Absolute zero-velocity measured in Sagnac Effect

[swansont]

But look very closely what is being describeac as nonisotropic' date=' SRT states that the relative velocity of frame and photon is always measured as C, correct" The nonisoptropic light motion is merely the recognition that the relative velocity of frame and photon is v - c or v + c. The speed of light wrt some Vf = 0 is still c. Nothing has really changed except the rhetoric. But no one is suggesting that light actually slows down or speeds up for the mere convenience of scientists constructing classical physical models of light motion. But that would be so cool if it did.

 

Swansot. histroically the Saganc effect came from experiments on rotaion. Only through time did the application generalize to not just rotation of circular wheels, but any turning shape was seen to give the same result. But while all this weas going on the mentality was thinking in terms that the system was a rotationall system, until even Einstein suggested that the Saganc unwrap the trajectories of the turning wheel and lineralize the effect.

So see the obedient result of that command by AE in the opening post of this thread.

 

I have concluded that the rotational Saganc effect is basically an accelerometer, the linear effect a motion indicattor, meaning uniform motion and perhaps measuring accelerating frame as well..

[/indent']

 

A rotating frame is not an inertial one, which means that you can't blindly apply SR to it. And "any turning shape" still qualifies as rotational.

 

Can you point me to where Einstein suggested "unwrapping" it?

 

I think your conclusion that the linear effect is a motion indicator is wrong; as you note it predicts that beams will be deflected by motion, and this is not observed.

[swansont]

If and when Johnny5 shows his detected frrame swapping error in MM' date=' I will give you my detected error. Virtually all the literature descibes the leg orthogonal to the frame motion is reflected sin the triangular trajectory where the frame "carries the beam along"as this is often described.

 

The postulates of the light are clearly stated that the photon moves isotropically regardless of the motion of the sources of the light. Secondly, to use the "go along with" interpretation would be to impose a moving frame's momentum compoinent on the photon thereby increasing the velocity of the light to c' > c. If the mirrors are properly adjusted for accurate 180 degrees relectioopn the photon would would return on the same physical trajectory path of the downward directed beam. The photons of both legs would then approach the eyepiece parallel wrt each other.

If the earh is moving at 30 km/sec (as assumed) then in 32 meters of roundt rip time of flight, the orthogonal beam would move a distance as calualted by:

32/3x10[sup']8

[/sup]

= 10.6 x10

^-8

seconds. This multiplied by the earth velocity of 30 km/sec returns a distance offset of .00318 meters = 3.18 mm.

 

MM should have been looking for 3.18 mm offset from the parallel (wrt the direction of motion) beam when the beams arrived at the eyepiece. This would be some sort of maximum offset. I betcha that MM & M adjuested the orthogonal mirror in oder to calaibrate the interferometer to a null positionj. After all they were using the wrong assumed physics for the reflection of light from an orthogonallyl moving mirror.

 

Let me confirm this: you think that in the interferometer's frame of reference, the orthogonal beam travels a triangular path if the device is properly adjusted? If so, what is the length of the base of the triangle?

 

Also, what "wrong assumed physics" were they using in deriving the equation?

[timo]

[indent']I hear what you are saying, but I am not quite following the maning of it all. As you have just stated it appears applicabnle to any situation, Atheist, I believe we have an understanding. I would say the same and have in different words: Photons emitted at point A strike parallel vertical mirrors at B and C and are reflected back to point A.

No, in the sense of relativity they are not reflected back to point A. I am talking about points in 4-dim space here. That is one misunderstanding of yours I´m complaining about all the time. But I admit I could have called the points in 4-space "events" for clearification. Just reread my post and replace "point" with "event".

 

 

I am still cautious on your meaning here as if I have missed something you are trying to say.

Yes, see above. Don´t expect it to be a minor remark. The step to stop thinking in 3-space and to start thinking in 4-dim spacetime is no as easy as it sounds.

 

 

If we look at the matter from a sheer "utility " concern, the coordinate system that works apporpriately need never be repalced until a model comes along with such a significant benefit increase that the change becomes mandatory and crucial, absolutely mecessary.

Not completely sure what you are talking about but sometimes it´s easier to tell someone "the bar is 50 meters up the road from that italian restaurant" than to give GPS coordinates.

 

Soemhow I think I overkilled this response, What do you think?

