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From: Dono. on 20 Oct 2009 10:50
On Oct 20, 3:03 am, tominlag...(a)yahoo.com wrote:
> On Mon, 19 Oct 2009 08:49:25 -0700 (PDT), "Dono." <sa...(a)comcast.net>
> wrote:
>
> >On Oct 19, 8:29 am, tominlag...(a)yahoo.com wrote:
>
> >> I've never published a physics paper in my life. The only
> >> "masterpieces" I have at Babin are physics papers by others published
> >> prior to 1939 that may be of interest to students. I have also posted
> >> some translations of historical papers.
> >> Do you "ever" check your facts?
>
> >You mean the one you just took down:
>
> I have no control over what Walter Babin puts up or takes down. I
> just went there and noted that both the French and English versions
> are linked to the same file name. I wrote a note to Walter to have
> the French link corrected. Thanks for pointing that out.
> Also, if you (or anyone else) are fluent in French language, please
> offer suggestions for changes and corrections to my translation(s).
>

So, when are you going to annswer my challenge (and Tom Roberts') that
the Sagnac experiment is incompatible with any form (including Ritz)
of emission theory?





From: Androcles on 20 Oct 2009 11:20

"Jonah Thomas" <jethomas5(a)gmail.com> wrote in message
news:20091020104319.28574cff.jethomas5(a)gmail.com...
> tominlaguna(a)yahoo.com wrote:
>> Jonah Thomas <jethomas5(a)gmail.com> wrote:
>
>> >I want to take this opportunity to review my understanding of
>> >emission theory.
>> >
>> >The fundamental tenet of emission theory is that light in vacuum
>> >travels at speed c relative to its source. The reason this is
>> >important is that it could possibly provide a simpler and more
>> >intuitive approach to derive relativity.
>> >
>> >Light sources often appear to produce concentric waves.
>> >http://i847.photobucket.com/albums/ab31/jehomas/concentric.gif
>> >
>> >But when they move they are thought to compress those waves.
>> >http://i847.photobucket.com/albums/ab31/jehomas/eccentric.gif
>>
>> This is a good place to begin the discussion. Your words above "when
>> they move" prompt the question: How do they know they are moving? In
>> the "eccentric" gif, you show a source moving along the -x axis... in
>> Aether. I'm guessing that you didn't intend to bring Aether into the
>> mix, but how else could a source know that it is moving and how fast?
>> And, with respect to what?
>
> That is a problem. It is not a problem for emission theories which make
> no such assumption. To me it looks like one of the problems that SR
> solved. If you get continuing eccentricity, not just while accelerating
> but during constant velocity, then you can tell how fast you are moving
> relative to the aether. So both SR and emission theories arrange for
> that not to happen. As I understand it, in SR you distort the
> measurements so that when you see somebody else moving you see the
> eccentric wavefronts, but they don't see that. If they could somehow see
> lightwaves moving away from them they would see nice round circles just
> as if they were standing still.
>
>> The type of representations in the gifs you posted date back to pre-
>> 1905. Relativity has a hard time with this issue because it presents
>> contradictions. That is why you hardly ever see those types of
>> representations in modern relativity texts. I only have French and
>> Resnick/Halliday at hand, and thumbing through them I see they have
>> omitted any such representations. To make sense of the Doppler
>> effect, relativity has to assume the eccentric Aether wave model.
>> For the emission theory, only the "concentric" gif applies, in the
>> absence of acceleration.
>
> Yes.
>
>> >If you could tell whether the waves were compressed then you could
>> >get a handle on absolute motion. But instead special relativity (SR)
>> >says that time and space are distorted so that everybody sees what
