Isnt asking whats at the edge of the universe in a way asking if the earth is flat rather than round?
Because "from my point of view," which can always be wrong I'd like to note, an explosion on a 3 dimensional space will expand in 3 dimensions. Now once the big bang happened, the fastest particles we know of are those of light, so that those are on the "edge" of the universe. Now, according to many theories, one cannot travel faster than light. If these three assumptions are all based on correct premises that are true themselves, it is impossible for one to reach the edge of the universe because it will be always be moving away faster than anything that may try to reach it. And not only that, but if one were to reach it, then moving toward the edge of the universe would be much like walking over the surface of the Earth, you would keep walking and walking and reaching the same point over and over again.
Now, like I said before and like to emphasize, none of this, except that the idea that nothing can travel faster than light came from my mind and has no scientific proof, so if it sounds lame to anyone with firther knowledge, excuse me