(obviously, I had myself figured in my first post... maybe)
Hypothesis: The Big Bang was a local phenomenon
I'm not a cosmologist, and I haven't taken a physics course in over a decade. What follows could very well be utter dreck. But I find the obsession with beginnings and endings annoying, and boundary conditions artificial.
It's commonly accepted that our universe is expanding, and perhaps surprisingly, that the rate of expansion is increasing. One conclusion drawn from this is that, if the Big Bang was the beginning, then the heat death of the universe is the end; the expansion continues until the universe is filled with a homogeneous low level of energy.
So now we have a beginning and an end. I can almost accept the latter, but how the former came about remains a matter of metaphysics.
Postulate: There exists a super universe, of infinite volume and with infinite energy, of which our universe is just one portion.
Like the theorized terminal of our own universe, this super universe with its infinite energy is also essentially in a state of heat death. However, if you were to focus on any particular area with sufficient detail, you'd find that the near homogeneous dispersion of energy is just that: near. That it is possible that at any point there is some probability that the level of energy present is greater or lesser than at points around it. These differentials ebb and flow, appearing and then smoothing out. Most of the time.
Once in a while the positive differential becomes great enough that it draws further energy into it faster than it can dissipate; the process is self-reinforcing, emptying its surroundings, creating a hole in the homogeneity. The density of this point increases with its appetite. At some point, the energy density crosses a threshold... and (big) bang! The energy is expelled. A new universe comes into being within the super universe. As it rushes outward, that energy surrounding the hole but not consumed before the ignition exerts its own pull, yielding accelerated expansion.
Well, that's pat. And probably rubbish. But let's run with it.
The Meaning of Infinity
I read a Scientific American article that described something like the situation above, although I don't recall if they derived it in quite the same way. The basis of the article was that, while our own universe at a particular time has a definite volume and finite amount of energy, there is all that other energy out there, and some of it is going through similar contraction and expansion. Given a particular volume and amount of energy, you can calculate the set of all possible distributions of the energy within the volume. Now, that is a large number. But it's not infinite.
Given our infinite super universe, we'll also have an infinite number of these expanding, normal, universes. Given a finite set of configurations that the energy can be in each of these universes, the authors then proceed to demonstrate how to calculate the probability that at a given distance, my identical twin in another universe is writing this exact same blog post in his universe.
And it's not just him, but an infinite number of twins. Now, the distances needed to come up with any reasonable probability (i.e. something I'd be willing to bet on) of this occurring are also quite large. But not infinite. But it's more than that... if you are willing to swallow the above and believe that it is possible, then you also need to accept that it is real and definite. There is an infinite number of me out there, at this same exact moment, placing this period. But also an infinite number that placed that period right before, or right after. Or at any time, ever. And there's an infinite number of you (and yes, I mean you, singular, not plural) reading this sentence, right now. And always has been, and will be.
Now my twins (perhaps that's no longer the right term?) and I will ponder the even larger set of not-quite-me's. Where and when I turned right in my universe, they turned left. Every possible fork followed, at all times. The what-might-have-been's of my universe are in some other one. And these I find more interesting than my twins, because I don't know what happened after that. Is one fork "better" than another?
Finally, a conceit: that, somehow, travel is possible between these universes. That a not-quite-me could appear in my universe and reveal the outcome of the choice not taken here. Or of a choice about to be taken. If it is possible, it will happen. To some of us. I think I'd like to meet my future self, or my more extroverted self. If I'm the one to travel though, I'd let myself know that, while not always easy, my set of choices is good.
(well, there ya go)