Re: A question about physicists and Einsteins SR Theory
From: Harry (harald.vanlintel_at_epfl.ch)
Date: 12/21/04
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Date: Tue, 21 Dec 2004 13:33:22 +0100
"John Kennaugh" <JKNG@kennaugh2435hex.freeserve.co.uk> wrote in message
news:EfwZTiBFA5xBFwmP@kennaugh2435hex.freeserve.co.uk...
> Harry writes
> >
> >"John Kennaugh" <JKNG@kennaugh2435hex.freeserve.co.uk> wrote in message
> >news:zEDklaKNJgwBFwYz@kennaugh2435hex.freeserve.co.uk...
> >> In message <slrncrbfja.f0.dubious@radioactivex.lebesque-al.net>, Bilge
> >> <dubious@radioactivex.lebesque-al.net> writes
> >> > David Johnson:
> >SNIP
> >
> >Allow me a few additional clarifications, as it's interesting stuff -
also
> >some questions:
> >
> >> >In relativity, time and space are on equal footing,
> >>
> >> You should perhaps question what that means and whether they should be.
> >> The history goes like this:
> >>
> >> Once upon a time there was a chap called Newton. To him velocities
> >> simply add. If you can throw a javelin at 30mph when standing still
then
> >> if you run at 6mph and throw it, it will travel at 36mph relative to
the
> >> ground.
> >
> >To be precise, that was because he assumed (a very reasonable assumption
at
> >the time) that mass is not affected by its speed relative to his
"absolute
> >space". Thus his law of conservation of momentum m*v is consistent with
the
> >Galilean transformation, implying no other physical effect from "absolute
> >space" than the existence of inertia and the need of inertial reference
> >frames for his laws. With the corrected mass law as proposed by Lorentz
we
> >obtain the modern relativistic corrections and the velocity-sum equation
of
> >Einstein.
>
> >> Newton thought that light was made up of little particles he
> >> called corpuscles and assumed that their speed would add to the speed
of
> >> the source like everything else does.
> >
> >- like he *assumed* that everything else does.
>
> Fair enough but one should always assumes the simplest model until it
> proves untenable. I am happy to rephrase it:
>
> "[He] assumed that their speed would add to the speed of the source like
> everything else appeared to do."
>
> >> Newton was completely wrong. Light
> >> is not made up of particles called 'corpuscles', we now know that they
> >> are called 'photons' :o).
> >
> >He was mainly wrong with his particle concept for light bending.
>
> >> He lost out to the wave-ether theory of light. This says that
everywhere
> >> in the universe is filled with something called the ether and that
light
> >> is a wave, a disturbance, propagated in that ether at a constant speed
> >> relative to the ether. One can conclude from this that if the speed is
> >> constant w.r.t the ether it will not be effected by the speed of the
> >> source (shorthand - source independence) neither will it be constant
> >> w.r.t the observer.
> >>
> >> An experiment was devised to detect the existence of the ether -
> >> Michelson- Morley experiment (shorthand MMX). It didn't
> >
> >- to be precise: it did not detect the expected signal that was predicted
> >from the used model -
> >
> >> which lead to a
> >> bit of a crisis. It represents a cross roads in physics or really more
> >> of a T-junction.
> >
> >Even more than a T junction, looking at what you write below.
> >
> >> In one direction you have Walter Ritz. The basic argument is very
simple
> >> - If there is no ether then a source is surrounded by nothing which can
> >> effect the speed of light so the only thing which can effect the speed
> >> of light are the physical processes taking place in the source. i.e.
the
> >> speed of light must add to that of the source. Light was found to be
> >> made up of photons, particles, they don't need an ether and there seems
> >> no conceivable reason why their speed should not be c relative to the
> >> source ejecting them.
> >
> >But if light consists of particles, why *would* its speed be c and
> >independent of energy...
>
> Essentially if space is empty there is nothing else which can make its
> speed c other than the processes taking place in the source. Why its
> speed is c is a valid question but does not effect that argument.
