MacM's Closure to a Length Contraction Thread

[MacM]

It was requested that I establish a new thread and defend the concept of no spatial contraction.

I have previously posted logical alternatives and have pointed out that there is (has been) no supporting emperical data in the 100 years of relativity for the concept of spatial length contraction.

That LC is nothing more than a mathematical construct based on the prior assumption made in SR with respect to the non-existance of an absolute frame (note that "Absence of Evidence is not Evidence of Absence").

Since it is not possible to prove a negative it appears to me that in contrast to Rule #13, it becomes incumbant upon objectors to post data showing that length contraction has been demonstrated and my concept therefore is false.

Saying SR has been thoroughly tested and passed every test in no manner proves that which has not been observed nor tested since the test data collected is not to the exclusion of alternative explanations.

Beyond that I do not have further comment or arguement on the subject.

[Nereid]

There seems to me to be a number of different ideas in this post; would you please clarify the following?

assumption made in SR with respect to the non-existance of an absolute frame

To what extent are you claiming that:

• 1) There is an absolute frame?
• 2) No tests have been done concerning the existance of such a frame?
• 3) The existance of such a frame is testable?
• 4) There is an alternative to SR, consistent with the relevant experimental and observational results?

[Ken G]

Originally Posted by MacM

Saying SR has been thoroughly tested and passed every test in no manner proves that which has not been observed nor tested since the test data collected is not to the exclusion of alternative explanations.

It sounds to me like you are confusing a prediction, which is what theories are responsible for, with an explanation, which is what pedagogies are responsible for. As you have no objection to the predictions of special relativity, you obviously are objecting to the pedagogy that involves saying that moving things contract. But this is a common problem in relativity, that the words you choose to explain what is happening rely inextricably on the approach you take to quantifying what is happening-- in other words, they depend on your choice of coordinate system. The way I like to think of this is, reality actually contains less information than the coordinatization that we use to quantify it would tend to lead us to think. All reality really includes are things that are invariant to the coordinate system, i.e., the results of experiments. This is the difference between a theory and a pedagogy-- the theory itself only includes the invariant elements, but the pedagogy also brings in arbitrary elements that are convenient for the application of the theory. As an example, on another thread it was debated if the Earth has to be rotating, or if it may be viewed as standing still, while the rest of the universe is in rotation. But the answer is, Earth rotation is a pedagogy, not a theory. So it sounds to me like you have a legitimate beef if people are taking the conventional pedagogy of special relativity too seriously (and attributing unique reality to it), whereas only the predicted results of experiments has claim to such a serious interpretation. On the other hand, if you accept that length contraction is part of the conventional pedagogy, and is useful for arriving at predicted results of experiments (so the prediction is unique even though the pedagogy is not), then you see there really is no problem with the theory of special relativity after all.

[MacM]

Originally Posted by Nereid

There seems to me to be a number of different ideas in this post; would you please clarify the following?To what extent are you claiming that:

1) There is an absolute frame?

I certainly would not say I can prove it but I do think it is indicated in some way by current data.

2) No tests have been done concerning the existance of such a frame?

Here is where the "You cannot prove a negative" comes in. What possibly could be posted which proves no test had ever been done. I feel therefore it becomes incumbant on those that disagree to post proof of such a test to falsify my claim.

3) The existance of such a frame is testable?

I think it might well be possible to find tests that have been done and analyize the data to see if the motion to the CMB is reflected in it (if the tests are sufficiently documented to be able to verify test cnditions and timing (orientation to the motion to the CMB.

If not then I believe a linear accelerator could indeed be scheduled to look specifically for such correlation.

BTW: The maximum deviation in data for such an affect would be 1/2,000,000 (5E-7).

4) There is an alternative to SR, consistent with the relevant experimental and observational results?

I believe so but it requires indepth consideration to see if it violates any observation or emperical findings.

If you accept that the trip time of the moving observer is fully accounted for by the dilated tick rate of his clock then it becomes apparent that no length contraction has occured.

What is being done is to take the view of the observer and his proper time as being equivelent t' = t such that mathematically you now have TWO choices.

1 - Conventional SR where spatial distance contracts. But that generates some rather uncomfortable if not impossible physical realities.

2 - The alternative is that the common sense idea that relative velocity means +v and -v are equal is in error. Here you have two factors.

a - In a universal sense +v = -v. Where "v" as a numerical value is not considered but only the universal distance covered in a universal elapsed period.

b - v is frame dependant as a mathematical conclusion of the ratios of the physical realities in that frame.

