Speed of Light: A universal Constant?
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From: bz on 28 Apr 2005 17:31 H@..(Henri Wilson) wrote in news:6qh2719jtnb1lc58444ahvv95vbj5eb9uc(a)4ax.com: > On Thu, 28 Apr 2005 09:29:19 +0000 (UTC), bz > <bz+sp(a)ch100-5.chem.lsu.edu> wrote: > >>H@..(Henri Wilson) wrote in >>news:iv4171dfq7360sat39573jv7cu08ff3cdm(a)4ax.com: >> > >>>>> >>>>> Let's imagine we can spin a double sided mirror at 200 rps at a >>>>> 48cms radius. The peripheral speed is about 60000 cms/sec, or >>>>> 0.000002c. >>>> >>>>that is only 12,000 rpm. I know we can go 90,000 rpm or 1500 rps. >>>>> >>>>> If the experiment is carried out over 300 metres, light travel time >>>>> is around 1 microsec. >>>> >>>>right. >>>> >>>>> >>>>> O------------300m--------------L---S >>>> >>>>I wouldn't say that 300 m would be >>>>> >>>>> A light source L is placed near the rotating mirrors, S. The >>>>> reflected light moves at c+2v. >>>> >>>>1) there will be no rotating mirrors. The light source, which will >>>>launch a beam of light tangential to a single point on the edge of the >>>>wheel will be an optical fiber fed from a laser at center of the >>>>rotating wheel. >>> >>> Well, you should consult George Dishman. He claims that light from a >>> moving mirror is not affected by the mirrors's speed. >>> A laser beam passing along a bent fibre is like a beam deflected >>> infinitesimally by each of an infinite number of mirrors. >> >>Yes, but an optical fiber is going to be much more stable under the high >>g conditions that will exist at the edge of the spinning disk. >> >>> >>>> >>>>I want the source of the photons to really be moving. No c+2v, it will >>>>be c+v and c-v as we rotate the source in different directions. >>>> >>>>At some moment during the rotation, the beam will be aimed directly >>>>down the line that passes by detectors 1 and 2. >>> >>> Have you considered how weak it will be at trhe receiver. >> >>Yes. A laser beam at 1 km is still going to be detectable. Heck, I can >>see returns from my laser pointer, when I hit stopsigns over 1/2 mile >>away. > > But if you flash it past at a speed equivalent to a rotation rate of > 60000 rpm your eyes would NOT detect one flash. Right, there would be 1000 flashes per second at 60000 rpm. > The brightness will be reduced by the ratio of the target width to the > circumference of the circle. It will be reduced even more because I am going to make the beam go through a couple of irises to make sure the beam is only going down one rather narrow path. But, if it is too dim with one source, I can glue multiple fibers from the source to the edge of the disk and increase the number of pulses, or just let the experiment run longer. When you properly capture data from a repeating phenomina, you can sum the data. Signals add, noise doesn't. Sum enough data and you get an excellent signal to noise ratio. > >> >>This experiment does NOT depend on the laser beam being well collimated. >>I could use an LED instead. I just want a moving source with a stable, >>known wavelength. >> >>> Even at 300 >>> metres it will flash past very quickly. >> >>Sie Sie, the photons will flash past at c. > > wrong. This is exactly the point upon which we disagree. > >> >>> The width of your detector will limit the accuray of the sensing time. >> >>The width of the Photo multiplier tube will have nothing to do with the >>sensing time. It will limit how WIDE the pulse is, but not how long it >>takes to travel the distance. > > No, you don't understand the experiment at all. I understand the experiment that I propose. I have no idea what you understand about my experiment but earlier you thought I would be using a double sided mirror and looking at coming and going at the same time, so it just might be you that does not understand my proposed experiment. I am sorry if I have not been clear enough about it. I have changed designs several times, but my intent has been to show that the time-of-flight of light from a [captive] moving source is independent of the speed of the source by showing that the transit time between two points is constant regardless of the motion of the source. If I do that, it will invalidate BaT, right? ..... -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: George Dishman on 28 Apr 2005 18:38 "Henri Wilson" <H@..> wrote in message news:fpe27115f8om936ebb4euvuu2m1j144t1v(a)4ax.com... > On Thu, 28 Apr 2005 00:02:02 +0100, "George Dishman" > <george(a)briar.demon.co.uk> > wrote: > >> >>"Henri Wilson" <H@..