I do think the same. That´s why I restricted my answer on the parts I understood. My main point is still that you seem to mix up classical view and relativisitic view.

[geistkiesel]

Let me confirm this: you think that in the interferometer's frame of reference' date=' the orthogonal beam travels a triangular path if the device is properly adjusted? If so, what is the length of the base of the triangle?

 

Also, what "wrong assumed physics" were they using in deriving the equation?[/quote']

Thde base of the triangle is the length of the path of the interferometer during the tie the beam is translated down (1leg) and reflects at the apex then returns (2nd leg).

The beam of light reflecting from a flat surface perpendicular to the beam will reflect the beam back along the original trajectory of the beam whether the mirror is moving or at rest wrt the beam trajectory. This is where the beam is DRAWN HISTORICALLY AS A TERIANGLE, an error.

[geistkiesel]

One of the implications of SR is that the Michelson interferometer isn't[/i'] a motion detector.

What ever the MM results are there is the ever oresent ambiguities inherent in the results. Thje first is the cinsistent finding of the 8km/sec absolute motion (MM and Miller confirmed) together with the imposed error assumed by virtually all reviewers of the MM resuls (Miller included). Th error is the assumption that the orthogonal reflection on the moving mirror "dragez the beam along with the moving interferometer thus creating an extended path length for the reflected beam.

 

Until these questi8ons are fullt answered there is little valyue in using MM to prove one thing or another, or to impose any assumptions regarding SR and classical physics,

I have been reluctantly discussing these issues, with little ,if any, direct response. We can discuss the matters of MM all week long, but we are fancifying the progress of the discussions by our speculations.

[geistkiesel]

No, in the sense of relativity they are not reflected back to point A. I am talking about points in 4-dim space here. That is one misunderstanding of yours I´m complaining about all the time. But I admit I could have called the points in 4-space "events" for clearification. Just reread my post and replace "point" with "event".

This much I gathered, however the use of the 4-dim world is SR structered is it not? The use of the coordinate systems of classical vs. 4-dim imposes ambiguities from the inherent differences imposed by the basic physical assumptions that are contradictory from the get go.

 

Were I to agree that the measure of relative velocity of frame and photon was always c for all uniformly moving frames I wouldn't be in this duiscussion, but i see the opposite. If we observe a duck flying in a straight line at uniform motion from any number of inertial fremes, we will not arrive at a duck version of SR, will we? It is only when we assume the constancy of the relative velocity of frame and ducks that we would construct such a model directly analogous to SR as we know it. Electromagetic dynamics is the only entity in the observeable universe that we make the constancy of the speed of light assumptions and this as an exception to all other motion. Because there was an inherent inability to consider situations and conditions that would allow one to measure the relative velocity of the speed of light measured from the frame, that got us where we are. This is the pnly reason why some discard the concept of absolute space and time. The moving frame is considered a special place in a universe where everthing is moving. Some are taught to reject the ratioanal and the observed and to believe in the mentally constructed which is based on the rejection of even attempting to measure the relative velocity of frame and photon. It has gotten to a point that any measurement of the absloute velocity of any entity is rejected by SR theorists, not from any inherent identifiable error in the experimental arrangement, but from a pure theoretical objection. Theory vs. Experimental results is where the battle is being raged, and all the philosophical rhetoric outlining the problem offers nothing to any resilutuion of the discussion.

 

I trust you can see my objections. If we are told that under no circumstances will any measurement of the relative velocity of frame and photon ever be measuarble as different than c, i.e. c - v, or c + v measuremnts as relative findings, are not true and accurate measurements. I expected no less of a response when I offered the example described in the opening post of this thread. I would think, as I did think, that if there was some intrinsic experimental error in the described system that that error would be so obvious that to point to the error would be a trivial task for the average SR theorist.

 

AS I described the system in the figure I see nothing that includes or discludes SR. The only assumption I made, the speed of light is independent of the motion of the source of light. I see this as used improperly when translated to mean the speed of light will always be measured as C wrt any source. This statement is a direct contradiction of the basis of SR. If the motion of light is independent of the motion of the souerce, then why make a statement that the speed of light will always be emasured as C from any frame. Why insert an exception to the independence piostualte of light?

