I know no physics, but I read that while the observable universe is finite, for all physicists know the universe is infinite. How is this compatible with the Big Bang hypothesis? Does it mean that it's possible that at some point space expanded at literally infinite speed? Or something else?
Edit: This question is answered by the comment referring to how the Big Bang did not occur at a point.
As ACuriousMind comments, Big Bang wasn't an explosion at a point, dispersing matter in all directions. It was the creation of space, and its subsequent expansion. The Universe may or may not be infinite. If it is finite, is was born finite, and will always stay finite, although dark energy seems to expand it to an arbitrarily large size.
If it is infinite — and currently, observational evidence suggest it is — is was born infinite, and always will be. It still expands, i.e. the distance between galaxies (that are not gravitationally bound to each other) will increase indefinitely.
There is no way that the Universe can transit between being finite and infinite.
