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by hook 5734 days ago
Probably a stupid question, but does this take into account the speed of light?
2 comments
teamonkey 5734 days ago
No, it doesn't take special relativity or general relativity into account. It's purely Newtonian physics.
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pavel_lishin 5734 days ago
How do you mean?
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hook 5733 days ago
The force of gravity is not instantaneous. It "travels" at the speed of light. The Earth is not attracted to where the Sun is "now", it is attracted to where the Sun was approx. 8 minutes ago (the length of time it takes for light to travel from the Sun to the Earth), and vice versa.
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mchouza 5733 days ago
The Earth is not attracted to where the Sun is "now", it is attracted to where the Sun was approx. 8 minutes ago

That's not entirely true as there are higher order effects in GR canceling this lag "to second order".

http://math.ucr.edu/home/baez/physics/Relativity/GR/grav_spe...

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