If you started seeing earlier versions of the same part of the universe that you now are standing in at an apparently large distance out in space, you pretty much know the universe is finite. Light travelling all the way around the universe and arriving back where it started would be a large clue that the universe was finite.
If you started seeing earlier versions of the same part of the universe that you now are standing in at an apparently large distance out in space, you pretty much know the universe is finite. Light travelling all the way around the universe and arriving back where it started would be a large clue that the universe was finite.