Pentcho Valev wrote:
On Jun 7, 12:15*pm, John Kennaugh
wrote:
Pentcho Valev wrote:
On Jun 6, 1:36*pm, John Kennaugh
wrote:
Tom Roberts wrote:

[... remainder displays utter ignorance of modern physics]

No I reject the mysticism of modern physics. A photon is a perfectly
ordinary particle not some mystical mathematical object. A photon has
mass and therefore shows that SR is wrong because SR says it cannot
travel at c if it has mass - and it does.

A photon has mass because:

1/ Its direction is affected by gravity as with any projectile with
mass.
2/ Its energy increases if it falls under gravity just like any other
object with mass.
3/ Its energy is reduced when it escapes from a gravity field just like
any other projectile.
4/ If photons hit a surface they produce pressure just as any other
particles with mass will.
5/ It is hard to show that if you stop a photon it has rest mass but If
you take a very high energy photon (massive) and near stop it you end up
with an electron and a positron - which have mass - and a low energy
photon to take away any excess mass.
6/ If you combine an electron and a positron then you get two photons
each of who's mass is equal to that of an electron (or a positron)

The equations Waldron produces show that a photon with a given energy
has a given mass and that one value gives the correct answer in all the
above. The mass equations all balance.

Tom Roberts and his superior brothers Jean-Marc Lévy-Leblond and Jong-
Ping Hsu have already solved this problem: Divine Albert's Divine
Special Relativity "would be unaffected" even if "it is ultimately
discovered that the photon has a nonzero mass (i.e. light in vacuum
does not travel at the invariant speed of the Lorentz transform)":

http://o.castera.free.fr/pdf/chronogeometrie.pdf
Jean-Marc Lévy-Leblond "De la relativité à la chronogéométrie ou: Pour
en finir avec le "second postulat" et autres fossiles": "D'autre part,
nous savons aujourd'hui que l'invariance de la vitesse de la lumière
est une conséquence de la nullité de la masse du photon. Mais,
empiriquement, cette masse, aussi faible soit son actuelle borne
supérieure expérimentale, ne peut et ne pourra jamais être considérée
avec certitude comme rigoureusement nulle. Il se pourrait même que de
futures mesures mettent enévidence une masse infime, mais non-nulle,
du photon ; la lumière alors n'irait plus à la "vitesse de la
lumière", ou, plus précisément, la vitesse de la lumière, désormais
variable, ne s'identifierait plus à la vitesse limite invariante. Les
procedures operationnelles mises en jeu par le "second postulat"
deviendraient caduques ipso facto. La theorie elle-meme en serait-elle
invalidee ? Heureusement, il n'en est rien ; mais, pour s'en assurer,
il convient de la refonder sur des bases plus solides, et d'ailleurs
plus economiques. En verite, le "premier postulat" suffit, a la
condition de l'exploiter a fond."

http://o.castera.free.fr/pdf/onemorederivation.pdf
Jean-Marc Levy-Leblond: "This is the point of view from wich I intend
to criticize the overemphasized role of the speed of light in the
foundations of the special relativity, and to propose an approach to
these foundations that dispenses with the hypothesis of the invariance
of c....We believe that special relativity at the present time stands
as a universal theory discribing the structure of a common space-time
arena in which all fundamental processes take place....The evidence of
the nonzero mass of the photon would not, as such, shake in any way
the validity of the special relativity. It would, however, nullify all
its derivations which are based on the invariance of the photon
velocity."

http://www.amazon.com/Einsteins-Rela...nd-Approaches-
Theoretical/dp/9810238886
Jong-Ping Hsu: "The fundamentally new ideas of the first purpose are
developed on the basis of the term paper of a Harvard physics
undergraduate. They lead to an unexpected affirmative answer to the
long-standing question of whether it is possible to construct a
relativity theory without postulating the constancy of the speed of
light and retaining only the first postulate of special relativity.
This question was discussed in the early years following the discovery
of special relativity by many physicists, including Ritz, Tolman,
Kunz, Comstock and Pauli, all of whom obtained negative answers."

http://groups.google.ca/group/sci.ph...1ebdf49c012de2
Tom Roberts: "If it is ultimately discovered that the photon has a
nonzero mass (i.e. light in vacuum does not travel at the invariant
speed of the Lorentz transform), SR would be unaffected but both
Maxwell's equations and QED would be refuted (or rather, their domains
of applicability would be reduced)."

Pentcho Valev


I believe that what you quote is saying a different thing to what I am
talking about. What is being discussed in your quote is I think a case
of hedging their bets and saying that if instead of having zero mass a
photon had a minute mass, all it would mean is that the theoretical
constant c would not be the speed of light and that photons would have
to travel at very slightly less than c.

