MacM's Closure to a Length Contraction Thread

[Ken G]

Originally Posted by MacM

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

The second is quite an interesting link, because it demonstrates the importance of the scheme used to synchronize clocks. That is kind of the "invisible" element of SR that people rarely make mention to, but it is crucial. The first link is a perfect example of this: it is the kind of garbage you come up with if you fail to recognize the significance of appropriate clock synchronizations.

[MacM]

Originally Posted by Nereid

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?

No. Not a valid point. There have been over a hlf dozen different tests which measured the absolute motion to the CMB over more than a decade of time. The values ranged from 200+km/sec to 600km/sec. However most were in the general range of 300-360km/sec. The average is around 300 km/sec.

Also there are other experiments (several) which have measured a East/West deviation in communications by wire signals which also vary in a dinural manner.

So this is not a case of one cosmic test but is based on numerous such results.

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

I am open to looking at any data which can be quantified both as to repeatability and to specific orientation at the time of the test. If the tests are of sufficient sensativity then they should be useful at looking for such absolute affect.

[MacM]

Originally Posted by Ken G

The second is quite an interesting link, because it demonstrates the importance of the scheme used to synchronize clocks. That is kind of the "invisible" element of SR that people rarely make mention to, but it is crucial. The first link is a perfect example of this: it is the kind of garbage you come up with if you fail to recognize the significance of appropriate clock synchronizations.

I wouldn't get to excited about these specific examples. If I am able to proceed with my scenario I believe you will see that such synchronization issues are irrelevant in the long term assessment.

[Nereid]

Originally Posted by MacM

No. Not a valid point. There have been over a hlf dozen different tests which measured the absolute motion to the CMB over more than a decade of time. The values ranged from 200+km/sec to 600km/sec. However most were in the general range of 300-360km/sec. The average is around 300 km/sec.

Well, the good news is that, as this forum has lots of 'astronomy nuts' on it, all the observed motions wrt 'the CMB frame' are well understood, and well constrained (if you'd like a summary, just holler).

The bad news, for your 'absolute frame' idea, is that I think you'll have an immensely difficult time showing that any observations can establish any 'absolute frame' similar to that of the CMB (unless, of course, you leave the realm of 'in principle, testably different predictions'; re-writing SR/GR in a way that includes an 'absolute frame', but cannot - even in principle - yield any exerimentally/observationally based test to distinguish it from SR/GR may well be possible, but then you're no longer doing science, IMHO).

But that's a path that, now, lies clearly before us (later).

Also there are other experiments (several) which have measured a East/West deviation in communications by wire signals which also vary in a dinural manner.

Such as? Please provide only the ones that you feel are the strongest.

So this is not a case of one cosmic test but is based on numerous such results.

I am open to looking at any data which can be quantified both as to repeatability and to specific orientation at the time of the test. If the tests are of sufficient sensativity then they should be useful at looking for such absolute affect.

Let's start with the Michelson-Morley experiments, and all its later variations, independent validations, etc, shall we?

What is your claim wrt these (i.e. that this set of classes of experiments are inconsistent with an 'absolute frame' more or less the same as the CMB)?

[Nereid]

Originally Posted by MacM

I wouldn't get to excited about these specific examples. If I am able to proceed with my scenario I believe you will see that such synchronization issues are irrelevant in the long term assessment.

I'm afraid I've lost much of my interest in your claims MacM, unless you can show - in as specific and detailed a way to answer my questions - that your idea leads to in principle observably different predictions from SR/GR.

I mean, creating a new set of theories which have exactly the same obserables as SR/GR may be an interesting intellectual exercise, but if there's nothing I can do with my lab equipment and telescopes to test whether it's a 'better' explanation of the universe than SR/GR, why should I bother? (this is, for avoidance of doubt, a rhetorical question).

[Nereid]

Originally Posted by MacM

[snip]

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

[snip]

I'm happy to discuss what constitutes science (and theories, and physics, etc), but not in this thread.

