Big Bang and Simultaneity question

[master_gopher]

I realize this question includes relativity, but I think it is more appropriate here than in that forum? [Tell me if I should cross-post it elsewhere; I'm new to this forum :)]

I'm working on a paper based on reading material that doesn't address big bang cosmology directly, but rather focuses on relativity, with a lot of emphasis on special relativity and its influence on time and simultaneity. The question I'm working on is:
"According to the currently accepted Big Bang Cosmology the universe is expanding uniformly. Hence there is no absolute rest but there is absolute simultaneity." Discuss.

I don't want a direct answer of course, just a little help with my research... as far as I can make out special relativity alone doesn't allow for absolute rest or absolute simultaneity, but this is not in reference to the big bang. So does the Big Bang have a significant effect on relativity, or vice versa? I think I'm in danger of sidestepping the question, but I'm not sure how the two ideas are actually linked. As far as I can see, lack of absolute rest is confimed by BB theory, since the universe is expanding in every direction, and not away from any central point of reference, while I can address simultaneity by explaining a thought experiment along the lines of the train-and-platform scenario. However, am I missing something vital? Should I be looking at general relativity as well, or something else not in the reading?

Thanks in advance.

 

[chronon]

Take a look at Ned Wright's cosmology tutorial which explains what the expansion looks like when you choose different coordinate systems, and in particular different time coordinates.

Personally, I think that absolute simultaneity appears in cosmology because people want to believe in absolute simultaneity rather than for any physical reason. See http://www.chronon.org/Articles/milne_cosmology.html for more discussion of this.

 

[Chronos]

The finite speed of light makes simultaneity a moot point in GR.