There is a second message in the quotes (designed to confuse mainly
zombies, not clever Einsteinians). Tom Roberts, Jean-Marc Lévy-Leblond
and Jong-Ping Hsu suggest that Einstein's 1905 light postulate is
obsolete and therefore even if the speed of light is variable, not
constant, special relativity "would be unaffected". Note that,
logically, this suggestion has nothing to do with the problem of the
mass of the photon.

OK. It is understandable why they would want that to be the case. Any
relativist who isn't acutely embarrassed by the origins of relativity
obviously hasn't studied and understood the history. Einstein's starting
point was unashamedly Lorentz's Aether Theory - a modification to
Maxwell's Aether Theory. Now to do the maths of LET one transforms to
and from the 'aether FoR'. Unfortunately the aether FoR is
indistinguishable from every other FoR. Fortunately that doesn't matter
because if you select any FoR as the aether frame and get the same
answer. There is nothing therefore to prevent you from always selecting
the observer's FoR as the aether frame and if you do that you get
something indistinguishable from SR. In other words one way of looking
at SR is that it is simply a mathematical approach to doing LET maths.
The theory is still that of Lorentz.
Another way of viewing it is that the followers of Maxwell -
Einstein and Lorentz included - interpreted the MMX as showing that for
some reason the observer always appears to be stationary w.r.t Maxwell's
aether. Lorentz had put forward an explanation as to why that is the
case - LET says that it is an illusion brought about by distortion of
measurement - Einstein didn't like that explanation so took a completely
empirical approach and said in effect "lets just accept that every
observer IS stationary w.r.t the aether, for whatever reason". The
second postulate simply describes exactly what an observer stationary
w.r.t the aether would experience.
Another way to look at it is that Einstein objected to the
asymmetry in the theoretical structure of LET and came up with a
'theory' (same maths) without a theoretical structure. To be fair to
Albert he tried to come up with something - his aether without the
immobility of Lorentz's - but failed. In essence (1920 lecture) he
argued in favour of the aether but against the accepted assumption that
an aether had to imply a unique FoR stationary w.r.t it. Put simply he
was suggesting, in deliberately vague terms, that there could be an
aether which every observer naturally finds himself stationary w.r.t. as
per the second postulate. The aether is of course central to his
thinking because it is the aether which controls the speed of light
which is why its speed is assumed to be not source dependent.
Physics was taken over by mathematicians who were enjoying the
new mathematical challenge and who casually ditched the aether without
realising the decision to accept Einstein's version of Lorentz's version
of Maxwell's aether theory look somewhat dodgy without it. Decades later
the "aether" has become a taboo word and the origins of relativity
remain the skeleton in the cupboard which anyone can discover if they
care to look under the mountains of spin which have been added in 100
years. Despite the fact that Maxwell's wave in aether theory was
disproved firstly by the MMX and then by the discovery that light isn't
waves but particles SR is based upon the assumption that Maxwell's
theory is impeccable. One would not accept the ditching of 3 long
accepted and apparently sensible axioms of physics in order to retain a
theory unless one considered that theory to be anything less than
impeccable would one?

Now there are attempts to distance physics from the embarrassing 2nd
postulate by using mathematical wizardry to show that the Lorentz
transforms can be derived only from the first postulate. It is possible
that it can be done - I'll deal with the implications later - but
certainly one example I have seen involves mathematical 'slight of
hand'. That is the treatment I found in an on-line Harvard university
text book. One must understand that Lorentz transforms and Galilean
transforms are not 2 from a set of many transforms they are the only two
options. The Lorentz transforms use up all possible degrees of freedom.
The text I mentioned seemed overly complex considering what it was
trying to show and at one point imported an equation from one of the
Appendices. The average student being lazy would probably not bother to
check but I did. It had a constant in it x, (I think) and when I tracked
back I found that x=1 corresponded to the Galilean transform and that
having imported the equation into the main text he divided by x-1. The
result is of course then invalid for Galilean transforms so he was left
only with Lorentz transforms.

It is possible that is a bad example and I admit that others I have seen
are beyond my mathematical capabilities but the bottom line is that
ballistic theory is completely consistent with the first postulate. It
differs only w.r.t the second postulate so if what is claimed is true SR
and Ballistic theory must be mathematically identical. This isn't as far
fetched as it seems. If you look at my thread "Does SR transform to
Ballistic theory1" I show that in several quite widely different
experiments both theories give the same result and I suggest that just
as the geocentric theory of the solar system managed to transform the
maths to give the right answer that what Lorentz transforms do is
transform a wrongly based theory in order to give the same answer as the
correctly based ballistic theory. In both cases the problem is incorrect
but unshakeable belief. In one case a belief that everything goes around
the earth and in the second that Maxwell's wave in aether theory is
impeccable despite it having been experimentally disproved.

