My mind is just imploding trying to think about how everything began to exist, what was there before, and whether space has edges – what would that even look like? Are scientists as mindfucked as me? Are there any theories?
Quizznor: Our best guess is an infinite universe.
Following the cosmological principle, we know the universe is looking the same in every direction (on large scales anyway).
Furthermore, we know from experiments that the [curvature of space]( https://en.m.wikipedia.org/wiki/Curvature#Space) is (very close) to zero.
Combining these two things leaves us with an infinite universe as the most likely scenario.
cosmotravella: Accepting the concept of the big bang, there must be an advancing boundary of all that we see as the universe. But what this is expanding into is an impossible question.
ToasterFanclub: Think of it this way, we can only ever possibly observe out to the edge of the observable universe. That doesn’t mean things stop there though. Just because nothing could ever reach us from there doesn’t mean it doesn’t exist. It just means it can never impact us. As far as we are concerned anything beyond that doesn’t exist, and whatever is past that, we would likewise not exist for.
The universe appears to be at least as big as we can theoretically observe. Thus, as far as we are concerned, that’s as big as the universe is. We have no way of ever telling if it only extends an inch past what we can see, a hundred trillion lightyears past, or if it’s truly infinite. All of those things would look exactly the same from here.