system
Given the following post, respond as if you're commenting on Reddit:
human
What shape is the universe?

I had a very strange thought come to my head today. The earth is round, correct? Well what if (not saying it is) the universe was round? I know that everyone says it's endless but if the universe was round in "shape" then that could mean it's in its own form of galaxy! Probably just sounds stupid, but I was blown away by the concept!
gpt
This is a major unsolved problem in astronomy.

Present evidence proves that the universe is 'close' to flat, but curvature kicking in on scales of a quarter trillion or more light years cannot be ruled out.

If curvature does kick in on that scale, traveling in one direction far enough can possibly return you to where you started.