4. The "equivalence principle" was invoked by Regner in a post directed to you no less???...LOL That was not "invoking" the equivalence principle the way I read it.. It merely stated that Einsteins principle corroborated what was being discussed. Read it again, and don't try to put on it more than was stated. "this is also stated" OK a corroboration by Einstein...see the word also! This is also stated in Einsteins equivalence principle Philip.