Learn more physics!
Q.1 How big is our universe, where is the ending?
Q.2 Are we the only planet with living things?
- Ben Yew
Toronto, Ontario, Canda
1. We don't know if the universe is finite or infinite. It goes for at least 14 billion light years away from here. Within any successful model of our current universe, it must actually extend mathematically more than ten times farther out than that. There is no evidence that it has any ending. If it's finite, that just means that it wraps back around, with no edge.
2, We have no idea if there are other planets with living things. Some people think they have arguments indicating there should be lots of such planets, but the arguments are shaky at best. If we're lucky, maybe we'll find some evidence of life elsewhere, but it hasn't turned up yet.
(published on 03/04/07)
Follow-up on this answer.