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Oppenheimer, J. Robert

(Encyclopedia)Oppenheimer, J. Robert ŏpˈənhīˌmər [key], 1904–67, American physicist, b. New York City, grad. Harvard (B.A., 1925), Ph.D. Univ. of Göttingen, 1927. He taught at the Univ. of California and t...

sonar

(Encyclopedia)sonar sōˈnär [key], device used underwater for locating submerged objects and for submarine communication by means of sound waves. The term sonar is an acronym for sound navigation ranging. The mai...

mass, in physics

(Encyclopedia)mass, in physics, the quantity of matter in a body regardless of its volume or of any forces acting on it. The term should not be confused with weight, which is the measure of the force of gravity (se...

Ovshinsky, Stanford Robert

(Encyclopedia)Ovshinsky, Stanford Robert, 1922–2012, American inventor and scientist, b. Akron, Ohio. Self-taught, he developed a new type of lathe in the 1940s, the first of many innovations and patents. Special...

Chu, Steven

(Encyclopedia)Chu, Steven, 1948–, U.S. physicist and government official, b. St. Louis, Mo., grad. Univ. of Rochester (B.S., A.B. 1970), Univ. of California, Berkeley (Ph.D. 1976). He worked from 1978 at Bell Lab...

Zeeman effect

(Encyclopedia)Zeeman effect, splitting of a single spectral line (see spectrum) into a group of closely spaced lines when the substance producing the single line is subjected to a uniform magnetic field. The effect...

exclusion principle

(Encyclopedia)exclusion principle, physical principle enunciated by Wolfgang Pauli in 1925 stating that no two electrons in an atom can occupy the same energy state simultaneously. The energy states, or levels, in ...

catabolism

(Encyclopedia)catabolism kətăbˈəlĭzˌəm [key], subdivision of metabolism involving all degradative chemical reactions in the living cell. Large polymeric molecules such as polysaccharides, nucleic acids, and ...

carbon cycle

(Encyclopedia)CE5 Carbon cycle carbon cycle, in biology, the exchange of carbon between living organisms and the nonliving environment. Inorganic carbon dioxide in the atmosphere is converted by plants into sim...

Bhabha, Homi Jehangir

(Encyclopedia)Bhabha, Homi Jehangir jəhänˌgērˈ bäˈbä [key], 1909–66, Indian physicist, b. Bombay (now Mumbai). He was educated at the Royal Institute of Science, Bombay, and at Cambridge, England, where h...