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From: Jonah Thomas on 22 Oct 2009 03:39 "Androcles" <Headmaster(a)Hogwarts.physics_p> wrote: > "Jonah Thomas" <jethomas5(a)gmail.com> wrote > > 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? It isn't easy to measure speed. In my high school science class we measured the speed of sound. One guy had a signal gun borrowed from the athletics department. Another guy had a stopwatch borrowed from the athletics department. They separated so many paces apart. The first guy waved and shot, and the second guy turned on the stopwatch when he saw the wave and turned it off when he heard the shot. But you can't measure lightspeed that way because you can't see when the other guy is pulling the trigger except at lightspeed. What you can measure easily is frequency relative to you. And given a constant speed and a constant frequency, you can easily measure wavelength. Doppler shift is a change in observed frequency. Assuming light travels as waves which have a wavelength and frequency relative to their source, any relative motion between you and the source will change the frequency you observe. If the waves behave as if the source is stationary with respect to the hypothetical medium they travel in, then any relative motion between you and the source will fit the doppler effect you get for a moving receiver and a stationary source. The frequency and the perceived direction will change according to that velocity. > > 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. Sure. The best example I've seen that appears to contradict that is the stuff about novas. Astronomers look at the places that novas happened and see stuff they interpret as the aftermath of some catastrophic event. The usual interpretation is that something exploded and sent stuff fast in all directions, and the stuff it pushed so fast was still radiating fiercely. They calculate that if the lightspeed varied, first we'd see the stuff that got pushed out forward, and then later we'd see the atual nova, and later still we'd see the flaming material that got shot fast in the other direction. The nova would be bright for months or possibly years. But in practice they always seem to be over in a few days. Would you argue that the expanding stuff was not that bright compared to the actual nova, so we don't notice its light? That it actually does go on for years so we don't notice it's there? Something else? You've suggested that some novas come from something that accelerates relative to us, so that it just happens we get a lot of slow light and faster light all hitting us at once. > > 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. That describes about half of the ellipse. When it starts *away* then the wave crests get even farther apart, and then as it slows down they start moving closer together again. > > 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. Has that been done? > >> >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. I'm still bogged down calculating interference patterns between light traveling different speeds. If you assume that light still travels at c+v and c-v after it leaves a beam-splitter and enters an interferometer, that gives you a result that's independent of the length of the path the light took to arrive, though not independent of the speed of the emitter. What happens if you make a Sagnac device on a turntable, and you put the emitter at the center facing out and then the beamsplitter sends the light off in two big circles.... If the light keeps its source's velocity then its speed ought to be c and maybe it has some kind of angular velocity, a turning speed of some sort? You'd get your light moving at c unless you had a "laser cavity" that moves and sends light forward and back. Wouldn't that last case give you a different result from the usual sagnac experiment? At least it would requlre a different explanation. Anyway, I'm having some trouble figuring out what it takes for light that has different speeds, wavelengths, and/or frequencies to interfere at all.
From: Jonah Thomas on 22 Oct 2009 06:10 HW@..(Henry Wilson DSc). wrote: > Jonah Thomas <jethomas5(a)gmail.com> wrote: > >"Androcles" <Headmaster(a)Hogwarts.physics_p> wrote: > >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote > >> > tominlaguna(a)yahoo.com wrote: > > >> >> >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? > > > >It isn't easy to measure speed. In my high school science class we > >measured the speed of sound. One guy had a signal gun borrowed from > >the athletics department. Another guy had a stopwatch borrowed from > >the athletics department. They separated so many paces apart. The > >first guy waved and shot, and the second guy turned on the stopwatch > >when he saw the wave and turned it off when he heard the shot. > > > >But you can't measure lightspeed that way because you can't see when > >the other guy is pulling the trigger except at lightspeed. > > > >What you can measure easily is frequency relative to you. And given a > >constant speed and a constant frequency, you can easily measure > >wavelength. > > > >Doppler shift is a change in observed frequency. > > I don't think you can make broad statements like that for light when > nobody really has any idea what is oscillating and how? This is one of > the big mistakes that has been made for centuries...regarding light as > some kind of moving oscillator. It is obviously much more complicated > than that. Nor can it be regarded as producing a classical traveling > wave, even though wave theory can be used to explain some of its > characteristics. You can get measure a radio signal and watch your oscilloscope and measure something periodic in time. You can look at interference through a thin slit and see something that appears to be periodic in space or mmaybe time. You measure something that's periodic. Whatever the complications, they have to be copatible with what you can measure. That might not be a traveling wave or a moving oscillator, but the observed periodicity has to be a part of whatever you decide it is. > However, in the case of a radio signal, it is true that the doppler > shift is a change in the observed arrival rate of its > cycles.....cycles of radiation produced by electrons accelerating in > an antenna. But this same process cannot be automatically assumed to > apply to photons. I think it's a reasonable assumption that electromagnetic radiation is all fundamentally similar, varying continuously by whatever it is we call frequency. It looks like it's made by moving charges, particularly by moving charges that have a changing acceleration. (Not just accelerated charges, charges