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Astro*Dictionary by Michael Erlewine





1 article for "Jeans, Sir James Hopwood"

Jeans, Sir James Hopwood [Astro*Index]

(Sept. 11, 1877 - Sept. 16, 1946) English mathematician and astronomer. Born at Ormskirk, Lancashires; died at Dorking, Surrey, England.

He applied his mathematics to the study of rapidly spinning bodies, and their methods of breaking up under the stress of centrifugal force. He demonstrated that the nebular hypothesis was untenable in the form presented by Laplace. The planets of the solar system contain 98% of the angular momentum, while the Sun rotates very slowly. He argued that this situation would not obtain, had the system condensed from a whirling gas cloud. Jeans suggested that a passing star had drawn a large 'cigar-shaped' mass from the Sun, and imparted to it a large angular momentum. The mass, then, condensed forming the planets. However, a new version of the nebular hypothesis was advanced by others (such as Weizacker) which discredits catastrophic theories for the origin of the solar system, making it reasonable to assume that planetary systems may, indeed, be common. Jeans became known for his popular books for the layman on astronomy, among which were The Universe Around Us (1929) and Through Space and Time (1934).

See also:
♦ Laplace, Pierre Simon, Marquis De


Astro*Index Copyright © 1997 Michael Erlewine