gwyn@Brl-Bmd.ARPA (01/30/83)
From: Doug Gwyn <gwyn@Brl-Bmd.ARPA> Not unnaturally, I received several inquiries about my statement that faster-than-light information transfer could allow one to find out about local events before they happened. My reasoning was based on the "fact" that causality propagates at the speed of light. Upon looking over the argument, I now see that it is not really sound, since similar arguments can be given for slower-than- light information transfer. (The idea is, a signal from a distant coordinator would start a causal chain and simultaneously tip off the observer to what was about to happen to him.) Since the reasoning didn't hold up, I am retracting the statement. Most embarrasingly, this whole approach to the problem is incompatible with the v <-> c^2 / v mapping I mentioned in another note! Sorry...