe Mu, an interdisciplinary Belgian group focusing on linguistics and rhetoric
Lemuria, a hypothetical lost continent
MU may stand for:
Mauritius' ISO 3166-1 alpha-2 country code
China Eastern Airlines's IATA code
Manchester United Football club
The Mothers' Union, global Anglican women's organisation
Monitor unit, a unit used in radiation therapy
Centimorgan or "map unit", a unit of recombinant frequency in genetics
Multiple unit, such as a rail diesel car
MU puzzle, a puzzle in Gödel, Escher, Bach
University of Mumbai, formerly called the University of Bombay
Marquette University
Marshall University
Miami University, a public university in Oxford, Ohio
Millersville University of Pennsylvania
Miskatonic University  
University of Missouri, a public university in Columbia, Missouri 
Mahidol University, a University in Thailand
Manipal University, a university in Karnataka, India
MU (70's band), an early 1970s psychedelic group led by Merrell Fankhauser and Jeff Cotton
MU (00's band), a 00's electro-punk group made up of producer Maurice Fulton and his wife Mutsumi Kanamori.
Mirror Universe (Star Trek), fictional parallel universe in which the plots of several Star Trek television episodes take place
Magic-User, a class type in D&D, HackMaster, and many fantasy RPGs
 Musician, an enlisted rating in the United States Navy
 Isuzu MU Wizard
 Micron Technology
Nu could mean:
 Nu, a letter in the Greek alphabet: lowercase ν, uppercase Ν
 Nu (kana), the Japanese characters ぬ and ヌ
 NU (sound project)
 Nu (mythology), the male form of the Egyptian goddess Naunet
 Nu (Chrono Trigger), a fictional species from the video game Chrono Trigger
 .nu, the Internet top-level domain for Niue
 Nu people, a Chinese ethnic group
 Nu river or Salween River
 U Nu or Mr. Nu, a former Burmese prime minister
 Nǀu language, a moribund Tuu (Khoisan) language spoken by the Nǁnǂe people in South Africa
 Nu Gundam, in the anime Mobile Suit Gundam: Char's Counterattack
 "Nu"? is a Yiddish word meaning "so?" now also absorbed into English meaning "so, what's happening?" or "so, what do you say?"
In universities:
 Naresuan University, a public university in Phitsanulok, Thailand
 Niagara University, a Roman Catholic university in Niagara County, New York
 Northwestern University, an American research institution in Evanston, Illinois
 Northeastern University, an American research university in Boston, Massachusetts
 Norwich University, a private American military and traditional university in Northfield, Vermont
 National University (Philippines), a private, non-sectarian university in Manila, Philippines

In other abbreviations:
 Nunavut (NU), the largest and newest territory in the territories of Canada
 Nahdatul Ulama (NU), an Islamic group in Indonesia
 Nusselt number (Nu), a dimensionless heat transfer ratio
 Nucellar embryony (Nu+), a form of seed reproduction that occurs in certain plant species
 Bhutanese ngultrum (Nu.), Bhutan's official currency

In codes:
 Japan Transocean Air IATA airline designator
 Nicaragua NATO country code
 Niue ISO 3166 country code
In music:
 Nu metal, a fusion genre of Heavy Metal
Omega is the last letter in the Greek alphabet. See that article for more uses of the upper case (Ω) or lower case (ω) letter as a symbol.

Omega could also mean:

Alphabet 
 Omega (Cyrillic), the Cyrillic counterpart of Greek omega.

Mathematics 
 Lambert W function, also known as the omega function.
 Omega constant, a specific value derived from Lambert's W function.
 Chaitin's constant, or Halting Probability, written as Ω.

Science 
 Omega loop, a protein motif
 Omega-3 fatty acid
 Omega-6 fatty acid
 Omega-9 fatty acid
 Omega particle, a subatomic particle
 Omega, in sociobiology, the lowest rank in a dominance hierarchy
 In cosmology, the density parameter

Technology 
 Omega (camera), a brand of cameras and enlargers
 OMEGA Navigation System, the first worldwide radio navigation system
 Omega SA, a Swiss watch company
 Omega (TeX), a Unicode extension of the TeX typesetting system
 Omega drivers, third-party drivers for ATI and nVidia graphics cards

Military 
 OMEGA, a Latvian special operations unit
Philosophy 
 Omega point, an idea in philosophy (eschatology) advanced by Pierre Teilhard de Chardin

Places in the United States 
 Omega, Georgia
 Omega, Oklahoma
 Omega D.C., a gay bar in Washington, D.C.