If you wish, I will start (yet another) thread in BAUT's General Science section on this topic.

In the meantime I merely note that your opinion differs significantly from my own, and that even Popper abandonded the 'naive falsificationism' view of what constitutes science, for reasons that include a very easy demonstration that such a view is easily falsified.

[MacM]

Originally Posted by Nereid

I'm afraid I've lost much of my interest in your claims MacM, unless you can show - in as specific and detailed a way to answer my questions - that your idea leads to in principle observably different predictions from SR/GR.

I mean, creating a new set of theories which have exactly the same obserables as SR/GR may be an interesting intellectual exercise, but if there's nothing I can do with my lab equipment and telescopes to test whether it's a 'better' explanation of the universe than SR/GR, why should I bother? (this is, for avoidance of doubt, a rhetorical question).

We seem to be getting a diversification here between where clj4, yourself and others are going.

I think (or at least I thought) I made the distinction between SR and my view rather clear. It should produce results nearly identical to current emperical data (the exception being this underlying minor deviation which would demonstrate the existance of absolute motion vs relative motion) as being correct physics.

The major differance, and I feel it is extremely important, is what it does not include and that is predictions of reciprocity of relavistic affects, spatial length contraction and v = c as a limit.

Eliminating those I think are signifigant differances worth exploring. How to do that seems to be where we are diversifying.

I am suggesting that one can come to some conclusions via the gendankin route. Having agreed on such results you then might find you have greater interest in researching existing data or performing specific new tests to confirm or falsify the view.

[Nereid]

Originally Posted by MacM

We seem to be getting a diversification here between where clj4, yourself and others are going.

I think (or at least I thought) I made the distinction between SR and my view rather clear. It should produce results nearly identical to current emperical data (the exception being this underlying minor deviation which would demonstrate the existance of absolute motion vs relative motion) as being correct physics.

The major differance, and I feel it is extremely important, is what it does not include and that is predictions of reciprocity of relavistic affects, spatial length contraction and v = c as a limit.

Eliminating those I think are signifigant differances worth exploring. How to do that seems to be where we are diversifying.

I am suggesting that one can come to some conclusions via the gendankin route. Having agreed on such results you then might find you have greater interest in researching existing data or performing specific new tests to confirm or falsify the view.

[moderator mode]
If you wish to continue with this gedanken route, then please make that very clear.

Please also make it clear that you are making no claims whatsoever about any experimental or observational support for a "CMB" (or similar) absolute frame (at least until your 'gedanken experiment' discussion has run its course).

If you'd like to do both, but want to keep them 'clean', then please start a separate thread on experimental/observational results which are (or are not) consistent with an 'absolute frame'.

Note that, under the ATM rules, if you make statements about experimental/observational results being consistent with an 'absolute frame' (or not - as you did in the OP), they can be challenged (and you will have to defend them); if you don't want these things to be part of your 'gedanken experiment', then make it clear they are outside the scope of your claims.
[moderator mode]

[MacM]

Originally Posted by Nereid

[moderator mode]
If you wish to continue with this gedanken route, then please make that very clear.

Please also make it clear that you are making no claims whatsoever about any experimental or observational support for a "CMB" (or similar) absolute frame (at least until your 'gedanken experiment' discussion has run its course).

If you'd like to do both, but want to keep them 'clean', then please start a separate thread on experimental/observational results which are (or are not) consistent with an 'absolute frame'.

Note that, under the ATM rules, if you make statements about experimental/observational results being consistent with an 'absolute frame' (or not - as you did in the OP), they can be challenged (and you will have to defend them); if you don't want these things to be part of your 'gedanken experiment', then make it clear they are outside the scope of your claims.
[moderator mode]

OK. Lets give it a try.

This is merely a gendankin to explore possible cracks in the shell that surrounds SR.

I take your response here to be a "Yes" as to the question posed above and will now ask the next question. These questions are establishing the foundation of agreement from which to evaluate the gendankin.