In the rest frame that is v = d / t

In the moving frame it is v' = d / t'

This does generate higher velocity calculations in the moving frame but that makes sense keeping in mind that the clock being used to time the trip is ticking more slowly.

The fact that it results in superluminal velocites has no actual impact on its validity in that SR causes superluminal velocites as well by contraction of many light years of space in relatively short time periods of time as one approaches v = c.

In the case of SR these superluminal velocites are shielded from observation by the creation of event horizons to the moving observer. That might also apply to the alternative view but the realitiy of that I think must wait for actual experiment to determine.

[MacM]

Originally Posted by Ken G

It sounds to me like you are confusing a prediction, which is what theories are responsible for, with an explanation, which is what pedagogies are responsible for. As you have no objection to the predictions of special relativity, you obviously are objecting to the pedagogy that involves saying that moving things contract..........

........, then you see there really is no problem with the theory of special relativity after all.

While I agree with most of your post I take exception to parts.

I would not agree that it is a matter of confusion about prediction and explanation.

I disagree with the predictions including reciprocity. I don't object to any of the predictons which have been tested and emperically confirmed.

But reciprocity of these functions and length contraction have not been tested and there is no direct evidence for their support. It appears there exists a more logical cause for the data than the concept of relative velocity with its reciprocity and creation mathematically of spatial length contraction.

[Ken G]

I see that you are indeed claiming that SR will be in error when compared with experimental results, I did not realize that you were making that claim. There is a wealth of observational data to the contrary of your claim. Take reciprocity-- experiments have been done with two observers in different frames, and sure enough their results are entirely understandable within the context of having the same concept of their relative velocity. Super accurate clocks on GPS satellites, compared to similar clocks on the ground, are an example of this. If there were a problem at the accuracy level you quote (5e-7), we would know this. Indeed, down to 1e-11 or better relativity works quite well (generalizing SR to include gravity). I'm really not clear on why, if we have v=d/t and v'=d'/t', that you wish to claim d=d' when that does not hold for either t or v. What do you think is so special about d, anyway?

[MacM]

Originally Posted by Ken G

I see that you are indeed claiming that SR will be in error when compared with experimental results, I did not realize that you were making that claim. There is a wealth of observational data to the contrary of your claim. Take reciprocity-- experiments have been done with two observers in different frames, and sure enough their results are entirely understandable within the context of having the same concept of their relative velocity.

Please post ONE such example.

Super accurate clocks on GPS satellites, compared to similar clocks on the ground, are an example of this. If there were a problem at the accuracy level you quote (5e-7), we would know this. Indeed, down to 1e-11 or better relativity works quite well (generalizing SR to include gravity).

The 5E-7 deviation would be detectable if done specifically to find it. GPS is hardly an example of how to find it in that GPS moves in a generally circular orbit and hence any absolute motion becomes +v + (-v) and nulls out of the accumulative data.

Not sure your understanding of GPS is accurate. The orbiting clock is prelaunch calibrated to a net decrease in tick rate by 38us/day. GR affects cause an increase of 45us/day while the orbit velocity affect would cause a 7.2us/day loss.

More importantly the orbit clock does not find the surface clock as ticking slower due to relative vleocity. Also, did the H&K pilots find their expectations (according to SR) that the surface clocks had accumulated less time than their airborne clocks?

FYI: GPS uses absolute motion of orbit by using the ECI frame (Earth Centered Inertial) as a referance. Further relative velocity gamma calculation of a clock at the equator vs the orbiting GPS results in -5.8us/day, not the emperically dervied -7.2us/day figure.

GPS is only correct because it does not use SR but uses absolute velocity of orbit to a preferred common rest frame the ECI.

I'm really not clear on why, if we have v=d/t and v'=d'/t', that you wish to claim d=d' when that does not hold for either t or v. What do you think is so special about d, anyway?

It is not a matter of d being special. One would have thought "t" was special but data shows that is not the case. The point is taking an unbiased assessment of data and understanding there is no basis to conclude spatial contraction is real but in fact that it is more rational to believe that the moving frame will calculate a different velocity.

Have you actually taken a deep breath and a few seconds to consider the fact that the trip time is fully accounted for by the dilated tick rate of the clock being used to time the trip and therefore there is no physical room mathematically for contraction to have occured?

No, contraction, is clearly a mere mathematical construct based on equivelance of proper times between frames where such times are not universally equal. (That has been demonstrated by emperical data of moving clocks). It is an assumption based on the moving observer concluding mathematically d = vt' and not d = v't'.

One must look beyond this option and see what the consequences are. The consequences of the SR view are difficult to accept as reality.

