On Monday, April 8, 2019 at 11:16:25 PM UTC-6, agrays...@gmail.com 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
