Universe loop?

Question

Lets assume the Universe stops expanding. If I go in one direction long enough, would I eventually come back to the exact same spot?

Answer 1

We don't know. Presumably it is a flat plane with sides, i.e., you can't travel around it even though it is not flat, it is hard to explain. The only way to travel around is through a black hole.

Answer 2

yes

Answer 3

That is unknown.  We don't know the topology (the shape, more or less) of the universe--in particular, we don't know whether it's curved positively, negatively, or uncurved at all.  If it's positively curved, the answer to your question is yes.

At the present time, the universe seems very flat.  But it's possible that the curvature is positive, but very small--so small as to be undetectable with current instruments.