There's the idea of the "observable universe," in that we can only see what light allows us to see. But wouldn't the unobservable part of the universe have had some effect on the observable part when things were closer together? Is it possible to infer things about the unobservable part of the universe from those effects? I don't know much about astronomy, so if there's a name for what I'm talking about I could read about, that would be enough of an answer for me.