I Are Galaxies Moving or is Space-Time Expanding?

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Galaxies appear to be moving away from each other due to the metric expansion of space-time rather than their own motion. This expansion is coordinate-dependent, meaning that in local coordinates, galaxies can be seen as moving away. The analogy of balls on a rubber belt illustrates how galaxies are carried along as space expands. The discussion raises the question of whether galaxies are truly moving or if they are stationary while space-time expands around them. Ultimately, the nature of this movement is tied to the concept of metric expansion.
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Are galaxies are really moving away.Or galaxies are stationary but space-time expends so galaxies move with it ? Or maybe they could be same thing ?
 
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Google "metric expansion". There is no (well, very little and for a different reason) proper motion of far distant galaxies with respect to the Earth, it's metric expansion.
 
phinds said:
Google "metric expansion". There is no (well, very little and for a different reason) proper motion of far distant galaxies with respect to the Earth, it's metric expansion.
This is a coordinate dependent statement. In "local" normal coordinates, galaxies are certainly moving away.
 
Orodruin said:
This is a coordinate dependent statement. In "local" normal coordinates, galaxies are certainly moving away.
t16_Hubble_expansion.gif

Like here its metric expention I guess.Here galaxies are standing still but universe expends so galaxies are moving with a velocity.Galaxies are moving away with a velocity v but not for they have a speed itself,Space time carries galaxies ?
 
Arman777 said:
Are galaxies are really moving away.Or galaxies are stationary but space-time expends so galaxies move with it ? Or maybe they could be same thing ?
Take a rubber belt and put 5-6 balls on it as if it's a kind of bead. Then pull the belt in opposite directions. You'll see the process itself.
 
acidmatic said:
Take a rubber belt and put 5-6 balls on it as if it's a kind of bead. Then pull the belt in opposite directions. You'll see the process itself.

I understand..
 
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