Our moon spins and orbits around the Earth, which rotates and revolves around the our sun--the center of a solar system, sitting right within the Orion Arm, which probably spins in some aspect of its own, subject to the rotation the entire Milky Way galaxy experiences. Even our galaxy is subject to some movement as the universe expands and mayhap revolves around something bigger than we can imagine. Given the nature of all these things, couldn't we logically suppose there is some sort of "center of the universe" our galaxy revolves about?
Anyway--I'm just wanting to know: exactly why does this occur? My hypothesis is simply that, when a bypassing object comes within range of a gravitational field, it's least difficult route is a spiral path, orbiting the object. Sometimes it'll just be a simple tangent, and miss the orbit altogether. A subquestion might be, why isn't orbital decay a big deal? Why hasn't the Earth fallen into the Sun? Explain centrifugal force?
Thanks.
2007-07-06
11:47:57
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5 answers
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asked by
Anonymous