I was thinking, if the universe is space and time expanding, lets say in 3D (like a sphere). And it is doing that in a constant or not constant speed, there is a debate about that, never mind that but we know the speed we know it's expanding. So what would happen if we traveled faster than the expanding universe and we reached the end? What would we see? would we be out of space/time ? Would laws of physics work outside the universe?
The concept of the expansion of the universe is hard to get your head around. We describe the universe is infinitely large, and it is expending into itself. So, there is no outside, You can't leave the cosmos. If you could find the edge of the universe and exit through that edge, you would re-enter the universe from the other side. Edges of the universe are linked together. Thus, you could never leave.
The theory of muulti-universes states that law of Physics would be different in another universe. String theory predicts that there are 9 spatial dimensions, so there is many ways those dimensions could be arranged.