Quote:The speed of light is always the proper speed, unless specified differently.
Of course the proper speed of light is always c, (I'd even say it was tautologically true, since it's pretty much just the statement that a null path is a null path) and I'm not disagreeing with that. In fact, a few posts ago I said exactly that.
My point was that two accelerated observers can measure different coordinate lightspeeds.
Quote:The speed of light does not vary because some observer happens to be ignorant of the laws of physics. His corrections can amply be supplied by one who does know relativity.
I didn't say that. I meant that if he doesn't know to correct his coordinate time interval such that light is travelling on a ds=0 path, then the coordinate speed he measures can differ from c. Does this mean that the "true" speed of light is not c? Well, that depends entirely on what you mean by the speed of light in a non-inertial frame. Perhaps the best way to deal with the problem is just to construct a locally inertial frame, in which it is obvious and the coordinate speed and the proper speed have the same value.
Galileo was a man of science oppressed by the irrational and superstitious. Today, he is used by the irrational and superstitious who claim they are being oppressed by science - Mark Crislip
