Isn't it just basically the same as hyperspace travel from Asimov and basically everybody who copied (ahem) him afterwards? The gravity well thing is the same in Asimov as well. It's not instantaneous, because you still have to travel through the fifth dimension to get there. I guess it's called "folding" because you warp spacetime so it folds over itself, and a wormhole forms. To illustrate how it would work in a one dimensional universe (the .... is not part of the universe - the forum reduces consecutive spaces to a single space):
____________________________
.............|..............................\
.............|<--Wormhole............|
.............|...............................|<--"Fold" in space
________|___________________/
Here, the linear universe is folded over in a second dimension, and a wormhole forms through "hyperspace" (ie the 2nd dimension) to bridge to sections of the universe very far apart, reducing the travel distance. You still have to travel, but it's a shorter distance. In our four-dimensional (ignoring string theory, of course) spacetime, the fold would take place through the fifth dimension.
- Reiginko
