Re: Relativity conundrum

[Pentcho Valev <pvalev@BAS.BG>]

Ken Caviness wrote:

> Pentcho Valev wrote:
>
> > The analysis of the following situation may prove instructive. The person on
> > the train measures the speed of light by sending the beam crosswise - from one
> > side to a mirror on the other etc. There are two possibilities:
> >
> > 1. The person DOES NOT KNOW that the train is moving with a speed v with
> > respect to the railway. So he/she obtains c' = x'/t, where x' is the distance
> > between the sides of the train and t is the time measured.
>
> This is all the person can do, using distance & time as measured by meter
> sticks & clocks at rest in her own reference frame.
>
> > 2. The person KNOWS that the train is moving with a speed v with respect to the
> > railway and accordingly determines the "real" distance x the beam has gone
> > through:
> >
> > x^2 = (x')^2  +  (vt)^2
> >
> > Eventually he/she calculates the "real" speed of light:
> >
> > c = x/t = gamma.c'
> >
> > where gamma = [1 - (v/c)^2]^(-1/2)
>
> This is in incomplete, mixed-reference-frame treatment of the problem.  If the
> person on the train insists on using distances (*) as measured by observers on
> the platform, why is she so inconsistent as to use _time_ as measured by _her_
> clocks (*)?

She does not suspect that time might be different in the two frames. So she finds
that the speed of light is c' in the train frame but c in the railway frame. Then she
repeats the experiment by replacing light with e.g. a bullet - the same result. By
the way, it seems to me that what you call "mixed-reference-frame treatment" is used
in Michelson-Morley experiment but I have to think more. In any event, the version
CONSTANT TIME - VARIABLE SPEED OF LIGHT deserves attention. Einstein's alternative -
VARIABLE TIME - CONSTANT SPEED OF LIGHT - does indeed follow from Lorentz equations
but Lorentz equations do not follow from Einstein's axioms.

> She could use time as measured by clocks at rest with respect to
> the station platform,

How could she do this? She would have to leave her frame and move to the other one -
I am not sure this is unproblematic with respect to the conventional theory (if time
is constant this is unproblematic).

> and will then again find that light travelled at speed
> c.
>
> (* Neither distances nor times measured by observers at rest with respect to
> the station platform turn out to not agree with distances/times measured in
> her own reference frame.)

Provided Lorentz equations are correct. I am curious to see Lorentz own axioms,
arguments etc. Good or bad, they are legitimate whereas Einstein's contribution to
Lorentz equations is zero and even negative.

Pentcho