 

This is an inaccurate meaning of the independent motion of light. No activity of the source will have any affect on the motion of the emitted light. is hoe I read it, but to then measure the speed of light wrt a point on a inertial frame moving at some v > 0 wrt Ve, embankment, that I must then jump thriough the SR hoops and effectively negate the velocity of the frame is too much. Every external observer to the frame making the measurement, from their external position, will come up with a relative velocity Vc - Vf = Vcf < C. The moving observer measures Vc - Vf = Vcf = Vc.

 

 

 

Yes, see above. Don´t expect it to be a minor remark. The step to stop thinking in 3-space and to start thinking in 4-dim spacetime is no as easy as it sounds.

The difficulty to engage in that kind of thinking is indeed not easy. The writings I am familiar with state (in many versions), that one must give the learned "rational" thinking process and that what one observes is "not the reality" of the universe, are true statements. To accept SR one must discard rational observations.

 

 

 

Not completely sure what you are talking about but sometimes it´s easier to tell someone "the bar is 50 meters up the road from that italian restaurant" than to give GPS coordinates.

the two examples you mentioned are from consistent coordinate systems, so if you are talking to the town drunk, or the astronaut, there may be the easiest way to give directions to one or the other.

 

I do think the same. That´s why I restricted my answer on the parts I understood. My main point is still that you seem to mix up classical view and relativisitic view.

 

I make the attempt to determine which system is being used.We are in a debate' date=' of sorts, each explaining their own perceptions and attempting to indicate the errors in the other's perceptions, so I agree it is not an easy task. Hiowever, we do agree, there is the bar down the road apiece, where we may all gather and discuss the matter, or we could just let St. Peter sort it all out.[/indent']

[swansont]

Thde base of the triangle is the length of the path of the interferometer during the tie the beam is translated down (1leg) and reflects at the apex then returns (2nd leg).

The beam of light reflecting from a flat surface perpendicular to the beam will reflect the beam back along the original trajectory of the beam whether the mirror is moving or at rest wrt the beam trajectory. This is where the beam is DRAWN HISTORICALLY AS A TERIANGLE' date=' an error.[/quote']

 

In the MM experiment, the beam path is not drawn as a triangle in the interferometer frame. The velocity addition is drawn that way, because that's how you add vectors.

 

It's drawn as a triangle in the ether frame, because it has to travel that path. If the mirror is moving wrt the ether frame, then you could assemble things so that the laser spot and mirror size were the same, or use an aperture to get the same effect. Under your scenario, the beams would be aligned in the interferometer frame, and the light would hit the mirror. But in the ether frame, the mirror would move and the light would miss. You can't have the light hit in one frame and miss in the other - either something happens or it doesn't. If it happens in one frame, it happens in all frames.

[swansont]

What ever the MM results are there is the ever oresent ambiguities inherent in the results. Thje first is the cinsistent finding of the 8km/sec absolute motion (MM and Miller confirmed) together with the imposed error assumed by virtually all reviewers of the MM resuls (Miller included). Th error is the assumption that the orthogonal reflection on the moving mirror "dragez the beam along with the moving interferometer thus creating an extended path length for the reflected beam.

 

Until these questi8ons are fullt answered there is little valyue in using MM to prove one thing or another' date=' or to impose any assumptions regarding SR and classical physics,

I have been reluctantly discussing these issues, with little ,if any, direct response. We can discuss the matters of MM all week long, but we are fancifying the progress of the discussions by our speculations.[/indent']

 

Did Miller use some other equation for his experiments, or did he use the "incorrect" MM interferometer equation? What is the correct equation, according to you?

[geistkiesel]

Did Miller use some other equation for his experiments, or did he use the "incorrect" MM interferometer equation? What is the correct equation, according to you?

Miller used the incorrect equation. the correct equation will have the light reflected back up the trajectory of the down photon. The photon has traveled a total of 30 meters (miller's interferometer) in 30/3x10

⁸

seconds, or 10

^-7

sec. Assuming the earth frame moving at 30,000 m/sec the frame will have moved 30 x 10

³

x 10

^-7

= 3mm, if my arithmatic is correct.

The beams will be moving parallel to each other just before arriving at the scintillation screen. As Ching-Chuan Su has found that the Sagnac effect excludes influence of the orbital motion of the earth I(using global GPS data), the 3 mm is large by a factor of approxinmately 100. This places the expected offset of motion in the micron range and due exclusively to rotational motion of the earth.

