Is the inverse-square law valid for all cosmological distances?

[clamtrox]

Your statement here has nothing to do with my question.

I can see that this discussion is not going to work out. :-)

 

[yuiop]

Why do you think that Newtonian Doppler shift is currently assumed?

Because distant Hubble objects are assumed to be stationary relative to their "local space" and so they are assumed to be not subject to relativistic time dilation which is a function of peculiar velocity relative to local space. Therefore the classic Doppler shift formula which does not include time dilation is used. In a flat-space-no-gravity model a receding object with a high relativistic velocity would have to be time dilated and so the relativistic Doppler equation would have to be used.

What model you use depends on what you measure, but what you measure depends on what model you assume.

 

[Chalnoth]

Because distant Hubble objects are assumed to be stationary relative to their "local space" and so they are assumed to be not subject to relativistic time dilation which is a function of peculiar velocity relative to local space. Therefore the classic Doppler shift formula which does not include time dilation is used. In a flat-space-no-gravity model a receding object with a high relativistic velocity would have to be time dilated and so the relativistic Doppler equation would have to be used.

The peculiar motion of galaxies is generally pretty small compared to relativistic velocities, typically less than 1000 km/sec or so. It can't get much greater because any object that moves rapidly with respect to the expansion quickly catches up to the expansion. The only reason why some things move that fast at all is because they're in the vicinity of some nearby massive object that they're falling towards or in orbit around.

 

[yuiop]

The peculiar motion of galaxies is generally pretty small compared to relativistic velocities, typically less than 1000 km/sec or so. It can't get much greater because any object that moves rapidly with respect to the expansion quickly catches up to the expansion.

I understand that, but in the flat-space-no-gravity model there is no peculiar motion. Peculiar motion only belongs to the Hubble flow idea where Hubble objects are receding at the same velocity as the "local space". The simplistic Special Relativistic interpretation does not consider a vacuum or space itself to be a substance with a measurable velocity, which has etheristic implications.

 

[Chalnoth]

I understand that, but in the flat-space-no-gravity model there is no peculiar motion.

Okay, but that model doesn't describe our universe. So why consider it?