Wang / Sagnac Devices
in [Relativity]
|
Prev: Relativity ring problem - what shape is this?
Next: BUY CHEAP TEXTBOOKS | College Textbooks | Used Textbooks |
From: Inertial on 20 Oct 2009 07:33 "Androcles" <Headmaster(a)Hogwarts.physics_p> wrote in message news:LoeDm.15544$l82.469(a)newsfe12.ams2... > > <tominlaguna(a)yahoo.com> wrote in message > news:cijqd51ksec50psf7o5pm98doa8a0vjo3s(a)4ax.com... >> On Mon, 19 Oct 2009 11:03:49 -0400, Jonah Thomas <jethomas5(a)gmail.com> >> wrote: >> For the emission theory, it always looks like the concentric gif. >> >>>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. >> >>>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. >> >>>(Exactly why emission-theory light should travel at >>>different speeds in a Sagnac or Wang apparatus is one of the things we >>>don't have clear. Some people say it might not, for one reason or >>>another.) The two arrive at the detector at the same time, >> >> Disagree. They arrive at different times due to changes in optical >> path lengths. > > > You have a good grip on it, Tom. Part of the problem you have to > deal with is the determination of just what is the detector. In the > minds of Jonah and many others they consider the beam splitter > to be the detector, it is the point where the contra-rotating beams > meet. However, the actual detector is some distance away > where the beams have travelled in parallel for some distance, > and of course they do so with different velocities as experiment > has shown. Androcles has no idea as always.
From: tominlaguna on 20 Oct 2009 08:45 On Mon, 19 Oct 2009 08:49:25 -0700 (PDT), "Dono." <sa_ge(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: > >http://www.wbabin.net/historical%5Cdufour3.pdf ? > > >Anyways, are you going to plug in the equations of Waldron's theory >into the Sagnac experiment or are you just going to continue >blathering about how it is consistent with the experiment? Babin says he fixed the problem. The French original should be available now.
From: Jonah Thomas on 20 Oct 2009 09:18 I'm tired of talking to you because you consistently repeat the same biases, but once more dear friends into the breach.... "Inertial" <relatively(a)rest.com> wrote: > "Jonah Thomas" <jethomas5(a)gmail.com> wrote > [snip] > > 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. > > Yes .. just like a bullet out of a gun > > > The reason this is important is that > > it could possibly provide a simpler and more intuitive approach to > > derive relativity. > > Relativity says the same thing. Light always travels at c relative to > its source. > > However, the nature of spacetime and how velocities combine when you > change frames of reference means that c (+) v = c (where (+) is the > velocity composition operator). So when you 'add' the velocity of the > source to the speed of light, you still get c. Yes. > > 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 > > Thats right. > > Its because the emission point of each successive wavefront is not the > same point as the previous wave front Yes, that's what your theory says must happen. > > 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. > > What you show in that diagram is what SR says you would see. > > > But if the light moved at c+v and c-v etc, > > If the + and - are velocity composition, then that is what SR says it > does. > > > then everybody would see it > > moving the same way without requiring time dilation and length > > contraction. > > Why should everyone see the same thing? If the way people calculate light moving is the way the light actually moves, then you don't need to calculate length compression and time dilation to get them to see it that way. > > 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. > > Its not a matter of bias. How would you know? You're biased. > > 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. > > People often use ideas that work well when lightspeed is a constant, > > which do not apply when lightspeed varies. > > The net speed light travels through a medium can be less than c, of > course. And then the speed is observer dependant. Bear with me on this. > > 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. > > Yeup > > > That is, they depend only > > on wavelength when the speed is constant. When you have light that > > comes into the interferometer at different speeds, > > Why would you do that? If the light happens to have different speeds, that will affect the way it interferes. Say you get light from a single source that has two different speeds going into the interferometer, each of them self-interferes identically but the two different parts of the light will not interfere the same way they would if they were traveling at the same speed. This is your cue to say that we know light always travels at the same speed because we have measured it with interferometers and we don't get the interference we would expect if it was not always the same. ;) > > then frequency and speed