Hacker News new | ask | show | jobs
by ninkendo 842 days ago
I don’t really see how Olbers’s paradox proves that the Universe is finite, merely that the observable universe is finite. The observable universe is finite because (a) it’s expanding and (b) the speed of light is finite. Both of these can be true in an infinite universe (an infinite universe can still expand everywhere, which can be counterintuitive but it’s true.)
2 comments

The observable universe is finite because the light started at some point in time (and the corresponding distance in light years).

It says less about the size of the universe, than its age.

It also talks about red-shift. Olbers couldn't know that, but even if our universe was here forever we still wouldn't have a lit night sky.
"and eternal static universe."
Doesn't that assume that an infinite amount of time has already passed? Which seems like a contradiction in terms.
I don't see how it would be a contradiction in terms; we can easily speak of the possibility of an infinite amount of time in the future, why not also in the past?

(It may be factually wrong, but that's not a contradiction in terms).