--
John Kennaugh

GSS wrote:
On Jun 5, 4:09 pm, John Kennaugh
wrote:
.........
In Maxwell's theory a 'field' is a
stress in the aether. If one accepts the no aether doctrine of modern
physics then clearly it cannot be a stress in the aether but physics has
failed to say what else it can physically be. On the contrary it has
arbitrarily made it a key doctrine that it doesn't need to.
--
John Kennaugh

Dear Kennaugh,



With reference to your above quoted observations, kindly share your
opinion/information on the following relevant points.
(a) Did Maxwell distinguish between his notion of 'aether' and the
physical space with characteristic properties of permittivity,
permeability and intrinsic impedance?

Permittivity and permeability are physical properties of Maxwell's
aether. They are the physical properties which determine at what speed
the wave propagates in the propagating medium. If you talk about space
with those physical properties you are simply describing the aether.

Historically the aether or rather aethers predate Newton. They were
first proposed to explain magnetic and electrostatic action at a
distance. The thinking was that a force requires some sort of
'connecting rod' through which to act. It was proposed that everywhere
there existed aethers. Charges caused stresses in the aether and the
interaction of the stress patterns caused the actions at a distance
force observed.

Oersted, Ampere and Faraday established links between charge and
magnetism and it was Faraday's relationships which were the basis of
Maxwell's electrodynamics. The impact of Maxwell was enormous because he
showed that a single aether explained:
a field = a stress pattern in the aether,
action at a distance magnetic and electrostatic forces (interaction
between stress patterns)
and the propagation of light (the stress propagating through the
medium).

What Physics has done is to fudge the issue. It has accepted the no
aether doctrine without following it through. It has retained the idea
of the existence of an independent field, independent of anything
causing it. 'Space in which independent fields can exist' is simply a
renamed aether.

Note that contrary to popular myth Einstein did not come up with a
theory which didn't need the aether - he argued for its retention
neither did anyone at the time (1905) see the MMX as indicating that
there is no aether as your book states. On the contrary both Lorentz's
theory and Einstein SR theory were attempts to save Maxwell's wave in
aether theory from the threat posed by the MMX.

IF the MMX had been seen as indicating that there is no aether then the
obvious question becomes "if the speed of light is not controlled by and
constant w.r.t the aether then what does control it and what is it
constant w.r.t.?" The obvious answer to which is certainly not that the
speed of light is constant w.r.t the observer observing it as there is
no possible causality. The only logical answer is that it must be
constant w.r.t the source but Einstein did not get that answer because
he wasn't trying to answer that question. The question as far as both
Lorentz and Einstein were concerned was "Why does the speed of an
observer w.r.t the aether always appear to be zero?" - as per the MMX.

Lorentz put forward an explanation as to why that is the case - LET says
that it is an illusion brought about by distortion of measurement due to
speed relative to the aether - Einstein didn't like that explanation so
took a completely empirical approach and said in effect "lets just
accept that every observer IS stationary w.r.t the aether, for whatever
reason". The second postulate simply describes exactly what an observer
stationary w.r.t the aether would experience and is a statement of what
was the generally accepted view - the particulate nature of light having
had no significant effect on the thinking.

A couple of decades later the aether became unpopular and the "no aether
doctrine" was accepted not because of any experiment which showed it did
not exist, nor through any theoretical wizardry but by the totally
arbitrary decision that physical interpretation was no longer to be
considered an essential compliment to the mathematics.

Now there is a perfectly sound reason to get rid of the aether and that
is because light isn't made up of waves but of particles and particles
don't need an aether. In fact if it existed it would get in the way. In
order to follow through that idea I believe one has also to address the
question of action at a distance. The reason the aether was invented in
the first place was that force acting at a distance was seen as being
different to the way all other force appeared to act but today we know
different in that we now believe that ALL force acts at a distance. I
think one should accept that as axiomatic - requiring no explanation.

However if one takes that view then a 'field' becomes metaphysical. It
is the 'field of influence' of a charge (say). It is a map of the action
at a distance force and direction which *would* act on a probe charge
*if* a probe charge were placed at a given point. From this viewpoint
independent fields cannot exist without a source of influence and if
photons carry fields along with them then they must contain charge.
While Maxwell's theory should no longer be considered as a true model of
nature its predictive accuracy clearly shows a link between charge and
light in that Maxwell's equations are all based on relationships
relating to charge. If there is a link between charge and light there
must be a link between charge and photons which is what light is made up
of.

