Ignore the speculative physics. How can the universe have any boundary at all, let alone an expanding one?
I’m always curious about what’s on the other side of the wall at the end. 🤔😂👍
I figure the black nothingness goes on forever, and the "edge" of the universe is just where you start seeing stars and matter and stuff. Like, imagine you're standing on a black surface that goes on in every direction for as far as the eye can see. Now imagine you throw a handful of salt on it. The universe is that handful of salt. Once you get beyond where the last few grains of salt are, there's nothing.