>
> It is tied in with 'what is a photon?'. My own suggestion which is pure
> speculation is that a photon spins which is why it has a property we
> call frequency.
No proper frequency at all is required for a photon to "have" a frequency
relative to a detector.
> If it spins and moves forward at c relative to the
> source then there is a distance in which it will complete one revolution
> which might be what we think of as wavelength.
That would be one *twist*, without any rotational motion!
> If energy is related to
> the speed of spin it is possible for any amount of energy to be emitted
> while keeping the speed constant. - I still haven't addressed the
> question as to why the speed is constant - merely pointed out that a
> requirement to carry away different amounts of energy does not imply a
> need for different speeds and even if my speculation is wide of the mark
> that whatever what we call the frequency of a photon (nu in planks
> equation) it is this property which varies with energy level not the
> speed. c would seem to be the maximum speed at which an electric force
> can act so such a force will therefore eject a massless particle at c
> relative to the source ejecting it and any particle with mass will be
> less than c. A particle with mass, if subjected repeatedly to an
> electrical force which can itself only act at c, will never reach c but
> will get nearer and nearer to it. If an electric field cannot make a
> particle travel at more than c relative to itself but can increase the
> energy of the particle in some other way then like a photon there must
> be an alternative mechanism for storing energy other than speed. In
> relativity this is put down to an increase in mass (whatever mass is) in
> a photon it is put down to frequency (whatever frequency is) both
> represent energy so we have energy, mass, and frequency as all aspects
> of the same thing.
Not too bad. I still think that a medium requires less assumptions, and it
appears to me that "Doppler" experiments have been conclusive.
> >There is a number of other unanswered questions with such models, e.g.
how
> >can something without substance be called a particle and why would an
atom
> >emit them in the "shape" of violin rods (proper mass and frequency are
> >zero).
>
> I do not understand your reference to violin rods nor your comment that
> frequency is zero. It is certainly 'interpretation' of some kind based
> upon one theory when we are discussing another. My argument is not that
> I have any answers nor that Ritz had all the answers (he died in 1909 so
> he didn't have long to develop his theory and his battle with Einstein
> was short). My argument is that this route has never been adequately
> explored and no one has tried to find whether there are answers to the
> questions and whether the result would give a simpler model than present
> theory.
>
> After all there was nothing wrong with assuming the earth was at the
> centre of the solar system it is just that if you put the sun at the
> centre everything looks much simpler. Having the earth at the centre
> would never have been disproved if there had not been an alternative
> theory to challenge it. If you have only got one theory, or if no one
> admits the existence of another theory, that theory remains
> unchallenged. Relativity works - but no one has tried the alternative to
> see if it works better.
>
> >> In the other direction you have Lorentz who basically thought that the
> >> wavelike behaviour of light was just too convincing and he thought up a
> >> fix for the wave ether theory
> >
> >- it was a unification of Newton's and Maxwell's theories incl. their
> >metaphysics.
> >
> >> whereby matter moving through the ether is
> >> changed in such a way as to nullify attempts to detect the motion. The
> >> interaction between ponderable matter and the ether he expressed
> >> mathematically as the Lorentz transforms. His theory stated that
> >> although there was an ether underpinning the laws of nature you
couldn't
> >> detect it and from a measurement point of view the laws of nature would
> >> appear the same to all inertial observers.
> >
> >- exactly like the relativity of Newton,
>
> exactly
>
> > but adapted to the newly discovered reality.
>
> The 'newly discovered reality' was that the ether which displaced the
> relativity of Newton in the first place was found not to exist.
Indeed the kind of ether that some proposed in defiance of Newton was again
not found to exist. But the newly discovered reality consisted of phenomena
such as electromagnetic mass increase and the isotropic reflection times of
light within moving frames despite its wave character.
