Re: Paul Draper, what is mass, fundamentally?
palsing
> I had high hopes -- really -- that perhaps one misguided soul would
> read something sensible and say, "Oh... Really?...Oh. I see I was
> confused. OK, I get it now. Now what about...?" My head knew better,
> my heart does not.
It would be nice if this were true, but it doesn't appear to be.
In this case, specifically, it should have been you who was found to
be misguided, and said; "Oh... Really?...Oh. I see I was confused. OK,
I get it now..."
I don't think you could have actually gone back and read the section
entitled;
§ 1. Definition of Simultaneity
... from this page;
http://www.fourmilab.ch/etexts/einstein/specrel/specrel.pdf
... which is where you got this formula...
http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img6.gif
... where Einstein said;
"In order to render our presentation more precise and
to distinguish this system of co-ordinates verbally from others which
will be
introduced hereafter, we call it the “stationary system.”
He clearly wanted to distinguish the "stationary system" from any
moving system, and went on to say...
"Thus with the help of certain imaginary physical experiments we have
settled what is to be understood by synchronous stationary clocks
located at different places, and have evidently obtained a definition
of “simultaneous,” or “synchronous,” and of “time.” The “time” of an
event is that which is given
simultaneously with the event by a stationary clock located at the
place of
the event, this clock being synchronous, and indeed synchronous for
all time
determinations, with a specified stationary clock."
... and it seems clear that both clocks are stationary, that is, v =
0, and that is why your original equality is only valid when v = 0. No
matter what you might otherwise think, here Einstein defined a special
case, his 'stationary system'.
\Paul A