>>14414267You can't think of the expanding universe as having a box with a tiny bubble at the center, and that bubble gets bigger and bigger. There is no inside of the bubble or outside of the bubble, so there is no center of the bubble (which would be the center of the box, too).
In the analogy we're looking at, the universe is the -surface- of the expanding bubble. No inside, no outside ... just the surface. And there is no center of the surface of a sphere, right? There's no center of the surface of a beach ball, for example.