[clj4]

The consequences of the SR view are difficult to accept as reality.

Well, this pretty much sums up your arguments. There is a large class of people that reject relativity because it is counter their intuition. A lot of science is counterintuitive and still correct.

[Nereid]

Originally Posted by MacM

I certainly would not say I can prove it but I do think it is indicated in some way by current data.

In another thread you posted a link to a paper in Apeiron, concerning interpretations of atmospheric muon decays.

Anything else?

Here is where the "You cannot prove a negative" comes in. What possibly could be posted which proves no test had ever been done. I feel therefore it becomes incumbant on those that disagree to post proof of such a test to falsify my claim.

It's easy enough to turn into a series of positives. For example, what constraints do each of the >~100 experiments and sets of observations referenced here and >~200 here* put on the existence of such an absolute frame?

For example

• the Eöt-Wash and LURE tests of the Weak Equivalence Principle
• the NIST, U. Washington, and Harvard tests of Local Lorentz Invariance
• the "null" redshift test of local position invariance
• Hipparcos tests of the deflection of light; Voyager, Cassini, etc tests of the Shapiro time delay
• the many tests done with the Hulse-Taylor pulsar, and now the double pulsar
• Gravity ProbeB

It may be that you need to specify, at least at OOM level, what absolute frame you expect to find, before you can assess the extent to which any of these >~300 experiments constrains your idea.

Do you now have enough in the way of positives to work on (so that you can answer my question)?

I think it might well be possible to find tests that have been done and analyize the data to see if the motion to the CMB is reflected in it (if the tests are sufficiently documented to be able to verify test cnditions and timing (orientation to the motion to the CMB.

But doesn't this assume that the absolute frame is at rest wrt the CMB? Why, a priori, should you assume that?

If not then I believe a linear accelerator could indeed be scheduled to look specifically for such correlation.

BTW: The maximum deviation in data for such an affect would be 1/2,000,000 (5E-7).

Why?

What was the sensitivity of the muon result in Apeiron?

I believe so but it requires indepth consideration to see if it violates any observation or emperical findings.

If you accept that the trip time of the moving observer is fully accounted for by the dilated tick rate of his clock then it becomes apparent that no length contraction has occured.

What is being done is to take the view of the observer and his proper time as being equivelent t' = t such that mathematically you now have TWO choices.

1 - Conventional SR where spatial distance contracts. But that generates some rather uncomfortable if not impossible physical realities.

2 - The alternative is that the common sense idea that relative velocity means +v and -v are equal is in error. Here you have two factors.

a - In a universal sense +v = -v. Where "v" as a numerical value is not considered but only the universal distance covered in a universal elapsed period.

b - v is frame dependant as a mathematical conclusion of the ratios of the physical realities in that frame.

In the rest frame that is v = d / t

In the moving frame it is v' = d / t'

This does generate higher velocity calculations in the moving frame but that makes sense keeping in mind that the clock being used to time the trip is ticking more slowly.

The fact that it results in superluminal velocites has no actual impact on its validity in that SR causes superluminal velocites as well by contraction of many light years of space in relatively short time periods of time as one approaches v = c.

In the case of SR these superluminal velocites are shielded from observation by the creation of event horizons to the moving observer. That might also apply to the alternative view but the realitiy of that I think must wait for actual experiment to determine.

And what experiments could one perform - in principle - that would determine this?

I see that clj4 beat me to it wrt "rather uncomfortable if not impossible physical realities"; surely what matters isn't how uncomfortable or impossible a theory seems to us, wrt any 'physical reality'? Isn't is principally a question of how well predictions from the theory match the good experimental and observational results?

*I note that one of the muon experiments referenced in this paper reports (my bold): "The sidereal variation of this transition frequency is then tracked yielding a limit on b_J of |b_J|<5x10^-22m_mu". This may have nothing whatsoever to do with absolute frames, or it may also be strongly inconsistent with the Earth moving through one.

[Nereid]

Originally Posted by MacM

[snip]

One must look beyond this option and see what the consequences are. The consequences of the SR view are difficult to accept as reality.

The EPR paradox experiments seem to show that the universe is an exceedingly weird place, and create feelings of deep discomfort in many people (who take the time to think about it).

Nonetheless, there are no competing theories to account for the results, nor is there much room for conclusions other than that the 'paradox' was resolved pretty unambiguously in QM's favour.

Universe 1, Einstein et al. 0

Where are the alternative theories (to GR)? Where are the inconsistencies between SR or GR and experiment/observation (other than one atmospheric muon experiment reported in Apeiron)?

