On Jul 7, 8:52 am, PD <thedraperfam...@gmail.com> wrote: > On Jul 6, 3:03 pm, colp <c...@solder.ath.cx> wrote: > > > On Jul 7, 3:07 am, PD <thedraperfam...@gmail.com> wrote:
> > > The problem, you see, is that the comic-book statement you are using > > > as your launching point belongs in COLP's Oversimplified Relativity. > > > It's not a comic book statement any more than Einstein's statement > > that a moving clock lags behind a stationary clock is a comic book > > statement. > > Not so. Einstein's statement included things that you have discounted.
I haven't discounted them.
> For example, he makes note of specific events, rather than just making > the general statement that "moving clocks" run slow.
The description of the specific events only serves to illustrate that it is the moving clock that runs slow compared to the stationary clock.
> Furthermore, he > makes EXPLICIT mention of the statement that the clocks at points A > and B are initially synchronized IN THE K FRAME.
Assuming that they weren't synchonized in my general description of "the moving clock runs slow" would be arbitrary and illogical. Remember I was talking about _the_ clock, in reference to the moving clock described in "Electrodynamics of Moving Bodies", not to a clock in an arbitrary system.
> A contradiction would > arise by making the clock at B the moving clock only if the clocks are > claimed to be intially synchronized also in the K' frame -- but they > are NOT, and this is the essential detail that you have missed.
No, it isn't a missing detail, it is an implication of Einstein's first postulate of relativity.
Here is Einstein's description of the clocks:
"If at the points A and B of K there are stationary clocks which, viewed in the stationary system, are synchronous; and if the clock at A is moved with the velocity v along the line AB to B, then on its arrival at B the two clocks no longer synchronize, but the clock moved from A to B lags behind the other which has remained at B ..."
Let us call the moving system K', in which the moving clocks at A' and B' are synchronized for an observer in K'. The stationary system K also has two clocks, but these two clocks are synchronized for an observer in K. Frames K and K' move at a constant velocity with respect to each other.
If there is no preferred frame of reference then there is no reason why the clocks at A' and B' cannot also be synchronized for an observer in K', just as the clocks at A and B are for an observer in K, due to the symmetry of the two frames and their respective clocks.