[swansont]

Miller used the incorrect equation. the correct equation will have the light reflected back up the trajectory of the down photon. The photon has traveled a total of 30 meters (miller's interferometer) in 30/3x10

⁸

seconds' date=' or 10[sup']-7

[/sup]

sec. Assuming the earth frame moving at 30,000 m/sec the frame will have moved 30 x 10

³

x 10

^-7

= 3mm, if my arithmatic is correct.

The beams will be moving parallel to each other just before arriving at the scintillation screen. As Ching-Chuan Su has found that the Sagnac effect excludes influence of the orbital motion of the earth I(using global GPS data), the 3 mm is large by a factor of approxinmately 100. This places the expected offset of motion in the micron range and due exclusively to rotational motion of the earth.

 

If Miller used the wrong equation, how can you quote his results as being valid?

 

AFAIK GPS doesn't exclude the orbital Saganac due to nonexistence, it ignores it because it's small - 365 times smaller than the rotational Sagnac because the Sagnac effect depends on angular speed, not linear speed, and so it it excludes itself - the largest the rotational term can be is ~ 200 ns. But the MM interferometer does depend on linear speed, so it is a gross misapplication of results for you to apply the terms of one experiment to a completely different one.

 

It seems that your thesis is that there should be deflection of the perpendicular beam but not a speed correction. The example I gave before, with the fiber coupling, contradicts that argument. Are you going to continue to ignore this?

[geistkiesel]

If Miller used the wrong equation' date=' how can you quote his results as being valid?

 

AFAIK GPS doesn't exclude the orbital Saganac due to nonexistence, it ignores it because it's small - 365 times smaller than the rotational Sagnac because the Sagnac effect depends on angular speed, not linear speed, and so it it excludes itself - the largest the rotational term can be is ~ 200 ns. But the MM interferometer does depend on linear speed, so it is a gross misapplication of results for you to apply the terms of one experiment to a completely different one.

 

It seems that your thesis is that there should be deflection of the perpendicular beam but not a speed correction. The example I gave before, with the fiber coupling, contradicts that argument. Are you going to continue to ignore this?[/quote']

How can Sagnac exclude Orbital data because it is too small yet detect rotational motion of the earth which is on the order of 1/100 orbital velocity. I claim the MM and Miller's data is skewed by the difference in the error that they and everybody esle used. However, the results are of magitude only. As I remember I was criticizing the use of MM data to explain SRT. In any event MM and Miller's data was consistent even tho both misused the laws of physics in creating the measure of the time of flight for the deflected beam.

 

You can answeer the question yourself : Does a beam moving perpendicular toa moving mirror reflect perpendicular to the mirror or is that eam deflected in the general direction of the moving mirror [which would impose a component of velocity on the light beam]?

 

 

I do not understand what you mean by "speed correction". The interferometer moves a few microns while the beam is deflected and returned in a total of 32 meters total. I took your meaning to be a correction of interferometer speed.

 

There is only a delay in the signal as the beam is deflected and return as the intrerferometer moves through space on the order of microns when using rortational data anada the orbital data is ignored. MM might depend on linear speed, but how do you assert rotational speed to linear in the MM experiment?

Here is the paper where global GPS data does not find an orbital effect and finds rotational motion only.

 

 

Here is a quote by Robn Hatch regarding the linear vs. rotaional effect of Sagnac:

 

"In the GPS system a non-rotating earth-centered isotropic-light-speed frame is assumed. Again, the motion of the receiver during the time the signal transits from the satellite to the receiver must be accounted for to obtain precise navigation results. In the GPS context, this effect is referred to as the one-way Sagnac effect and is blamed upon the rotation of the earth. But the receiver must account for its motion during the transit time no matter the source of the motion. It does not matter whether or not it follows a circular trajectory. The critical range which must be determined is the position of the satellite at the time the signal was transmitted and the position of the receiver at the time of its receipt. The path the receiver followed during the time of flight of the signal is completely irrelevant. This is consistent with the argument of Ives [3] that even the original Sagnac experimental results were not specifically due to rotation. Ives suggested an experimental proof designed to show the effect did not require rotation. In a beautiful modification of Ives suggestion, Ruyong Wang [4] has constructed what he calls a Fiber Optic Conveyer (FOC) which directly verifies that linear motion does not affect the speed of light."

