The Theory of Quantum Gravity

I'd like to know how this relates to previous theories. You said there were other optical or maybe optical mechanical theories of gravity earlier. What from those things have you brought in and what sort of things maybe have you not kept? I just don't see how you can have small polarization effects like that generating forces over very long distances. And that's a problem with generality. People use generality to try to explain gravity just through spacetime curvature. The mechanism is not clear and it just really leads nowhere, turning the matter over the theories of quantum gravity.