Actually, no one knows how it was done.
Is just only gravity or other causes that led to the curvature of space and what’s more with such an effect that entire universe is actually completely twisted in itself.
So maybe that’s why these famous examples such that starting from any point of the universe, we always return to the starting point.
So all this simplifying if we moved with great speed trying to reach to the ends of the universe following the fleeing galaxies (carried by force of expansion space), because without any doubt it is destination of their travel we not see the boundaries of our universe but only we’ll return to the starting point… Milky Way.
But the fact that science can prove that the boundaries of the universe doesn’t exist as a result of assumptions that space is curved absolutely doesn’t mean that the universe itself as a specific area in which this is done the crazy dance of our universe isn’t a part of other area, about differing properties, partly or entirely from ours. and i aren’t considering the idiotic Multiverse theory.
This is really a wonderful theory… or maybe that isn’t true?
This is really a great theory… without fruitless speculation which came first … chicken … egg … Suddenly we have a sizeable bird (inflation) and since then the theory is wonderful.
The theory has the right of course to deal with only certain fragments of processes or events. it is reasonable and justified because our mind isn’t perfect, is too limited in reasoning and understanding to describe the universe as a whole… so we are getting to know fragments, we are linking them with our guesses and the fantasy, so we have a wonderful theory. all, of course, must be consistent, logical, and have common sense… just our Mathematical Universe (in this case, however, we must delete “common sense”)!
But even in the slightest degree without taking into account the effect of the divine power in the creation of this wonderful universe, suppose we probably don’t have any illusions the universe appears to us in all its (true) essence…
Or maybe it is not true? … and maybe in this case also we lack common sense! … or maybe, however, we have the illusion that all our great scientific tools are capable of capturing the whole objective truth… and our (wonderful) mind is full of great opportunities to understand it all… or algorithms interpreting data are subtle enough to capture something we should think about it really deeply.