> wrote in message >>news:28107116lmsk694q33fpre15ufn6uk47rs(a)4ax.com... >>> On Wed, 27 Apr 2005 22:04:23 +0100, "George Dishman" > >>>> http://www.briar.demon.co.uk/Henri/Huygens.gif >>>> >>>>I'm sure you can sort out the relation between >>>>the angles but hopefully this explains how the >>>>slope of the wavefront would get changed. >>> >>> Except that the position of A' moves during the time light >>> goes from A to A'. >>> Is that not important? >> >>The diagram is easiest to understand in the mirror >>frame so the motion would be a rotation of the >>mirror about a point midway between B and A'. Take >>the mid-point as the reflection of a notional ray >>which exactly joins the source to the detector. >>The effect is to make it either slightly concave >>or slightly convex depending on which beam we are >>considering but the motion is so small in the time >>involved the effect is negligible compared to the >>inherent spread of even a laser. >> >>> I assume the distance B-A' is related to some property >>> of the mirror surface. >> >>No, you can simply think of it as the width >>of the light beam but really it is just two >>arbitrarily close hypothetical rays within >>the beam. It should be clear that the angles >>are independent of the width, only the ratio >>of the speeds affects the result. > > All Right. Here's something for you to think about, then: > > / > | > | > s O > | > | > / > > Imagine a pair of 45 degree mirrors spinning around a central source, s. > > If such a configuration was used to test the BaT, what would you expect > the > light beams speed to be towards a distant observer, O. That's a more complex setup because the distance from the mirror to O is not constant so there is a longitudinal speed component, but the same technique would work. The speed of the light hitting the mirror is the magitude of the vector sum of the mirror velocity and that of the light, each measured in the lab frame. The apparent angle of incidence of the light onto the mirror would be reduced (nearer to the normal) as the speed increases. What you need next is the speed of the reflected light relative to the mirror. As I have said a number of times, there are two obvious possibilities but maybe more I haven't considered. The first is that the speed of the reflected ray is equal to that of the incident ray. The alternative is that the ray is re-emitted ballistically at c regardless. You would have to tell me which to use. Given the angle and speed of incidence and the speed of the reflected ray, the diagram shows how to work out the angle of the reflected ray relative to the mirror. Then find the vector sum of that and the velocity of the mirror to find the velocity of the light in the lab frame. The magnitude of that is your answer. >>>>You have gone beyond that and found the >>>>quantitative result that even a four mirror >>>>setup gives the wrong result for a ballistic >>>>model. I'm impressed Henri. >>> >>> How do you know it is the wrong result? >> >>Because you said "At high speeds, the path >>length difference under BaT appears to be >>slightly less than half that according to >>SR.". The SR prediction was first tested in >>1913 and has been checked many times since >>then so there is no doubt it is accurate. >>For example it is the basis of the design >>for the fibre gyro industry and they would >>soon scream if it didn't work. > > Of course, what you claim to be an 'SR prediction' is really the 'AETHER' > prediction. No. We have gone over this already. If I want to make a prediction using SR, then I can start with the assumption that the light travels at c in any inertial frame. That is what I did and what you have done in your animation, it illustrates the SR prediction. You have to realise that a diagram isn't exclusive, the same picture can illustrate more than one model. In this case however, we can note that it cannot be an aether prediction since the speed of the lab through the aether is not considered but that is beside the point, your animation illustrates the SR prediction whether any can coincidentally be illustrated the same way or not. > If it IS true, it is not the result of any silly maths postulate. It is > the > physical consequence of the fact that the Earth apparently DOES have a > natural > reference frame aound itself. Or, as SR says, it is due to physical geometry. >>>>... The key is that the >>>>experiment has been run by many people and >>>>the amount of the delay has been measured >>>>very accurately so an error even of a factor >>>>of two would be obvious. >>> >>> Well, I'm not