On Monday, April 8, 2019 at 11:16:25 PM UTC-6, [email protected] wrote: > > In GR, is there a distinction between coordinate systems and frames of > reference? AG >
Here's the problem; there's a GR expert known to some members of this list, who claims GR does NOT distinguish coordinate systems from frames of reference. He also claims that given an arbitrary coordinate system on a manifold, and any given point in space-time, it's possible to find a transformation from the given coordinate system (and using Einstein's Equivalence Principle), to another coordinate system which is locally flat at the arbitrarily given point in space-time. This implies that a test particle is in free fall at that point in space-time. But how can changing labels on space-time points, change the physical properties of a test particle at some arbitrarily chosen point in space-time? I believe that such a transformation implies a DIFFERENT frame of reference, in motion, possibly accelerated, from the original frame or coordinate system. Am I correct? TIA, 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
