So this is gonna sound ridiculous, but I want to push my curiosity to the limit. Gravitational waves propogate at the speed of light, like most things in the universe. My first question is : is this propogation slowed down by anything? The Higgs field perhaps? 2nd question ; I assume that gravity waves act like other waves, and that they are susseptible to interference, and perhaps other quantum mechanical effects. Does this mean that excitations in a gravity field (graviton a) be entangled with another excitation in the field? P.S. Sorry about spelling/grammar errors. I'm on a phone.