If science proved that the universe didn't have a beginning would you question your faith?

[Architeuthus]

I think the problem is we don't really have a unified theory yet. Loop quantum gravity, which shows some promise, posits that the universe was contracting before it expanded and that it never reached the point of a singularity. It got to a certain size and then "bounced" and at the bounce the entropy resets. From what I've read and watched, it does not say that the universe will necessarily contract again. I am not a physicist and am only an interested layman. So I could be completely off and feel free to correct me. I'm speaking from the standpoint of philosophy.

Cyclic universes seem to require (1) contraction back to a "big crunch" that can become the next "big bang," as well as (2) a "resetting" of all parameters. AFAIK, all current cyclic-universe models are speculative and not supported by evidence.

There are also infinitely-branching universe models, which are quasi-cyclic. They too are speculative and not supported by evidence (and in breach of Occam's Razor).

I think also a distinction needs to be made between "eternal" and "infinite". Eternal, as I inform it, would mean existing for all of time.

If I was sloppy on that, I apologise. Of course, "eternal" does mean "infinite on the time axis."

Agreed. There had to be something to cause the first action and that something had to be uncaused, i.e. eternal.

Well, if you have an eternal universe of interacting "building blocks," then there was no "first action," and there are infinite causal chains resulting from interactions between those building blocks (which have been interacting for an infinitely long period of time). The universe thus evolves like this:

... -> U -> U -> U -> ....

The alternative is some (for want of a better phrase) monolithic eternal "something" M that produces the "first action" as well as the set of initial building blocks

... MMMMMMMMMMMMMMMMMM -> U -> U -> U -> ....

Of course, that runs into the problem that, if the M -> U event was going to occur, why didn't it occur earlier?

In addition (as the Stoics realised), in the interacting-building-blocks approach, if the universe has a finite number of possible states (which is likely if it is finite in size), then the universe must be effectively cyclic in that at least one state of the universe must be repeated infinitely often (and, on plausible assumptions, every state must be repeated infinitely often, including the state the universe is in now, where you and I are communicating -- which seems a little hard to swallow).

Yes but if you point to something that existed to explain existence, then you haven't made any progress in explaining existence.

Well, no. You still have to explain the monolithic eternal "something." But (1) that might be easier to explain, and even if it's not (2) the "two phase" explanation might be the correct explanation.

I use the concept "existence" to denote the sum total of everything that exists. It is synonymous with "universe" as I use it.

I'm using "universe" to mean the physical universe which we observe. And I'm not going to assume that all that exists is physical.