And so that question will remain, I believe. It has always bugged the hell out of me, how we can talk about its curvature, permeability, permativity and a bunch of its other properties without having the faintest clue of what IT is. Or maybe I have to wait till grad school.

It is because all these properties are just numbers in some physical equatons. They are all the effects of some experiments. The equations just use numbers to get other numbers and if both sides of the equations agree then the equation is correct and proceeded to become a law of physics from theory.

But the reality of space will not be determined by experiments. There is no such equation, not because no one has found it yet but is the fact that it can never be found. It's an identity problem not a balancing problem between two distinct identities.