>> >they ought to see.
>>
>> That all seems to be correct; but there is no such thing as absolute
>> motion in the realms of SRT or emission theory. Only in Aether
>> theory.
>
> Sure. Everybody sees what they would see if they personally were at
> absolute rest. Of course there isn't really any absolute rest since
> everybody can do it.
>
> I read that there's a bar in Tulsa, OK which has a brass plaque embedded
> in the floor with the label "This is the absolute center of the
> universe." It might not be the absolute center. It might not be the only
> absolute center. But very likely it's the only plaque that makes the
> claim.
>
>> >But if the light moved at c+v and c-v etc, then everybody would see
>> >it moving the same way without requiring time dilation and length
>> >contraction. You might still get some time dilation etc, but some of
>> >the weirdness might vanish. This is why it is an issue on
>> >sci.physics.relativity. If it was only a question of precisely how
>> >light works, then it would be more a question for
>> >sci.physics.electromag. But since it could affect relativity, some of
>> >the people who are biased against SR want emission theory to be true,
>> >while the people who are biased in favor of SR categorically deny any
>> >possibility that any form of emission theory could possibly be true.
>>
>> Light only moves at c with respect to its source. It is the relative
>> motion of the observer to the source that causes the observer to
>> realize the +v or -v component. I'll probably say this a dozen times
>> during the discussion: The source doesn't know it is moving.
>
> Sure.
>
>> >The problem I run into is that it appears nobody understands emission
>> >theory well enough to give a convincing argument what it should do.
>> >People often use ideas that work well when lightspeed is a constant,
>> >which do not apply when lightspeed varies.
>>
>> Point well made! I am a student of emission theory; certainly no
>> expert. The de Sitter argument (1913) and the Eddington eclipse
>> observations (1920) shut down any further investigation of the Ritz
>> emission theory (1908). Unfortunately, Ritz died a year later.
>>
>> >For example, Androcles says that (mostly?) you cannot measure
>> >wavelength. You can only measure frequency. Well, of course you can
>> >measure wavelength with an interferometer. Intererence patterns
>> >depend only on wavelength, not on frequency or speed. That is, they
>> >depend only on wavelength when the speed is constant. When you have
>> >light that comes into the interferometer at different speeds, then
>> >frequency and speed do matter and you cannot predict interference
>> >patterns knowing only wavelength and the phase shift at the entrance.
>> >
>> >For emission theory to have a good effect on relativity, it's
>> >necessary that the wavelength be the same independent of the
>> >lightspeed, so that the light will look like
>> >http://i847.photobucket.com/albums/ab31/jehomas/concentric.gif
>> >instead of
>> >http://i847.photobucket.com/albums/ab31/jehomas/eccentric.gif
>>
>> For the emission theory, it always looks like the concentric gif.
>
> Yes. You could have an emission theory where it does not. Speed =
> wavelength*frequency. You could allow wavelength and frequency to vary
> when speed does not, if there was a reason to do so, and then you'd have
> an emission theory that did not look like the picture. But that would
> destroy the main reason to be biased in favor of emission theories.
>
>> >If the wavelength is constant, then frequency must vary with speed.
>>
>> Again, who's speed? What's speed? Frequency changes are sensed
>> through the Doppler Effect when there is relative motion between
>> source and sensor.
>
> Light's speed. If the speed that light reaches you depends on the
> velocity of its source, then you might be receiving light that has
> different speeds relative to you.

