Posted: Thu Aug 31, 2006 3:49 am
Just off a vague idea of the method for determining the position of a centre of mass/gravity, that point would move in line with the ratio of the Moon's mass compared with that of the Earth. If the Earth is, I dunno, 20 times more massive, then by the same measurement it should take around one and a half billion years for the centre of gravity to clear Earth's surface.
That's easily enough within time. Once you hit a ratio of about 100 in Earth's favour it would take longer than the expected lifetime of the sun... but considering the ratio of the two bodies' diameters isn't that large, and using a (admittedly crude and not entirely precise) cubic relationship between that and volume/mass... it may well be easily under 100. Then again, it might not.
(Clearly I can't be bothered doing my homework properly.)
That's easily enough within time. Once you hit a ratio of about 100 in Earth's favour it would take longer than the expected lifetime of the sun... but considering the ratio of the two bodies' diameters isn't that large, and using a (admittedly crude and not entirely precise) cubic relationship between that and volume/mass... it may well be easily under 100. Then again, it might not.
(Clearly I can't be bothered doing my homework properly.)