what would cause space-time to neatly fold? I understand the concept of the curves, such as those caused by mass or gravitation on light for example, but these diagrams of space-time neatly folded and parallel, while meant to be symbolic or conceptual, are just too convenient for a ‘wormhole’ than can be traversed.
Spice from Giant Worms would do it..................
Cosmic Laundromats and Dry Cleaners.
As you point out, these are basic conceptual representations. Really what you're seeing is a 2-D image of space being bent across a higher dimension (third). In reality, our 3-D space would likely be "bent" via a higher (fourth) dimension. This wouldn't be perceptible to us anymore than a 2-D creature could understand us bending a piece of paper over itself and poking a hole through the two parts.