whose acceleration is changing.) I don't know whether there's some other way to generate it. There are probably subtle differences between radio waves created by electrons that go wherever human being are cunning enough to direct them, versus electrons that do what they have to inside atoms. Maybe the differences aren't subtle. But I see no reason to deny the fundamental similarity. > Also, in my ballistic diffraction grating analysis, I did use the > arrival rate of 'wavecrests' as a determining factor. The 'wavelength' > being an absolute distance determined in the source frame by a > completely unknown process. Yes. It's a black box. You don't know what you're measuring, but if you know what outputs to expect for each set of inputs then you have a good basis to speculate about what's in the box, and a simple model that works is better than a table of inputs and outputs. > >Assuming light travels > >as waves which have a wavelength and frequency relative to their > >source, any relative motion between you and the source will change > >the frequency you observe. > > You cannot make such an assumption. Yes, I can and nobody can stop me. The assumption could be wrong, though. > For one thing, it likens light to sound or > water waves. which it is not, and the PE effect rules it out anyway. > Light is particulate. It looks to me like the PE effect could be showing that atoms are particulate, not the light waves that interact with atoms. Are you sure it shows that the light is particulate too? The light could be particulate but I don't see that PE proves it. > >If the waves behave as if the source is stationary with > >respect to the hypothetical medium they travel in, then any relative > >motion between you and the source will fit the doppler effect you get > >for a moving receiver and a stationary source. The frequency and the > >perceived direction will change according to that velocity. > > That's another way of saying that the observed doppler shift depends > on one's relative speed in the source frame. Yes. But more than that, the doppler effect is different when it's you moving relative to the medium versus the source moving relative to the medium. Light might not have any medium to move in, or the medium might let it move relative to the velocity of its source, or maybe the wave model breaks down even after you throw away the medium for the wave. It looks to me like SR says to split the difference -- to treat it as if the source and the receiver each have half the velocity relative to the medium. (Or is it a geometric sum? I forget.) It looks to me like emission theories say to treat it as if the source is stationary relative to the medium and it's always the receiver that moves relative to the medium. > >> > 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. > > > >Sure. The best example I've seen that appears to contradict that is > >the stuff about novas. Astronomers look at the places that novas > >happened and see stuff they interpret as the aftermath of some > >catastrophic event. The usual interpretation is that something > >exploded and sent stuff fast in all directions, and the stuff it > >pushed so fast was still radiating fiercely. They calculate that if > >the lightspeed varied, first we'd see the stuff that got pushed out > >forward, and then later we'd see the atual nova, and later still we'd > >see the flaming material that got shot fast in the other direction. > >The nova would be bright for months or possibly years. But in > >practice they always seem to be over in a few days. Would you argue > >that the expanding stuff was not that bright compared to the actual > >nova, so we don't notice its light? That it actually does go on for > >years so we don't notice it's there? Something else? You've suggested > >that some novas come from something that accelerates relative to us, > >so that it just happens we get a lot of slow light and faster light > >all hitting us at once. > > > >> > 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. > > > >That describes about half of the ellipse. When it starts *away* then > >the wave crests get even farther apart, and then as it slows down > >they start moving closer together again. > > > >> > 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. > > > >Has that been done? > > Velocity curves based on conventional doppler shift are performed and > published regularly. > But as I have shouted many times to deaf ears, there is also a doppler > shift due to the source's acceleration....and that shift is 90 out of > phase wrt gthe conventional velocity one. > ADoppler cannot exist in SR. So you have lots of actual doppler shifts recorded for double stars, that you can do your own computations for? Sweet. > When simulating star brightness curves, one has to also match it's > phase with the calculated velocity curve. Without the acceleration > conponent, there is likely to be no good match, a point that has been > used in the past by some people here in an attempt to refute the > ballistic predictions. So they show you something that seems unbelievable calculated your way, and you show them something that seems unbelievable calculated their way. It's a mug's game. My thought is that really fast orbits that change brightness real fast are not plausible. So there must be some other explanation. > >> >> >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. > > > >I'm still bogged down calculating interference patterns between light > >traveling different speeds. > > > >If you assume that light still travels at c+v and c-v after it leaves > >a beam-splitter and enters an interferometer, that gives you a result > >that's independent of the length of the path the light took to > >arrive, though not independent of the speed of the emitter. What > >happens if you make a Sagnac device on a turntable, and you put the > >emitter at the center facing out and then the beamsplitter sends the > >light off in two big circles.... If the light keeps its source's > >velocity then its speed ought to be c and maybe it has some kind of > >angular velocity, a turning speed of some sort? > > > >You'd get your light moving at c unless you had a "laser cavity" that > >moves and sends light forward and back. Wouldn't that last case give > >you a different result from the usual sagnac experiment? At least it > >would requlre a different explanation. > > > >Anyway, I'm having some trouble figuring out what it takes for light > >that has different speeds, wavelengths, and/or frequencies to > >interfere at all. > > When you mention 'speed', you must also give the speed reference. In this particular context, I'm of course talking about speed relative to the interferometer.
