Re: Michelson-Morley experiment

From: Androcles (dummy_at_dummy.net)
Date: 12/31/04 

Date: Fri, 31 Dec 2004 18:10:58 GMT

"RP" <no_mail_no_spam@yahoo.com> wrote in message
news:33lhevF41q390U1@individual.net...
>
>
> Androcles wrote:
>
>> "RP" <no_mail_no_spam@yahoo.com> wrote in message
>> news:33lcj0F418475U1@individual.net...
>>
>>>
>>>hasuinterceptor wrote:
>>>
>>>
>>>>Hi guys!
>>>>
>>>>This is my visit to this here forum. I'm googled it out because I
>>>>have
>>>>a question (or, as some might say it, a series of 'hidden'
>>>>questions)
>>>>regarding the Michelson-Morley experiment.
>>>>
>>>>Here are two links to the experiment just in case:
>>>>
>>>>http://en.wikipedia.org/wiki/Michelson-Morley_experiment
>>>>http://scienceworld.wolfram.com/physics/Michelson-MorleyExperiment.html
>>>>
>>>>
>>>>This experiment was meant to prove the existance of ether (and it
>>>>failed, of course). Now, people are telling me that this experiment
>>>>also proves that the speed of life is stable and is not dependant on
>>>>the speed or state of the observer (A. Einstein's theory).
>>>>
>>>>Can anyone possibly explain to me how is that? I've went through
>>>>this
>>>>experiment in my mind for very long, but was unable to reach a
>>>>rational conclusion as to this matter.
>>>>
>>>>I would appretiate any help.
>>>
>>>Special relativity explains the null result by setting the speed of
>>>light as an observational constant. IOW, by setting the apparatus
>>>perpetually *at rest* with respect to the medium in its own frame.
>>>That is, if it isn't moving wrt the medium, then there would be no
>>>fringe shift expected. The difference between this theory, and the
>>>absolute ether theory, is that their predictions differ when the
>>>state of motion of the apparatus is changed. Since the Earth changes
>>>in its motion wrt any given inertial frame over the course of the
>>>year, then the absolute ether theory cannot maintain that the
>>>apparatus was at rest wrt the medium on every trial. I.e. it could
>>>only have been at rest for a single moment, at most, wrt the medium.
>>>The special relativistic solution is thus in keeping with the
>>>results, and the absolute ether is an impossibility, i.e. it was
>>>disproved by the experiment(s).
>>>
>>>Proofs of the truth of any given theory is however an impossibility,
>>>and because of this, neither does MMX prove that special relativity
>>>is the 'de facto' correct theory. The evolution of theory depends
>>>upon the process of elimination, that is, it is possible to
>>>*disprove* theories but not to prove them. Some theories may account
>>>equally as well for a particular phenomenon as do other competing
>>>theories. The one may OTOH take as general premises views that are
>>>contradicted by experiments in other domains. These experimentally
>>>falsified theories are thus clearly only *accidentally* successful in
>>>the domain to which they apply well, i.e. they are special cases of a
>>>more general theory, and their terms were improperly interpreted. By
>>>successive elimination of faulty theories such as these, the most
>>>generally successful of them are established and retained until yet
>>>more general solutions are developed. This applies without question
>>>to special relativity, in that it was soon discovered that its domain
>>>was limited to inertial frames.
>>>
>>>The MMX disproves the *absolute ether* theory in that an absolute
>>>ether, through which light propagates in wave-like motion, would have
>>>resulted in the observation of fringe shifts. No fringe shift was
>>>observed, that is, none that corresponded to motion wrt an absolute
>>>space (absolute ether). IOW, the MMX proved only one thing, i.e. that
>>>light doesn't propagate through a fixed (stationary in all points wrt
>>>itself) medium.
>>>
>>>There are however several competing theories remaining that also were
>>>not disproved by the experiment. OTOH, each of those theories makes
>>>quantitative predictions in other domains as well, and many can thus
>>>be filtered out through other means. The most successful of those, in
>>>the macroscopic domain, has been general relativity, of which special
>>>relativity is a limiting case valid when there are no gravitational
>>>fields present in the system under study, or a good approximation
>>>when those fields are negligible in magnitude. Though it isn't the
>>>most intuitive solution, it is the most versatile theory by far (of
>>>those that have been considered), in that it describes the greatest
>>>number of behaviors with the least number of premises. Though special
>>>relativity successfully accounts for the null result of the MMX, it
>>>isn't a general solution, no more so than some of its competitors,
>>>and was later superseded by general relativity for this very reason.
>>>
>>>As Androcles notes, the ballistic model of light equally well
>>>explains the null results of the MMX. What he consistently fails to
>>>note, however, is that special relativity *is* a ballistic model, one
>>>that simply defines the terms *time* and *distance* differently than
>>>does Newton. Thus the equations of motion in special relativity
>>>differ in form from those that Androcles expects.
>>>
>>>Don't get into the relativity debate. I argued for years against
>>>special relativity only to find that it was my very objections that
>>>were the premises that led to general relativity. The problem seems
>>>to be that those handful who actually understand the theory are
>>>typically inept at relating that understanding. And then there are
>>>those who claim to understand it but don't, and are prone to make
>>>statements on its behalf that simply do not follow from the theory.
>>>IOW, there are idiots on both sides of the debate, and your best bet
>>>is to forget about trying to have serious discussion about it on
>>>usenet.
>>>
>>>Richard Perry
>>
>>
>> Good advice, Richard. However, I have difficulty with your assertion
>> that GR is a valid model since it takes no account of such empirical
>> data as
>>
>> http://www.androc1es.pwp.blueyonder.co.uk/Compare.JPG
>>
>> Both diagrams have distance vertically and time horizontally. The
>> vertical distance is many many light years. The observer is at top
>> and
>> the source at bottom.
>>
>> In the upper diagram, the speed of light is constant and the spacing
>> between the lines occurs at transmission, whereas in the lower
>> diagram the speed of light is added to the speed of the source, the
>> spacing between the lines occurs only at the position of the
>> observer. Either way, the observer sees the same effect, but must
>> invoke general relativity's time dilation for the upper diagram. See
>> http://nobelprize.org/physics/laureates/1993/taylor-lecture.pdf
>> If we add velocities, the lower diagram is correct and the interval
>> between the pulses is regular at transmission, but is seen to be
>> irregular, but if we believe what we see then the pulses are
>> transmitted irregularly at source.
>>
>> I strongly suggest that Occam's Razor makes the lower diagram the
>> correct one.
>>
>> I see nothing of value in pretending spacetime is distorted "out
>> there"
>>
>> to make agreement with our subjective observations. Objectively, the
>> velocity of light must be source dependent.
>>
>> You say "The special relativistic solution is thus in keeping with
>> the results, [of MMX]" but I have to take issue with that.
>>
>> The x-axis arm of MMX is length contracted by
>>
>> xi = (x-vt)/sqrt(1-v^2/c^2) and the y-axis arm has no contraction.
>>
>> Standing alone, that might then be in agreement with Lorentz's
>> analysis
>>
>> of contraction and re-introduce the aether. Except for one thing:
>>
>> Michelson was assuming would be c-v, c+v in one arm but not the
>> other.
>>
>> Einstein claims it to be c (the same c) in both arms.
>>
>> Same speed of light, one arm shorter than the other. That produces a
>> shift.
>>
>> Now, if Einstein had proposed a longitudinal time dilation and not a
>> transverse time dilation, it might still possibly manage to be
>> fringeless,
>>
>> and indeed Einstein DOES say tauX = (t-vx/c^2) / sqrt(1-v^2/c^2).
>>
>> What is definitely missing is tauY = (t-vY/c^2) / sqrt(1-v^2/c^2).
>>
>> He got into trouble with his transverse and longitudinal mass, too.
>>
>> Androcles
>
> There is no contraction of either arm in special relativity, the
> interferometer is at rest wrt the medium in its own frame.