> >BTW it was Poincare who derived the Lorentz transforms and announced -
based
> >on Lorentz' theory - the "new mechanics" that reestablished the PoR.
> >
> >> Einstein (with some conceptual help from Poncere) decided that the
> >> answer was correct but the way of reaching it was unconvincing.
> >
> >Lorentz agreed and later preferred Einstein's top-down approach.
>
> I understand from Lorentz supporters that Lorentz always referred to GR
> as "Einstein's theory" he claimed SR was his - but I do not know if they
> are correct.
Not exactly, for he didn't realise the full consequences of his theory until
Einstein explained it (he had overlooked or skipped through the intermediate
publications of Poincare).
> >> That the
> >> idea that the laws of nature are the same for all observers, that there
> >> is no such thing as absolute velocity, that velocity was always
relative
> >> could be considered as an axiom - The principle of relativity. (short
> >> hand PoR).
> >
> >BTW this was not really new, not even Poincare was original about it
> >although Poincare may have been the first writer to use the expression
> >"PoR".
> >Notice the enormous conceptual gap between Newton, Maxwell, Lorentz ,
> >Poincare on the one hand and Einstein on the other hand, eventhough
Einstein
> >used their expressions.
>
> In Sir Edmund Whittaker's The History of Theories of Aether and
> Electricity, published in 1953, there is apparently a chapter on
> relativity, entitled, "The Relativity Theory of Poincare and Lorentz."
> Einstein isn't mentioned until the thirteenth page of that chapter and
> is credited only with adding the Doppler and aberration equations
> suggesting that the gap between Poincare and Einstein was only in
> presentation and in grabbing the headlines.
Interesting. Indeed, Poincare didn't acknowledge Einstein at all, and it's
easy to understand why. But I thought that Einstein also provided the
velocity addition equation.
> >Where Ritz was in that conceptual dividing line is not clear to me.
>
> The idea of the ether had its ups and downs.
I pointed out a different dividing line, between Natural Philosophy and the
idea that only mathematics matters for physics.
> Its low point was when it
> was decided it needed to be a solid stiffer than steel. Maxwell gave it
> a huge boost by showing light to be concerned with electricity and
> magnetism. The MMX was a major blow to the ether if not to Maxwell's
> equations. If you take Lorenz's theory Maxwell's equations remain
> intact. If you say that MMX showed there to be no ether Maxwell's
> equations become solutions to an unknown problem.
>
> Maxwell's equations failed when Rayleigh tried to use them to explain
> black body radiation. Plank succeeded in explaining black body radiation
> by assuming light generation was quantised. Einstein explained the
> photo-electric effect by simply assuming light remained quantized (as
> per Plank) throughout its life. Surely this sidelines Maxwell's
> equations as being useful, approximate, mathematical models who's
> applications are limited. Light is made of particle as Newton said.
A particle is a form of matter. In my definiton, light seems to have no rest
mass and therefore isn't made up of particles.
> There is no need for an ether, particles don't need one. If no ether
> space is empty and there is nothing but the source for the speed of
> light to be constant with. The real question is what is a photon. If one
> was starting from scratch one would assume that it is something ejected
> by the source at c when an electron falls to a lower energy state but
> relativity insists that its speed is source independent and that surely
> seriously inhibits progress because of a total lack of causality.
Only Einstein's interpretation of it.
> We
> have known about photons for 100 years. We have known about the DNA
> molecule for a percentage of that time. Little progress has been made on
> the one, massive progress on the other. Surely that is indicative that a
> wrong assumption is hampering progress?
>
> >> You will hear that Einstein based his theory on the PoR and that that
> >> removed the need for the ether. What you are unlikely to hear is the
> >> fact that Walter Ritz's theory is completely consistent with the PoR
> >> also. The difference, and therefore what specifically defines
relativity
> >> comes in the second postulate of relativity which does not come from
the
> >> PoR at all. In fact Einstein described the second postulate as being
> >> 'apparently irreconcilable' with the PoR.
