[CarrotAndStick]

Space is curved, and it looks like space is closed, and has a finite amount of mass.

Say this space is the Earth's surface. What happens when a "spaceship" pierces out of it, or attempts to do so?

Will it disappear at the boundary and re-appear at the diametrically opposite boundary, like in some of those video games?

[MrB]

I’ve written some “universe” games, and the toroidal universe that you’re referring to is one of the easiest to implement...