Then
xi = (x-vt)/sqrt(1-v^2/c^2)
is totally meaningless drivel.

"Examples of this sort, together with the unsuccessful attempts to
discover any motion of the earth relatively to the ``light medium,''
suggest that the phenomena of electrodynamics as well as of mechanics
possess no properties corresponding to the idea of absolute rest. They
suggest rather that, as has already been shown to the first order of
small quantities, the same laws of electrodynamics and optics will be
valid for all frames of reference for which the equations of mechanics
hold good. We will raise this conjecture (the purport of which will
hereafter be called the ``Principle of Relativity'') to the status of a
postulate, and also introduce another postulate, which is only
apparently irreconcilable with the former, namely, that light is always
propagated in empty space with a definite velocity c which is
independent of the state of motion of the emitting body. These two
postulates suffice for the attainment of a simple and consistent theory
of the electrodynamics of moving bodies based on Maxwell's theory for
stationary bodies. The introduction of a ``luminiferous ether'' will
prove to be superfluous inasmuch as the view here to be developed will
not require an ``absolutely stationary space'' provided with special
properties, nor assign a velocity-vector to a point of the empty space
in which electromagnetic processes take place. " -- Einstein 1905.

"The law of the propagation of light in vacuo would then have to be
replaced by a more complicated law conformable to the principle of
relativity. The development of theoretical physics shows, however, that
we cannot pursue this course. The epoch-making theoretical
investigations of H. A. Lorentz on the electrodynamical and optical
phenomena connected with moving bodies show that experience in this
domain leads conclusively to a theory of electromagnetic phenomena, of
which the law of the constancy of the velocity of light in vacuo is a
necessary consequence. Prominent theoretical physicists were therefore
more inclined to reject the principle of relativity, in spite of the
fact that no empirical data had been found which were contradictory to
this principle."--Einstein 1920.

  If OTOH we
> assume a frame in motion wrt the interferometer, then the speed of
> light is c both ways wrt our moving frame, but however the arms are
> now in motion. Thus wrt our moving frame, the two-way speed of light
> is c/gamma^2 wrt the longitudinal arm and c/gamma wrt the transverse
> arm. Thus the longitudinal arm must be contracted by a factor 1/gamma
> in order to provide a null result. You can alternately use your
> ballistic model in a Galilean context to provide the same result.
> You're not only frame jumping, but mixing models as well.

What are you talking about?
 It is YOUR OTOH, not mine.
If anyone is frame jumping or mixing models, you are.
Androcles.

>
> Richard Perry
>
>
>
>

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