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Tombaugh, Clyde William

(Encyclopedia)Tombaugh, Clyde William tŏmˈbô [key], 1906–97, American astronomer, b. Streator, Ill. Although lacking formal training or a college degree, he was hired in 1929 as an assistant by the Lowell Obse...

multiple birth

(Encyclopedia)multiple birth, bringing forth of more than one offspring at birth. Although many smaller mammals bear several young at a time, multiple births are relatively uncommon in humans and other primates. Tw...

computer music

(Encyclopedia)computer music, term used to describe music composed or performed with the aid of a computer. The first substantial piece of music composed on a computer was the Illiac Suite (1956) by the avant-garde...

Newcomb, Simon

(Encyclopedia)Newcomb, Simon no͞oˈkəm, nyo͞oˈ– [key], 1835–1909, American astronomer, b. Nova Scotia, grad. Lawrence Scientific School, Harvard, 1858. Living in the United States from 1853, he was appointe...

hearing aid

(Encyclopedia)hearing aid, device used in some forms of deafness to amplify sound before it reaches the auditory organs. Modern hearing aids are electronic. They contain a tiny receiver and a transistor amplifier, ...

Tesla, Nikola

(Encyclopedia)Tesla, Nikola tĕsˈlə [key], 1856–1943, American electrician and inventor, b. Croatia (then an Austrian province). An ethnic Serb, he immigrated to the United States in 1884, worked for a short pe...

rhenium

(Encyclopedia)rhenium rēˈnēəm [key], metallic chemical element; symbol Re; at. no. 75; at. wt. 186.207; m.p. about 3,180℃; b.p. about 5,625℃; sp. gr. 21.02 at 20℃; valence −1, +2, +3, +4, +5, +6, or +7....

Glauber, Roy Jay

(Encyclopedia)Glauber, Roy Jay, 1925–2018, American physicist, b. New York City, Ph.D. Harvard, 1949. From 1952 he was on the faculty at Harvard, where he became a professor in 1956. Glauber was the co-recipient,...

control systems

(Encyclopedia)control systems, combinations of components (electrical, mechanical, thermal, or hydraulic) that act together to maintain actual system performance close to a desired set of performance specifications...

tone

(Encyclopedia)tone. In music, a tone is distinguished from noise by its definite pitch, caused by the regularity of the vibrations which produce it. Any tone possesses the attributes of pitch, intensity, and qualit...