Yeah, so? What do think Doppler shift is?


>
> I may have this wrong, but it looks to me like when the source
> accelerates, the eccentric approach says that during acceleration the
> leading wavecrests get successively closer to each other. (Trailing
> light crests get farther apart. I won't talk about htem more now.) The
> faster the acceleration the bigger the difference between successive
> crests. Then when the acceleration ends the crests stay as close as they
> ever got, and stay that way until the next acceleration.
>
> But I think emission theory ought to say that when a light source
> accelerates, the leading wavecrests get closer to each other, and the
> faster the acceleration the closer they get.

Oh happy happy joy joy.
http://www.androcles01.pwp.blueyonder.co.uk/Doolin'sStar.GIF
The steeper the slope, the greater the speed. Fast light emitted
later catches up and passes slow light emitted earlier.



> But then when the
> acceleration decreases they get farther apart again, and when the
> acceleration ends they are as far apart as they were before the
> acceleration started.

Yeah, that happens when you go around an ellipse. Most orbits
are elliptical.

> The doppler effect that you may get after the
> acceleration-part waves pass you, is due entirely to the change in speed
> of the light, which causes a frequency shift.

Yeah, and we can get the velocity curve of the star from the Doppler shift.


>
>> >So OK, your lightbeam has been split into two parts that travel at
>> >different speeds.
>>
>> Disagree. They travel at the same speed with respect to the source.
>
> Yes, but rather than deal with a frame that has constant radial
> acceleration, I can calculate in an inertial frame where it's easier,
> and if I assume relativity is not involved then I should get the same
> result. If I can't make that work then maybe I need relativity after
> all.

Go on then, show us what you are made of.


From: Darwin123 on 20 Oct 2009 17:26
On Oct 19, 8:13 pm, Jonah Thomas <jethom...(a)gmail.com> wrote:
> Darwin123 <drosen0...(a)yahoo.com> wrote:
> >     Charles Ives was a physicist who strongly disblieved in general
> > relativity. This is Charles Ives the physicist, not Charles Ives the
> > composer. In any case, he wrote some books on why general relativity
> > is wrong. Most of his "experiments" were thought experiments. I read
> > some pages in Ives book relating to the Sagnac effect. I believe Ives
> > analysis was wrong.
> >      Charles Ives described a thought experiment to show why the
> > Sagnac effect contradicted relativity. He never actually performed
> > this experiment, but simply guessed what the results would be based on
> > symmetry. However, the symmetry that he hypothesized did not exist in
> > the equivalent real-world systme.
> >     He proposed a Sagnac interferometer consisting of a highly
> > reflective ring of material. There would not be separate mirror, but a
> > continuous curve of reflective material. He proposed that the ring was
> > completely circular, so that the optical system had complete radial
> > symmetry. A rotation by any angle would not change the system, in his
> > model, by any amount. Suppose two traveling waves are propagating in
> > opposite directions in this circular cavity.
> >      His argument was that since the cavity is radially symmetric,
> > there is no way the light waves can "know" that the cavity was
> > rotating. The surface of this smooth cavity is smooth and featureless.
> > Motion can not show itself on a featureless surface. Thus there could
> > be no beats between the two waves, and thus no Sagnac effect. Since
> > the Saganc effect is predicted by relativity, the fact there is no
> > Sagnac effect for such a cavity means relativity is wrong.
> >      Note he didn't make the main error provided by members of the
> > group. He did not claim the Saganc effect contradicts relativity. His
> > arguement was that the Sagnac effect couldn't exist under certain
> > conditions that were consistent with relativity.
> >        First, let me point out that such a system has been made..
> > Sagnac cavities have been constructed using fibers connected in a
> > circle. There are no separate mirrors in such a cavity. The reflective
> > surface is a continuous curve. The Sagnac effect has been observed
> > with such continuously curved surfaces. So what went wrong with Ives'
> > analysis?
>
> If the emitter and the detector move with the mirror, which they had
> probably better do, then you get a Sagnac effect because they are
> moving. I believe you could get a sagnac effect with the source and
> detector moving even if they were bouncing light off mirrors that did
> not move. But like Ives I have not done the experiment.
This is probably true (I am not sure). However, in this case the
source and detector are also under the influence of centripetal
forces. Therefore, they are "accelerating" in the special relativity
sense. The detector can't be part of the inertial frame because it is
accelerating.
My argument was that the cavity itself is accelerating in the
sense of special relativity. The atoms and electrons of the reflective
cavity are accelerating. So even if the source and detector are not
accelerating (the usual case), the Sagnac effect will still occur (the
always case).
What Herbert Ives the physicist said
I have to thank Androcles for correcting me. The physicist and
composer were both named Herbert Ives, not Charles Ives.
Unfortunately, it does not make Ives correct (or his music any
better).
>
> > 1) The cavity, though "continuously curved," is made of atoms.
> > 2) The free electrons on the surface, that cause the reflection of light, are also discrete up to the limits of quantum mechanics.
> > 3) The light itself consists of nodes and antinodes. >
> I doubt all that matters.

>Get your detector and emitter moving along the
> mirror cylinder and you'll get a Sagnac effect with the mirror not
> moving at all. If it doesn't matter whether the mirror moves then it
> does not matter abouut the astoms and the free electrons and the
> antinodes.
>
> But I could be wrong.