Here is the Hatch reference to the claim that the Sagnac effect does not require rotation

[swansont]

How can Sagnac exclude Orbital data because it is too small yet detect rotational motion of the earth which is on the order of 1/100 orbital velocity.

 

 

Because the Sagnac effect depends on the angular speed, not the linear speed. For as much as you've posted on the subject, one might think that you'd know this.

 

Su and Hatch are proposing ether-based theories, which have not been substantiated. Su admits "This reinterpretation is fundamentally different from that based on the special relativity, although the difference is quite small in magnitude." IOW, don;t hold your breath waiting for this to be confirmed. You can't use ether theories to attempt to show defects in relativity.

[geistkiesel]

Because the Sagnac effect depends on the angular speed' date=' not the linear speed. For as much as you've posted on the subject, one might think that you'd know this.

 

Su and Hatch are proposing ether-based theories, which have not been substantiated. Su admits "This reinterpretation is fundamentally different from that based on the special relativity, although the difference is quite small in magnitude." IOW, don;t hold your breath waiting for this to be confirmed. You can't use ether theories to attempt to show defects in relativity.[/quote']

 

Wait for what to be confirmed? The paper is confirmation of what it says. You aren't suggesting some "official panel" determines the applicability of scientific claims are you?

 

I am not trying to find defects in realtivity. I am showing that relativity is not necessary to explain the Sagnac effect. There is a difference you know.

 

And by the way no one has pointed to any defects in the schematic figure in the opening post of this thread. I wonder why that is?All teh paper stated in teh title was that an absolute zero velocity is achievable. And does not the experiment design demonstartae the simplicity of this?

 

In this same direction Ashby's paper does not show relativity effects in GPS, thouigh he claism certain phenomena are relativistic. Put Ashby's paper up to Hatch'es, Kelly's and Su's PAper and what do you get? I get that SRT is not intrinsically a part of GPS activity.

 

Thjis is the belated link that demonstartes that the Sagnac effect is not purely rotational.

Here is the concluding paagraph of the link:

 

"We have proved that for a general configuration of the Sagnac experiment, and on the assumption that light travels with respect to the fixed laboratory, the difference in time for two beams going in opposing directions to traverse the light path is the Sagnac formula.

To synopsize, the facts of the Sagnac tests are as follows:

1. The light beams are in synchronism when released.

2. The light beams are not in synchronism when they have completed one turn of the apparatus.

3. Any observer on board the rotating apparatus, or stationary in the laboratory, will observe identical fringe shifts. If the observer is in the laboratory, there would be a very small Doppler effect when observing the moving apparatus, but, this is insignificant and will not make any observable difference to the result. There was no Doppler effect whatever, in the original Sagnac test, because the observations were made aboard the spinning disc, and the observation point was at a constant distance from the point of interference.

4. The light is behaving as if it were travelling at constant speed relative to the laboratory. It ignores the spinning of the apparatus. The light does not travel at a constant speed relative to the observer aboard that spinning apparatus. As seen from the mathematical derivation from Figure 2, the light does not go at a speed of c with respect to the observer upon the spinning apparatus. Going in one direction, it measures as going slower than c, and going in the other direction it measures as going at a speed higher than c.

5. Time and distance aboard a spinning disc are identical with time and distance in the stationary laboratory. They are also identical aboard an object that is moving at uniform velocity in a straight line.

 

Conclusion

 

The Sagnac effect applies to uniform straight-line motion, just as it does to rotational motion. "

[swansont]

Wait for what to be confirmed? The paper is confirmation of what it says. You aren't suggesting some "official panel" determines the applicability of scientific claims are you?

 

Experiments demonstrate the validity of scientific claims. The paper cannot both propose a model and claim success without some empirical evidence being presented. And since Su points out the difference between his theory and accepted theory is very small, you can't currently confirm his theory.

 

I am not trying to find defects in realtivity. I am showing that relativity is not necessary to explain the Sagnac effect. There is a difference you know.

 

And by the way no one has pointed to any defects in the schematic figure in the opening post of this thread. I wonder why that is?All teh paper stated in teh title was that an absolute zero velocity is achievable. And does not the experiment design demonstartae the simplicity of this?

