Androcles, please stay out of this thread if you cannot be constructive
and polite.
Thanks,

Peter Riedt

Peri of Pera wrote:
PD wrote:
Peri of Pera wrote:
PD, the MMX is the starting point and foundation of SR. Without MMX,
Lorentz could not have produced his contraction conjecture and formula
and AE would not have grappled with the constancy of light.

Peter Riedt

This is not historically correct. Einstein was worried about light from
the point of view of Maxwell's equations. The MMX only confirmed the
ideas that had already developed from that. Note that Einstein derived
the Lorentz transformation from the assumption of the constancy of
light speed, not the other way around.

PD

PD, AE did not derive the Lorentz transformation. Contraction was
proposed by Fitzgerald. The mathematical form of the contraction
hypothesis was created by Voigt, Larmor and Lorentz and is known as the
Lorentz transformation (I refer to it as 'the contraction formula'). AE
acknowleges Lorentz as the author in his book from which I have quoted
in this thread.


AE *did* derive the Lorentz transformation from the PoR in his 1905
paper. You need only read the paper to see the derivation there. You
perhaps meant to say that AE did not *originate* the Lorentz
transformation, and indeed that is correct, which is why we call it the
Lorentz transformation and not the Einstein transformation. However, AE
approached it as a derivative product of his postulates, not as the
fundamental basis for SR.

PD

"Peri of Pera" wrote in message
oups.com...
| Androcles, please stay out of this thread if you cannot be
constructive
| and polite.
| Thanks,
|
| Peter Riedt

Peter Riedt, please stay out of this thread if you cannot discuss
physics.
**** you too.
Androcles.

"Peri of Pera" wrote in message
oups.com...

| PD, AE did not derive the Lorentz transformation.

Lorentz didn't include time.
Ergo the cuckoo transformation is all Einstein.
Androcles

Peri of Pera wrote:
PD wrote:
Peri of Pera wrote:
PD, the MMX is the starting point and foundation of SR. Without MMX,
Lorentz could not have produced his contraction conjecture and formula
and AE would not have grappled with the constancy of light.

Peter Riedt

This is not historically correct. Einstein was worried about light from
the point of view of Maxwell's equations. The MMX only confirmed the
ideas that had already developed from that. Note that Einstein derived
the Lorentz transformation from the assumption of the constancy of
light speed, not the other way around.

PD

PD, AE did not derive the Lorentz transformation. Contraction was
proposed by Fitzgerald. The mathematical form of the contraction
hypothesis was created by Voigt, Larmor and Lorentz and is known as the
Lorentz transformation (I refer to it as 'the contraction formula'). AE
acknowleges Lorentz as the author in his book from which I have quoted
in this thread.

Interesting...
Contraction is experimentally confirmed in the near-field
of an electromagnetic coupling structu
http://www.conformity.com/0102reflectionsfig3.gif from:
http://www.conformity.com/0102reflections.html
http://farside.ph.utexas.edu/teachin...es/node46.html

Sue...


Peter Riedt

Peri of Pera, heir apparent to the doogie of howser,

Tom Roberts wrote:

The constancy of the speed of light in locally-inertial frames is not
any sort of "illusion", it is a well-established experimental FACT.


Tom Roberts

Tom, the points which I am making a


...both pointless and inane.


immediately follows. If referred to the system K1, the propagation of
light takes place according to this equation. We thus see that the
velocity of transmission relative to the reference-body K1 is also
equal to c. The same result is obtained for rays of light advancing in
any other direction whatsoever. Of cause this is not surprising, since
the equations of the Lorentz transformation were derived conformably to
this point of view."

Thank you for that regurgitation of the kook manifesto. I don't
know what I would have done without being able to see the same
aimless rambling about relativity from yet another person who
clearly should have first studied relativity before weighing in
with an opinion.

"Peri of Pera" wrote in message
oups.com...
Bill, read the quote I have given in this threat from AE's book. AE
acknowledges the Lorentz transformation which gives the Fitzgerald
contraction hypothesis its mathematical form.

