How would we know?
Is this a fair analogy?
You’re walking a straight line. You obviously “started” from somewhere, and you’re walking “towards” another point. A beginning, and an end.
But you’re on a sphere. That line, infinitely extended, wraps right back to where it began. There’s no beginning or end.
Time may be like that. Yes, our universe had a Big Bang. Perhaps that Big Bang came about as a result of a multi-verse situation, i.e. there are Big Bangs all of the time, we’re just observing a universe that can support observers. But while our universe had a beginning-- just like our walk on the sphere-- the multi-verse is timeless, like that line on the sphere.
I find multiverse theory elegant in this regard. It allows our universe to have a beginning (and eventually, an end-- big crunch, big freeze or big rip, one way or the other), yet the entire mechanism is timeless.
Hurts to wrap the head around it, but the multiverse doesn’t play by our universe’s rules.
Here’s my theory: let’s assume for a moment that our universe is, at a very fundamental level, described by rigorous mathematical rules (even if those rules involve things like probability and stuff… I’m not saying it’s deterministic). I’d argue that for things which can be described purely with logic and mathematics, there’s no difference between something that COULD exist and something that DOES exist.
Think about the Mandelbrot Set. Seems to me that it exists, and its existence is independent of whether anyone on earth or anywhere else has ever thought of it, or is currently looking at a picture of it. So if you come up with some more complicated similar thing (perhaps a cellular automaton) in which life can exist, ie, the classic that-universe-is-just-a-simulation-on-our-computer setup, then I’d argue that that universe already existed before we started modeling it and exists after we stopped modelling it. In other words, turning of our computer in no way interferes with the lives and existences of the inhabitants of that universe.
I don’t know if there is anything you could call a principle that allows it. But like other posters have said, it might be possible. There’s enough other crazy stuff out there.
My limited understanding is that, just like Voyager says, something with zero net energy might be able to come into existence out of nothing. This comes from a college intro. to physics class, and I didn’t just hear it today, so maybe everything I heard has been disproved.
Sgt. Pepper.
“The downbeat.”
–Cliffy
I wouldn’t say that the mandelbrot set exists regardless of whichever; I’d say the facts about it which follow from its definition are true regardless of whichever. There’s a difference. For example, you could devise a set of rules that model a simulation wherein life (or somehing that simulates it pretty good) would come into existence in the simulated world. The fact that rules would imply the existence of the simulated life is true, regardless of whatever, but the existence of this simulated life is predicated upon the simulation first being run in reality.
Possibly already mentioned (and definitely nothing but speculation), but I was watching a show on the Science Channel about M-Theory, and one of the physicists on the show did the best job of explaining one possible theory that would take us beyond the singularity of the Big Bang…and it was fairly easy even for someone like me to understand. How he explained it is this…the universe we observe is basically on the surface of a large, multi-dimensional membrane. Like a soap bubble. There are LOTS of these membranes out there…billions, hundred of billions, possibly an infinite number. The membranes, or 'branes aren’t static either…they ripple, like the surface of a lake, and sometimes they contact each other.
When 'branes touch they produce unbelievable amounts of heat and radiation…enough to cause the instantaneous formation of a new 'brane (and universe). Supposedly, according to the show, if we could heat up space high enough we could create a new universe ourselves, which would bud off from our universe in an incredibly short time and would expand much like we have observed our own universe to have done 14 and a half billion years ago…IOW, it would create it’s own space completely separate from ours. The clumps of matter we observe (galaxies, stars, planets, etc) were where those two initial 'branes touched in the moment of the formation of our own universe.
I have no idea how widely accepted M-Theory is (or even if I’m getting the salient features correct here), but that was the best explanation I’d ever heard for what COULD have happened before the initial creation of our universe. And the theory, with it’s possibility of infinite other universes was extremely cool. Sometimes I really wish I had gone into physics, instead of engineering…
-XT
This is an adequate layman explanation, but M-Theory (which is actually a collection of five different models) is accepted only in the sense that it is considered a not-entirely-flaketastic possibility. There is neither experimental verification of any aspect of the theory, nor any promise of being able to falsify it in any material way for the foreseeable future; the kinds of energies required to observe this interaction of branes is quite literally cosmic. This is an area of physics in which the professionals actually have little advantage over enthusiasts in terms of really comprehending the phenomena; while the (very complex) math is beyond the ability of the casual student, the intuitive description of what may or may not be occurring is pretty much just as accessible to an unschooled reader of Scientific American as to a physics Ph.D.
Stranger
Well, glad I didn’t mangle it too much then. I’m certainly only an interested layman. My degree was in aero-space engineering, not physics or cosmology, and I haven’t used my degree for anything but an interesting point on my resume for over 20 years.
I DO enjoy watching Michio Kaku and the other people on the Science Channel, even though I’m well aware that it’s not REAL science, as you’ve pointed out to me in the past. 
It’s fun to watch and interesting, even if it’s the (extremely) lite version of real science…
-XT
Let me hit the pipe and I’ll 'splain it to you
I endorse this message.
“I don’t know and neither do you” is about as good as it gets.
That is trotted out constantly, but it is not right. Just because a cause cannot be seen (or understood) does not mean one does not exist. Let’s say I’m in a room, and every time I take a step the light over head flashes off then on again. This goes on all day long—or all year. Then one day while I’m sleeping in my hammock, the light flashes. Does this mean that an even occurred with no cause. Or that there might be a kid outside the room who found the light switch?
Back to Heisenberg. We don;t know if that particle traveled from another place or actually created itself out of nothing, thereby increasing the matter in the universe. I vote for the former, but either way, Heisenberg is mute on causality. It’s has to do with what is observed, not why or how.
My background isn’t physics, but even if the universe comes from ‘something’ (meaning something before our universe had the equivalent of mass, form, energy, etc) then where did that ‘something’ come from? You end up with the same problem all over again.
Is nothing in the set of all sets?
If not careful, your definition of nothing can easily cause it to become something.
Here we have limitations with language. For something to exist, it implies that it is something. Nothing, by definition, does not exist. So the question becomes, is there a difference between nothing and a complete lack of something? Is it possible for a lack of something to…well, not exist, but…be a possible state of…well, not the universe, but…uh…
I think I need to lie down.
Maybe a quote would help. I don’t know if this is actually the correct answer now. It does seem to speak to the OP, so here ya go:
“Nothing is what rocks dream of”.
I’m not a religious man, but if you believe the universe came from nothing, you have more faith than any religious person I know.
I watched that this weekend, and what a great talk it was. It left me longing to hear the stuff that he mentioned he skipped in the interest of time.
I think you’re saying that there might be other unseen causes responsible for this apparent randomness. I know that, in the case of quantum entanglement, the idea of hidden variables has pretty much been ruled out, and I thought that same idea applied to quantum uncertainty. In other words, things provably are really random and not just the result of some as-yet undiscovered determinism. IANAQP so if someone who understands it better could add to this, I’d appreciate it.
Religious people believe that god is uncaused. So, there’s no difference.