do > > matter and you cannot predict interference patterns knowing only > > wavelength and the phase shift at the entrance. > > You use an interferometer on light from a known source. Yes, you start with light from a known laser or a known star and then you do something to it, and then you look at the interference pattern. That's what we're talking about. > > For emission theory to have a good effect on relativity, it's > > necessary that the wavelength be the same independent of the > > lightspeed, > > Which experiment shows is not the case Experiment shows that it's not the case provided that we understand all about how light interferes. When you imterpret the experiments your bias influences your thinking. So for example, you assumed you knew how emission-theory light would interfere even when all the theory you've ever heard about interference assumes constant lightspeed. You won't know what emission theory predicts about interference patterns until you actually work it out or until somebody tells you. But you assume you already know and that it predicts the wrong thing. (And it very well might predict the wrong thing. But you don't know, you only assume without ever noticing the assumption.) > > 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 > > If the wavelength is constant, then frequency must vary with speed. > > So OK, your lightbeam has been split into two parts that travel at > > different speeds. (Exactly why emission-theory light should travel > > at different speeds in a Sagnac or Wang apparatus is one of the > > things we don't have clear. Some people say it might not, for one > > reason or another.) The two arrive at the detector at the same time, > > with different speeds > > As measure by whom? Speed is relative to the observer. If two beams of light arrive at the same place and the same time at different speeds, it isn't an issue which observer thinks they arrive at different speeds. If you have a way to measure lightspeed and you are at that place and time, then measure them and tell us what you get. But don't measure them with interference until you have a solid theory how interference patterns change with speed. When light speeds up does the wavelength change or the frequency or both? > In sagnac, both the beams arrive at the detector at c relative to the > detector. According to emission theory, relative to the detector, > they take the same time to get there, they have the same wavelength > and the same frequency. How did you decide that they have the same wavelength and the same frequency relative to the detector? I agree that some emission theories say that they will arrive at the same time, presumably relative to everybody since emission theorists tend to discard relativistic simulataneity arguments and also this is an event at one time and one place. > [snip more of the same] > > > To construct an emission theory you must specify what light does on > > reflection, what it does on refraction, and how interference works > > for light that travels at different speeds. > > Except, of course, there are experiments that show that light from a > moving source does not travel at c+v. Which rules out all emission > theories. What assumptions were made while interpreting those experiments? Are you sure they did nothing to assume constant lightspeed when they made their interpretations?
From: Androcles on 20 Oct 2009 09:32 "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.... What newsreader are you using? Don't you have a killfile? They are designed for bigots and trolls like the inert one. > "Inertial" <relatively(a)rest.com> wrote: >> "Jonah Thomas" <jethomas5(a)gmail.com> wrote > >> [snip] >> > 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. >> >> Yes .. just like a bullet out of a gun >> >> > The reason this is important is that >> > it could possibly provide a simpler and more intuitive approach to >> > derive relativity. >> >> Relativity says the same thing. Light always travels at c relative to >> its source. >> >> However, the nature of spacetime and how velocities combine when you >> change frames of reference means that c (+) v = c (where (+) is the >> velocity composition operator). So when you 'add' the velocity of the >> source to the speed of light, you still get c. > > Yes. > >> > 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 >> >> Thats right. >> >> Its because the emission point of each successive wavefront is not the >> same point as the previous wave front > > Yes, that's what your theory says must happen. > >> > 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. >> >> What you show in that diagram is what SR says you would see. >> >> > But if the light moved at c+v and c-v etc, >> >> If the + and - are velocity composition, then that is what SR says it >> does. >> >> > then everybody would see it >> > moving the same way without requiring time dilation and length >> > contraction. >> >> Why should everyone see the same thing? > > If the way