Quote:
Originally Posted by sjastro
There are two issues here the expansion of space-time and the movement of objects in space-time. A common mistake is to think there is no difference between the two.
A galaxy unaffected by gravity is moving away from us but is located at the same postion in space-time.
A galaxy affected by gravity can move in space-time, in other words it's location in space-time changes.
In this case gravity is not overcoming space-time expansion at all, rather it is performing work in moving objects in space-time.
There are no inconsistancies.
Regards
Steven
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Precisely. It's easy to distinguish between the two regimes. One is an expansion of spacetime itself and this is independent of any movement of objects within spacetime.
Notice how I said "within" spacetime and not "with" spacetime. Two different scenarios with entirely different causal mechanisms. One due to the Big Bang, the other to gravity between objects.