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Chamberlin, Thomas Chrowder

(Encyclopedia)Chamberlin, Thomas Chrowder, 1843–1928, American geologist, b. Mattoon, Ill., grad. Beloit College, 1866. He was professor of geology at Beloit (1873–82), president of the Univ. of Wisconsin (1887...

sidereal time

(Encyclopedia)sidereal time (ST), time measured relative to the fixed stars; thus, the sidereal day is the period during which the earth completes one rotation on its axis so that some chosen star appears twice on ...

observatory, orbiting

(Encyclopedia)observatory, orbiting, research satellite designed to study solar radiation, electromagnetic radiation from distant stars, the earth's atmosphere, or the like. Because the atmosphere and other aspects...

planetesimal theory

(Encyclopedia)planetesimal theory plănˌĭtĕsˈəməl [key]: see solar system. ...

photovoltaic cell

(Encyclopedia)photovoltaic cell: see photoelectric cell; solar cell. ...

phosphorescence

(Encyclopedia)phosphorescence fŏsˌfərĕsˈəns [key], luminescence produced by certain substances after absorbing radiant energy or other types of energy. Phosphorescence is distinguished from fluorescence in th...

Nuclear Regulatory Commission

(Encyclopedia)Nuclear Regulatory Commission (NRC), an independent U.S. government commission, created by the Energy Reorganization Act of 1974 and charged with licensing and regulating civilian use of nuclear energ...

civil time

(Encyclopedia)civil time, local time based on universal time. Civil time may be formally defined as mean solar time plus 12 hr; the civil day begins at midnight, while the mean solar day begins at noon. Civil time ...

McMahon, Brien

(Encyclopedia)McMahon, Brien (James O'Brien McMahon), 1903–52, American statesman, b. Norwalk, Conn. After practicing law, he became a judge in Norwalk, and from 1933 to 1936 he served in the office of the U.S. A...

power, in physics

(Encyclopedia)power, in physics, time rate of doing work or of producing or expending energy. The unit of power based on the English units of measurement is the horsepower, devised for describing mechanical power b...
 

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