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Beer's law

(Encyclopedia)Beer's law [for August Beer], physical law stating that the quantity of light absorbed by a substance dissolved in a nonabsorbing solvent is directly proportional to the concentration of the substance...

spectroheliograph

(Encyclopedia)spectroheliograph, device for photographing the surface of the sun in a single wavelength of light, usually one corresponding to a chief element contained in the sun, e.g., hydrogen or calcium; the re...

Granit, Ragnar

(Encyclopedia)Granit, Ragnar, 1900–1991, Swedish physiologist, M.D., Univ. of Helsinki, 1927. A professor at the Univ. of Helsinki from 1927, he joined the faculty of the Karolinska Institute, Sweden, in 1940. Gr...

Wineland, David Jeffrey

(Encyclopedia)Wineland, David Jeffrey, 1944–, American physicist, b. Milwaukee, Wis., Ph.D. Harvard, 1970. Wineland has been a researcher at the National Institute of Standards and Technology and the Univ. of Col...

Hubble's law

(Encyclopedia)Hubble's law, in astronomy, statement that the distances between galaxies (see galaxy) or clusters of galaxies are continuously increasing and that therefore the universe is expanding. Hubble's law ...

Mayweather, Floyd, Jr.

(Encyclopedia)Mayweather, Floyd, Jr., 1977–, American boxer, b. Grand Rapids, Mich., as Floyd Joy Sinclair. He began boxing at an early age, coached by his father, a welterweight boxer whose name he subsequently ...

solar cell

(Encyclopedia)solar cell, semiconductor devised to convert light to electric current. It is a specially constructed diode, usually made of forms of crystalline silicon or of thin films (as of copper indium gallium ...

Appia, Adolphe

(Encyclopedia)Appia, Adolphe ädôlfˈ äpˈpyä [key], 1862–1928, Swiss theorist of modern stage lighting and décor. In interpreting Wagner's ideas in scenic designs for his operas, Appia rejected painted scene...

xerography

(Encyclopedia)xerography zərŏgˈrəfēˌ [key], also called electrophotography, method of dry photocopying in which the image is transferred by using the attractive forces of electric charges. A beam of light, us...

Manichaeism

(Encyclopedia)Manichaeism mănĭkēˈənĭzəm [key], religion founded by Mani (c.216–c.276). Several Christian emperors, including Justinian, published edicts against the Manichees. St. Augustine, in his yout...