_heretic

So are you saying that all references frames, backwards in time, all converge into one reference frame?

So, in cosmology, is consideration normally given to how we go from this absolute time, at the big bang, to multiple relative times?

Can you confirm that with something peer reviewed? It sounds like something I should be highly dubious about.

So we think we know that time began at the Big Bang. Why isn't there are universal time as a consequence of that?

I am aware that that is the idea. What I am not clear on is that if time does "begin" how can we have all of these various fields forming? It gives the impression that there is a universal time under which these events are unfolding. Expect relativity tells us that can't be the case. To put it loosely, each thing has its own time.

If that's the case, what's time dilation, length contraction and relativity of simultaneity supposed to be?

Thanks for the suggestions, I'll look into them

I, myself, am of the view that the universe has always existed in some form. This abstraction of "absolute nothingness" is useful in as far as being a self-refuting idea.

So Prof Cox is in error it seems. Did your Professor explain the correct understanding of the principle?

Thanks that has made it a little clearer. What I'm still having trouble grasping is how, with a specific origin of time at the Big Bang, there is not one linear universal progression of time that would come out of it.

But this is only with respect to "our" reference frame. There isn't really a 'cosmic timeline'; so how can we say time had a starting point as if to suggest space-time appeared and started ticking away. Yet GR tells us time does not just 'tick-away' in the background. (Note! I'm not rejecting the fact of the Big Bang here).

General relativity tells us that there is no universal time. It all depends on your frame of reference and velocity relative to other things. So how can it be that time "began" at the Big Bang? - which is the conventional viewpoint.

Are there any experiments I would ideally be able to do, say, on my lawn with cheap equipment, to test special relativity?

I see. I didn't grab that paraphrase from a book on quantum gravity, however, it was from his book: The Road to Reality: A Complete Guide to the Laws of the Universe, which is about the standard model of particle physics, general relativity, special relativity and possible TOEs. So, anyway, special relativity has been worked out with QM. What about EPR situations?