Going back to your original question - permittivity is now not a
property of space. What you have is the action at a distance force
between charge. Naturally this is modified if something containing
charged particles - i.e. matter - is placed between the charges. How
much it is modified depends on the material and the effect is described
by what we call permittivity. While Free space is given a value in order
to get our familiar units of capacitance it is not a physical property
as space. It is simply the action at a distance force between charges
when nothing exists to modify it. It is a property of charge not of
space.

Once you say that space can have a modifying effect, can have physical
properties you have reinvented the aether.


(b) Did he quantify the stress at any point in the 'aether' with a
stress tensor?
(c) Did he also use strain tensors in his analysis of the stressed
state of the aether?
(d) How did he correlate the stress and strain tensors at any point in
the aether?
(e) Did he establish any equilibrium equations of elasticity in terms
of stress or strain tensors in the aether?
(f) If so, did he present any solutions of those equilibrium
equations?

I don't believe that the word 'tensor' was a part of Maxwell's
vocabulary.

--
John Kennaugh

John Kennaugh wrote:
Tom Roberts wrote:
John Kennaugh wrote:
The idea that a photon 'interferes' with itself is absurd in the
classic sense of the word 'interfere'.
Sure. But the QUANTUM meaning of the word is what applies. The photon
is NOT a "classical" object.

That is the modern view certainly but physics has now embraced mysticism
to such an extent that the phrase "quantum particle" is used almost as
an incantation forbidding anyone from trying to make sense of it.

Nonsense. It is just "forbidden" for idiots who do not understand basic
quantum mechanics to "make sense of it". And there is a simple and
obvious solution: LEARN SOMETHING!


Remember, however, that in QM the waves do not propagate in the
same direction; indeed, they normally propagate in all possible
directions....

As I say physics has embraced mysticism big time.

"Sufficiently advanced technology is indistinguishable from magic."
-- Arthur C. Clarke

You merely substitute "mysticism" for "magic". If you would LEARN about
modern physics, you would not be mystified.


A photon has mass because:
[...]

If you had any understanding of modern physics, you would understand why
EVERY ONE of your claims here is wrong, and NONE OF THEM imply that a
photon has mass. Specifically: giving photons a mass larger than the
current upper limit causes electrodynamics to not agree with
experiments. EVERY ONE of your items is fully consistent with photons
having zero mass.


Tom Roberts

On Jun 8, 9:08 pm, John Kennaugh
wrote:
GSS wrote:
On Jun 5, 4:09 pm, John Kennaugh
wrote:
.........
In Maxwell's theory a 'field' is a
stress in the aether. If one accepts the no aether doctrine of modern
physics then clearly it cannot be a stress in the aether but physics has
failed to say what else it can physically be. On the contrary it has
arbitrarily made it a key doctrine that it doesn't need to.
--
John Kennaugh

Dear Kennaugh,
With reference to your above quoted observations, kindly share your
opinion/information on the following relevant points.

(a) Did Maxwell distinguish between his notion of 'aether' and the
physical space with characteristic properties of permittivity,
permeability and intrinsic impedance?

Permittivity and permeability are physical properties of Maxwell's
aether. They are the physical properties which determine at what speed
the wave propagates in the propagating medium. If you talk about space
with those physical properties you are simply describing the aether.

Historically the aether or rather aethers predate Newton. They were
first proposed to explain magnetic and electrostatic action at a
distance. The thinking was that a force requires some sort of
'connecting rod' through which to act. It was proposed that everywhere
there existed aethers. Charges caused stresses in the aether and the
interaction of the stress patterns caused the actions at a distance
force observed.

Has this phenomenon of 'stresses in the aether' caused by charges and
the 'interaction of stress patterns' been technically or
quantitatively analyzed by any scientist so far? If so which
parameter(s) represented the 'stresses in the aether' in relevant
equations?

Oersted, Ampere and Faraday established links between charge and
magnetism and it was Faraday's relationships which were the basis of
Maxwell's electrodynamics. The impact of Maxwell was enormous because he
showed that a single aether explained:
a field = a stress pattern in the aether,
action at a distance magnetic and electrostatic forces (interaction
between stress patterns)
and the propagation of light (the stress propagating through the
medium).

What Physics has done is to fudge the issue. It has accepted the no
aether doctrine without following it through. It has retained the idea
of the existence of an independent field, independent of anything
causing it. 'Space in which independent fields can exist' is simply a
renamed aether.

How do you mentally visualize an 'independent field'?
...........
A couple of decades later the aether became unpopular and the "no aether
doctrine" was accepted not because of any experiment which showed it did
not exist, nor through any theoretical wizardry but by the totally
arbitrary decision that physical interpretation was no longer to be
considered an essential compliment to the mathematics.