[MacM]

Originally Posted by clj4

Well, this pretty much sums up your arguments. There is a large class of people that reject relativity because it is counter their intuition. A lot of science is counterintuitive and still correct.

Counter intuitive is one thing physically impossible to justify is another. Particularily when such matters are not supported emperically.

[MacM]

Originally Posted by Nereid

Anything else?It's easy enough to turn into a series of positives. For example, what constraints do each of the >~100 experiments and sets of observations referenced here and >~200 here* put on the existence of such an absolute frame?

Appeals to authority are not rebuttals. One test can disprove a theory in spite of 1 million which support it. I have no intention of digging through hundreds of tests pointing out what they do not demonstrate.

For example

• the Eöt-Wash and LURE tests of the Weak Equivalence Principle
• the NIST, U. Washington, and Harvard tests of Local Lorentz Invariance
• the "null" redshift test of local position invariance
• Hipparcos tests of the deflection of light; Voyager, Cassini, etc tests of the Shapiro time delay
• the many tests done with the Hulse-Taylor pulsar, and now the double pulsar
• Gravity ProbeB

It may be that you need to specify, at least at OOM level, what absolute frame you expect to find, before you can assess the extent to which any of these >~300 experiments constrains your idea.

I am not going on wild goose chases. If you think any ONE of these tests are tests of reciprocity or length contraction then post it and explain precisely how it achieves that goal.

Do you now have enough in the way of positives to work on (so that you can answer my question)?

No. You have given NONE. You have merely listed a bunch of tests none of which were for the purpose or can be construed to support reciprocity or length contraction.

But doesn't this assume that the absolute frame is at rest wrt the CMB? Why, a priori, should you assume that?Why?

You really shouldn't assume anything. That is what got you in trouble at the outset. No the CMB may not be at rest, it is infact a dynamic place, but our solar system has an anisotropy to it showing we have motion relative to it and it is generally thought to be throughout the universe. I could not think of a better canidate to at least start to look at the absolute frame concept.

But certainly as long as you refuse to look you will not find it or any data to suport it.

What was the sensitivity of the muon result in Apeiron?And what experiments could one perform - in principle - that would determine this?

Not sure of the sensitivity but I will research it and see if I can get an answer to that.

I see that clj4 beat me to it wrt "rather uncomfortable if not impossible physical realities"; surely what matters isn't how uncomfortable or impossible a theory seems to us, wrt any 'physical reality'? Isn't is principally a question of how well predictions from the theory match the good experimental and observational results?

Correct and I am still awaiting any data to show the prediction regarding reciprocity or length contraction.

*I note that one of the muon experiments referenced in this paper reports (my bold): "The sidereal variation of this transition frequency is then tracked yielding a limit on b_J of |b_J|<5x10^-22m_mu". This may have nothing whatsoever to do with absolute frames, or it may also be strongly inconsistent with the Earth moving through one.

Nothing but disclaimers to preclude being labled adversly. They clearly speak of an absolute velocity vs relative velocity to earth. Closing with "May nots" for CYA purposes does not alter the signifigance of their findings.

[clj4]

Ah, now I see your problem : you think that there is such a thing as reciprocal length contraction and you demand an experiment that proves it.
OK, this is one of the weaker of the two "paradoxes", is the poor cousin of Dingle's paradox. Anyway, reciprocal length contraction does not exist. It is provable in about 1 page of formulas.
Suffice to say that SR DOES NOT CLAIM that reciprocal length contraction exists, quite the contrary, it refutes such a notion. Neither does "mutual time dilation" exist (2 pages of calculations). Happy now?

[Nereid]

Originally Posted by MacM

Appeals to authority are not rebuttals. One test can disprove a theory in spite of 1 million which support it. I have no intention of digging through hundreds of tests pointing out what they do not demonstrate.

It seems that I have not been sufficiently clear.

Let me try again.

GR has been subject to a large number of tests, both experimental and observational.

It has passed all such test to date, with flying colours. (The only apparent exception that I know of is the muon thing which you referenced in another thread).

You are claiming that no test to date (other than, perhaps, the muon one) has examined some 'absolute frame' idea which you have.

I - and others - have asked you about the ways in which this idea of yours might be tested, in principle.

So far, you have not answered how such an idea might be tested, in principle.

I have no idea whether any - or all - the hundreds of tests of GR done to date would show inconsistency with your idea of an 'absolute frame' or not.

One key reason I have no such idea is that - it seems to me - your idea produces no (quantitative) predictions.

If there are no such predictions, it cannot be tested, even in principle.