Since relavistic affects are formulated, they are calcuable.

Do you agree that if we assume SR valid we can apply its predictions in a useful manner to the gendankin so as to have synchronized control.?

(This is not meant to claim synchronizing of relativity of simulataniety but to render it moot)

[Ken G]

What do you mean by synchronized control? Also, can you summarize again the gedankin you mean, and the possible interpretations you are giving? Note that it is always possible to come up with equivalent interpretations that don't agree with the standard interpretation, and it is interesting to do so, but does not constitute a new theory.

[Grey]

Originally Posted by Nereid

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.

And as I pointed out in the first thread where this was mentioned, the error range in the data is rather too large to be able to observe the effects MacM and the authors of that paper are asserting. The authors acknowledge the large error range, too.

[MacM]

Originally Posted by Ken G

What do you mean by synchronized control? Also, can you summarize again the gedankin you mean, and the possible interpretations you are giving? Note that it is always possible to come up with equivalent interpretations that don't agree with the standard interpretation, and it is interesting to do so, but does not constitute a new theory.

The gendankin has not yet been described. I was trying to reach a concensus on what is agreed before posting it.

Sybnchronized in this context simply means that the affects can be accounted for and compensated for in the gendankin.

[MacM]

Originally Posted by Grey

And as I pointed out in the first thread where this was mentioned, the error range in the data is rather too large to be able to observe the effects MacM and the authors of that paper are asserting. The authors acknowledge the large error range, too.

Agreed. Nor would I claim it as a proof but only that it is extremely interesting and merits further consideration.

[MacM]

Since no specific objection has been raised to the question I'll move on to the last question before posting the gendankin.

Do you agree that the only time dilation which can be considered an actual change in time is that which becomes recorded by accumulation of time on a clock when compared in the same frame as the rest clock?

That is certain illusions of perception due to motion of the observer do not constitute actual change in time. To be a change in time then the twin must physically be younger when compared back together.

[Grey]

Why don't you just describe what you're actually imagining? Your question is a little strange. I'd still consider it time dilation if I measure a different clock moving at a different rate, but I'd certainly agree that it's a more dramatic result if I can bring two originally synchronized clocks back together and show that they are no longer synchronized. By the way, it's a "gedanken" experiment, from the German word for "thought".

[Disinfo Agent]

It's Gedankenexperiment in German, for pedants, and "thought experiment" in plain English.

[Ken G]

Originally Posted by MacM

Do you agree that the only time dilation which can be considered an actual change in time is that which becomes recorded by accumulation of time on a clock when compared in the same frame as the rest clock?

This one might cause problems, depending on what you mean by "in the same frame". I agree there is a big difference between what two clocks say when you compare them side by side, and what they appear to say when you look at them from different distances. But it is also important to recognize that the latter brings in two completely separate issues, the first is illusions due to time of flight effects, and the second is actual relativity, which is what you get after correcting for time of flight effects. So what I'm saying is, it is valid to observe the passing of time in a distant system, so long as you correct for the time of flight effects, but then you will still find time dilation as a leftover effect. We should not rule out this type of "observation", lest we rule out all of astronomy as a branch of physical observations.

[MacM]

Originally Posted by Grey

Why don't you just describe what you're actually imagining? Your question is a little strange. I'd still consider it time dilation if I measure a different clock moving at a different rate, but I'd certainly agree that it's a more dramatic result if I can bring two originally synchronized clocks back together and show that they are no longer synchronized. By the way, it's a "gedanken" experiment, from the German word for "thought".

Bear with me I started writting it last night but had to take one of our grandsons to the hospital for a shot due to high fever. I'll be working on it this week end.

[MacM]

Time Dilation (Spatial Length Contraction) Gendanken:

************************************************** ***
This gendanken is to test the assertions made by the relative velocity view of Special Relativity.

