Our spiral galaxy is about 100,000 LY across. We feel the gravity from far-away stars from their position 100,000 years ago, but they aren't in the same place anymore.
2007-07-09
07:51:13
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8 answers
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asked by
Hgldr
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in
Science & Mathematics
➔ Astronomy & Space
OK. some people thought I meant a single star. I mean the gravitational effect of all of the billions of stars in the milky way. As they all morph into a spiral shape, each star feels the gravitational effect from the others at varying delay times.
2007-07-09
08:42:12 ·
update #1
the answer from "aviophage" was interesting. Is this in line with the theory of relativity? There aren't gravity "waves"?
2007-07-09
17:24:42 ·
update #2
By now I've got a few contradicting answers ranging from a well thought-out answer from a PhD to a guy writing about spit. I don't think gravity is instantaneous. I'll post a similar question again.
2007-07-11
13:47:38 ·
update #3
....
hang spit out of your mouth (gross i know)
but with gravity it becomes longer
no gravity..stays the same shape
therefor gravity effects shape
2007-07-09 07:55:21
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answer #1
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answered by Anonymous
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The force of gravity has much to do with the shape of galaxies, but it is not correct to think of gravity as having a "speed." Gravity is not a form of energy, a wave, or a particle. Gravity is a property of the space-time continuum, in the same way that color is a property of paint or bark is a property of doggie.
By the way, if through some magic the sun suddenly ceased to exist or was moved very far away as a physical object, we would feel the effects on earth instantly. It would take eight minutes for the light to stop arriving, but the sun's gravity would be taken away instantly. The earth would fly out of its orbit and head off into the darkness at about 70,000 mph.
Don't hold your breath. It won't happen.
2007-07-09 17:31:03
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answer #2
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answered by aviophage 7
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If the sun was suddenly removed ('beamed away') right now, we'd have no idea for about 8 1/3 minutes. That includes both light & gravity.
But, while the sun's sudden absence would be an enormous difference, a star 5 light years away or 50,000, wouldn't affect us much; A little, to be sure, but by & large, the effect would be very small.
2007-07-09 15:24:28
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answer #3
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answered by quantumclaustrophobe 7
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Even though stars have moved in the time it takes for the gravitational signal to get to us, that effect is accounted for by gravitomagnetism, the GR equivalent of magnetism for gravity. The upshot is that, for the most part, one can consider gravitational interactions to be instantaneous.
2007-07-09 15:18:03
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answer #4
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answered by ZikZak 6
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A word.......You are making an assumption that gravity travels at the speed of light. While mathematically proven/defined by the Theory of General Relativity, it hasn't been measured or observed.
2007-07-09 16:37:07
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answer #5
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answered by Anonymous
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Gravitational attraction is not instantaneous, it travels at the speed of light.
2007-07-12 11:52:10
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answer #6
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answered by johnandeileen2000 7
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The black hole in the middle of the galaxy is what has the gravity for the galaxy.
2007-07-09 16:16:12
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answer #7
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answered by JOHNNIE B 7
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speed of gravity?
gravity doesnt have speed.
all things have a gravity, even ones that far away.
however the amount of gravity from those stars, masses, etc. is so minor that i doubt it moves a atom and if it does not very fast.
2007-07-09 14:57:41
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answer #8
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answered by adam s 2
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