I am not going on wild goose chases. If you think any ONE of these tests are tests of reciprocity or length contraction then post it and explain precisely how it achieves that goal.

OK, let's start with any one of these hundreds of experiments (you choose).

We'll find the relevant papers which detail the methods and results, and you can supply us with predictions - from your idea of an 'absolute frame' - of what the experimental results would be (or rather, would have been). We can then see the extent to which that test was (or was not) inconsistent with your idea. OK?

No. You have given NONE. You have merely listed a bunch of tests none of which were for the purpose or can be construed to support reciprocity or length contraction.

Well, who can tell? Without your quantitative predictions ...

You really shouldn't assume anything. That is what got you in trouble at the outset. No the CMB may not be at rest, it is infact a dynamic place, but our solar system has an anisotropy to it showing we have motion relative to it and it is generally thought to be throughout the universe. I could not think of a better canidate to at least start to look at the absolute frame concept.

Without any indication of what sort of motion any piece of test equipment, or spot on the Earth, has (wrt any 'absolute frame'), how can you analyse any data from any experiment or observation (to determine whether there is any 'motion wrt the absolute frame' or not)?

But certainly as long as you refuse to look you will not find it or any data to suport it.

Not sure of the sensitivity but I will research it and see if I can get an answer to that.

Correct and I am still awaiting any data to show the prediction regarding reciprocity or length contraction.

In respect of what?

SR's predictions re "length contraction" are clear (aren't they?), and they are beyond our ability to test, today (aren't they?).

"reciprocity" seems to be an idea no one else who has posted to these threads seems to understand (except to the extent that it's a non-issue - there are no inconsistencies). Perhaps you could have another go at stating, more clearly, what the observable effects of this "reciprocity" would be?

Nothing but disclaimers to preclude being labled adversly. They clearly speak of an absolute velocity vs relative velocity to earth. Closing with "May nots" for CYA purposes does not alter the signifigance of their findings.

I suggest that the onus is on the claimants - in this case, anyone making a claim about an 'absolute frame' or 'reciprocity' - to show that these claims are consistent with all good, pertinent experimental and observational results.

A good place to start would be a clear, quantitative prediction of the results of an experiment or observation that we could, in principle, carry out today, with the technology we have (today).

[MacM]

Originally Posted by clj4

Ah, now I see your problem : you think that there is such a thing as reciprocal length contraction and you demand an experiment that proves it.
OK, this is one of the weaker of the two "paradoxes", is the poor cousin of Dingle's paradox. Anyway, reciprocal length contraction does not exist. It is provable in about 1 page of formulas.
Suffice to say that SR DOES NOT CLAIM that reciprocal length contraction exists, quite the contrary, it refutes such a notion. Neither does "mutual time dilation" exist (2 pages of calculations). Happy now?

Not entirely correct. I wasn't thinking of reciprocity of length contraction but reciprocity of time dilation. Now time dilation has been demonstrated. At least as far as clock dilation might go. It remains to be seen if clock dilation is actually time dilation.

With respect to length contraction I see no evidence that it exists at all much less with reciprocity.

I find it amazing how many people respond with issues which are not germain and ignore the simple fact which I continue to repeat.

"The trip time of the moving clock is FULLY accounted for by the dilated tick rate of the clock and based on the same distance".

There can be no physical distance change. If distance and time both changed then the affect becomes compounded and you wouldn't get answers that correspond with observaton.

Spatial contraction is a mere mathematical construct based on ignoring the dilated tick rate of the clock used to time the trip. That is you are using an altered measurement standard and ignoring the standard change by setting t' = t.

We know physically that is not true. It is really no different than claiming the football game took two hours instead of one because you are watching it in slow motion.

[Nereid]

There seems to be one question not yet answered:

Originally Posted by Nereid

Why?

Perhaps this question isn't clear.

Let me try again.

How is this 'maximum deviation' value of ~0.5 ppm determined? What assumptions were made in that determination?

[clj4]

Not entirely correct. I wasn't thinking of reciprocity of length contraction but reciprocity of time dilation. Now time dilation has been demonstrated. At least as far as clock dilation might go. It remains to be seen if clock dilation is actually time dilation.

LOOK AT POST 13, RECIPROCAL TIME DILATION DOES NOT EXIST.

[MacM]

Originally Posted by Nereid

It seems that I have not been sufficiently clear.

Let me try again.

GR has been subject to a large number of tests, both experimental and observational.

It has passed all such test to date, with flying colours. (The only apparent exception that I know of is the muon thing which you referenced in another thread).

