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cam, mechanical device

(Encyclopedia)cam, mechanical device for converting a rotating motion into a reciprocating, or back-and-forth, motion, or for changing a simple motion into a complex one. A simple form of cam is a circular disk set...

Stieglitz, Alfred

(Encyclopedia)Stieglitz, Alfred stēgˈlĭts [key], 1864–1946, American photographer, editor, and art exhibitor, b. Hoboken, N.J. The first art photographer in the United States, Stieglitz more than any other Ame...

vortex

(Encyclopedia)vortex vôrˈtĕks [key], mass of fluid in whirling or rotary motion. To simplify the analysis, vortex motion usually describes motions in a frictionless fluid. In such cases the absence of friction w...

Eastman, George

(Encyclopedia)Eastman, George, 1854–1932, American inventor, industrialist, and philanthropist, b. Waterville, N.Y. By mass production of his photographic inventions, Eastman enormously stimulated the development...

Riboud, Marc

(Encyclopedia)Riboud, Marc, 1923–2016, French photojournalist. After fighting in the resistance during World War II, he studied engineering. In 1952 he moved to Paris, where he met Henri Cartier-Bresson, who beca...

Brownian movement

(Encyclopedia)Brownian movement or motion, zigzag, irregular motion exhibited by minute particles of matter when suspended in a fluid. The effect has been observed in all types of colloidal suspensions (see colloid...

holography

(Encyclopedia)holography hŏlŏgˈrəfē, hō– [key], method of reproducing a three-dimensional image of an object by means of light wave patterns recorded on a photographic plate or film. Holography is sometimes...

children's book illustration

(Encyclopedia)children's book illustration, any type of picture or decorative work produced for books specifically intended for a youthful audience. During the 1960s a number of seldom-used techniques were introd...

acoustics

(Encyclopedia)acoustics əko͞oˈstĭks [key] [Gr.,=the facts about hearing], the science of sound, including its production, propagation, and effects. Various branches of acoustics that deal with different aspects...

echo, in acoustics

(Encyclopedia)echo, reflection of a sound wave back to its source in sufficient strength and with a sufficient time lag to be separately distinguished. If a sound wave returns within 1⁄10 sec, the human ear is in...