[zach_garwood]

It doesn't expand into anything. Spacetime is all there is. As it expands, there's just more of it.

Astrophysics, like quantum physics, isn't intuitive in the same way that classical, human-scale physics is to us.

[Maursault]

> It doesn't expand into anything. Spacetime is all there is. As it expands, there's just more of it.

But what if it isn't, and everything except for space is actually shrinking, galaxies, nebula, stars, planets, are actually getting smaller at a fantastic rate?

I'm not serious.