Not sure how we are jumping from SR to GR here but I'll let that be for now.

You are claiming that no test to date (other than, perhaps, the muon one) has examined some 'absolute frame' idea which you have.

I - and others - have asked you about the ways in which this idea of yours might be tested, in principle.

So far, you have not answered how such an idea might be tested, in principle.

1 - I would not say that I have some idea about an absolute frame. I do have a strong intuition that it is more suitable (fits data) better than SR's relative veloicty with reciprocity.

It would seem to me that if one begins to look at test data which can be taken in brief periods to limit vector change due to earth's rotation, orbit, etc or experiments that could be articulated so as to maintain a cosmic vector, could determine if there is an underlying anisotropy.

Keep in mind this would be a small change in data due to any absolute motion and would have a signal to noise ratio of several million to one.

Accelerated particles in a linear accelerator decay times might be one possible test. The applied energy, vector, etc would have to be meticulously recorded to see any motion to the CMB (or any other anisotropy.

I have no idea whether any - or all - the hundreds of tests of GR done to date would show inconsistency with your idea of an 'absolute frame' or not.

One key reason I have no such idea is that - it seems to me - your idea produces no (quantitative) predictions.

Of course it does. It would predict that you should find equivlent deviation in SR data based on orientation during the test. The magnitude of such deviation would be less than 5E-7 of the primary signal.

For example. Given a particle that is accelerated to 0.999c in the local frame. If you now consider that the solar motion to the CMB is 0.001c then by velocity addition the motion would be 0.999002c, not c.

The differance between 0.999c and 0.999002c is gamma=22.36627204 and 22.38868 or 0.1% but that is only when orientation is at its maximum the affect would exist between 0.00% and this maximum.

We'll find the relevant papers which detail the methods and results, and you can supply us with predictions - from your idea of an 'absolute frame' - of what the experimental results would be (or rather, would have been). We can then see the extent to which that test was (or was not) inconsistent with your idea. OK?

I sincerely doubt you will have information about any test which can determine orientation during the test and for which the same test can be replicated but at some different orientation.

If so then it would be interesting to see such data but I don't think it exists.

Well, who can tell? Without your quantitative predictions ...Without any indication of what sort of motion any piece of test equipment, or spot on the Earth, has (wrt any 'absolute frame'), how can you analyse any data from any experiment or observation (to determine whether there is any 'motion wrt the absolute frame' or not)?In respect of what?

Precisely. that is why specific testing must be done to insure orientation to the measured ansitropy is recorded and compared to the same test at different orientations.

SR's predictions re "length contraction" are clear (aren't they?), and they are beyond our ability to test, today (aren't they?).

Yes and if unfalisifiable then the theory does not meet the standard to be called theory. It is a hypotheses.

"reciprocity" seems to be an idea no one else who has posted to these threads seems to understand (except to the extent that it's a non-issue - there are no inconsistencies). Perhaps you could have another go at stating, more clearly, what the observable effects of this "reciprocity" would be?I suggest that the onus is on the claimants - in this case, anyone making a claim about an 'absolute frame' or 'reciprocity' - to show that these claims are consistent with all good, pertinent experimental and observational results.

A good place to start would be a clear, quantitative prediction of the results of an experiment or observation that we could, in principle, carry out today, with the technology we have (today).

Reciprocity is inherent in the equivelence of inertial frames. That is the idea that since you cannot tell (ignoring modern day capacity to actually measure such motion to the CMB) which is moving, any relative velocity is considered to be in the other frame and your frame is at rest.

That is clock "A" is at rest and clock "B" has a relative ve4loicty of 0.866c such that gamma=2 and "B" ticks at only one tick per two ticks of "A".

But then according to the equivelence of inertial frames principle "B" is at rest and it is "A" that has all motion and hence "A" must be ticking at the rate of one tick per two ticks of "B".

As a matter of perception due to some illusion of motion this can "Appear" to be the case but that I contend is not time dilation. This is na observatinal issue and has nothing to do with the tick rate of the clock and time it is accumulating. True time dilation is only that which is demonstrated by an accumulation of different amounts of time on each clock when subsequently compared in the same frame.

[MacM]

Originally Posted by Nereid

There seems to be one question not yet answered:Perhaps this question isn't clear.

Let me try again.

How is this 'maximum deviation' value of ~0.5 ppm determined? What assumptions were made in that determination?

That value was merely considering that the absolute motion measured to the CMB by different methods over several years has varied from 280km/sec to around 360km/sec. I used 300km/sec as a general number wich is 0.001c gamma for that is 1.0000005.