people calculate light moving is the way the light actually > moves, then you don't need to calculate length compression and time > dilation to get them to see it that way. > >> > 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. >> >> Its not a matter of bias. > > How would you know? You're biased. > >> > 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. > >> > People often use ideas that work well when lightspeed is a constant, >> > which do not apply when lightspeed varies. >> >> The net speed light travels through a medium can be less than c, of >> course. And then the speed is observer dependant. > > Bear with me on this. > >> > 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. >> >> Yeup >> >> > That is, they depend only >> > on wavelength when the speed is constant. When you have light that >> > comes into the interferometer at different speeds, >> >> Why would you do that? > > If the light happens to have different speeds, that will affect the way > it interferes. Say you get light from a single source that has two > different speeds going into the interferometer, each of them > self-interferes identically but the two different parts of the light > will not interfere the same way they would if they were traveling at the > same speed. > > This is your cue to say that we know light always travels at the same > speed because we have measured it with interferometers and we don't get > the interference we would expect if it was not always the same. ;) > >> > then frequency and speed do >> > matter and you cannot predict interference patterns knowing only >> > wavelength and the phase shift at the entrance. >> >> You use an interferometer on light from a known source. > > Yes, you start with light from a known laser or a known star and then > you do something to it, and then you look at the interference pattern. > That's what we're talking about. > >> > For emission theory to have a good effect on relativity, it's >> > necessary that the wavelength be the same independent of the >> > lightspeed, >> >> Which experiment shows is not the case > > Experiment shows that it's not the case provided that we understand all > about how light interferes. When you imterpret the experiments your bias > influences your thinking. So for example, you assumed you knew how > emission-theory light would interfere even when all the theory you've > ever heard about interference assumes constant lightspeed. You won't > know what emission theory predicts about interference patterns until you > actually work it out or until somebody tells you. But you assume you > already know and that it predicts the wrong thing. (And it very well > might predict the wrong thing. But you don't know, you only assume > without ever noticing the assumption.) > >> > 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 >> > If the wavelength is constant, then frequency must vary with speed. >> > So OK, your lightbeam has been split into two parts that travel at >> > different speeds. (Exactly why emission-theory light should travel >> > at different speeds in a Sagnac or Wang apparatus is one of the >> > things we don't have clear. Some people say it might not, for one >> > reason or another.) The two arrive at the detector at the same time, >> > with different speeds >> >> As measure by whom? Speed is relative to the observer. > > If two beams of light arrive at the same place and the same time at > different speeds, it isn't an issue which observer thinks they arrive at > different speeds. If you have a way to measure lightspeed and you are at > that place and time, then measure them and tell us what you get. But > don't measure them with interference until you have a solid theory how > interference patterns change with speed. When light speeds up does the > wavelength change or the frequency or both? > >> In sagnac, both the beams arrive at the detector at c relative to the >> detector. According to emission theory, relative to the detector, >> they take the same time to get there, they have the same wavelength >> and the same frequency. > > How did you decide that they have the same wavelength and the same > frequency relative to the detector? I agree that some emission theories > say that they will arrive at the same time, presumably relative to > everybody since emission theorists tend to discard relativistic > simulataneity arguments and also this is an event at one time and one > place. > >> [snip more of the same] >> >> > To construct an emission theory you must specify what light does on >> > reflection, what it does on refraction, and how interference works >> > for light that travels at different speeds. >> >> Except, of course, there are experiments that show that light from a >> moving source does not travel at c+v. Which rules out all emission >> theories. > > What assumptions were made while interpreting those experiments? Are you > sure they did nothing to assume constant lightspeed when they made their > interpretations?
