Evidence for Lorentz Contraction?

On Apr 3, 6:16*am, Tom Roberts wrote in
sci.physics.relativity:
doug wrote:
maxwell wrote:
I take an alternative view. *That MMX-type experiments were trying to
validate Maxwell's theory. *The null results indicate that this theory
was wrong.

Well, actually, they indicated that maxwell was right.

No, they indicated that Maxwell's theory was wrong (along with a number
of other experiments trying to measure "motion wrt the aether"). Do not
confuse today's theory of Classical Electrodynamics with Maxwell's
theory. Maxwell's theory had more vectors and fields than we use today,
at least one of which was related to absolute motion relative to the
aether frame.

In the late 1800s to the early 1900s a new theory of electrodynamics was
inaugurated, using Maxwell's equations, but not his aether, vortexes,
etc. I don't know the detailed history.... But I do know that's why we
call them "Maxwell's equations", and not "Maxwell's theory".

Tom Roberts

Bravo Honest Roberts! Yes the Michelson-Morley experiment did refute
Maxwell's theory (more precisely, its implication that the speed of
light is independent of the speed of the light source) but why don't
you add that the selfsame experiment did confirm Newton's emission
theory of light (more precisely, its implication that the speed of
light is DEPENDENT on the speed of the light source):

http://philsci-archive.pitt.edu/arch.../02/Norton.pdf
John Norton: "Einstein regarded the Michelson-Morley experiment as
evidence for the principle of relativity, whereas later writers almost
universally use it as support for the light postulate of special
relativity......THE MICHELSON-MORLEY EXPERIMENT IS FULLY COMPATIBLE
WITH AN EMISSION THEORY OF LIGHT THAT CONTRADICTS THE LIGHT
POSTULATE."

http://books.google.com/books?id=JokgnS1JtmMC
"Relativity and Its Roots" By Banesh Hoffmann
p.92: "Moreover, if light consists of particles, as Einstein had
suggested in his paper submitted just thirteen weeks before this one,
the second principle seems absurd: A stone thrown from a speeding
train can do far more damage than one thrown from a train at rest; the
speed of the particle is not independent of the motion of the object
emitting it. And if we take light to consist of particles and assume
that these particles obey Newton's laws, they will conform to
Newtonian relativity and thus automatically account for the null
result of the Michelson-Morley experiment without recourse to
contracting lengths, local time, or Lorentz transformations. Yet, as
we have seen, Einstein resisted the temptation to account for the null
result in terms of particles of light and simple, familiar Newtonian
ideas, and introduced as his second postulate something that was more
or less obvious when thought of in terms of waves in an ether."

James H. Smith "Introduction à la relativité" EDISCIENCE 1969 pp.
39-41: "Si la lumière était un flot de particules mécaniques obéissant
aux lois de la mécanique, il n'y aurait aucune difficulté à comprendre
les résultats de l'expérience de Michelson-Morley.... Supposons, par
exemple, qu'une fusée se déplace avec une vitesse (1/2)c par rapport à
un observateur et qu'un rayon de lumière parte de son nez. Si la
vitesse de la lumière signifiait vitesse des "particules" de la
lumière par rapport à leur source, alors ces "particules" de lumière
se déplaceraient à la vitesse c/2+c=(3/2)c par rapport à
l'observateur. Mais ce comportement ne ressemble pas du tout à celui
d'une onde, car les ondes se propagent à une certaine vitesse par
rapport au milieu dans lequel elles se développent et non pas à une
certaine vitesse par rapport à leur source..... Il nous faut insister
sur le fait suivant: QUAND EINSTEIN PROPOSA QUE LA VITESSE DE LA
LUMIERE SOIT INDEPENDANTE DE CELLE DE LA SOURCE, IL N'EN EXISTAIT
AUCUNE PREUVE EXPERIMENTALE. IL LE POSTULA PAR PURE NECESSITE
LOGIQUE."

Pentcho Valev

Pentcho Valev wrote:
On Apr 3, 6:16 am, Tom Roberts wrote in
sci.physics.relativity:
[MMX experiments]
indicated that Maxwell's theory was wrong (along with a number
of other experiments trying to measure "motion wrt the aether").

Yes the Michelson-Morley experiment did refute
Maxwell's theory (more precisely, its implication that the speed of
light is independent of the speed of the light source)

No, the Michelson-Morley experiment did NOT "refute" the "implication"
that the speed of light is independent of the speed of the light source.
It refuted MAXWELL'S THEORY. Experiments can only refute THEORIES, not
"implications". Indeed, we know that SR includes this "implication" and
yet is fully consistent with this experiment.


but why don't
you add that the selfsame experiment did confirm Newton's emission
theory of light

Because that was not part of the discussion.


http://philsci-archive.pitt.edu/arch.../02/Norton.pdf
John Norton: "Einstein regarded the Michelson-Morley experiment as
evidence for the principle of relativity, whereas later writers almost
universally use it as support for the light postulate of special
relativity......THE MICHELSON-MORLEY EXPERIMENT IS FULLY COMPATIBLE
WITH AN EMISSION THEORY OF LIGHT THAT CONTRADICTS THE LIGHT
POSTULATE."

Yes, this one experiment is consistent with emission theories of light.
But there are LOTS of other experiments, and many of them are
inconsistent with emission theories.

You chide me for omitting mention of your favorite
alternative, but you omit far more important facts,
that make your alternative untenable.


Grow up. Get a life. You repeat the same nonsense so often that I and
most other sensible people just ignore you most of the time. Your posts
include a serious naiveté and an irritating style that indicates gross
immaturity on your part. Stop wasting your time posting nonsense to the
net, and go LEARN something about modern physics.


Tom Roberts

On Apr 3, 4:57*pm, Tom Roberts wrote:
Pentcho Valev wrote:
On Apr 3, 6:16 am, Tom Roberts wrote in
sci.physics.relativity:
[MMX experiments]
indicated that Maxwell's theory was wrong (along with a number
of other experiments trying to measure "motion wrt the aether").

Yes the Michelson-Morley experiment did refute
Maxwell's theory (more precisely, its implication that the speed of
light is independent of the speed of the light source)

No, the Michelson-Morley experiment did NOT "refute" the "implication"
that the speed of light is independent of the speed of the light source.
It refuted MAXWELL'S THEORY. Experiments can only refute THEORIES, not
"implications".

Whoever told you that, Honest Roberts? Any theory normally has many
implications (conclusions), some of them possibly correct, others
possibly false. It is so obvious that experimental results initially
contadict SINGLE CONCLUSIONS. Then the theory is either rejected or
repaired but this depends on additional theoretical analysis.

Just consider the standard textbook calculation of the Michelson-
Morley experiment: your brothers Einsteinians use constant speed of
light (independent of the speed of the light source) and obtain a
theoretical result inconsistent with the experimental result. In other
words, the experimental result contadicts (refutes) the constant speed
of light assumption. If your brothers Einsteinians could find courage
to replace "c" with the respective formulas given by Newton's emission
theory of light, they would obtain a theoretical result consistent
with the experimental result.

Indeed, we know that SR includes this "implication" and
yet is fully consistent with this experiment.

Special relativity can be regarded as the aether theory plus a
protective belt built by FitzGerald and Lorentz. Read Lakatos, Honest
Roberts.

Pentcho Valev