But it is important to note that the absolute motion will have a greater impact on tests if the test is pushed a near as possible to a v = c. That should be clear now from my prior post where 0999c particles would have a 0.001 deviation due to the added motion to the CMB when orientation is changed.

[MacM]

Originally Posted by clj4

LOOK AT POST 13, RECIPROCAL TIME DILATION DOES NOT EXIST.

OK. I missed that. I saw your comment regarding no length contraction reciprocity.

Now it is my turn to reverse roles. If you assert reciprocity doesn't exist that runs counter to the generally accepted equivelence of frames as advocated by SR.

How do YOU assertain which frame will suffer time dilation or contraction?

The rule is the "A" frame is at rest and "B" is in motion AND "B" is at rest and "A" is in motion.

[clj4]

Originally Posted by MacM

OK. I missed that. I saw your comment regarding no length contraction reciprocity.

Now it is my turn to reverse roles. If you assert reciprocity doesn't exist that runs counter to the generally accepted equivelence of frames as advocated by SR.

How do YOU assertain which frame will suffer time dilation or contraction?

The rule is the "A" frame is at rest and "B" is in motion AND "B" is at rest and "A" is in motion.

Look here, have fun:

http://www.mathpages.com/home/kmath024/kmath024.htm

Your question is 50 years old, has been solved many times . The link has a nice story.

[MacM]

Originally Posted by clj4

Look here, have fun:

http://www.mathpages.com/home/kmath024/kmath024.htm

Your question is 50 years old, has been solved many times . The link has a nice story.

Stories are nice but I really hope you can do better than post Dingle and talk about inverted partial derivitives.

To get back to the issue of inherent reciprocity in Special Relativity you might try reading here:

******************* Extract ************************
http://www.mathpages.com/home/kmath307/kmath307.htm

This principle is usually extended to include reciprocity, meaning that for any two systems S1 and S2 of inertial coordinates, if the spatial origin of S1 has velocity v with respect to S2, then the spatial origin of S2 has velocity -v with respect to S1. The existence of this class of reference frames, and the viability of the principles of relativity and reciprocity, are inferred from experience. Once these principles have been established, the relationship between relatively moving inertial coordinate systems can then be considered.
************************************************** ***

I'll merely note that yo have not answered the question of how YOU have determined which frame will undergo time dilation or length contraction. Are you going to do that or are you going to continue to ignore the question?

[clj4]

YOU have determined which frame will undergo time dilation or length contraction. Are you going to do that or are you going to continue to ignore the question?

read the story on Dingle...

[MacM]

Originally Posted by clj4

read the story on Dingle...

I have now read this:

http://home.netcom.com/~heensle/phys/twins.html

You would also do well to read this:

http://arxiv.org/PS_cache/physics/pdf/0512/0512196.pdf

[MacM]

clj4,

You and I agree "There is no reciprocity". However, we do so for different reasons. Mine is that I hold a view where length contraction does not occur and it is against the SR relative velocity view.

You purport to support SR yet claim no recirocity. Since reciprocity is inherent in SR and it is openly stated in books and turorials on SR, I have asked you several times now to support your assertion.

I repeat once more:

"Given clocks "A" and "B" which have a relative velocity between them how do YOU determine WHICH will experience time dilation and length contraction?"

Will you be answering anytime soon? I don't mean by posting a link to discuss Dingle's mathematical errors but by stating in detail YOUR method of determining which "A" or "B" will be affected.

We are waiting.

[clj4]

Originally Posted by MacM

clj4,

You and I agree "There is no reciprocity". However, we do so for different reasons. Mine is that I hold a view where length contraction does not occur and it is against the SR relative velocity view.

You purport to support SR yet claim no recirocity. Since reciprocity is inherent in SR and it is openly stated in books and turorials on SR, I have asked you several times now to support your assertion.

I repeat once more:

"Given clocks "A" and "B" which have a relative velocity between them how do YOU determine WHICH will experience time dilation and length contraction?"

Will you be answering anytime soon? I don't mean by posting a link to discuss Dingle's mathematical errors but by stating in detail YOUR method of determining which "A" or "B" will be affected.

We are waiting.

You mean, YOU are waiting. Everyone else knows the answer.
Read this one, especially the last sentence (there is no paradox)

http://sheol.org/throopw/dingle-paradox01.html

[MacM]

Originally Posted by clj4

You mean, YOU are waiting. Everyone else knows the answer.
Read this one, especially the last sentence (there is no paradox)

http://sheol.org/throopw/dingle-paradox01.html

OK. I've read it :

"Each clock "slower" than the other. One slower when compared at E1. The other one slower when compared at E2.