It takes place in deep space away from any large masses and involves only timing during inertial conditions such that GR affects can be ignored. (Hint do not regurgitate the "Twins" arguement).

The space station shall be labled "A". Two shuttle craft on board are labled "B" and "C". The scientist aboard are planning a mission to test SR and are aware of complexities of testing which would involve Relativity of Simultaneity and so they opt to lay out a flight schedule where only inertial relative velocity to the space station will be timed.

Acceleration/deceleration and simultaneity issues are circumvented making it possible to consider only the predictions regarding relative velocity and time dilation hence indirectly length contraction.

They decide to launch the shuttles in opposite directions simultaneously with equal acceleration for the same period of time according to a master clock in the space station, such that they each achieve a relative velocity of 0.866c to the station. That makes gamma = 2.000 and means each shuttle clock must tick at the rate of one tick for each two ticks of the master clock aboard the station.

The flight schedule is precalculated such that when mathematically the shuttles have reached their target velocity they begin to coast and become inertial and at that time the clocks aboard the shuttles and the space station all begin to record time. Both shuttles transmit a start information signal to the space station.

One can argue about this being simultaneous or not but it doesn't affect the conclusions of the test and can be ignored.

The point is all clocks are recording time at their proper rate while in an inertial (rest) state. The space station and each shuttle is equipped with several clocks.

The capital letter designates in which frame the clock is mounted, followed by "m" means it is the master clock ticking at the proper time rate for that frame. Followed by "a", "b" or "c" means it has been calibrated to reflect the time of the master clock of the frame designated by the small letter. Followed by a "p" means the time is what is predicted by relativity for observers of the frame designated by the capital letter or followed by a "c" means it is calibrated to tick in synch with clock Am for control purposes.

All of these calibrations can be made via precalculation of Special Relativity predictions.

Since the time dilation is precalculated based on the planned flight schedule it is known that (assuming Special Relativity is valid) the proper shuttle clocks, Bm and Cm, will be ticking at one half the rate of Am. Control monitoring clocks have been precalibrated and installed in each shuttle to run at two ticks per each tick of clocks Bm and Cm. They are labled Bac and Cac.

The space stations shuttle prediction monitoring clocks are labled Abp and Acp and are calibrated to tick at one half the rate of Am so as to allow the station operators to know what time has accumulated aboard the shuttles.

The monitors Bac and Cac allow the pilots of the shuttles to see and operate in accordance with the rate that time is passing back at the space station clock Am.

Due to Velocity Addition the relative velocity between "B" and "C" is 0.9897c and Gamma is 6.984 and their clocks each tick at the rate of only 143 ticks per 1,000 ticks of the other.

Respective prediction clocks have been precalibrated in B and C so as to accumulate time of the other as predicted by Special Relativity. That is the clocks will only record 143 ticks for each 1,000 ticks of the respective local proper time clocks Bm and Cm are labled Bcp and Cbp.

The flight schedule is set to be 10 hours inertial testing from the Am clock.

So that after 36,000 ticks (seconds) according to Am and according to Bac and Cac all clocks stop. Each shuttle transmits a stop information signal back to the space station.

Again the simultaneity of these actions can be argued but have no bearing on the issue at hand and can be ignored.

The results of this test are as follows:

Am = 36,000 Abp = 18,000 Acp = 18,000

Bac = 36,000 and stops all B clocks.
Cac = 36,000 and stops all C clocks.

Bm = 18,000 Cm = 18,000

Bap = 9,000 Cap = 9,000

Bcp = 2,574 Cbp = 2,574

Put into a more understandable configuration where predicted accumulated times of clocks A, B and C are more obvious:


Clock A
------------
Am = 36,000 Test master clock reading.
Bac = 36,000 Shuttle B test control clock.
Cac = 36,000 Shuttle C test control clock.
Bap = 9,000 Shuttle B's incorrect prediction of Am time.
Cap = 9,000 Shuttle C's incorrect prediction of Am time.

