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Wien, Wilhelm

(Encyclopedia)Wien, Wilhelm vĭlˈhĕlm vēn [key], 1864–1928, German physicist. He was professor at the universities of Giessen (1899), Würzburg (1900–1920), and Munich (from 1920). He received the 1911 Nobel...

particle detector

(Encyclopedia)CE5 Particle detector—Bubble chamber: A. Pressure drops as piston is raised; B. Charged particles passing through chamber ionize atoms in liquid; C. Bubbles form around atoms and form visible tra...

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...

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...

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 ...

Orbiting Solar Observatory

(Encyclopedia)Orbiting Solar Observatory (OSO), series of eight orbiting observatories (see observatory, orbiting) launched between 1962 and 1971 by the National Aeronautics and Space Administration (NASA) to study...

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...

angstrom

(Encyclopedia)angstrom ăngˈstrəm [key], abbr. Å, unit of length equal to 10−10 meter (0.0000000001 meter); it is used to measure the wavelengths of visible light and of other forms of electromagnetic radiatio...