| Since gravity is a symptom of the presence of matter, gravitational changes ride along with matter travelling as fast as the matter (responsible for this gravitational symptom) can possibly move. At best, only the destruction of matter can move at the speed of light, so a reduction of gravity may propagate, as fast as the dispersal of the dematerialization and subsequent radiation. Accumulation of mass as a knock-on pile-up of massive particles would need to be studied, to assess how quickly the shadow of newly created matter can induce its respective gravitational phenomenon. Figure star nurseries and supernovae events (and similar generative or cataclysmic reactions) would be the place to look. LIGO studies try to do exactly that, but the investigators seem to relish conflating an interpretation that favors signal transmission, and thus "particle/wave duality" because math. Gravity-as-a-wave, meanwhile would be sort of like an illusory sound-as-a-wave being a byproduct of kinetic energy in a material aggregate serving as a bystander medium of propagation. Sound is not it's own "force" although we can readily recognize the phenomenon as a principle that behaves with similar attributes, parameters and effects as observed elsewhere, in other fundamental systems. That LIGO instruments can detect gravitational influence in one part of the apparatus, before the other part of the apparatus registers the phenomenon, is really not unlike saying dominos demonstrate gravitational waves, because toppling the first domino does not topple the last domino instantaneously. That photons can be influenced by a side-effect of material accumulation, bending or altering their path of travel probably says something about the photon or the environment being travelled through, more than it does about space and time. |
But the environment they travel through is space and time.