From: Jonah Thomas on 20 Oct 2009 10:43
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. 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. 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. 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. > >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. > >(Exactly why emission-theory light should travel at > >different speeds in a Sagnac or Wang apparatus is one of the things > >we don't have clear. Some people say it might not, for one reason or > >another.) The two arrive at the detector at the same time, > > Disagree. They arrive at different times due to changes in optical > path lengths. Here's the argument why they would arrive at the same time. In the inertial frame, the source has velocity v. Emission theory says we should expect light emitted in one direction to travel at c+v and in the opposite direction at c-v. Will they continue to travel at those speeds when they change direction? That depends on which emission theory you prefer. Are they getting continually absorbed and re-emitted by the fiber optic medium, and does that affect the speed? Sure, if the cable is being rotated that ought to require the light to travel at c+v and c-v no matter what direction it started. So if you believe in continual absorption and re-emission then it doesn't matter which emission theory you prefer, in fiber optic cable they will travel at c+v and c-v. If one light beam travels at c+v but the detector moves away from it at v, while the other beam travels at c-v and the detector moves toward it at v, then the optical path lengths are different but the difference in lightspeed exactly balances it. They should arrive at the same time. That's the argument. There could be unexamined assumptions in it that I haven't noticed yet. Note the absorption/re-emission thing. It was traditionally argued that relativity gave precisely the correct amount of phase shift, while some emission theories predicted half that amount and were therefore wrong. I suggested earlier that if a fiber optic cable has light travel through it at 2/3 c, and the reason for that is that the light spends 1/3 of its time being absorbed and re-emitted and 2/3 of its time traveling at c, then in a FOG the phase shift should be 2/3 of what you'd otherwise predict. 2/3 of the time the light travels at c, and 1/3 of the time it travels at v or -v along with the cable and the detector. But I was told here (as near as I understood it) that according to relativity, light in fiber optic cable is instantly absorbed and re-emitted and it spends 100% of its time traveling at 2/3 c. > > with > >different speeds and different frequencies but the same wavelength. > >You can predict the location of the first interference minimum for > >the c-v wave. You can predict the location for the c+v wave. It will > >be the same place because with a constant lightspeed that location > >depends only on wavelength, regardless what the constant lightspeed > >is. The two waves will be slightly out of phase even though they were > >in phase when they entered the interferometer, because they travel at > >different speeds and they reach the screen at different times. > >(Assuming they keep their speed difference after they bounce off a > >mirror and then travel in the same direction.) Where will the waves > >interfere with each other? They have the same wavelength so we can > >calculate where their first interference minimum will be. But wait, > >they have different speeds so we will have to adjust that for the > >speed difference. And now we have found our first interference > >minimum, and -- they have different frequencies too! If they do > >destructive interference for awhile they will then do constructive > >interference. This is not an interference minimum after all. > > Discussed above... > > >It looks to me like to get interference, the waves must have the same > >frequency, not the same wavelength. At least they need the same > >frequency when they reach the screen. > > Same wavelength and same speed, different arrival times. Same wavelength, same speed, same frequency. If the light was traveling at c+v and c-v before, it must speed up or slow down. What makes it do that then, rather than earlier? Or does your emission theory say it speeds up and slows down earlier? > >But -- what speed does emission > >theory predict for refracted light? It goes through a slit and > >changes direction, does it change anything else? Wavelength? > >Frequency? Speed? > > If there is no relative motion between the source and the slit, > nothing changes. What happens to light when you refract it? Does it keep the same speed and wavelength? What about when you refract it with gravity? > >I can construct a lot of different emission theories and at most one > >of them can be correct. It looks like some of them won't get Sagnac > >interference or Wang interference at all, ever. People who think when > >you've disproved one emission theory you've disproved them all, don't > >follow the details. > > Big hugs on that statement!!! > > > But why should they? They already know that all > >emission theories are wrong because they know SR is right and SR says > >lightspeed is constant in all directions with respect to the source > >and also with respect to every possible target. If that's true then > >obviously it can't be true