 

But it isn't an actual experiment' date=' is it? Or have you actually done this measurement?

 

I did point out that the Michelson interferometer is an equivalent measurement, and that everybody not named Miller that does the experiment concludes that we can't measure absolute velocities, because there is no preferred frame that everybody will agree is at rest.

 

In this same direction Ashby's paper does not show relativity effects in GPS, thouigh he claism certain phenomena are relativistic. Put Ashby's paper up to Hatch'es, Kelly's and Su's PAper and what do you get? I get that SRT is not intrinsically a part of GPS activity.

 

I get that Ashby actually worked on GPS, and that the other two are trying to advance alternate theories. Relativity is undeniably part of GPS, as is the Sagnac effect.

 

 

Thjis is the belated link that demonstartes that the Sagnac effect is not purely rotational.

Here is the concluding paagraph of the link:

 

"We have proved that for a general configuration of the Sagnac experiment' date=' and on the assumption that light travels with respect to the fixed laboratory, the difference in time for two beams going in opposing directions to traverse the light path is the Sagnac formula.

To synopsize, the facts of the Sagnac tests are as follows:

1. The light beams are in synchronism when released.

2. The light beams are not in synchronism when they have completed [b']one turn of the apparatus[/b].

3. Any observer on board the rotating apparatus, or stationary in the laboratory, will observe identical fringe shifts. If the observer is in the laboratory, there would be a very small Doppler effect when observing the moving apparatus, but, this is insignificant and will not make any observable difference to the result. There was no Doppler effect whatever, in the original Sagnac test, because the observations were made aboard the spinning disc, and the observation point was at a constant distance from the point of interference.

4. The light is behaving as if it were travelling at constant speed relative to the laboratory. It ignores the spinning of the apparatus. The light does not travel at a constant speed relative to the observer aboard that spinning apparatus. As seen from the mathematical derivation from Figure 2, the light does not go at a speed of c with respect to the observer upon the spinning apparatus. Going in one direction, it measures as going slower than c, and going in the other direction it measures as going at a speed higher than c.

5. Time and distance aboard a spinning disc are identical with time and distance in the stationary laboratory. They are also identical aboard an object that is moving at uniform velocity in a straight line.

 

Conclusion

 

The Sagnac effect applies to uniform straight-line motion, just as it does to rotational motion. "

 

I can't fathom the misunderstanding that lets one use "spinning disc" as a test bed, and make any conclusion that includes the phrase "straight-line motion."

 

The fatal flaw in Kelly's paper is that he apparently doesn't understand what an inertial frame is. His Sagnac derivation, from what I could tell, is fine, but he concludes that because the rotating observer sees a speed of light other than c, that this applies to all frames. A rotating frame is not inertial, and you can measure absolute rotation. How? By measuring that the speed of light isn't c, which is precisely what the Sagnac effect does! But you can't "unfold" it and make the same conclusion about an inertial frame.

[BlackHole]

The rotating ring is an accelerated frame of reference, while the constancy of the speed of light © applies only in inertial frames of reference (uniform motion).

[geistkiesel]

The rotating ring is an accelerated frame of reference, while the constancy of the speed of light © applies only in inertial frames of reference (uniform motion).

I understand, but what if any measurements taken in a turning frame are indistinguishable from uniform motion? may we apply SRT there?

[BlackHole]

[indent']I understand, but what if any measurements taken in a turning frame are indistinguishable from uniform motion? may we apply SRT there?[/indent]

 

I'm no expert but i think relativity applies only to inertial reference frames. In the case of an accelerating reference frame, special relativity does not apply.

[Johnny5]

I'm no expert but i think relativity applies only to inertial reference frames. In the case of an accelerating reference frame, special relativity does not apply.

 

SR has formulas in v.

 

Differentiate them to give you formulas in a.

 

Then investigate the meaning of the symbolic statements, and decide whether or not the meaning is inconsistent with something you already know. This is a rather complex task by the way.

 

Regards

[geistkiesel]

Experiments demonstrate the validity of scientific claims. The paper cannot both propose a model and claim success without some empirical evidence being presented. And since Su points out the difference between his theory and accepted theory is very small' date=' you can't currently confirm his theory.

 

 

 

But it isn't an actual experiment, is it? Or have you actually done this measurement?

