Ok, so I just found out that gravity travels at exactly the speed of light. I had previously thought that it must travel instantaneously because it's directly related to mass, which is an "instantaneous" value, in my mind. I see how I was wrong now. My question now is why the speed of light? If nothing travels faster than the speed of light, and if a photon (if it could) would feel as though it exists everywhere in the universe at once, what does gravity 'feel'? Does gravity and light take up the same space at the same time from their own perspective? If so, why do we have photons as wave/particles, but gravity is just a curvature in spacetime? Is it possible these curves are nothing more than light waves with extremely large wavelengths? It seems much too coincidental for light and gravity to propagate at the same maximum velocity. Also, what bothers me is light's speed through a medium. I assume it's some sort of pseudo-friction effect for light to slow through a medium... probably due to electromagnetic fields warping the otherwise straight-line path of light (again, this is only an assumption). What of gravity, though? If light is "slower" through a medium, would gravity be as well? If not, then would gravity be traveling faster than the speed of light in that particular instance? If so, then why do objects of high mass accelerate towards each other. Let's say you have two very dense objects suspended in a translucent non-vacuum medium. The two objects would naturally accelerate towards each other in the suspension, but does that mean that the gravity is actually traveling faster than light through the medium? I'm really curious.