at all convinced. There are a few other factors to >>> consider >>> yet. >> >>Yes, that's where I see your real challenge. >>You would need to exhaust all the possible >>effects before you could be convinced, but >>I think this experiment has a far better >>chance of giving you an answer than any >>other. The simplest ballistic model is >>ruled out but there are a number of ways >>you might try to construct a theory that >>fits the data. > > Well, George, you claimed there would be NO fringe shift under the BaT > model. > That appears to be incorrect. I hadn't really considered the four mirror case so if I said that, I was wrong. What I did say, and stand by, is that interferometric fibre gyros should not work according to Ritzian theory. > You will also notice that the beams behave almost identically at lower > speeds, > for both models. The 'factor of two' is only obvious at very high rotation > speeds. A factor of 2 remains a factor of 2 at any speed. >>> I'm not sure about the correct departure angle from the source. >>> >>> Also, I have to look at the reflection at each mirror more closely. >> >>The launch angle is easy, it is whatever is >>necessary for the light to reach the detector. > > Presumeably, if he apparatus is set up whilst NOT rotating, the beams will > be > aligned so that both hit the mirror at the same spot. For an iFOG, the light is constrained in the fibre so reaches the detector at any speed. In the four mirror case, if you spin it fast enough with a very thin beam, the detector could move out of the beam in the time it takes to traverse the table. You are then repeting the rotating mirror measurement of the speed of light. In a Sagnac experiment, the speeds are usually far slower. > The animation shows that both move sideways during rotation, under both > models. > That is not what I expected and I will be having a closer look. It is what I expected, the mirrors move slightly sideways but at realistic speeds it will be a tiny fraction of the beam width. > It could be a > second order effect that shows up at very high rotation speeds. Remember that the gyros have a maximum rate which is quite low, only tens of rpm in the examples we looked at. > I will improve the program using much higher precision and, like I said, > with a > magnification of the point where the beams meet. I will also make it > produce > some actual figures. Excellent idea. >>You only get interference if two beams fall on >>the same spot simultaneously (it is of course >>the emission time that differes slightly while >>we are finding the arrival time difference). > > Well apparently they DO NOT....according to both the BaT and aether. they > bith > move sideways in the SAME direction but by different amounts. You are assuming a zero-width beam. >>The harder part is that the required launch >>angle depends on the angles at all the >>reflections. The diagram we discussed at the >>top then relates that back to the ratio of the >>speeds so hopefully that reduces the variables >>but the speed depends on the details of your >>ballistic model so that's about as far as I >>can go to help. > > There is a lot more to this problem than one would think. Yes. That's why I think you need to think each aspect through before you can reach any conclusion. >>> I have already made up a new version of the program with a much higher >>> resolution than 1 pixel. I took out the timer and replaced it with a >>> 'for >>> ..loop', using machine delay instead. >>> The problem was that the mirrors were in place one pixel before the ray >>> reached >>> it but had moved before the ray left...and I thought the reflection >>> angles >>> might be slightly out. However the higher resolution made no noticeable >>> difference so the current demo appears OK. >> >>OK, that's a good check of robustness. >>Eventually, you should do this analytically >>but it is essential to understand the various >>processes involved first and I think your >>simulation is invaluable for that. > > I have now put the faster and more accurate version on the website. I'll look over the weekend, I just got home and it's nearly midnight. regards George