Automobiles 
 Opel Omega, a car model by Opel/Vauxhall
 Oldsmobile Omega, another General Motors car, mechanically unrelated to the above

People 
 Kenny Omega, ring name of Canadian professional wrestler Tyson Smith (born 1983)
Fiction 
 Omega (Doctor Who), a fictional character from the television series
 Omega (Doctor Who audio), a Big Finish Productions audio drama based on Doctor Who
 The Omega Directive, an episode of Star Trek: Voyager
 Omega Ranger, a character from Power Rangers: S.P.D.
 The Omega Man, a 1971 science fiction film
 Omega, an alias of O'Malley, a character in Red vs. Blue
 Omegamon and Omegamon X, the Japanese names for the Digimon characters, Omnimon, as well as his X-Antibody counterpart, Omnimon X
 Doctor Omega, a 1906 science fiction novel by Arnould Galopin
 Omega (novel), a science fiction novel by Jack McDevitt
 A character in the Maximum Ride series.
 The Omega Lock in Transformers Cybertron.
 Omega (film), a Greek thriller, directed by Vasilis Blioumis
Comic books 
 Omega Red, a comic book supervillain in the Marvel Comics universe
 Omega-level mutant, the most powerful Marvel Comics mutants
 Omega (comics), a comic book villain from the Legion of Super-Heroes
 Omega Men, a DC Comics superhero group
 Omega the Unknown, a 1970s Marvel Comics series created by Steve Gerber

Video games 
 Omega (1987 computer game), a Roguelike game
 Omega (1989 computer game), a game by Origin Systems
 Omega (Dead or Alive), the final boss of Dead or Alive 3
 Omega (Final Fantasy), a recurring boss in the Final Fantasy series
 E-123 Omega, a character in the Sonic the Hedgehog series
 Omega, one of the main antagonists and the final boss of Mega Man Zero 3
 Omega is the pseudonym used by Naoki Maeda for the song "MAX300" from DDRMAX: Dance Dance Revolution 6thMIX
Music 
 (Omega) y su Mambo Violento, a Dominican musical group
 Omēga and the Mechanical Animals, a fictitious rock band portrayed by Marilyn Manson on their album Mechanical Animals
 Omega (band), a Hungarian rock band
 Omega No. 5, an album by Scaterd Few
 Omega (song), a song by Rebecca St. James
 Deathspell Omega, a French black metal band
 The Omega Rising, an album by Profundi, a Swedish black metal band
 Omega Recording Studios, a recording school and studio located outside of Washington D.C.

Other uses 
 Omega (cider), a strong white cider
 Omega Psi Phi, African American fraternity and member of the National Pan-Hellenic Council
 Organization of Modern Extreme Grappling Arts (OMEGA), a wrestling promotion owned by Matt and Jeff Hardy
 Omega Development Site, planned to be one of Europe's largest business parks, in Warrington, Cheshire
Phi could mean:

The letter phi
The golden ratio
Euler's totient function
 A statistical measure of association reported with the chi-square test
Pi (math), , or π, is the mathematical constant equal to a circle's circumference divided by its diameter.

Pi may also refer to:

Letter Pi (π)

Pi (letter), the Greek letter
Lowercase π:
 π (film), a 1998 film directed by Darren Aronofsky
  (pi function), the prime-counting function
 Pi bond
 Osmotic pressure
 A song from the Kate Bush album Aerial
 Shorthand for pion
 A men's fragrance from Givenchy
 The symbol for political life used in Boethius' Consolation of Philosophy
Uppercase Π:
 The product symbol
  (Pi function), the Gamma function when offset to coincide with the factorial
 , the reciprocal of the Pi function

Pi as a word
 Pi (instrument)
 Pi (.hack), a fictional character from the multimedia franchise .hack//G.U.
 Pi Magazine
 Pi Recordings, a record label
 "Pi", a song from the Hard 'n Phirm album Horses and Grasses; the song ends at 3:14
 Pi, a member of Team Robo in Sega Soccer Slam
 Pi, a fictional character in the novel Life of Pi
 Pi County, county in Sichuan, China
Psi could mean:

As a word
 Psi (Cyrillic) (Ѱ, ѱ), a letter of the early Cyrillic alphabet, adopted from Greek
 Psi (Ψ, ψ) a letter of the Greek alphabet
 Psi (comics), a character in DC Comics
 Psi (instant messaging client), a popular Jabber client program
 Psi (parapsychology), psychic or paranormal phenomena

As a Greek letter
 J/ψ particle, a subatomic particle
 Wavefunction in Quantum Mechanics, ψ
 In mathematics, Ψ is used to denote the angle between the tangent and the x-axis in the intrinsic coordinates system
 Again in mathematics, Ψ is also used to denote the Digamma and Polygamma functions.
 In physical chemistry, Ψ represents water potential, the potential energy of a water solution relative to pure water.
 Ψ stands for psychology and psychologist, often used in the logo of various psychological associations -- for example, see IUPsyS.

psi
 Pounds per square inch, a unit of pressure
Sound recording and reproduction is the storage of sound and playing it back so that a person can hear the same sound more than once. It is a process wherein sound waves are captured by a machine. The machine converts the waves into electrical signals or digital data, that are then stored on recording media (such as gramophone records, cassette tapes, compact discs or computer hard drives). The sound can then be played back by reversing the process.

