Is the Universe Infinite or Finite? I was having that debate with a friend of mine today. My position was that it is finite because it is expanding. My logic was that the fact that is expanding indicates that it must be finite, because how could something be infinite and getting bigger?
His position was that it was infinite though he couldn't really explain why he thought that. (to give you some context, he also believes his daily horoscope offers him meaningful guidance and that aliens built the pyramids).
You may have guessed by now that neither one of us are physicists, so to settle the argument, I proposed that we contact an expert.
Confident of my correctness, I suggested to my buddy that we should have friend of this here site @seanmcarroll (the brilliant physicist and author of "From Eternity to Here") give us an answer.
I tweeted at Sean the subject line of this thread and he was kind enough to tweet me back in a matter of minutes. He said:
"Nobody knows. Sometimes that's the answer."
He then tweeted
"There may not even be an answer. de Sitter space (e.g.) can be finite or infinite depending on how you slice it."
So not wanting to badger Sean with follow up questions, I ask you: If we know the Universe is continually expanding (which to me suggests that it has a finite size that is increasing), how can it be labeled as anything other than finite?
But not because of anything the spots are doing, it's the space between that's moving, via expansion.
After seeing the responses here, I'll have to agree with Sean. How would you know something like that? Although it is fun to think that if you go fast enough, you could go so far back in time that you wink out of existence.
And greetings to you, Rick.
Or, if that's your preference, you could simply live another 40-50 years, and do exactly the same thing --