eli5 How does gravity work? Where does it come from?

Question

eli5 How does gravity work? Where does it come from?

In: 28

Answer 1

[There is a theory](https://en.wikipedia.org/wiki/Entropic_gravity) that or universe is actually 2D, it just looks 3D, and that the 2D waves somehow decay or spread out which in the 3D version looks like stuff clumps together.

That theory is probably just sci-fi, though. The real answer is nobody knows – it just is.