I understand what wormholes are to a layman's degree, and perhaps a bit more - a "portal" in the structure we call spacetime. What I do not understand is why we consider their existance at all. (kind of like the superstrings, ho ho ho) I've come to understand that there is some reason to believe they pop up here and there at subatomic level, but once again, nothing beyond that. I can appreciate the idea of how our universe could be wrapped in a superdimensional manner which could allow for "shortcuts", similar to how you could go to one pole of a sphere to the other through the sphere rather than going all the way around (in a 2-dimensional world, that is), but other than fantasies and dreams of FTL travel, is there a good reason to believe they actually exist? Oh yes, a small question (mostly unrelated) - How does a photon react to gravity? I know it's pulled in by black holes, but in what manner? Do they immediately change direction towards the black hole at c, or do they orbit around it ad infinitum, getting closer and closer? The second seems more plausible, with gravity "crooking" photons (and makes more sense in the spacetime model, as well as, well, my head's physics engine). And since a photon can't travel at a speed slower than c, I assume that it is simply impossible to emot a photon "away" from a black hole.