It doesn't matter if you decide to ignore the atomic scale details
of the experiment. Relativity is not a "complete" theory in the sense
that the equations of relativity uniquely determine the path of the
particles or light. There is no unique equation of motion, or equation
of state, that describes all systems with Lorentz invariance (or
covariant invariance).
Relativity on a macroscopic scale provides a good short cut
through all the electrodynamic and quantum mechanical details that
would completely describe the system. The kinematic parts of
relativity precisely describe what happens on a macroscopic scale, and
give no clue as to what happens on the scale of atoms and electrons.
The nice thing about the kinematics of relativity is that they are
scale invariant.
That is part of the reason that relativity is anti-intuitive. As
has often been said, relativity doesn't tell you why it happens. You
could read that as meaning that relativity is scale invariant.
For example, there are covariant expressions for thermodynamic
quantities. Einstein himself showed that entropy is a scalar that does
not vary with inertial reference frame. So one can describe a
macroscopic system in thermodynamic terms without violating
relativity. On the other hand, there are covariant equations of
motions for the electrons. If you wanted to go into submicroscopic
detail of what happens to this macroscopic system, you could do so
without violating relativity.
The equations of relativity are scale invariant. There is nothing
intrinsically microscopic about them. Thus, there is no explanation
built into relativity as to what happens on a microscopic scale.
However, experimental systems can be described at different scales by
different dynamical equations. Relativity applies to all these scales.
I think this issue of being invariant to scale is a feature of
symmetry properties. Regardless of the details of the system, physics
equations generally split up into symmetry properties and coupling
strengths. When you describe any system (e.g., classical,
relativistic, or quantum), properties split up into symmetries and
coupling strengths.
Relativity is a symmetry, and hence doesn't tell you anything about
coupling strengths.
In the case of the Sagnac effect, the usual derivation totally
ignores what is happening on an atomic level. Now, the reflectivity of
the mirror is highly dependent on the atomic scale structure of the
mirror material. Common mirrors are reflective because the silver
backing conducts electricity. The silver backing conducts electricity
because some electrons in the silver are free to move. A different
explanation is required for dielectric mirrors. However, it still
comes down to the motion of electrons.
If you really wanted to describe the Sagnac effect in atomic scale
detail, you would have to model the motion of electrons in
the mirrors. You have to model the mtion of the atoms in the mirrors.
For consistency, you would have to use relativistic equations for the
motions of electrons. Of course, this is a level of detail unnecessary
for understand the Sagnac cavity on a macroscopic level.
The relativistic explanation usually given is an end run around
the atomic scale explanation. Its is a macroscopic explanation.
Embedded in this derivation is the microscopic details. Like, how do
the electrons in the mirror move to create reflection?
I think Herbert Ives didn't understand this. He treated relativity
like it was an equation of motion which it is not. He ignored the
question of why the material reflects light. He decided that if there
is no feature obvious to the naked eye, then there is no microscopic
properties that are important. He was wrong.
From: Inertial on 21 Oct 2009 04:52

"Jonah Thomas" <jethomas5(a)gmail.com> wrote in message
news:20091020091828.45318101.jethomas5(a)gmail.com...
> I'm tired of talking to you because you consistently repeat the same
> biases, but once more dear friends into the breach....


I have no bias other than the truth and common sense. You however, seem not
to be so blessed.


From: Inertial on 21 Oct 2009 04:55

"Jonah Thomas" <jethomas5(a)gmail.com> wrote in message
news:20091020091828.45318101.jethomas5(a)gmail.com...
[snip]
>> > The problem I run into is that it appears nobody understands
>> > emission theory well enough to give a convincing argument what it
>> > should do.
>>
>> Its not the emmission itself, what it is is that emmision theory
>> assumes reality is simple euclidean goemetry, newtonian physics and
>> galilean transfroms. Experiment shows reality isn't like that.
>
> So the next question is what is the minimum alteration to euclidean
> geometry, newtonin physics and galilean transforms that would get an
> emission theory to work.

Using Lorentz transforms instead of Galilean transforms. Then emission
theory works. LT are the ones we find work experimentally.


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