Re: A little challenge for relativists.


Androcles wrote:
> "Sue..." <suzysewnshow@xxxxxxxxxxxx> wrote in message news:1130856937.685148.293750@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> |
> | Androcles wrote:
> | > "shuba" <tim.shuba@xxxxxxxxxxxxx> wrote in message news:tim.shuba-0E8A1F.06162301112005@xxxxxxxxxxxxxxxxxxxxx
> | > | O'Harry wrote:
> | > |
> | > | > I don't think that the PoR in
> | > | > itself can lead to an invariant speed (it didn't in the time of Newton), for
> | > | > that at least one additional assumption is needed.
> | > |
> | > | In the case of Galilean Relativity, the invariant speed c is
> | > | infinite,
> | >
> | > BULL***! In Galilean relativity light leaves the source
> | > at a speed of 300,000km/sec.
> | > In SR it leaves the observer and travels to the source first,
> | > reflects and then comes back to the observer.
> | > "For velocities greater than that of light our deliberations become meaningless; we shall, however, find in what follows, that the velocity of light in our theory plays the part, physically, of an infinitely great velocity."
> | > Ref http://www.fourmilab.ch/etexts/einstein/specrel/www/.
> | > Androcles.
> |
> | Well... Does the pithball attract the comb
> | or does the comb attract the pithball?
> |
> Do the skeletal muscles move the skeleton or does the skeleton move the muscles?
> Is the trace on a seismograph caused by the paper strip moving under the
> pen or the pen moving along the paper?
> Does the electron fall toward the proton to emit a photon or does the proton fall toward the electron?
> Does the Sun revolve around the Earth once a day or does the Earth rotate
> on its axis?
> Is the Sagnac effect caused by the apparatus rotating while the observer is
> stationary or the observer revolving while the apparatus is stationary?
>
> "Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of the conductor and the magnet, whereas the CUSTOMARY VIEW [my capitals] draws a sharp distinction between the two cases in which either the one or the other of these bodies is in motion.
> Examples of this sort ... will hereafter be called the "Principle of Relativity''.
> We will raise this conjecture to the status of a postulate and then we'll call it a first approximation.
> Pith balls move faster towards combs than combs move toward a pith balls,
> by the clock of the moving pith ball having a different time to the clock of the stationary comb.
What a co-incidence!
Light moves faster through a sparse gas than a dense gas.
<< The free charge is the total charge less the charge
contributed by polarization, and amounts to that part of
the charge that can move, while polarization charge cannot.
The electric displacement is composed of two different
things, and is best considered a mathematical artifice
that makes it easier to express certain problems.

In the mechanical theory of the electromagnetic field, E
is looked upon as similar in nature to P, the polarization
of the ether instead of the polarization of matter. It was
then convenient to think of E as a cause, and D as an effect,
and even in a vacuum to set D = eoE, where the permittivity
eo was like an elastic constant. This view was totally wrecked
by relativity, but it survives in the system of electromagnetic
units based on the practical units, where it expresses nothing
of physical meaning, and confuses many calculations, especially
in magnetism, and makes relativistic electrodynamics of
materials very confusing indeed. It is much easier to work in
Gaussian units, as I have done here, and convert to practical
units when required.>>

....<< Air has a dielectric constant 1.0006, and it usually may
be assumed to be 1 with little error. Polyethylene is 2.26,
polystyrene 2.54-2.56, teflon 2.1, lucite 2.8, and plexiglas
3.12. Polyvinylchloride has 4.55, pyrex glass 5.00, window
glass 7.6-8, and steatite 5.5-7.5. Mica can have from 2.5-8,
but good mica is 6.4-7.5. >>
--J. B. Calvert
http://www.du.edu/~jcalvert/phys/caps.htm

Sue...


> Androcles.
>
>
> | Sue...
> |

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