I think that gravitation is caused by the "disappearance" of the local space. In my view, space is not a real vacuum, but a room filled with a thin, not yet measurable, "fluidic" force-field, which is a conductor for light and electro-waves. Therefore I like to call it the "electro-ocean".
Real vacuum can't be created, because the spacefluid will fill the gap immediately. When a body, with it's mass, is present in space, it "sucks" up the energy around it, and the rest of space is dragged inwards, filling the vacuum. Thus, objects in space move closer to each other - not because they attract each other, but because the distance between them is narrowed.
If the space-fluid, or medium, is not elastic, this "gravity"-pull will move with infinite speed through the whole Universe. If space is elastic, gravity moves in a slower speed.
Since no one has been able to detect gravitation waves, I guess it's because the spacefluid can't be stretched. It's density is constant, because of a one-state nature.
This perhaps could be likened with draining a sea. No matter how small amount of water you tap from it, the whole sea's surface will sink. It's not just the surrounding area that will sink, but the whole sea.
So, gravitation is draining the electro-ocean, and every "floating" object in it has to follow. And every decrease would be felt through all the Universe, if one were able to detect it.
Wouldn't this save Einstein's theory, and yet allow information to travel "faster" than light? Shortening space doesn't change the speed of the traveler, it only changes the length of the travel.