From: Henri Wilson on 28 Apr 2005 19:02 On Thu, 28 Apr 2005 21:11:51 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >H@..(Henri Wilson) wrote in >news:b8h2719k4fhf6m6shbrsd7hqsbag8p3gh4(a)4ax.com: > >>> >>>Which is exactly what I am trying to demonatrate to the BaT people. >>> >>>They think that c'=c+v >>>They think that the speed of light is dependent on the velocity of the >>>source. >> >> No they don't. >> >> They say: >> 1) 'speed of light' is a meaningless expression on its own. > >we disagree. The 'speed' of anything is a meaningless expression anywhere, anytime. > >> All speeds >> must be defined as relative. >we agree with the exception of things like light and sound that have >constant velocities (assuming vacuum for light, uniform media for sound). For sound, speed is defined as relative to he medim in which it is conveyed. For light in vacuum, there is no reference medium. The only reference is its source. The claim that light travels at 'c' wrt all observers is unsubstantiated and nonsensical. > >> 2) Tthe speed of light happens to be 'c' wrt its source, > >we agree. > >> 'c' being a universal constant. >> 3) Light from a moving source will move at c+v relative to the observer. > >We disagree. >Light moves at c wrt observer, wrt source, wrt all possible observers. The claim that light travels at 'c' wrt all observers is unsubstantiated and nonsensical. >> >>>They actually think that the wavelength is constant and the speed >>>varies. >> >> The frequency of an EM signal refers to the rate at which 'wavecrests' >> pass a point. > >We agree. > >> Under the BaT, that rate is obviously dependent on relative light speed. > >True, also under SR, GTR, and Newtonian physics. Not so under SR. If so, it would not accommodate doppler shifts at all. > >> How could the distance between any two point be physically affected by >> observer movement? There are lots of differently moving observers :) > >So? Each different observer can observe a different frequency, if their >motion relative to the source is different. That has nothing whatsoever to do with the physical distance between the points. Accept: OBSERVER MOVEMENTS DON'T AFFECT ANYTHING. > >It works that way with the doppler shift due to a moving sound source. Why >wouldn't it work that way with light? Light doesn't travel through a medium. > >> >> That is what you are other SRians claim...and in all seriousness!! >> HaHa!!!! > >Do you agree that BaT does NOT apply to sound? How could it. Sound is a moving disturbance in a fixed medium. >Do you agree that the speed of sound is independent of the speed of the >source? Of course the speed of sound in the medium is independent of the source. > >If you don't agree, then we can easily do experiments that will show you >are wrong. Where is the connection between sound and light. You obviously have a lot to learn. HW. www.users.bigpond.com/hewn/index.htm Sometimes I feel like a complete failure. The most useful thing I have ever done is prove Einstein wrong.
From: Henri Wilson on 28 Apr 2005 19:08 On Thu, 28 Apr 2005 21:31:22 +0000 (UTC), bz <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >H@..(Henri Wilson) wrote in >news:6qh2719jtnb1lc58444ahvv95vbj5eb9uc(a)4ax.com: > >> On Thu, 28 Apr 2005 09:29:19 +0000 (UTC), bz >> <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >> >>>H@..(Henri Wilson) wrote in >>>news:iv4171dfq7360sat39573jv7cu08ff3cdm(a)4ax.com: >>> >> >>>>>> >>>>>> Let's imagine we can spin a double sided mirror at 200 rps at a >>>>>> 48cms radius. The peripheral speed is about 60000 cms/sec, or >>>>>> 0.000002c. >>>>> >>>>>that is only 12,000 rpm. I know we can go 90,000 rpm or 1500 rps. >>>>>> >>>>>> If the experiment is carried out over 300 metres, light travel time >>>>>> is around 1 microsec. >>>>> >>>>>right. >>>>> >>>>>> >>>>>> O------------300m--------------L---S >>>>> >>>>>I wouldn't say that 300 m would be >>>>>> >>>>>> A light source L is placed near the rotating mirrors, S. The >>>>>> reflected light moves at c+2v. >>>>> >>>>>1) there will be no rotating mirrors. The light source, which will >>>>>launch a beam of light tangential to a single point on the edge of the >>>>>wheel will be an optical fiber fed from a laser at center of the >>>>>rotating wheel. >>>> >>>> Well, you should consult George Dishman. He claims that light from a >>>> moving mirror is not affected by the mirrors's speed. >>>> A laser beam passing along a bent fibre is like a beam deflected >>>> infinitesimally by each of an infinite number of mirrors. >>> >>>Yes, but an optical fiber is going to be much more stable under the high >>>g conditions that will exist at the edge of the spinning disk. >>> >>>> >>>>> >>>>>I want the source of the photons to really be moving. No c+2v, it will >>>>>be c+v and c-v as we rotate the source in different directions. >>>>> >>>>>At some moment during the rotation, the beam will be aimed directly >>>>>down the line that passes by detectors 