Clock B
-------------
Bm = 18,000 Shuttle B master proper time clock test reading.
Abp = 18,000 Station A's correct prediction for Bm test reading.
Cbp = 2,574 Shuttle C's incorrect prediction of Bm test reading.


Clock C
-------------
Cm = 18,000 Shuttle C master proper time clock test reading.
Acp = 18,000 Station A's correct prediction for Cm test reading.
Bcp = 2,574 Shuttle B's incorrect prediction of Cm test reading.


SUMMARY:

Before others point this out let me acknowledge that you are going to be inclined to claim that this test is not testing the affect of motion on clocks in that I am controlling the clocks with precalibrated timers so as to stop at preselected accumulated times per Special Relativity predictions.

But don't throw up your hands yet. There is some interesting things that can infact be demonstrated here.

1 - Accumulated times based on tick rates predicted by Special Relativity due to only relative motion do not agree with times actually accumulated in the test.

2 - The assumption that Special Relativity is valid results in evidence which shows that the theory requires physical clocks to accumulate time at multiple rates so as to satisfy predictions of multiple observers having different relative velocities. A physical impossibility.

3 - The fact that these times are based on actual affects of motion is verfiable in that the start/stop information signals sent from the shuttles can be used to determine that infact the test period was 36,000 seconds according to the master clock Am.

That is all data is based on the same universal time period to a common standard. In that regard the issue of simultaneity which is generally used to mask such comparisons is rendered moot.

In this manner IF the affect of motion were not as per SR then the clock readings would still be the same BUT start/stop signals differentail duration from the shuttles would not be 36,000 seconds according to the master control clock Am.

4 - Special Relativity requires that clocks B and C both tick at a rate of 0.5 / 1 to the space station clock. That is B and C are ticking at a common rate inspite of the fact that they have a relative velocity to each other which also requires them to tick at rates of about 1 tick to 7 ticks of the other. Impossible reciprocity and impossible ticking conditions for all views.

Note Added: lables for test results in red. It should be noted that it is reciprocity predictions which fail, not the primary gamma calculations.

[Ken G]

The conundrum is all based on the simultaneity of the stop signals. All the number of clicks are as reported, as near as I can tell (there are a lot of clocks here!), but that doesn't mean the B and C clocks will stop at the same time for B. In fact, the B clock, which is going 7 times faster, stops long before the C clock does (from B's point of view of course-- C would say exactly the opposite). That's how it is able to have the same number of ticks. I don't see the problem, the resolution is in the length contraction of the distance that C's stop signal must propagate from B's point of view-- it's a very small distance, so C must send it's "stop" signal long after B.

[MacM]

Originally Posted by Ken G

The conundrum is all based on the simultaneity of the stop signals. All the number of clicks are as reported, as near as I can tell (there are a lot of clocks here!), but that doesn't mean the B and C clocks will stop at the same time for B. In fact, the B clock, which is going 7 times faster, stops long before the C clock does (from B's point of view of course-- C would say exactly the opposite). That's how it is able to have the same number of ticks. I don't see the problem, the resolution is in the length contraction of the distance that C's stop signal must propagate from B's point of view-- it's a very small distance, so C must send it's "stop" signal long after B.

I'm afraid your analysis is incorrect. All clocks stop after 36,000 seconds per clock Am, if the start/stop information signals from the shuttles compute that SR infact works as advocated.

If not the clocks will still read as stated but will have run for a different period of time.

In either case SR fails since assuming SR is correct means B and C must tick at the same rate to A (hence equal to each other) yet they have relative velocity and must not tick equal to each other.

Your effort to introduce simultaneity is why others have not understood this flaw previously. But simultaneity has no bearing on the test. All clocks tick for the same amount of standard time, 36,000 seconds per Am, if the start/stop signals compute that those signals were 36,000 seconds apart according to Am.

Time accumulated by a clock is in direct relation to its tick rate and the period of time allowed to run.