Do you consider it as an overbearing dominance of mathematics over
physics or an overbearing dominance of mathematicians over physicists
during the 20th century?
.............

(b) Did he quantify the stress at any point in the 'aether' with a
stress tensor?
(c) Did he also use strain tensors in his analysis of the stressed
state of the aether?
(d) How did he correlate the stress and strain tensors at any point in
the aether?
(e) Did he establish any equilibrium equations of elasticity in terms
of stress or strain tensors in the aether?
(f) If so, did he present any solutions of those equilibrium
equations?

I don't believe that the word 'tensor' was a part of Maxwell's
vocabulary.
--
John Kennaugh

In that case kindly clarify whether your observation - "In Maxwell's
theory a 'field' is a stress in the aether", is your own
interpretation of Maxwell's theory or Maxwell had actually used the
concept of 'stress in the aether' in his theory? If Maxwell did use
the concept of 'stress in the aether', kindly give some example of a
field parameter which was used to represent the 'stress in the aether'
in the field equations.

GSS
http://www.geocities.com/gurcharn_sandhu/index.html

On Jun 6, 6:33 am, GSS wrote:
On Jun 5, 12:25 am, " wrote:

On Jun 4, 8:20 am, GSS wrote:

(brevity snip)

Yes, I have not discussed the electron diffraction phenomenon in this
book.

In my opinion, the fringe pattern in the electron beam diffraction
experiments is a consequence of diffraction from sharp edges (or the
electron biprism) and not a result of mutual interference of matter
waves of electrons.

If that were the case a double-slit pattern would be the simple
linear sum of the individual slits' patterns, but that isn't what's
seen.

The formation of Fresnel fringes resulting from the arrival of
individual electrons passing through a tiny hole in a carbon film had
been experimentally demonstrated by Hermann, Krahl, K¨ubler, M¨uller,
and Rindfleisch in 1971.

Yes, and?

Secondly, in the electron-beam version of
Young's two-slit diffraction experiment, an electron biprism is used
which is not exactly equivalent to the two-slit setup.

http://physicsworld.com/cws/article/print/9745

"...in 1961 Claus Jönsson of Tübingen, who had been one of
Möllenstedt's students, finally performed an actual double-slit
experiment with electrons for the first time (Zeitschrift für Physik
161 454). Indeed, he demonstrated interference with up to five slits."

Exactly what is your quibble with the electron biprism? Do you also
quibble with the optical version?

http://www.physique.ens-cachan.fr/fr...oton/index.htm

And I don't think quantization of mass or charge
has anything to do with this phenomenon. Even in the interference of
photons, there is no question of 'self-interference'.

I see no room for any other interpretation of the one-photon-at-a-
time, two-slit version; an interference pattern slowly builds up, but
there's nothing for any given photon _to_ interfere with except
itself. Again if it were simple diffraction the double-slit pattern
would be the simple linear sum of the individual slits' patterns, but
it isn't.

Well, let me offer *another* interpretation.
In such experiments, one-photon-at-a-time is supposed to free one-
electron-at-a-time which could then be detected through appropriate
instrumentation. The point however is that if there were (say) seven-
photons-at-a-time coming in a mutually coupled group of photons, they
too will be able to dislodge or free only one- electron-at-a-time from
the relevant electron orbital. In that case only one photon out of
the group will be 'used up' and the remaining photons will just move
on. As pointed out in my previous post, photons of the same frequency
can get coupled through mutual interactions to form group packets or
streams of photons.. Practically it will be almost impossible to
isolate (or obtain) one-photon-at-a-time unless the emission of each
and every photon from each of the corrosponding atoms is strictly
controlled. What has been actually done however is to obtain one-
electron-at-a-time and *assume* the dislodging photon to be just one-
at-a-time instead of a coupled group of many-photons-at-a-time. Such
a group of many photons can break up into two sub-groups while passing
through 'two-slits' and undergo interference process after passing
through the slits.

Hope it is a convincing interpretation!

No.

http://www.physique.ens-cachan.fr/fr...ton_source.htm


Mark L. Fergerson

GSS wrote:
On Jun 8, 9:08 pm, John Kennaugh
wrote:
GSS wrote:
On Jun 5, 4:09 pm, John Kennaugh
wrote:
.........
In Maxwell's theory a 'field' is a
stress in the aether. If one accepts the no aether doctrine of modern
physics then clearly it cannot be a stress in the aether but physics has
failed to say what else it can physically be. On the contrary it has
arbitrarily made it a key doctrine that it doesn't need to.
--
John Kennaugh

Dear Kennaugh,
With reference to your above quoted observations, kindly share your
opinion/information on the following relevant points.

