Let me preface this by saying that I’m aware of the Big Bang thread-- this is a slightly different question.
Theoretically, the universe is much larger than the ‘observable’ universe. NASA has measured microwave background fluctuations and has come to the conclusion that the universe is likely infinite. In their words:
“This suggests that the Universe is infinite in extent; however, since the Universe has a finite age, we can only observe a finite volume of the Universe.”
(I’ve included the link below.)
This brings me to my question. If, at the moment of the Big Bang, all matter was in one location, it stands to reason that two particles which were once side by side are now an infinite distance from each other. How is this possible?
Either they traveled infinitely fast (I don’t see it, personally) or the universe couldn’t possibly be infinite (what would be beyond it?). An alternate hypothesis could be that the universe is also infinite in time as well as space, but that’s more of a Big Bang subject.
I’m a bit lost and I couldn’t find a good answer in the network of tubes. Any thoughts would be greatly appreciated.
When space itself expands, the particles embedded in it move apart more quickly than their actual velocity through space can account for.
Also, the observable universe *is *the bubble that resulted from the “Big Bang,” and the hypothetical exterior super-universe does not contain particles that resulted from the “Big Bang.”
The popular conception of the Big Bang is that everything was packed into a point. However, this really isn’t accurate.
At the moment of the Big Bang the universe was extremely dense. So the entire observable universe could be packed into a very small space. However, if the universe as a whole is infinite in extent, it was infinite in extent at the moment that it came into existence. It was extremely dense everywhere, stretching out to infinity. There was never a time when the universe transitioned from not-infinite to infinite.
Right. If the Universe is infinite now, it was always infinite even at the Big Bang. If it was finite at the time of the Big Bang, it is still finite now.
I guess I can’t bring myself to believe in an infinite universe. It seems impossible to me. But then again, my brain didn’t evolve in order to allow me to contemplate the extent of the Universe, so perhaps you shouldn’t put to much store in my intuition.
There’s a difference between particles that are within our universe, but are outside of our light-cone and thus are not part of the “observable universe” and things that are outside our universe.
It’s certainly possible that our universe is a subset of some meta-universe, but that’s not what “the observable universe” means.