I have read it. It does not mention the Lorentz-Fitzgerald contraction
hypothesis anywhere - not could it since it is a hypothesis about a
hypothetical aether which SR rejects. Answer me one little question - in
the MMX experiment what is the arms moving relative to for them to contract
and explain the null result? SR says since they have no motion relative to
the experimenter then no contraction occurs and the result will be
hypothesis

To claim that AE and SR do not use contraction is absurd.

That is not my claim - I clam it does not use the Lorentz-Fitzgerald
contraction hypothesis - nor can it since it is a hypothesis about an
aether. I carefully explained in a previous post the contraction that SR
does have is a result of space-time geometry and is not applicable to the MM
experiment since the arms of the device are stationary and hence not subject
to contraction.

It is a fundamental tenet of SR.

You are confused.

BTW the contraction hypothesis does not require an ether.

Wrong:
http://www.answers.com/topic/luminiferous-aether
'Another, completely different, attempt to save aether was made in the
Lorentz-Fitzgerald contraction hypothesis, which posited that everything was
affected by travel through the aether. In this theory the reason the
Michelson-Morley experiment "failed" was that it contracted in length in the
direction of travel. That is, the light was being affected in the "natural"
manner by its travel though the aether as predicted, but so was the
experiment itself, cancelling out any difference when measured. Even Lorentz
was not very happy with this suggestion, although it did neatly solve the
problem.'

But even if you interpret it to be motion wrt to the observer then it is
irrelevant to the MMX because the arms have no motion relative to the
observer.

AE appears to have disallowed the ether but still accepted the Lorentz
transforms.

That is because in SR the aether is not required nor is an ad hoc hypothesis
about the aether like the Lorentz-Fitzgerald contraction hypothesis.

Bill


Peter Riedt

Sue... wrote:
Peri of Pera wrote:
PD wrote:
Peri of Pera wrote:
PD, the MMX is the starting point and foundation of SR. Without MMX,
Lorentz could not have produced his contraction conjecture and formula
and AE would not have grappled with the constancy of light.

Peter Riedt

This is not historically correct. Einstein was worried about light from
the point of view of Maxwell's equations. The MMX only confirmed the
ideas that had already developed from that. Note that Einstein derived
the Lorentz transformation from the assumption of the constancy of
light speed, not the other way around.

PD

PD, AE did not derive the Lorentz transformation. Contraction was
proposed by Fitzgerald. The mathematical form of the contraction
hypothesis was created by Voigt, Larmor and Lorentz and is known as the
Lorentz transformation (I refer to it as 'the contraction formula'). AE
acknowleges Lorentz as the author in his book from which I have quoted
in this thread.

Interesting...
Contraction is experimentally confirmed in the near-field
of an electromagnetic coupling structu
http://www.conformity.com/0102reflectionsfig3.gif from:
http://www.conformity.com/0102reflections.html
http://farside.ph.utexas.edu/teachin...es/node46.html

Sue...

Sue, your three references are about something different. More
importantly, MMX cannot be explained using contraction. The experiment
and the observer move at the same v. Equipment and rods are subject to
the same contraction if it existed. I would say that expansion of the
perpendicular arm has the same effect in the experiment as contraction
of the parallel arm. Perhaps you can tell me why contraction should be
preferred over expansion?

Peter Riedt

"Peri of Pera" wrote in message
oups.com...
| Sue, your three references are about something different. More
| importantly, MMX cannot be explained using contraction. The experiment
| and the observer move at the same v. Equipment and rods are subject to
| the same contraction if it existed. I would say that expansion of the
| perpendicular arm has the same effect in the experiment as contraction
| of the parallel arm. Perhaps you can tell me why contraction should be
| preferred over expansion?
|
| Peter Riedt

When you look at the arms they are already contracted. They
expand to normal in their own frame of reference.

For example, a trackside observer sees a 32 car train passing by,
but a passenger on the train can walk along 40 cars if the velocity
of the train is 0.6c. To do that he has to add his own velocity u
to the velocity of the train v so that the trackside observer sees him
walking at V = (u+v)/(1+uv/c^2).
Nobody knows when the other 8 cars fell off the train.
Androcles.