From: Jonah Thomas on 22 Oct 2009 06:14 "Inertial" <relatively(a)rest.com> wrote: > "Henry Wilson DSc." <HW@..> wrote > > Jonah Thomas <jethomas5(a)gmail.com> wrote: > >>Doppler shift is a change in observed frequency. > > Or wavelength .. Or both Doppler shift is a change in observed frequency. Not wavelength. I'm not always precise in my wording but still I want to ask you to be.
From: tominlaguna on 22 Oct 2009 07:04 On Tue, 20 Oct 2009 07:50:38 -0700 (PDT), "Dono." <sa_ge(a)comcast.net> wrote: >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? > Fair enough; you are making a reasonable request. Let me start by saying that I haven't opened half of all the messages that have been posted, so I don't know if I will be repeating answers already provided by others or not. The first thing that we need to agree upon is semantics; I went through some of this with Inertial, but it needs repeating. I use the symbol c to denote the speed of light. In the ballistic theory, by definition, the speed of light is c with respect to its source. (I have decided to use the term "ballistic" theory to denote the theory of Ritz / Waldron, rather than "emission" theory. I'm doing this because there seems to be some confusion between emission theory and re-emission theory. Clarifying further, both of those theories advocate that light is emitted from its source at c. But the re-emission theory goes on to claim that light is reflected at c with respect to any reflecting surface. The ballistic (emission) theory states that light is reflected from a surface at c with respect to the mirror image of the source. In other words, if there is no relative motion between the source and the mirror, the image of the source does not move, and therefore light is reflected at c with respect to the mirror (and obviously, the non-moving image of the source). Further to the reflection issue, if there is no relative motion between source and mirror, the light arrives at the mirror at c and is reflected from the mirror at c. As such, the angle of incidence and the angle of reflection are equal. There is no Snell's Law violation. I hope you will pause here and re-read what I have just said because I think herein lays the crux of the misunderstanding about ballistic theory and how it differs from the re-emission theory. The next semantics issue to address is "actual speed of light" verses "apparent speed of light." For this, we need to look at the diagram at the Mathpages site: http://www.mathpages.com/rr/s2-07/2-07.htm My first impression of the equation construction below the top diagram would leave me embarrassed and appalled if I was a relativist. The author is claiming that light is moving at c+v and c-v. Wait a minute; I thought the 2nd Postulate said that light only travelled at c. Light only travels at c, so where has the author erred? Through sloppy use of terms he has misrepresented the "apparent speed of light" with the "actual speed of light". The proper way to construct the equation is through this approach: Let L = the circumference. Let v = omega*r = the tangential speed Let T' = the circuit time in the clockwise direction Let T" = the circuit time in the counter-clockwise direction To make a circuit in the clockwise direction: cT' = L + vT' On the left side of the equation we have the product of the actual circuit speed, c, and the actual circuit time, T', giving us the actual distance travelled. On the right side of the equation, we have the actual path length plus the change to the path length caused by the rotation. Solving for T' we obtain: T' = L/(c - v) and through similar steps: T" = L/(c + v). Finding the difference of the travel times yields the Sagnac equation. Pausing again for emphasis... Light ONLY travels at speed c around the Sagnac loop in either direction. Now let's refer to the actual Sagnac diagram which is located at: http://commons.wikimedia.org/wiki/File:Sagnac-Interferometer.png Now we'll follow the clockwise beam from start to finish and numerate each step for later identification: 1. Light is emitted from source O at c with respect to that source. 