(a) Did Maxwell distinguish between his notion of 'aether' and the
physical space with characteristic properties of permittivity,
permeability and intrinsic impedance?

Permittivity and permeability are physical properties of Maxwell's
aether. They are the physical properties which determine at what speed
the wave propagates in the propagating medium. If you talk about space
with those physical properties you are simply describing the aether.

Historically the aether or rather aethers predate Newton. They were
first proposed to explain magnetic and electrostatic action at a
distance. The thinking was that a force requires some sort of
'connecting rod' through which to act. It was proposed that everywhere
there existed aethers. Charges caused stresses in the aether and the
interaction of the stress patterns caused the actions at a distance
force observed.

Has this phenomenon of 'stresses in the aether' caused by charges and
the 'interaction of stress patterns' been technically or
quantitatively analyzed by any scientist so far? If so which
parameter(s) represented the 'stresses in the aether' in relevant
equations?

I suggest you consult the work of Maxwell. He was a far better
mathematician than I am. Essentially he took the relationships which
Faraday had produced relating to charge and magnetism (which is still
charge) and realised the similarity between these relationships and the
wave equations of fluid dynamics. In other words he saw in those
equations the equivalent of stress strain displacement etc. an analogue
of all those properties in a fluid which allow a wave to propagate.
Taking the analogy a step further he calculated at what speed the 'wave'
would propagate at. The speed of propagation in a fluid depends on two
parameters. The equivalent parameters in his new wave equations were
Faradays constants of permeability and permittivity. From these
parameters he calculated at what speed the electromagnetic wave would
propagate at in a vacuum if such a thing did in fact exist and was
surprised to find it was the same as the speed of light.


Oersted, Ampere and Faraday established links between charge and
magnetism and it was Faraday's relationships which were the basis of
Maxwell's electrodynamics. The impact of Maxwell was enormous because he
showed that a single aether explained:
a field = a stress pattern in the aether,
action at a distance magnetic and electrostatic forces (interaction
between stress patterns)
and the propagation of light (the stress propagating through the
medium).

What Physics has done is to fudge the issue. It has accepted the no
aether doctrine without following it through. It has retained the idea
of the existence of an independent field, independent of anything
causing it. 'Space in which independent fields can exist' is simply a
renamed aether.

How do you mentally visualize an 'independent field'?

Einstein thought it through as follows:

"The next position which it was possible to take up in face of this
state of things appeared to be the following. The aether does not exist
at all. The electromagnetic fields are not states of a medium, and are
not bound down to any bearer, but they are independent realities which
are not reducible to anything else, exactly like the atoms of ponderable
matter."

Einstein is here pointing out that the alternative is that instead of a
'field' being a state in a medium, what I describe as stress in the
aether as per Maxwell, a 'field' may be made up of physical 'stuff' - a
sort of matter.

"This conception suggests itself the more readily as, according to
Lorentz's theory, electromagnetic radiation, like ponderable matter,
brings impulse and energy with it, and as, according to the special
theory of relativity, both matter and radiation are but special forms of
distributed energy, ponderable mass losing its isolation and appearing
as a special form of energy. More careful reflection teaches us,
however, that the special theory of relativity does not compel us to
deny ether. We may assume the existence of an ether; only we must give
up ascribing a definite state of motion to it..." 1920 lecture.

Put simply Einstein suggests an alternative but comes down in favour of
sticking with the idea that a field is 'stress in the aether'. I agree
with Einstein that IF an independent field exists those are the two
alternatives although I think he is too restrictive in that the
"physical stuff" alternative may be matter of a different form to that
we are familiar with but it must nevertheless fit in with other concepts
of matter.

I personally do not believe that independent fields can exist because I
do not believe in the aether - the reason it was postulated is no longer
valid and I don't accept the alternative that a field consists of
mysterious physical stuff. The concept of a physical field should have
been junked when the aether was junked.

..........
A couple of decades later the aether became unpopular and the "no aether
doctrine" was accepted not because of any experiment which showed it did
not exist, nor through any theoretical wizardry but by the totally
arbitrary decision that physical interpretation was no longer to be
considered an essential compliment to the mathematics.

Do you consider it as an overbearing dominance of mathematics over
physics or an overbearing dominance of mathematicians over physicists
during the 20th century?

According to one prominent physicist the three most important thing you
need to be a physicist are maths, maths, and maths. You cannot talk of
"the dominance of mathematics over physics" because you can no longer
define physics as being different to mathematics of distinguish between
physicists and mathematicians.