Tom Roberts wrote:
Peri of Pera wrote:
1. Lorentz explained the null result of MMX as due to contraction of
the parallell arm.

No, that was Fitzgerald. Lorentz used Lorentz transforms.


2. AE agreed with Lorentz (refer AE quote below).

Your quote does not support your assertion. That uses the Lorentz
transform, not merely length contraction.


3. MMX is the starting point and foundation of SR.

Not true. Go read Einstein's 1905 paper, and you'll find no reference to
the MMX. Later in life Einstein stated he could not remember if he was
aware of Michelson and Morley's result when he wrote it.

Einstein's starting point was purely theoretical (but supported by a
half-dozen experiments): he took the then-radical point of view that
Maxwell's equations were true, fundamental, and in accord with the PoR;
he followed their implications and SR just popped out....


The contraction
formula is used by SR. If it falls, so does SR.

Sort of true. SR really uses the Lorentz transform, not merely length
contraction.


4. There is an unexplained redundency in the contraction conjectu Is
the MMX null result due to the nature of light (ie constancy) or is it
due to contraction? If c is a constant why is contraction necessary and
if contraction is real how can c be constant (ie must c not vary to
accommodate the contraction at different v)?

That does not matter. One simply makes a prediction using SR and
compares to measurement.

But in fact you are confused. The "length contraction" is _PART_ of the
reason c is constant, as explained by SR. The actual explanation is the
Lorentz transform (not merely length contraction as you seem to think).


5. MMX only shows that light travels over both MMX arms using the same
time. The speed of light may very well be a constant but this is not
proven by MMX or required by it.

Sure. That, too, is irrelevant. One simply makes a prediction using SR
and compares to measurement.


Tom Roberts

Tom, AE's 1905 paper is incomplete. He revised his thinking over many
years until his death. The following is a quote from:

Albert Einstein: Relativity
(revised 1924 edition of Dec 1916 1st edition)
Part I: The Special Theory of Relativity
Chapter 16 EXPERIENCE AND THE SPECIAL THEORY OF RELATIVITY (excerpt)

".....In one of the most notable of these attempts Michelson devised a
method which appears as though it must be decisive. Imagine two
mirrors so arranged on a rigid body that the reflecting surfaces face
each other. A ray of light requires a perfectly definite time T to
pass from one mirror to the other and back again, if the whole system
be at rest with respect to the æther. It is found by calculation,
however, that a slightly different time T1 is required for this
process, if the body, together with the mirrors, be moving relatively
to the æther. And yet another point: it is shown by calculation that
for a given velocity v with reference to the æther, this time T1 is
different when the body is moving perpendicularly to the planes of the
mirrors from that resulting when the motion is parallel to these
planes. Although the estimated difference between these two times is
exceedingly small, Michelson and Morley performed an experiment
involving interference in which this difference should have been
clearly detectable. But the experiment gave a negative result -- a
fact very perplexing to physicists. Lorentz and FitzGerald rescued the
theory from this difficulty by assuming that the motion of the body
relative to the æther produces a contraction of the body in the
direction of motion, the amount of contraction being just sufficient
to compensate for the differeace in time mentioned above. Comparison
with the discussion in Section 11 shows that also from the
standpoint of the theory of relativity this solution of the difficulty
was the right one. But on the basis of the theory of relativity the
method of interpretation is incomparably more satisfactory. According
to this theory there is no such thing as a " specially favoured "
(unique) co-ordinate system to occasion the introduction of the
æther-idea, and hence there can be no æther-drift, nor any experiment
with which to demonstrate it. Here the contraction of moving bodies
follows from the two fundamental principles of the theory, without the
introduction of particular hypotheses ; and as the prime factor
involved in this contraction we find, not the motion in itself, to
which we cannot attach any meaning, but the motion with respect to the
body of reference chosen in the particular case in point. Thus for a
co-ordinate system moving with the earth the mirror system of
Michelson and Morley is not shortened, but it is shortened for a
co-ordinate system which is at rest relatively to the sun......"

Peter Riedt