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uncertainty principle

(Encyclopedia)uncertainty principle, physical principle, enunciated by Werner Heisenberg in 1927, that places an absolute, theoretical limit on the combined accuracy of certain pairs of simultaneous, related measur...

Bradbury, Ray

(Encyclopedia)Bradbury, Ray (Raymond Douglas Bradbury) brădˈbĕrˌē, –bərē [key], 1920–2012, American writer, b. Waukegan, Ill. A popular and prolific writer of science fiction who did much to bring the ge...

platinite

(Encyclopedia)platinite, alloy that is 46% nickel and 54% iron. It is used in the manufacture of electric lightbulbs because its coefficient of expansion, i.e., the rate at which its volume increases with temperatu...

Lee, David Morris

(Encyclopedia)Lee, David Morris, 1931–, American physicist, b. Rye, N.Y., Ph.D. Yale, 1959. Lee joined the faculty at Cornell in 1959, moving to Texas A&M Univ. in 2009. He was a co-recipient, with Douglas Os...

hydrogenation

(Encyclopedia)hydrogenation hīdrôjˈənāˌshən, hīˌdrəjənāˈshən [key], chemical reaction of a substance with molecular hydrogen, usually in the presence of a catalyst. A common hydrogenation is the harde...

eye bank

(Encyclopedia)eye bank, site for the collection, processing, and assignment of donated eyes. A donor's eyes are removed as soon as possible after death, sealed in a sterile container, and sent to the eye bank. Ther...

radiosonde

(Encyclopedia)radiosonde rāˈdēōsŏnd [key], group of instruments for simultaneous measurement and radio transmission of meteorological data, including temperature, pressure, and humidity of the atmosphere. The ...

stellar structure

(Encyclopedia)stellar structure, physical properties of a star and the processes taking place within it. Except for that of the sun, astronomers must draw their conclusions regarding stellar structure on the basis ...

electret

(Encyclopedia)electret, solid electrically insulating, or dielectric, material that has acquired a long-lasting electrostatic polarization. Electrets are produced by heating certain dielectric materials to a high t...

integrated circuit

(Encyclopedia)integrated circuit (IC), electronic circuit built on a semiconductor substrate, usually one of single-crystal silicon. The circuit, often called a chip, is packaged in a hermetically sealed case or a ...