sci.physics.particle

On Mar 31, 6:46 pm, Tom Roberts wrote:
> Darwin123 wrote:
> He wrote in German, which does not distinguish between speed and
> velocity as we do in English.
Sorry, I may have been referring to the wrong article. I was
thinking of an English translation of one of his papers, where the
word velocity was used for the tangential component of velocity.
>
> > 1) The "stationary" clock wasn't stationary. The clock located at the
> > NBS station was moving with the earth.
>
> Hmmm. Einstein's original paper predated the NBS by many decades (:-)).
Yes, but many experiments validating both SR and GR were and are
being done long after Einstein died. I made the mistake of thinking
you were interpreting one of these very real experimental results. In
particular, I thought you were referring to the Hafale-Keating 1971
experiment. Basically, the experiment follows one of Einsteins
scenarios for special relativity. The results really were exactly what
Einstein predicted. A later experiment by the same group of people
verified general relativity. But as far as special relativity is
concerned, I think the 1971 HK experiment remains a classic.
>
> In his 1905 paper, he says explicitly that "stationary" is merely used
> as a LABEL; it has no "absolute connotations".
Hafele and Keating may have been a little sloppy as far as their
terminology. I think I remember them referring to the NBS station as a
"stationary clock." This may be part of the misunderstanding. The NBS
station can not be stationary in the Einstein definition because it
was accelerating. However, anyone without dyslexia who reads their
paper in context could see that the NBS station was NOT an inertial
frame. It followed one of Einsteins thought experiments rather
closely, but may have used the word stationary differently. Of course,
Einstein wrote in German as you pointed out. The translator may be at
fault. Maybe Hafele and Keating were sticking to correct English
usage.
>
> > 2) All three clocks had a different radial acceleration.
>
> I have no idea which experiment you are attempting to discuss.
From the Wikipedia description.
" The Hafele-Keating experiment was a test of the theory of
relativity. In October of 1971, J. C. Hafele and Richard E. Keating
took four caesium-beam atomic clocks aboard commercial airliners and
flew twice around the world, first eastward, then westward, and
compared the clocks against those of the United States Naval
Observatory."
I was referring to the Hafele-Keating experiment in 1971. There
was recently an even more accurate version of it, but I had read the
original papers on this particular experiment. I argued with someone
on one of these forums regarding this experiment. The article said
that it confirmed special relativity and he said that it disproved
special relativity. I went so far as to send him copies of the
article, with my explanation.
My dyslexic and antigovernment debate opponent went wrote back
how he was right, all government scientists are liars, it obviously
disproved special relativity, etc. etc. I note many people on the web
get the very strange idiea that the HK experiment disproved
relativity. There are emotional issues involved, but I think at their
root is a misunderstanding about acceleration. There is acceleration
in special relativity, and all the clocks in the HK experiment were
accelerating.
One of the things my opponent kept on harping on was the
difference between speed and velocity. And of course whenever he
showed me his math, he consistently got the sign of the velocity
wrong. One of the things he said was that a speed shouldn't have a
sign. So wherever the "speed" had a negative sign, he flipped it to
positive.
There is a less extreme position that the 1971 HK experiment
was a test of general relativity. It was a test of GR only so far as
SR is part of GR. The experimental conditions were set up so the
difference in gravitational potential was entirely negligible. This
was an SR experiment. It verified SR and nothing else.