The other issue which becmes obvious is that assuming tick rates are physical changes (i.e. actual changes in time) then B and C only reach 18,000 ticks during the 36,000 tick test per Am.

Also since B and C only accumulate 18,000 ticks and according to SR from their perspective A is ticking at 1 tick per two of their ticks then SR predicts that Am will only have 9,000 ticks when they reach 18,000 ticks.

That can be seen to not be possible.

All the introduction of simultaneity does is have the clocks run for different periods. While that might produce the results you want those results become an observational illusion of time and not the specific gamma function affecting tick rate alleged to occur.

Added note: The propagation time for the shuttle signals is calcuable and from that the actual duration of accumulating time at predicted tick rate can be determined also.

[MacM]

Originally Posted by Ken G

This one might cause problems, depending on what you mean by "in the same frame". I agree there is a big difference between what two clocks say when you compare them side by side, and what they appear to say when you look at them from different distances. But it is also important to recognize that the latter brings in two completely separate issues, the first is illusions due to time of flight effects, and the second is actual relativity, which is what you get after correcting for time of flight effects. So what I'm saying is, it is valid to observe the passing of time in a distant system, so long as you correct for the time of flight effects, but then you will still find time dilation as a leftover effect. We should not rule out this type of "observation", lest we rule out all of astronomy as a branch of physical observations.

We are in full agreement. I was merely pointing out that one is physical change in time (i.e. - the Twin affect) whereas the others are perception or illusions of measurement and should not be confused with actual physical time dilation.

[Celestial Mechanic]

A Response to "Time Dilation (Spatial Length Contraction) Gendanken":

Your experiment is not much of an experiment because not enough gedanken went into it. Despite all of clocks set up to run at differing rates, your experiment does not have any meaningful way of continuously monitoring that your clocks really are running at the rates that you claim. Despite your "hint" to not regurgitate the twins argument, your "experiment" is nothing more than the first half of the twins experiment, where in this case the shuttlecrafts B and C arrive at destinations 8.66 light-hours away from A.

The main problem that you and other anti-relativists have is this confusion over "tick rates" of clocks and the notion that the clocks are ticking at different rates. The clocks on board B and C are ticking normally and if they measure half as much elapsed time as A, it is because there is half as much elapsed time to measure. Period.

An analogy would be if two drivers set out from New York City to Los Angeles with known odometer readings on each car. One takes a northerly route through Chicago and Salt Lake City, the other takes a southerly route through St. Louis and Oklahoma City. When the odometers are read at the end of the journey and the mileage for each car computed they will be different. They are different because one of the drivers drove a longer distance, not because rulers "contracted" or "expanded" in some mysterious way. This is part of our daily experience, we have no trouble with it. The differing proper times of different world-lines is not part of our daily experience and that is why so many people have trouble understanding it.

In your experiment you guaranteed that B and C should experience 18,000 seconds of proper time and arrive at the same simultaneity with A after 36,000 seconds of time according to A. Nothing more and nothing less.

Your clocks on board calibrated to the presumed "rates" of the other clocks are meaningless without any measurements that said clocks are keeping time at that rate. If your observers were actually continuously recording signals from one another, they would not see the other clocks ticking at one-half or one-seventh the rate of the on-board clock, but at rates of 2-sqrt(3) and 7-4*sqrt(3) respectively. You forgot about the relativistic Doppler effect.

(A hint: many of these gedanken experiments use a velocity of 3/5 c because not only is gamma rational (5/4) but also the added velocity of two observers departing in opposite directions (15/17) and its gamma (17/8) are also rational numbers.)

In summary:

1. You have not demonstrated any discrepancy in your "experiment" because you have not really compared "tick rates" against the actual signals from the other clocks using the proper formalism.

2. No clock ticks at multiple rates. Each clock ticks at its normal rate and records exactly as much proper time as elapses for that world line. No more and no less.

