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adenosine triphosphate

(Encyclopedia)CE5 Adenosine triphosphate (ATP) adenosine triphosphate (ATP) ədĕnˈəsēn trīˌfŏsˈfāt [key], organic compound composed of adenine, the sugar ribose, and three phosphate groups. ATP serves ...

Fermi-Dirac statistics

(Encyclopedia)Fermi-Dirac statistics, class of statistics that applies to particles called fermions. Fermions have half-integral values of the quantum mechanical property called spin and are “antisocial” in the...

libido

(Encyclopedia)libido lĭbēˈdō, –bīˈ– [key] [Lat.,=lust], psychoanalytic term used by Sigmund Freud to identify instinctive energy with the sex instinct. For Freud, libido is the generalized sexual energy o...

quasar

(Encyclopedia)quasar kwāˈsär [key], one of a class of blue celestial objects having the appearance of stars when viewed through a telescope and currently believed to be the most distant and most luminous objects...

gamma-ray astronomy

(Encyclopedia)gamma-ray astronomy, study of astronomical objects by analysis of the most energetic electromagnetic radiation they emit. Gamma rays are shorter in wavelength and hence more energetic than X rays (see...

Raman effect

(Encyclopedia)Raman effect räˈmən [key], appearance of additional lines in the spectrum of monochromatic light that has been scattered by a transparent material medium. The effect was discovered by C. V. Raman i...

nonlinear dynamics

(Encyclopedia)nonlinear dynamics, study of systems governed by equations in which a small change in one variable can induce a large systematic change; the discipline is more popularly known as chaos (see chaos theo...

semantics

(Encyclopedia)semantics [Gr.,=significant] in general, the study of the relationship between words and meanings. The empirical study of word meanings and sentence meanings in existing languages is a branch of lingu...

Kusch, Polykarp

(Encyclopedia)Kusch, Polykarp, 1911–93, American physicist, b. Blankenburg, Germany, Ph.D. Univ. of Illinois, 1936. Kusch was a researcher, professor, and administrator at Columbia from 1937 to 1972 and a profess...

Fisher, Irving

(Encyclopedia)Fisher, Irving, 1867–1947, American economist, b. Saugerties, N.Y., Ph.D. Yale, 1891. He began teaching at Yale in 1890 and was active there until 1935. His earliest work was in mathematics, and he ...