Guy Blanchet wrote:
...............
> George Murphy a écrit: ...................
> > 3) Nowadays particle accelerators are designed with the assumption that the
> > relativistic relations between mass, velocity, energy, & momentum are correct, & these
> > machines would not work if those relations were wrong. The Tevatron at Fermilab, e.g.,
> > can accelerate protons to energies of 900 GeV (as in the experiments which found the top
> > quark - see, e.g., Chris Quigg, "Top-ology", Physics Today, May 1997). This energy is
> > (roughly) 1000 times the proton's rest energy, which means that v/c differs from unity
> > by only 5 x 10^-7. Thus the relativistic expressions seem to work up to such speeds.
>
> I have very often heard the comment that relativistic formulae "seem to work". The problem
> is that I cannot find proof of that!
1) I did not say they "seem to work." I said that the accelerators would not
work if the relativistic relations were wrong. If, e.g., the relationship between
particle energy E & radius of curvature of path R in a fixed magnetic field were
different from what is expected then a circular accelerator wouldn't function properly.
E.g., for v~c one gets R proportional to E from the relativistic formulae while for
the Newtonian ones you would have R proportional to E^(1/2).
2) Velocities of particles accelerated to near c, & having known energies, can
be measured with Cerenkov detectors.
3) The following from Taylor & Wheeler's _Spacetime Physics_ of 1966 (p.123) is
germane. "How well tested is relativity? 50 particle accelerators (estimated) that
produce particles of energy greater than 100 MeV, each operating 100 days a year, each
recording 200 collisions per day of operation in which departures from the relativistic
conservation laws would be apparent. Result: 1,000,000 tests per year, each with a
sensitivity of one part in 10^4 or better."
4) In a different area, the departure of the relativistic expression for energy
from the Newtonian one makes a significant contribution to the spin-orbit splitting
in atomic spectra. (See any book on quantum mechanics, using either the Dirac equation
or perturbation theory on the nonrelativistic wave functions.) This can be measured
very precisely by spectroscopy & agrees with the theory - with the inclusion, of course,
of hyperfine splitting, Lamb shift, &c.
And when I put the question to people who no doubt
> know the answer, they clam up tighter than clams in a swamp!
I hope I've been sufficiently talkative.
>I mentioned that my theory
> shows that Einstein would be shy by 12% at 0.9c ...which would not exactly qualify as
> a gross error.
It would be a "gross error" in the observations I mentioned above, & in fact
they show that there is no such effect. In order to discuss the matter further with any
profit you will have to say what your theory is - i.e., equations.
> I doubt very much if such a variance would significantly change particle
> accelerator design.
As I pointed out above, it would.
>I'm sure that amongst all the controls on an accelerator there must be, hidden away
>from the public's eye, a small dial labeled "Field Fudge Factor".
People who work with accelerators are trying to find out things about elementary
particles, not take part in some conspiracy to protect Einstein's reputation.
> > 4) There are absolutes in special relativity. The speed of light is the most
> > obvious, but electric charge and entropy are other examples.
>
> The constancy of the speed of light is not an absolute.
I said nothing about the "constancy" of the speed of light. It is an absolute
in the sense that all intertial observers will measure the same speed for a light ray
in vacuum. That is simply one of the theory's postulates: "Light is always propagated
in empty space with a definite velocity c which is independent of the state of motion
of the emitting body" (Einstein, 1905). Observations agree very well with this.
> The absolute is the ratio of
> distance over time after the necessary corrections have been made for relative motion.
Of course speed is distance over time but your concluding phrase is unclear.
When
> Michelson and Morley did their interferometer experiment, they were looking for signs of an
> "ether", an alledged supporting medium for light. Finding such a medium would have smacked
> of the absolute. It is the inability to prove the existance of ether that kicked off
> Einstein's theory of special relativity.
Historians of science, especially Holton, have sufficiently disposed of the idea
that the MM experiment was the _experimentum crucis_ for relativity. Einstein knew of
such experiments (the "unsuccessful attempts to discover any motion of the earth
relative to the 'light medium'" of his 1905 paper) but other considerations, such as the
symmetry of electrodynamic phenomena, his _Gedankenexperiment_ of trying to run
alongside a light wave, and the Fresnel-Fizeau drag coefficient seem to have been more
important for him.
Shalom,
George
George L. Murphy
gmurphy@raex.com
http://web.raex.com/~gmurphy/
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