> >>
> >> The second postulate in effect says that the speed of light is
> >> everywhere constant with respect to the observer observing it.
> >
> >To be precise, constant with respect to coordinate systems in constant
> >motion.
> >
> >> That in turn comes from the doctrine of source independence. If the
> >> speed of light from a stationary source is c for all observers (PoR)
and
> >> light speed is source independent, then it must be c for all observers
> >> whether the source is moving or not.
> >>
> >> Now comes the bit which is hard to fathom. The PoR is based on the idea
> >> that there is no ether
> >
> >- to be precise, Einstein's 1905 interpretation of the PoR was that no
ether
> >is needed.
>
> No. The PoR is invalid if the ether provides a reference and there is
> therefore a valid concept of absolute velocity.
What you state implies that Newton, Lorentz and Poincare would have used
invalid concepts.
I think exactly the contrary.
> It is not a question of interpretation.
It has *everything* to do with interpretation.
> What Einstein failed to establish was that the idea of
> source independence requires no ether. All he did was to establish that
> you can reconcile mathematically (not physically) the idea of source
> independence and the PoR if you ditch the axioms of absolute time and
> absolute distance.
And Poincare had established shortly before him that you can reconcile
mathematically AND physically the idea of source independence and the PoR if
you ditch the axioms that our instruments measure absolute time and absolute
distance.
> >> the second postulate is based on a property of
> >> the ether - no wonder it is apparently irreconcilable. In order to
> >> reconcile the irreconcilable, Einstein ditched both the axiom of
> >> universal time and of universal distance.
> >
> >Which was already ditched by Lorentz and Poincare, insofar as time and
> >distance refer to measurables...
>
> I agree.
>
> >
> >> You may conclude that having incorporated a property of the ether it is
> >> hardly surprising that he ended up deriving Lorentz's transforms.
> >>
> >> You might also care to wonder why people who don't believe in the ether
> >> would consider it so important to incorporate a property of the ether
> >> that they felt it was worth losing two axioms of physics to achieve it.
> >
> >But those "axioms" were lost anyway, don't you agree?
>
> You have missed the point. They were *not* lost in the Ritz theory
> which is completely consistent with the PoR.
I see.
> The idea of the ether is
> 'apparently irreconcilable' with the PoR so they axioms get lost if you
> either try to retain the ether as per Lorentz or if you try and retain a
> property of the ether as with Einstein.
Yes.
> You seem to happily accept that Einstein followed on the same path as
> Lorentz.
To the contrary, I just stressed the enormous philosophical gap between
them. Einstein's metaphysics is even incompatible with a single physical
reality, as you also pointed out yourself.
> If Lorenz's theory was wrong then why would you reject
> Lorentz's theory and accept Einstein's. Einstein's SR theory is simply
> Lorentz ether theory without the theory.
No, modern theories of physics are loose from metaphysics, only about
observables.
When you write "Einstein's SRT theory" I suppose it implies his
interpretations.
> Lorentz assumed source
> independence because he assumed an ether. Einstein gives no alternative
> justification for source independence. You do not solve the problem by
> saying "Light does not travel at c in the ether it travels at c in a
> FoR". That is fine if you are talking mathematics.
Not even so. Self-contradictions can be shown mathematically..
> If you are a
> scientist, light consists of real physical energy which can cause real
> physical effects. If it is made to travel at c in a FoR then it implies
> that a FoR (a mathematical abstraction mapping out an area of space)
> must correspond with something physical to produce the physical effect
> described in the maths. If the speed of light is not dependent upon the
> source as per Ritz then it must be dependent upon something else and
> that something else must take control the moment it leaves the source.
> Logically therefore space cannot be empty.
Still other models are conceivable.
> There is a second problem, a philosophical one.
I suppose that here you explain the selfcontradictory nature of Einstein's
metaphysics.
I'll skip that for now, as I know it very well.
Cheers,
Harald
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