that lightspeed is constant with respect > >to the source. > > More hugs... > > >To construct an emission theory you must specify what light does on > >reflection, what it does on refraction, and how interference works > >for light that travels at different speeds. (Assuming your theory > >says you can get light that is coherent enough to interfere, and make > >it travel at different speeds into the interferometer.) > > The Stewart paper (1911) is posted at Babin. He gives one of the > first and most accurate treatments of emission theory reflection. The > Waldron book (1977) has very good explanations for reflection and > refraction. Though I think Waldron made a few slight errors on the > reflection model. I'm not sure I can visualize a scenario when light > interferes at different speeds. If you have an emission theory in which light is emitted at c+v or c-v or somewhere inbetween and it keeps the speed when it changes directions, then what is to keep it from going into an interferometer with its original speed? If you can get light at c+v and c-v that interferes, then you might very well get light at c+v and c-v both going into the same interferometer at the same time. FOGs tend to use some sort of laser chamber that's connected to fiber optics at each end, right? It sends light out at both ends that are supposed to interfere? If it only makes light in one direction and then uses some sort of beamsplitter to make it go both ways then that doesn't apply. But if a FOG really does have an internal laser that shoots light out of both ends, and that light does interfere, then by emission theory it ought to go c+v c-v, right? You can make an emission theory that has light travel at almost-c everywhere except the deepest empty space where it travels c+v and c-v. But that would give you an emission theory that applies only to some things in astronomy and not to anything else. It would not be very important except to astronomers. > >As near as I can tell, Androcles just throws away the whole dilemma. > >He says that light is particles and only particles, so we don't have > >to worry about all this wavelength stuff. It makes a kind of sense. > >How do you get interference without lightwaves? Well you get > >interference with electrons and buckyballs, we can let the guys who > >think out buckyball interference explain it and then we'll use their > >explanation for light too. Particles and only particles, interference > >works as shown by experiment and we can make up stories later to > >"explain" how that works in terms of something else. (I don't claim > >to understand much of Androcles's idea yet. I won't call it a theory, > >he says he doesn't have any theory. I don't even understand > >interference as well as I did (or thought I did) before I started > >looking at it in detail. It seems like the more I learn the less I > >know.) > > At some future point on a separate thread, I would like to discuss > destructive interference. I don't understand it as well. > > >But you were talking about emission theory that had the light going > >the same speed in both directions. Superficially people would say > >that if the light from a moving source goes the same speed in all > >directions then it isn't an emission theory you are using. But the > >original Sagnac experiment had light from a stationary source, so > >that wouldn't have two speeds unless it got two speeds from bouncing > >off a moving mirror. A later Sagnac experiment had the light source > >revolving on the turntable, and the light went through a beamsplitter > >to travel in two opposite directions. It would not travel at c+v and > >c-v unless it changed velocity coming out of the beamsplitter. > >FOG-type Sagnac and Wang experiments may use a sort of laser built > >into the system that sends the same light in both directions. A naive > >view would say that the previous experiments should have all the > >light start out at the same speed and maybe keep the same speed, but > >this one should have the light start at c+v and c-v. It should then > >get a fundamentally different result from the others.... But it does > >not. So it is necessary to use an emission theory that is not that > >naive. > > When light is split, the two components are still travelling at the > same speed of the parent beam. You might like to look at the Dufour > and Prunier series of Sagnac experiments. They did all the possible > configurations. > > >Meanwhile, it looks to me like Wang has a result that various SR > >enthusiasts said was impossible because it would violate SR. At this > >point I believe he has the result. I also believe Tom Roberts's claim > >that it does not violate SR. What I think has happened is that these > >various SR enthusiasts misunderstood SR and did not actually know > >what would violate SR and what would not. I look forward to seeing > >what else they have misunderstood about SR. > > Dr. Wang's experiments have been very revealing to me. I continue to > learn from them, and have more to learn. > I think Tom Roberts is very knowledgeable and he provides a good > counterpoint. I agree. Tom Roberts is very knowledgeable. Also on the one occasion that I saw him make an argument that clearly did not make sense he stopped and found another approach rather than continue to repeat it. That alone would put him a giant step ahead of most posters here. |