IMO the former is approximate, and latter is exact. It seems to me that the qualifier "local" when describing the EP hides a multiple of sins. An observer can be in the vicinity of a very weak gravity field, or near a hugely intense gravity field, and get contrary detections of tidal forces depending on the accuracy of the measurement devices used, and the length of the enclosure to observe two test masses in free fall. In both cases we can find gravity indistinguishable from acceleration, OR distinguishable, depending on the design of the experiment. In the case of the 2nd law, I am not aware of any situation where it is violated.
As for GR, even if we assume geodesic motion in free fall is a postulate of the theory, a nagging question remains; if a test particle is released from a state of spatial rest (due to an external force ceasing to be applied); why does it start of move in a theory where no forces exist? AG -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/dcd7beb4-85dc-44d1-afb2-8ee8f00a99fbn%40googlegroups.com.
