I once had a guy with a masters in physics try to explain all of this to me during one of our discussions. What is out there where the universe ends? He used a paper model of the infinity symbol to try to explain it all. Still, it is hard for the human mind to contemplate that nothing exists where the universe ends. To me,even nothing is something.
This is a great thread with excellent replies. This subject has always fried my mind when I try to think about it.