As Waldron put it:
"Physics started to go wrong in 1905 when Einstein published his
relativity theory. Accepting the theory, physics abandoned the attempt
to understand nature, and asserted that the business of science is not
to understand but merely learn how to manipulate".

Dr Scott Murray puts it even simpler:
"The nature of the physicists' default was their failure to insist
sufficiently strongly on the physical reality of the physical world."


............

(b) Did he quantify the stress at any point in the 'aether' with a
stress tensor?
(c) Did he also use strain tensors in his analysis of the stressed
state of the aether?
(d) How did he correlate the stress and strain tensors at any point in
the aether?
(e) Did he establish any equilibrium equations of elasticity in terms
of stress or strain tensors in the aether?
(f) If so, did he present any solutions of those equilibrium
equations?

I don't believe that the word 'tensor' was a part of Maxwell's
vocabulary.
--
John Kennaugh

In that case kindly clarify whether your observation - "In Maxwell's
theory a 'field' is a stress in the aether", is your own
interpretation of Maxwell's theory or Maxwell had actually used the
concept of 'stress in the aether' in his theory? If Maxwell did use
the concept of 'stress in the aether', kindly give some example of a
field parameter which was used to represent the 'stress in the aether'
in the field equations.

I suggest you look at Maxwell's work. He is one of the heavyweights of
physics. I am amazed that someone contemplating producing a text book
would have the presumption to do such a thing without studying in depth
the father of field theory.
--
John Kennaugh

On Jun 9, 1:26*pm, John Kennaugh
wrote:


I suggest you consult the work of Maxwell. He was a far better
mathematician than I am.

And a better physicist. See below.

Essentially he took the relationships which
Faraday had produced relating to charge and magnetism (which is still
charge) and realised the similarity between these relationships and the
wave equations of fluid dynamics. In other words he saw in those
equations the equivalent of stress strain displacement etc. an analogue
of all those properties in a fluid which allow a wave to propagate.
Taking the analogy a step further he calculated at what speed the 'wave'
would propagate at. The speed of propagation in a fluid depends on two
parameters. The equivalent parameters in his new wave equations were
Faradays constants of permeability and permittivity. From these
parameters he calculated at what speed the electromagnetic wave would
propagate at in a vacuum if such a thing did in fact exist and was
surprised to find it was the same as the speed of light.


The two parameters that you refer to in material media are an inertial
factor that conveys the ratio of the response of the medium to the
impetus. The other is a stiffness factor that conveys how tightly one
bit of the medium connects to the next. For example, in a liquid,
these are the mass density and the compression modulus. In the case of
light, it was recognized very quickly that, if there were a material
medium, it would have to have a spectacularly small inertial factor
and a spectacularly large stiffness factor. This was the first hint
that something was amiss.

Maxwell later decided that treating the wave phenomenon like that of a
material medium was neither wise nor necessary, giving the fields a
life of their own, quite independent of any supposed material
substrate.

PD

PD wrote:
On Jun 9, 1:26*pm, John Kennaugh
wrote:


I suggest you consult the work of Maxwell. He was a far better
mathematician than I am.

And a better physicist.

I have never claimed to be either a physicist nor a mathematician. My
area of interest is the history and conceptual development which led to
modern physics.

See below.

Essentially he took the relationships which
Faraday had produced relating to charge and magnetism (which is still
charge) and realised the similarity between these relationships and the
wave equations of fluid dynamics. In other words he saw in those
equations the equivalent of stress strain displacement etc. an analogue
of all those properties in a fluid which allow a wave to propagate.
Taking the analogy a step further he calculated at what speed the 'wave'
would propagate at. The speed of propagation in a fluid depends on two
parameters. The equivalent parameters in his new wave equations were
Faradays constants of permeability and permittivity. From these
parameters he calculated at what speed the electromagnetic wave would
propagate at in a vacuum if such a thing did in fact exist and was
surprised to find it was the same as the speed of light.


The two parameters that you refer to in material media are an inertial
factor that conveys the ratio of the response of the medium to the
impetus. The other is a stiffness factor that conveys how tightly one
bit of the medium connects to the next. For example, in a liquid,
these are the mass density and the compression modulus.

Thank you for confirming what I said. I couldn't be bothered to look up
which mechanical parameters corresponded with the electrical parameters
of permeability and permittivity. It was not essential to my argument.

In the case of
light, it was recognized very quickly that, if there were a material
medium, it would have to have a spectacularly small inertial factor
and a spectacularly large stiffness factor. This was the first hint
that something was amiss.

The aether, if mechanical in the accepted sense, had to be a solid.


