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.