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ether, in physics and astronomy

(Encyclopedia)ether or aether, in physics and astronomy, a hypothetical medium for transmitting light and heat (radiation), filling all unoccupied space; it is also called luminiferous ether. In Newtonian physics a...

Baird, John Logie

(Encyclopedia)Baird, John Logie, 1888–1946, Scottish inventor. In 1926 he gave the first demonstration of true television with a televisor of his own invention that differed from later instruments in being partia...

astrometry

(Encyclopedia)astrometry: see astronomy.

radiation

(Encyclopedia)radiation rāˌdēāˈshən [key], term applied to the emission and transmission of energy through space or through a material medium and also to the radiated energy itself. In its widest sense the te...

radiometer

(Encyclopedia)radiometer rāˌdēŏmˈətər [key], instrument for detection or measurement of electromagnetic radiation; the term is applied in particular to devices used to measure infrared radiation. One of the ...

Coblentz, William Weber

(Encyclopedia)Coblentz, William Weber kōˈblĕnts [key], 1873–1962, American physicist, b. North Lima, Ohio, grad. Case School of Applied Science (B.S., 1900) and Cornell (Ph.D., 1903). From 1905 to 1945 he was ...

radar

(Encyclopedia)radar, system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, ...

Polanyi, John Charles

(Encyclopedia)Polanyi, John Charles, 1929–, Canadian chemist. Raised and educated in England, he worked as a researcher in Canada before taking a teaching position at the Univ. of Toronto in 1956. He used spectro...

Möbius, Augustus Ferdinand

(Encyclopedia)Möbius, Augustus Ferdinand mōˈbēəs, Ger. möˈbēəs [key],(1790–1868), German mathematician and astronomer, b. Schulpforta, Saxony. A professor of astronomy at the Univ. of Leipzig, he made im...

Abbot, Charles Greeley

(Encyclopedia)Abbot, Charles Greeley, 1872–1973, American astrophysicist, b. Wilton, N.H. He was acting director in 1896 and director in 1907 of the astrophysical observatory of the Smithsonian Institution; he wa...