/sci/ - Science & Math

Is space expansion bullshit?

There is no question that the further away a galaxy the faster it recedes from us (as described in Hubble's law), but why do people explain this observation by saying that space itself stretches or is created between galaxies? Especially when space is not some substance independently defined from the distance measurements we make, so saying that space is created between is the same as saying that the distance between the two galaxies increases, it does not explain anything.

If galaxies recede from a given point at a rate proportional to their distance away from it, then from any point it will appear that galaxies recede at a rate proportional to their distance as well. There is no need to invoke that weird-ass concept of space expanding, stretching or being created, all we have to say is that galaxies keep on going due to inertia with the speed the big bang imparted them (slowing down due to gravity and accelerating due to dark energy).

You might think there is a problem with that interpretation because far galaxies recede from us faster than light, but the thing is we don't observe these galaxies in our inertial reference frame (we see them as they were billions of years ago) so the postulate of special relativity that the speed of light is the same in all inertial frames doesn't hold here.

I honestly don't understand how or why they came up with space expansion in the first place when they noticed that galaxies recede with a velocity proportional to their distance