In short, "each clock slower than the other" is a misleadingly ambiguous way of stating a precisely defined relationship between clocks and coordinates. The dingle so-called-paradox simply does not show prefered-frame theories any more consistent than special relativity. "

It does not state there is no reciprocity, nor is it YOUR method of determining if it is "A" or "B" that will experience time dilation or length contraction.

If you are unable to answer the question then please simply say so and lets move on.

To re-emphasize I am refering only to time dilation as will be evidenced by comparison of clocks in a common frame since it would be the only true change in time. Not some illusion of motion.

[Tensor]

Originally Posted by MacM

"Given clocks "A" and "B" which have a relative velocity between them how do YOU determine WHICH will experience time dilation and length contraction?"

With what you've stated as a given-only two clocks-you can't. They are both entitled to claim the other experience's time dilation and length contraction. They will never meet again, given inertial motion only, and so can't determine which clock was moving slow or who was contracted. The reason cjl4 posted that story, is that what you are asking is simply a version of the twin paradox.

Now, you can postulate a third observer (such as the word YOU) in the given, but then YOU will have relative motion between the others and you will see both of the others contracted/dilated by different amounts, depending on their motion.

What you have done is to set up the YOU observer as some sort of absolute frame observer, and that is outside the scope of SR. SR doesn't admit to ANY absolute frame.

[MacM]

Originally Posted by Tensor

With what you've stated as a given-only two clocks-you can't. They are both entitled to claim the other experience's time dilation and length contraction. They will never meet again, given inertial motion only, and so can't determine which clock was moving slow or who was contracted. The reason cjl4 posted that story, is that what you are asking is simply a version of the twin paradox.

Now, you can postulate a third observer (such as the word YOU) in the given, but then YOU will have relative motion between the others and you will see both of the others contracted/dilated by different amounts, depending on their motion.

What you have done is to set up the YOU observer as some sort of absolute frame observer, and that is outside the scope of SR. SR doesn't admit to ANY absolute frame.

I have seen this arguement before but it simply is not true. The affects of relativity are calcuable and flight schedules can be planned such that both observers record time ONLY during inertial periods of the flight.

Simultaneity is not a protector of SR either in that to be "Relative Velocity" the conditions MUST be simultaneous.

I'll post a scenario demonstrating this failure.

To do that efficiently I think we should agree step by step and not rely on misunderstanding due to a complex scenario one time posting.

To start this process do you agree that discussing time dilation vs length contraction is a matter of conveince and clarity and not an actual change in topic since they are complimentary affects of SR and that where we have methods and emperical data for time dilation there is none known for length contraction.

Question: Are you willing to proceed with this discussion on length contraction using time dilation as a surrogate enity since it is easier to substantiate and they are complementary affects such that failure of one represents failure of the other.?

[Nereid]

Originally Posted by MacM

That value was merely considering that the absolute motion measured to the CMB by different methods over several years has varied from 280km/sec to around 360km/sec. I used 300km/sec as a general number wich is 0.001c gamma for that is 1.0000005.

But it is important to note that the absolute motion will have a greater impact on tests if the test is pushed a near as possible to a v = c. That should be clear now from my prior post where 0999c particles would have a 0.001 deviation due to the added motion to the CMB when orientation is changed.

Thanks.

But didn't you, in an earlier post^, caution us against making ad hoc, a priori assumptions? In this case, why assume that the motion of earthly labs is ~300 km/s? Couldn't it just as well be ~300 nm/s? or ~0.99999c?

Once you put some kind of number on the table (even if it's only an OOM, for back-of-the-envelope purposes), it becomes a whole lot easier to look at (historical) experiments and observations, for 'motion wrt an absolute frame' signals, n'est pas?

So how about this simplifying assumption: whatever the 'absolute frame' is, there will be a ~24 hour* periodic signal in any test data taken anywhere on the Earth's surface (except, perhaps, at the poles)? If you're OK with that, then all (!) we would need to do is do a Fourier transform on any dataset**, and look for a signal at ~24 hours (plus harmonics), right?

One advantage of this approach is that it is 'blind' to details of the 'absolute frame' - any ~24 hour (nearly) periodic signal would hint at such a frame, right?

^"You really shouldn't assume anything. That is what got you in trouble at the outset. No the CMB may not be at rest"
*It might, of course, be a ~12 hour signal, if it picked up only the amplitude.
**or equivalent; I'm not saying any one analytic technique is better than any other, just giving an example