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brake, in technology

(Encyclopedia)CE5 Shoe brake CE5 Disk brake brake, in technology, device to slow or stop the motion of a mechanism or vehicle. The vacuum brake system, or vacuum brake, depends upon the use of a vacuum to ...

planetary system

(Encyclopedia)planetary system, a star and all the celestial bodies bound to it by gravity, especially planets and their natural satellites. Until the last decade of the 20th cent., the only planetary system known ...

Reagan, Ronald Wilson

(Encyclopedia)Reagan, Ronald Wilson rāˈgən [key], 1911–2004, 40th president of the United States (1981–89), b. Tampico, Ill. In 1932, after graduation from Eureka College, he became a radio announcer and spo...

forestry

(Encyclopedia)forestry, the management of forest lands for wood, water, wildlife, forage, and recreation. Because the major economic importance of the forest lies in wood and wood products, forestry has been chiefl...

Metropolitan Opera Company

(Encyclopedia)Metropolitan Opera Company, term used in referring collectively to the organizations that have produced opera at the Metropolitan Opera House, New York City. The original house, at West 39th Street an...

atmosphere

(Encyclopedia)CE5 Atmosphere atmosphere [Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other plane...

laser

(Encyclopedia)CE5 Ordinary light sources produce incoherent light, while a laser produces a beam of coherent light. laser [acronym for light amplification by stimulated emission of radiation], device for the cr...

carbon

(Encyclopedia)CE5 The three solid forms of pure carbon: In the diamond crystal each carbon atom is surrounded symmetrically by four other carbons (at each of the four corners of a tetrahedron). In the graphite c...

skyscraper

(Encyclopedia)skyscraper, modern building of great height, constructed on a steel skeleton. The form originated in the United States. By convention, a skyscraper is a building that is used primarily for human h...

telescope

(Encyclopedia)CE5 Mirror arrangements for a reflecting telescope telescope, traditionally, a system of lenses, mirrors, or both, used to gather light from a distant object and form an image of it. Traditional o...