Can the "creation" of space in the Universe affect the speed of light?

[mister i]

TL;DR Summary

Can the expansion/creation of space in the universe affect the speed of light over long distances? (dividing the space traveled (including expanded space) by the travel time).

Can the expansion/creation of space in the universe affect the speed of light over long distances? (dividing the space traveled (including expanded space) by the travel time). If the Hubble constant is valid throughout the universe, it follows that from a certain Megaparsec of distance, galaxies should separate from us faster than light. Could the same thing happen to light? (I understand that not because this would imply an observer, but if we could see them we would see the galaxies move slower because the trail of their light would be slower)

 

[PeroK]

TL;DR Summary: Can the expansion/creation of space in the universe affect the speed of light over long distances? (dividing the space traveled (including expanded space) by the travel time).

Reference: https://www.physicsforums.com/forums/cosmology.69/post-thread

Can the expansion/creation of space in the universe affect the speed of light over long distances? (dividing the space traveled (including expanded space) by the travel time). If the Hubble constant is valid throughout the universe, it follows that from a certain Megaparsec of distance, galaxies should separate from us faster than light. Could the same thing happen to light? (I understand that not because this would imply an observer, but if we could see them we would see the galaxies move slower because the trail of their light would be slower)

In cosmology, the speed of light is constant (invariant) when measured locally. On cosmological scales, the speed of light over longer distances is not well defined.

In this posts, as in previous posts, you are trying to squeeze modern cosmology into a classical framework, using classical concepts. If you want to learn about cosmology, you will have to open your mind somewhat.

 

[PeterDonis]

the expansion/creation of space

Is not a real physical thing, it's a coordinate artifact, so it can't affect anything.

 

[PeterDonis]

If the Hubble constant is valid throughout the universe, it follows that from a certain Megaparsec of distance, galaxies should separate from us faster than light.

This "separation speed" is a coordinate speed and has no physical meaning. This was pointed out in one of your previous threads. As @PeroK [Edit--fixed] has commented, you are using a flawed conceptual scheme, and that's not going to change no matter how many questions along these lines you ask.

 

[Ibix]

As @Ibix has commented, you are using a flawed conceptual scheme, and that's not going to change no matter how many questions along these lines you ask.

I think you mean @PeroK.

OP - I assume this is a followup to my comment yesterday. The best way to ask your question is to ask if there are regions of the universe that will always be outside the future lightcone of some distant galaxy, no matter how far into the future we wait. Yes there are. Light from them will never reach us.

If you choose to describe spacetime in terms of "expanding space" then yes, this can be interpreted as the distance growing too fast for light to reach us. But describing this as space being created is wrong - you are looking at different sections of spacetime, not one "piece of space" that is growing.

 

[PeterDonis]

I think you mean @PeroK.

Oops, yes. Will fix.

 

[mister i]

OP - I assume this is a followup to my comment yesterday.

Thanks and sorry (I didn't see your reply yesterday)

 

[Ibix]

Locally light presents itself in one way however over vast distances the relationship with light may ultimately become deceptive i.e. is the observation discovering light that has been bent or interrupted via a black hole or galaxy/ large mass. Who is one to say that this light reaching us now is x amount of lightyears away IF the journey has not been interrupted in some way. Has anyone accounted that the sppee of this light may have been subjected to relatively over a vast distance etc.

Yes, we have considered the effect of the mass in the universe on light. That's literally what the standard cosmological models do.

Yes, we have considered the effects of varying density. These are things like the Integrated Sachs-Wolfe effect where an anomalous blueshift occurs due to a very large under-dense region. We also correct as best we can for the presence of local sources when examining things like the microwave background.