bitch, i'm fo sho wid it

[stuartwesterman]

Gravity travels through space with a speed, correct? And I presume it's safe to say that the speed in question is damn near close to c. In fact, I'm telling you--it is c. So I began to wonder... what else travels at the speed of light? Hmm.. nothing. Wait. Wait. I just find it remarkably interesting that two known things in our universe

Comments

[smandal]

* In current physics, all massless particles travel at the speed of light. Photons are quanta of a massless gauge field (for a theory with so-called U(1) symmetry). There are other such massless quanta, like gluons (up to self-mass corrections).

* You are on the right track with gravity-light duality -- gravitational "charge" is the spacetime stress-energy tensor, to which EM interactions like light can contribute.

* String theory tries to recreate physics in normal 4D with topological dynamics in 4 flat dimensions + 6 or 7 compactified dimensions. This is necessary because gravity seems to be made up of space itself, rather than some parameterized field on it with some symmetry.