1 and 2. >>>> >>>> Have you considered how weak it will be at trhe receiver. >>> >>>Yes. A laser beam at 1 km is still going to be detectable. Heck, I can >>>see returns from my laser pointer, when I hit stopsigns over 1/2 mile >>>away. >> >> But if you flash it past at a speed equivalent to a rotation rate of >> 60000 rpm your eyes would NOT detect one flash. > >Right, there would be 1000 flashes per second at 60000 rpm. > >> The brightness will be reduced by the ratio of the target width to the >> circumference of the circle. > >It will be reduced even more because I am going to make the beam go through >a couple of irises to make sure the beam is only going down one rather >narrow path. But, if it is too dim with one source, I can glue multiple >fibers from the source to the edge of the disk and increase the number of >pulses, or just let the experiment run longer. You haven't a clue. You have to be able to discriminate between individual pulses. You will need an extremely fast and sensitive PM for that. > >When you properly capture data from a repeating phenomina, you can sum the >data. Signals add, noise doesn't. Sum enough data and you get an excellent >signal to noise ratio. So what. Your experiment is to show that individual pulses froom a receding source take longer to reach you than the 'approaching' ones. > >> >>> >>>This experiment does NOT depend on the laser beam being well collimated. >>>I could use an LED instead. I just want a moving source with a stable, >>>known wavelength. >>> >>>> Even at 300 >>>> metres it will flash past very quickly. >>> >>>Sie Sie, the photons will flash past at c. >> >> wrong. > >This is exactly the point upon which we disagree. I am refering to the time taken for the pulses to pass the detector, not the speed at which they pass. >>> >>>> The width of your detector will limit the accuray of the sensing time. >>> >>>The width of the Photo multiplier tube will have nothing to do with the >>>sensing time. It will limit how WIDE the pulse is, but not how long it >>>takes to travel the distance. >> >> No, you don't understand the experiment at all. > >I understand the experiment that I propose. I have no idea what you >understand about my experiment but earlier you thought I would be using a >double sided mirror and looking at coming and going at the same time, so it >just might be you that does not understand my proposed experiment. > >I am sorry if I have not been clear enough about it. I have changed designs >several times, but my intent has been to show that the time-of-flight of >light from a [captive] moving source is independent of the speed of the >source by showing that the transit time between two points is constant >regardless of the motion of the source. > >If I do that, it will invalidate BaT, right? You will not do it. It cannot work. You would have yto perform it in remote space to be sure and then you will find that it supports the BaT. >.... HW. www.users.bigpond.com/hewn/index.htm Sometimes I feel like a complete failure. The most useful thing I have ever done is prove Einstein wrong.
From: bz on 28 Apr 2005 19:52
H@..(Henri Wilson) wrote in news:ftq271hf7qjtljjr8c9hgcehal99c8qlde(a)4ax.com: > On Thu, 28 Apr 2005 21:31:22 +0000 (UTC), bz > <bz+sp(a)ch100-5.chem.lsu.edu> wrote: > >>H@..(Henri Wilson) wrote in >>news:6qh2719jtnb1lc58444ahvv95vbj5eb9uc(a)4ax.com: >> >>> On Thu, 28 Apr 2005 09:29:19 +0000 (UTC), bz >>> <bz+sp(a)ch100-5.chem.lsu.edu> wrote: >>> >>>>H@..(Henri Wilson) wrote in >>>>news:iv4171dfq7360sat39573jv7cu08ff3cdm(a)4ax.com: >>>> >>> >>>>>>> >>>>>>> Let's imagine we can spin a double sided mirror at 200 rps at a >>>>>>> 48cms radius. The peripheral speed is about 60000 cms/sec, or >>>>>>> 0.000002c. >>>>>> >>>>>>that is only 12,000 rpm. I know we can go 90,000 rpm or 1500 rps. >>>>>>> >>>>>>> If the experiment is carried out over 300 metres, light travel >>>>>>> time is around 1 microsec. >>>>>> >>>>>>right. >>>>>> >>>>>>> >>>>>>> O------------300m--------------L---S >>>>>> >>>>>>I wouldn't say that 300 m would be >>>>>>> >>>>>>> A light source L is placed near the rotating mirrors, S. The >>>>>>> reflected light moves at c+2v. >>>>>> >>>>>>1) there will be no rotating mirrors. The light source, which will >>>>>>launch a beam of light tangential to a single point on the edge of >>>>>>the wheel will be an optical fiber fed from a laser at center of the >>>>>>rotating wheel. >>>>> >>>>> Well, you should consult George Dishman. He claims that light from a >>>>> moving mirror is not affected by the mirrors's