 

I did point out that the Michelson interferometer is an equivalent measurement, and that everybody not named Miller that does the experiment concludes that we can't measure absolute velocities, because there is no preferred frame that everybody will agree is at rest.

 

 

 

I get that Ashby actually worked on GPS, and that the other two are trying to advance alternate theories. Relativity is undeniably part of GPS, as is the Sagnac effect.

 

 

 

 

I can't fathom the misunderstanding that lets one use "spinning disc" as a test bed, and make any conclusion that includes the phrase "straight-line motion."

 

The fatal flaw in Kelly's paper is that he apparently doesn't understand what an inertial frame is. His Sagnac derivation, from what I could tell, is fine, but he concludes that because the rotating observer sees a speed of light other than c, that this applies to all frames. A rotating frame is not inertial, and you can measure absolute rotation. How? By measuring that the speed of light isn't c, which is precisely what the Sagnac effect does! But you can't "unfold" it and make the same conclusion about an inertial frame.[/quote']

Swansont, You are making the problem more complex than it deserves. When they discuss measuring speeds of lightr other than C, or "non-isotropically" they are not implying the light actually slows down or speeds up they are merely using the expressions c + v and C - v to determine the relative motion of frame and photons. The speed of klight is consgtant, at c, but light travels C - v faster tnaty v, or combines into a relative velocity c + V when frame and photon are moving in oppsote directions to each other.

[geistkiesel]

Swansont' date=' You are making the problem more complex than it deserves. When they discuss measuring speeds of lightr other than C, or "non-isotropically" they are not implying the light actually slows down or speeds up they are merely using the expressions c + v and C - v to determine the relative motion of frame and photons. The speed of klight is consgtant, at c, but light travels C - v faster tnaty v, or combines into a relative velocity c + V when frame and photon are moving in oppsote directions to each other.[/indent']

Swansont, you do realize that we are not going to resolve the issue of the integrity of SRT by the comparitive posts we have been exchanging? Like Miller confirmed MM, were you aware of this? How do we analyze the MM analogue experiments like the one that was done in a balloon high in the atmosphere? We are treating the issue as if SRT was on trial for murder, when it isn't on trial. I have attemted in the opening post of this thread, to deascribe a system void in Sagnac and. or SRT rhetoric and/or effects. I haven't been succesful so far, . I have just completed some serious thinking on the matter and I believe I have arrived at a solution that is neither , SRT , nor Sagnac.

I will be posting shortiy.

[BlackHole]

SR has formulas in v.

 

Differentiate them to give you formulas in a.

 

Then investigate the meaning of the symbolic statements' date=' and decide whether or not the meaning is inconsistent with something you already know. This is a rather complex task by the way.

 

Regards[/quote']

 

I was wrong. Special relativity can handle accelerating reference frames. In special relativity velocities are relative but acceleration is treated as absolute. In general relativity all motion is relative.

[Johnny5]

Special relativity can handle accelerating reference frames[/url']. In special relativity velocities are relative but acceleration is treated as absolute. In general relativity all motion is relative.

 

 

I love that site... Wolfram.

 

Regards

[Johnny5]

I have just completed some serious thinking on the matter and I believe I have arrived at a solution that is neither ' date=' SRT , nor Sagnac.

I will be posting shortiy. [/indent']

 

This is something I would like to see.

[swansont]

Swansont' date=' You are making the problem more complex than it deserves. When they discuss measuring speeds of lightr other than C, or "non-isotropically" they are not implying the light actually slows down or speeds up they are merely using the expressions c + v and C - v to determine the relative motion of frame and photons. The speed of klight is consgtant, at c, but light travels C - v faster tnaty v, or combines into a relative velocity c + V when frame and photon are moving in oppsote directions to each other.[/indent']

 

You use c+v or c-v in a non-inertial frame, but not an inertial one. You can measure whether or not you are in an inertial frame by whether the light appears to be moving at c relative to you.

[swansont]

I was wrong. Special relativity can handle accelerating reference frames[/url']. In special relativity velocities are relative but acceleration is treated as absolute. In general relativity all motion is relative.

 

You can measure the acceleration of an object using SR, because you can look at things from an inertial reference frame. But an observer in the accelerating frame, who attempts to apply SR, is going to get wrong answers from measurements.