system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What makes the observable universe "observable"?

And what makes the rest of the universe "unobservable"?
gpt
It is "observable right now from earth." It takes light time to travel. If thigs in the universe are so far away that they haven't been in existance long enough for their light to get to us, then when we look their direction there is nothing to observe.

And the kicker is that it appears that space is expandingat these distances faster than the speed of light, so there are probably objects beyond the observable universe that will never make it to us.