Abstract

Moon and Spencer maintain that there is a divergence between Einstein's analysis of simultaneity, as set forth in his fundamental paper on relativity of 1905, and my treatment of that concept in a recent publication. They write: “Einstein decided that simultaneity is meaningless in all cases of relative motion. … Grünbaum decided that even Einstein's restriction is not sufficiently stringent and that simultaneity is a questionable concept even with stationary observers. … Grünbaum rejects Postulate VI [which states that ‘If A and B are not in relative motion, the time taken for a pulse of radiation to travel in a vacuum from A to B is the same as from B to A’] and is thereby unable to synchronize clocks even when they are stationary.”