content: No doubt it could be used to communicate just like radio waves. I haven't read anything except your statement that gravity waves go through anything. I don't doubt it, but I also know next to nothing about it. If producing gravity waves is the secret in the sauce to anti-gravity, then it seems that generated gravity waves must interact with the gravity waves produced by the planet's mass. Would it behave similarly to the repelling effects of magnetic opposites? Would the earth's gravitational field prevent an generated gravity wave from traveling directly through the earth?  I have no idea, but it's fascinating.