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Schrödinger, Erwin

(Encyclopedia)Schrödinger, Erwin ĕrˈvĭn shröˈdĭng-ər [key], 1887–1961, Austrian theoretical physicist. He was educated at Vienna, taught at Breslau and Zürich, and was professor at the Univ. of Berlin (1...

vibration

(Encyclopedia)vibration, in physics, commonly an oscillatory motion—a movement first in one direction and then back again in the opposite direction. It is exhibited, for example, by a swinging pendulum, by the pr...

Weiss, Rainer

(Encyclopedia)Weiss, Rainer, 1932–, American physicist, b. Berlin, Germany, Ph.D. Massachusetts Institute of Technology, 1962. Weiss has been on the faculty of the Massachusetts Institute of Technology since 1964...

Davisson, Clinton Joseph

(Encyclopedia)Davisson, Clinton Joseph dāˈvĭsən [key], 1881–1958, American physicist, b. Bloomington, Ill. He joined the engineering department of the Bell Telephone Laboratories in 1917. Davisson worked on t...

e, in mathematics

(Encyclopedia)e, in mathematics, irrational number occurring widely in mathematics and science, approximately equal to the value 2.71828; it is the base of natural, or Naperian, logarithms. The number e is defined ...

Heisenberg, Werner

(Encyclopedia)Heisenberg, Werner vĕrˈnər hīˈzənbĕrk [key], 1901–76, German physicist. One of the founders of the quantum theory, he is best known for his uncertainty principle, or indeterminacy principle, ...

Sommerfeld, Arnold Johannes Wilhelm

(Encyclopedia)Sommerfeld, Arnold Johannes Wilhelm ärˈnōlt yōhänˈəs vĭlˈhĕlm zômˈərfĕlt [key], 1868–1951, German physicist and teacher. He received a Ph.D. at Königsburg Univ. in 1891 and was a prof...

sound

(Encyclopedia)CE5 Sound waves: An air pressure wave radiating outward from a loudspeaker is perceived as sound. sound, any disturbance that travels through an elastic medium such as air, ground, or water to be ...

Bothe, Walther Wilhelm Georg

(Encyclopedia)Bothe, Walther Wilhelm Georg, 1891–1957, German physicist, Ph.D. Univ. of Berlin, 1923. Bothe was a researcher at the Reich Physical and Technical Institute (1913–30) and a professor at Heidelberg...

Islam in Africa

(Encyclopedia)Islam in Africa, the development of the Muslim religion on the African continent. During Muhammad's lifetime a group of Muslims escaped Meccan persecution (615) by fleeing to Ethiopia, where the Negus...