speed. >>>>> A laser beam passing along a bent fibre is like a beam deflected >>>>> infinitesimally by each of an infinite number of mirrors. >>>> >>>>Yes, but an optical fiber is going to be much more stable under the >>>>high g conditions that will exist at the edge of the spinning disk. >>>> >>>>> >>>>>> >>>>>>I want the source of the photons to really be moving. No c+2v, it >>>>>>will be c+v and c-v as we rotate the source in different directions. >>>>>> >>>>>>At some moment during the rotation, the beam will be aimed directly >>>>>>down the line that passes by detectors 1 and 2. >>>>> >>>>> Have you considered how weak it will be at trhe receiver. >>>> >>>>Yes. A laser beam at 1 km is still going to be detectable. Heck, I can >>>>see returns from my laser pointer, when I hit stopsigns over 1/2 mile >>>>away. >>> >>> But if you flash it past at a speed equivalent to a rotation rate of >>> 60000 rpm your eyes would NOT detect one flash. >> >>Right, there would be 1000 flashes per second at 60000 rpm. >> >>> The brightness will be reduced by the ratio of the target width to the >>> circumference of the circle. >> >>It will be reduced even more because I am going to make the beam go >>through a couple of irises to make sure the beam is only going down one >>rather narrow path. But, if it is too dim with one source, I can glue >>multiple fibers from the source to the edge of the disk and increase the >>number of pulses, or just let the experiment run longer. > > You haven't a clue. If we knew what would happen, we wouldn't need to run the experiment. Clue me in. > You have to be able to discriminate between individual pulses. You will > need an extremely fast and sensitive PM for that. I have to be able to detect individual pulses. Yes. CCDs and PM tubes are available that detect single photons. The speed must be stable. >>When you properly capture data from a repeating phenomina, you can sum >>the data. Signals add, noise doesn't. Sum enough data and you get an >>excellent signal to noise ratio. > > So what. > Your experiment is to show that individual pulses froom a receding > source take longer to reach you than the 'approaching' ones. If it does that then c'=c+v is supported and a lot of other things fall. You are happy. If, as I suspect, it shows that TOFLS (time of flight light speed) is independent of source velocity, then BaT is invalidated. >>>>This experiment does NOT depend on the laser beam being well >>>>collimated. I could use an LED instead. I just want a moving source >>>>with a stable, known wavelength. >>>> >>>>> Even at 300 >>>>> metres it will flash past very quickly. >>>> >>>>Sie Sie, the photons will flash past at c. >>> >>> wrong. >> >>This is exactly the point upon which we disagree. > > I am refering to the time taken for the pulses to pass the detector, not > the speed at which they pass. Are you talking about the pulse width, as seen by the detector? The pulse width WILL change with the speed of the source. If we look at the leading edge of the pulse, it will travel at c between the two detectors. If we look at the trailinge edge of the pulse, it too will travel at c between the two detectors. >>>>> The width of your detector will limit the accuray of the sensing >>>>> time. >>>> >>>>The width of the Photo multiplier tube will have nothing to do with >>>>the sensing time. It will limit how WIDE the pulse is, but not how >>>>long it takes to travel the distance. >>> >>> No, you don't understand the experiment at all. >> >>I understand the experiment that I propose. I have no idea what you >>understand about my experiment but earlier you thought I would be using >>a double sided mirror and looking at coming and going at the same time, >>so it just might be you that does not understand my proposed experiment. >> >>I am sorry if I have not been clear enough about it. I have changed >>designs several times, but my intent has been to show that the >>time-of-flight of light from a [captive] moving source is independent of >>the speed of the source by showing that the transit time between two >>points is constant regardless of the motion of the source. >> >>If I do that, it will invalidate BaT, right? > > You will not do it. Why do you think that? > It cannot work. Why do you say that? > You would have yto perform it in remote space to be sure and then you Why? I don't expect gravity to be a significant factor. > will find that it supports the BaT. That would depend entirely upon the results, wouldn't it? -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap |