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sunspots

(Encyclopedia)sunspots, dark, usually irregularly shaped spots on the sun's surface that are actually solar magnetic storms. The spots are darker because the temperature of the spots is lower than that of the surro...

Néel, Louis Eugène Félix

(Encyclopedia)Néel, Louis Eugène Félix, 1904–2000, French physicist, Ph.D. Univ. of Strasbourg, 1932. He was a professor at the Univ. of Strasbourg from 1932 to 1945, when he joined the faculty at the Univ. of...

Stern, Otto

(Encyclopedia)Stern, Otto stûrn, Ger. ôˈtō shtĕrn [key], 1888–1969, American physicist, b. Germany, Ph.D. Univ. of Breslau, 1912. After resigning from his post at the Univ. of Hamburg in 1933, he became prof...

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...

magnetron

(Encyclopedia)magnetron măgˈnĭtrŏnˌ [key], vacuum tube oscillator (see electron tube) that generates high-power electromagnetic signals in the microwave frequency range. Its operation is based on the combined ...

Zeami Motokiyo

(Encyclopedia)Zeami Motokiyo zāˈäˈmē mōˈtōˈkēˈyō [key] or Kanze Motokiyo, c.1363–c.1443, Japanese actor, playwright, and drama theorist. Son of the itinerant actor Kanami, at the age of eleven Zeami a...

hysteresis

(Encyclopedia)hysteresis hĭsˌtərēˈsĭs [key], phenomenon in which the response of a physical system to an external influence depends not only on the present magnitude of that influence but also on the previous...

sound recording

(Encyclopedia)sound recording, process of converting the acoustic energy of sound into some form in which it can be permanently stored and reproduced at any time. In 1855 the inventor Leon Scott constructed a devic...

induction, in electricity and magnetism

(Encyclopedia)induction, in electricity and magnetism, common name for three distinct phenomena. Electromagnetic induction is the production of an electromotive force (emf) in a conductor as a result of a changing ...

maglev

(Encyclopedia)maglev: see magnetic levitation. ...