#### PeterDonis

Mentor

- 25,779

- 6,625

It doesn't have to "know" anything. The causality is forward, not backward. The locally accelerated body "knows" how much proper acceleration to feel based on the local spacetime geometry. In other words, the local spacetime geometry contains all of the information about the path curvature of every possible local worldline, and "path curvature" is the same as "proper acceleration".I can't make sense on how does the matter along the past lightcone "know" when to radiate the appropriate field to produce the right force at the right time on the locally accelerated body