system
Given the following post, respond as if you're commenting on Reddit:
human
Does gravity have "speed"?

I guess a better way to put this question is, does it take time for gravity to reach whatever it is acting on or is it instantaneous?
gpt
The real answer is more complicated than the standard "it travels at c" response everyone tends to see. Gravitational waves travel at c, as one would expect. But if you're talking about something like falling off a cliff, or orbiting around some heavy object, then gravity is instantaneous (as in the curvature field that gives rise to gravitational effects is already in place the moment you step off that cliff). Even changes in gravity are difficult to calculate because you need to include complicated terms like momentum and energy fluxes, stress and strain and pressure.