>>12595699The question assumes there's an end of stuff, whereas we can't know if there is any region of the universe which would be at the "edge of the stuff".
It may not exist and the universe might be homogenously filled with matter (an assumption in cosmology which has yet to be disproved).
If we assume everywhere in the universe is like where we are, then going in any direction, you'd never reach the end regardless of how fast and how long you go, because of the expansion of the universe.
There are parts of the observable universe which are getting away from us faster than the speed of light, and those parts are basically all of the observable universe beyond a certain distance from us. So, in our case, even if we go at the speed of light in any direction, we'd never reach those parts of the universe, so we can't escape our part of the stuff.
So to answer your question, we don't/can't know if there is a certain amount of stuff, and so we can't know what happens when you reach the end of it. (scientifically. you can always conjecture/make shit up, but it's probably unprovable)