Maxwell later decided that treating the wave phenomenon like that of a
material medium was neither wise nor necessary, giving the fields a
life of their own, quite independent of any supposed material
substrate.

You may well have read such a statement in a text book but it isn't
true. Authors of text books tend to re-write history. My understanding
is that Maxwell always thought of the aether as a mechanical medium.

"The development of the theory of electricity along the path opened up
by Maxwell and Lorentz gave the development of our ideas concerning the
ether quite a peculiar and unexpected turn. For Maxwell himself the
ether indeed still had properties which were purely mechanical, although
of a much more complicated kind than the mechanical properties of
tangible solid bodies." AE 1920 lecture

Einstein quite rightly links Maxwell with Lorentz as what is now found
in text books under 'Maxwell's theory' is Maxwell considerably developed
by Lorentz and added to. Even the "Maxwell's equations" found in modern
text books are Lorentz's re-work of Maxwell. Certainly Lorentz
did not consider that a "field has a life of its own" in his formulation
of LET which he published in 1892, by which time Maxwell had been dead
13 years.

Lorentz's contribution should not be underestimated. Einstein describes
his contribution as "the most important advance in the theory of
electricity since Maxwell". Neither should you see Lorentz's Aether
theory as merely an ad hoc fantasy as it is often portrayed.

As I have said the aether explained action at a distance force between
charge as well as the propagation of light. Lorentz produced his theory
in 1892 while the first successful theory of atomic structure was not
until Bohr in 1913. Lorentz suggested that a solid consists of a matrix
of charged particles held in equilibrium by their action at a distance
forces. He calculated what the effect would be if the aether
transmitting that action at a distance force was moving relative to the
solid and showed mathematically that the altered equilibrium would mean
that the solid would be shorted in the direction of motion as per the
Lorentz contraction. I understand that similar calculations today make
the electron orbits into ellipses - again giving the Lorentz
contraction.

Again modern texts play down the role of Lorentz, imply that his theory
was a bit silly and claim that Einstein came up with a theory which did
not require an aether. None of which is actually true. Einstein
clarifies his position in his 1920 lecture. He gives due credit to
Lorentz but objects to the "theoretical structure" of LET - the idea
that there is a unique and theoretically important FoR - the aether
frame - which is indistinguishable from every other FoR. He found such
asymmetry in the theoretical structure, not reflected in the world of
experience, unacceptable. He argues in *favour* of the aether but claims
that having an aether does not imply a unique FoR associated with it. As
his ideas were not developed and not accepted it is true to say that
Einstein objected to the asymmetry in theoretical structure of Lorentz's
theory and avoided it by producing a 'theory' without a theoretical
structure - in other words maths - the same maths as Lorentz's.

It was others who "got rid of the aether" not by experiment proving it
did not exist nor by any theoretical wizardry but by the totally
arbitrary decision to change the nature of physics such that physical
interpretation (theoretical structure) is no longer a necessary
compliment to the maths. A decision I don't agree with. Without that
decision Einstein would have had to come up with an alternative
theoretical structure to that of Lorentz otherwise his 'theory' isn't an
alternative theory and Lorentz's theory stands.

--
John Kennaugh
"Conformity may even bring you a university chair, but all advance comes
from non conformity. If there had been no troublemakers, no dissenters,
we should still be living in caves" - A J P Taylor

"John Kennaugh" wrote in message
.uk...
It was others who "got rid of the aether" not by experiment proving it
did not exist nor by any theoretical wizardry but by the totally
arbitrary decision to change the nature of physics such that physical
interpretation (theoretical structure) is no longer a necessary
compliment to the maths. A decision I don't agree with. Without that
decision Einstein would have had to come up with an alternative
theoretical structure to that of Lorentz otherwise his 'theory' isn't an
alternative theory and Lorentz's theory stands.

So true and yet so sad.
and that is why Einstein has "math alone for cause in some stuff"
such physics is actually "non-physical" and should be discarded
as The Science of Physics , and called The Science of Mathematical
Prediction



--
James M Driscoll Jr
Spaceman

"John Kennaugh" wrote in message
.uk

It was others who "got rid of the aether" not by experiment proving it
did not exist nor by any theoretical wizardry but by the totally
arbitrary decision to change the nature of physics such that physical
interpretation (theoretical structure) is no longer a necessary
compliment to the maths. A decision I don't agree with. Without that
decision Einstein would have had to come up with an alternative
theoretical structure to that of Lorentz otherwise his 'theory' isn't
an alternative theory and Lorentz's theory stands.

That's not right. Diligent searches for an aether failed
to find one. The Michelson-Morley experiments, for example.
The aether was not abandonded on a whim, but by empirical
necessity.