Most recordings are of music, people speaking or singing, and sound effects. They are usually used for entertainment (fun), or for scientific and historical reasons.

Sound is recorded onto a medium by different methods. The ways that recordings are made have changed a lot since sound was first recorded.

Technology
Technology

Analog cylinder
The first machines for recording sound were mechanical, not electrical. The phonograph was invented by Thomas Alva Edison in 1877. Phonographs have a spinning cylinder covered in a soft material such as tin foil, lead, wax, or amberol. Sound waves shake a small needle so that its motion carries the waves. As the cylinder turns, the needle draws the motion of the sound waves in the soft coating. This made the cylinder a recording of the sound that was in the needle.

This recording is played back by tracing another needle through the groove in the cylinder. This recreates the small vibrations in the playback needle. These vibrations could be amplified (made louder) to create louder, more audible sound.

The phonograph was useful for making single recordings, but a big disadvantage was the difficulty of making copies of the cylinders.
Analog disk
The problem of copying recordings got better with the invention of the gramophone (also called the phonograph in American English) around 1888. The gramophone works in much the same way as the phonograph, but instead of a cylinder, the needle's grooves are etched into a disk record which turns on a spinning table. Because the record media was flat, copying recordings was much simpler. Pressing the original recording onto a plate of shellac created a negative master, where the grooves were bumps on the surface instead of being scratched into the surface. The master could be used to produce many copies through the opposite process.

The first records were made mostly of rubber or shellac, but later records were made of  vinyl.
Originally, records spun at a rate of 78 rotations per minute, or 78 rpm. As technology got better, records could spin more slowly, but still reproduce sound better and play for longer amounts of time. 45 rpm became common in the middle 20th century, and by the late 1900s most records were 33 rpm.

Tape

In the late 1930s the tape recorder appeared. Tape recorders use a magnetic tape as a medium, with a recording head to store the sound on the tape. Sound waves are converted into an electrical signal inside the recorder. This signal goes into the head, where it changes the polarity of very small magnets. Tape moves past the head at a constant speed, and its magnetic particles are rearranged by these magnets to a pattern that represents the sound wave. These magnetic patterns are much like the small grooves of a cylinder or disc record in the way that they represent the vibration energy of sound waves.
When a tape is played back, it runs past a playback head which reads the magnetic patterns off the tape and converts them back into an electrical signal. The electrical signal can then be converted into sound waves or copied to some other kind of sound-processing machine.

A magnetic tape is divided into several tracks. Each track uses up part of the width of the tape, and can store a completely different recording that can be played back at the same time as the other tracks. A two-track tape has one track on half of the tape and another track on the other half. A four-track tape has four tracks all lying next to one another, like a highway with four lanes. Most tape recordings today are stereophonic (or stereo), meaning that they have two tracks which are meant to be played together. Usually one is played on the listener's left side and the other is on the listener's right side, to match the listener's two ears.
Early tapes were wound flat on a storage reel and transferred to a take-up reel as they were recorded or played. After recording or playback, they were rewound so that they were stored only on the storage reel. This kind of system is usually called reel to reel today. It is still used today for some professional recording and playback, but for home use reels were mostly replaced with other kinds of tape in the 1970s. Cassettes are small cartridges containing two reels inside. Cassettes move a four-track tape in either of two directions, corresponding to their side A and side B labels. The reel on the left contains the unplayed or unrecorded tape, and the reel on the right contains the tape that has already passed the recording or playback head. When you turn the cassette over, the tape still moves from left to right, but this is really the opposite direction. The "side A" recording plays two tracks as stereo, and the "side B" recording plays the other two.
Eight-track tapes were popular for a while in the 1970s and 1980s. Eight-tracks work much like cassettes, but the tape is a loop: it repeats after being played all the way through. Because it has eight tracks, there are four programs to select from, each in stereo. Eight-tracks are not very popular anymore, but can still be found in hobbyist collections.

Professional tape-recording systems may have even more tracks, or might use them differently. Usually a system like this is designed to allow someone to mix the tracks in different ways than they were originally recorded. However, there is a kind of recording called quadraphonic that uses four-track tape to play four different tracks at the same time. A good quadraphonic recording can sound much more "real" than stereo or monophonic recordings.
Digital Audio Tape
Tape recording technology was used from the early days of computing to store digital information. As computer technology improved, so did magnetic tape technology. In the 1980s Digital Audio Tape (DAT) technology emerged.  DAT is designed to work much like cassette, except DAT's magnetic patterns represent digital data instead of sound vibrations. This digital data is a digital audio recording which can be copied and reproduced with many different computer systems. Moving to digital takes the medium one step farther from the original sound. Instead of being a sound medium, the DAT is a data medium, and the data is a sound medium. This is more technically complex, but also more flexible. DAT has been used for many kinds of data recording, in addition to sound.