2. The light arrives at and is reflected off mirror m at speed c since there is no relative motion between m and O. 3. The light arrives at and is refracted though the collimator lens at C, arriving at speed c and departing at speed c since there is no relative motion between C and m. 4. The light arrives at the half-silvered prism mirror at j at speed c since there is no relative motion between C and j. 5. The light is split at j and departs the prism after refraction at speed c. (The other half is reflected off j at speed c and begins its counter-clockwise journey after a second refraction.) 6. The diagram identifies the clockwise beam with label T and the counter-clockwise beam with label R. 7. Beam T arrives at mirror M1 at c since there is no relative motion between M1 and J. The angle of incidence is 1/2 angle a1. 8. Beam T reflects off mirror M1 at speed c and at an angle of reflection of 1/2 angle a1. 9. Beam T arrives at mirror M2 at speed c since there is no relative motion between M1 and M2 and at an angle of incidence of 1/2 angle a2. 10. Beam T reflects off M2 at speed c and an angle of reflection of 1/2 angle a2. 11. Beam T proceeds to mirror M3 arriving at speed c since there is no relative motion between M2 and M3, arriving at an angle of incidence of 1/2 angle a3. 12. Beam T reflects off M3 at speed c and angle of reflection of 1/2 angle a3. 13. Beam T proceeds to mirror M4 arriving at speed c since there is no relative motion between M3 and M4, arriving at an angle of incidence of 1/2 angle a4. 14. Beam T reflects off M4 at speed c and angle of reflection of 1/2 angle a4. 15. Beam T arrives at the half-silvered prism mirror at j at speed c since there is no relative motion between M4 and j. 16. After refraction, Beam T passes through mirror j and after a second refraction proceeds toward telescope L at speed c. 17. It is at mirror j that Beam T and Beam R are mixed to produce interference fringes. 18. Beam T arrives at telescope L at c since there is no relative motion between mirror j and telescope L. 19. Beam T proceeds down the telescope and arrives at the photographic plate PP' at speed c since there is no relative motion between telescope L and the film at PP'. 20. The diagram properly shows that counter-clockwise beam R arrives before the clockwise beam T since it has traversed a shorter optical path length; made shorter due to rotation. 21. The reader can reconstruct the path steps in a similar manner for the counter-clockwise beam. Summarizing: A. The Ballistic Theory of Light has 2 Postulates: (1) Light is emitted at c with respect to its source and (2) light is reflected a c with respect to the mirror image of the source. B. With the Ballistic Theory of Light, the beams of light traverse the optical circuit at speed c in each direction. C. The angle of incidence equals the angle of reflection at all points of reflection. D. The counter-clockwise beam arrives sooner than the opposing beam because it has a shorter optical path length to traverse. E. The Ballistic Theory of Light is compatible with the Sagnac experiment. Please let me know your areas of disagreement.
From: Inertial on 22 Oct 2009 07:41
"Jonah Thomas" <jethomas5(a)gmail.com> wrote in message news:20091022061425.1731b689.jethomas5(a)gmail.com... > "Inertial" <relatively(a)rest.com> wrote: >> "Henry Wilson DSc." <HW@..> wrote >> > Jonah Thomas <jethomas5(a)gmail.com> wrote: > >> >>Doppler shift is a change in observed frequency. >> >> Or wavelength .. Or both > > Doppler shift is a change in observed frequency. Not wavelength. I'm not > always precise in my wording but still I want to ask you to be. Doppler is an effect on measured wavelength or frequency or both. You can have Doppler shifted frequency or Doppler shifted wavelength. You can find some definitions talk about Doppler shift as a frequency change http://wordnetweb.princeton.edu/perl/webwn?s=doppler%20shift http://en.wikipedia.org/wiki/Doppler_shift http://www.nps.gov/gis/gps/glossary.htm some talk about a wavelength change eg http://www.encyclopedia.com/doc/1O80-Dopplershift.html http://starchild.gsfc.nasa.gov/docs/StarChild/glossary_level2/glossary_text.html http://www.nps.gov/history/history/online_books/butowsky5/astro7.htm http://www.nrao.edu/imagegallery/glossary.shtml) http://www.flowmeterdirectory.com/sensor_terminology_a.html and some about both eg http://www.astro.bas.bg/~petrov/glossary.html http://earthguide.ucsd.edu/virtualmuseum/Glossary_Astro/gloss_a-f.shtml http://science.nasa.gov/newhome/help/glossary.htm So i think I was quite valid in saying it is an observed change in frequency or wavelength or both. For light we find that it is both. |