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Coblentz, William Weber

(Encyclopedia)Coblentz, William Weber kōˈblĕnts [key], 1873–1962, American physicist, b. North Lima, Ohio, grad. Case School of Applied Science (B.S., 1900) and Cornell (Ph.D., 1903). From 1905 to 1945 he was ...

Crab Nebula

(Encyclopedia)Crab Nebula, diffuse gaseous nebula in the constellation Taurus; cataloged as NGC 1952 and M1, the first object recorded in Charles Messier's catalog of nonstellar objects (see Messier catalog). It is...

Arnold, Benedict

(Encyclopedia)Arnold, Benedict, 1741–1801, American Revolutionary general and traitor, b. Norwich, Conn. As a youth he served for a time in the colonial militia in the French and Indian Wars. He later became a pr...

alpha particle

(Encyclopedia)alpha particle, one of the three types of radiation resulting from natural radioactivity. Alpha radiation (or alpha rays) was distinguished and named by E. R. Rutherford in 1909, who found by measurin...

scintillation counter

(Encyclopedia)scintillation counter, device for detecting and measuring radiation by means of tiny visible flashes produced by the radiation when it strikes a sensitive substance known as a phosphor (see phosphores...

sapodilla

(Encyclopedia)sapodilla, the edible fruit of Manilkara zapota (formerly Achras zapota), of the family Sapotaceae. The fleshy, brown fruit is the size of a small tomato, and has the flavor and texture of cinnamon, a...

fluorescence

(Encyclopedia)fluorescence flo͝orĕsˈəns [key], luminescence in which light of a visible color is emitted from a substance under stimulation or excitation by light or other forms of electromagnetic radiation or ...

happening

(Encyclopedia)happening, an artistic event of a theatrical nature, but usually improvised spontaneously without the framework of a plot. The term originated with the creation and performance in 1959 of Allan Kaprow...

Warner, Seth

(Encyclopedia)Warner, Seth, 1743–84, hero of the American Revolution, b. Roxbury, Conn. One of the group who, under Ethan Allen, resisted the New York claim to the New Hampshire Grants (now Vermont), he was outla...

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...