Conceptual question about warping spacetime

[dykuma]

First of all, I would like to admit that my understanding of general relativity is limited, though this will hopefully be remedied this summer when I take a GR class.

I think we have all seen a sci-fi movie where the characters are stuck in a space where they are trapped in a sort of "warp bubble", Basically like a strange game of pack man where going off the screen to the left places you back onto the same spot on the right side of the screen.

Is such a geometry for space possible in general relativity? Furthermore, is it possible to create such a space with the following qualities:

1. You are able to see, without any (or much) visual distortion, the place that you just left from.

2. You do not feel any anomalous accelerations, so if you were on earth, you would only feel Earth's gravity during the entire trip (looping back to the starting position).

In essence, the person needs to think that nothing is amiss while looping over the same space over and over again.

Just so we are clear, this is a question for a friend who is writing a story. She was hoping that I could help , but I know next to nothing about GR at the moment. Anyway, thanks for your help!

 

[PeterDonis]

Is such a geometry for space possible in general relativity?

Mathematically, it is possible to construct a spacetime with this geometry (and with the other properties you describe), yes. The spatial geometry would be what is called a flat 3-torus; the spacetime geometry would just be an infinite series of flat 3-torus spaces, one for each instant of time.

Whether this spacetime would be physically reasonable is a different question. For purposes of a sci-fi story, the physical reasonableness is not necessarily an issue.