Theory: I noticed at least space is behaving kinda like a gas or liquid inside a box (from which it cannot escape). Matter wanting space itself creates a spacial vacuum. Space tries to fill that up, putting pressure on the matter causing things to stay together. Since space is also time, this flow (the direction of the pressure) never settles from our perspectives, causing a wrapped spacial plane.
Things not liking to stay together try to expand, putting outward spacial pressure onto the surrounding space, but it cannot regain its lost space.
This let me to wonder if we're not actually kinda on some kind of plane inside a box. The only type of box that would be powerful enough to keep absorbing more space as well as containing it in such pressured way would be a black hole, so far I know.
Unfortunately we don't have samples of what happens inside a black hole, so... no clue. But somehow I expect something like what we're experiencing currently, only at a much faster rate.

Also, I suspect that bend spacetime is what causes the strong and weak forces as well.

Since I am not very knowledgable, I suspect /sci/ might know more.