Word: nebular
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Dates: during 1940-1949
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Whipple became famous last year for his work on the Dust-Cloud Hypothesis, the modern theory on how the solar system developed. His theory has virtually replaced the older Planetary and Nebular Hypotheses, which were proved implausible several years...
...casual kibitzer, cribbage is as baffling as the nebular hypothesis. Even though one may know that its main object is to form various counting combinations (like Pairs, Runs, Fifteens) and register them with wooden pegs until someone gets 61 (or 121 in a double round), one can listen to its time-honored lingo for hours without catching...
Ever since man perceived that the solar system is a cohort of planets revolving around a central sun, at different distances but in the same direction and in almost the same plane, he has wondered how it all started. Pierre Laplace, French mathematician (1749-1827), devised the celebrated "nebular hypothesis": that the solar system was originally a diffuse, whirling, gaseous mass. As this nebular mass became smaller and denser, it whirled faster, until centrifugal force threw off a ring of gas. The process was repeated, each gas ring coalescing into a planet and the sun finally settling down...
Later astronomers abandoned the nebular hypothesis. They found two things wrong with it: 1) it was unlikely that the rings would gather into planets; 2) the "angular momentum" was wrong. Angular momentum can be roughly defined as the amount of rotation in a system. In the solar system the planets have about 98% of the angular momentum, but only one-seventh of 1% of the solar system's mass, the rest being in the sun. The Laplace theory could not account for this discrepancy. It seemed more likely that there had been interference from outside...
...spite of this lack of agreement on forms of the encounter theory, modern astronomers have favored the theory in general. But last week it looked as though the encounter theory was about ready for the scrap heap, along with the nebular hypothesis of Laplace...