宇宙被认为是无限的，但也有边界。这个边界被称为宇宙的事件视界，距离我们约为16亿光年。如果我们能突破光速极限，穿越宇宙的边缘，可能会发现更多的宇宙。
What's at the edge of the universe and what happens if we try to get there?
You might be thinking, wait, how is there an edge to the universe if it's infinite?
This gets talked about a lot.
And people usually say one of the following.
The universe defines all of space and time that exists.
So that's one definition of universe.
But is it even part of our universe if we can never interact with it?
And what if our universe is very, very different beyond the edge?
The universe is infinite because general relativity tells us that the universe is demonstrably flat and therefore the galaxies go on forever.
But how flat?
