If Space is a vacuum with nothing in it, then what would the edge of the universe even mean

Question

…it would be a ‘border’ between nothing and nothing?

In: Planetary Science

Answer 1

I like the explanation that our dimension (3D) is like the surface of a balloon and the ballon itself is so to say in the 4th dimension. If the balloon inflates our universe expands. But there is no edge or border, though it might be interesting if one could hypothetically travel into one direction and come back from another direction one day.