[MacM]

Originally Posted by Celestial Mechanic

A Response to "Time Dilation (Spatial Length Contraction) Gendanken":

Your experiment is not much of an experiment because not enough gedanken went into it. Despite all of clocks set up to run at differing rates, your experiment does not have any meaningful way of continuously monitoring that your clocks really are running at the rates that you claim.

Unfortuantely you either didn't read the entire presentation or you didn't understand it. Your assessment is false. The interval between "Start" and "Stop" information signals sent by the shuttles insures that the space station can compute the interval between them and determine that they actually ran for the 36,000 seconds according to "Am".

This scenario is mathematically consistant and it demonstrates the flaw. It takes more than rhetoric to disregard it. Lets see you show mathematically any flaw with the setup and/or results.

The main problem that you and other anti-relativists have...

The only problem I have is getting relativists to actually think about what they are advocating.

..... is this confusion over "tick rates" of clocks and the notion that the clocks are ticking at different rates. The clocks on board B and C are ticking normally and if they measure half as much elapsed time as A, it is because there is half as much elapsed time to measure. Period.

Speaking of confusion:

Your assertion that "Proper" time is the same and that clocks are not ticking at different rates is frankly an unbelievable comment.

Your clocks on board calibrated to the presumed "rates" of the other clocks are meaningless without any measurements that said clocks are keeping time at that rate. If your observers were actually continuously recording signals from one another, they would not see the other clocks ticking at one-half or one-seventh the rate of the on-board clock, but at rates of 2-sqrt(3) and 7-4*sqrt(3) respectively. You forgot about the relativitistic Doppler effect.

Like I said you have not read the thread or fail to comprehend the issue. Doppler or any other illusion of motion measurement IS NOT time dilation of the sort which results in the Twin being younger. Only physical actual change in time can do that and that must be evidenced by actual comparative accumulated time over a common test period. Which BTW will be consistant with the dilated tick rate of the clock.

In summary:

1. You have not demonstrated any discrepancy in your "experiment" because you have not really compared "tick rates" against the actual signals from the other clocks using the proper formalism.

Think again. You are in error.

2. No clock ticks at multiple rates.

This is the only correct thing you have posted. It is also why SR is flawed. It mandates it and it is not possible.

Each clock ticks at its normal rate and records exactly as much proper time as elapses for that world line. No more and no less.

WOW. Of course if in the end the two clocks have recorded the same accumulated time then there has been no time dilation. If they do not then the tick rates have not been the same.

For your information "Proper Time" of moving frames are not the same tick for tick otherwise there would never be any recorded change of time..

For those that don't know here is a refresher link regarding clock tick rates:

************************ Extract ******************************
http://www.physics.nus.edu.sg/~phyte.../dilation.html

The Secret to Longevity: Time Dilation
--------------------------------------------------------------------------------

.................................................. ...................

The solution can be found in Einstein's theory of Special Relativity. When travelling at speed v, time actually slows down according to the equation:

t' = t / (1 - v^2/c^2)^1/2

What is meant by time dilation is that a moving clock will tick more slowly than when it is at rest.
************************************************** ************

[Celestial Mechanic]

Originally Posted by MacM

Unfortuantely you either didn't read the entire presentation or you didn't understand it. Your assessment is false. The interval between "Start" and "Stop" information signals sent by the shuttles insures that the space station can compute the interval between them and determine that they actually ran for the 36,000 seconds according to "Am".

Whoop-de-doo. They also ran for 18,000 seconds of their own proper time. Get used to it.

Originally Posted by MacM

This scenario is mathematically consistant and it demonstrates the flaw. It takes more than rhetoric to disregard it. Lets see you show mathematically any flaw with the setup and/or results.

I don't have to. You are the one proposing that your "gedanken" experiment shows a flaw in special relativity. The burden of proof is on you. I have shown where your assertions of different "rates" for clocks is invalid and that your experiment does not measure the "rates" of any clocks.

Originally Posted by MacM

The only problem I have is getting relativists to actually think about what they are advocating.

I have thought about it for some time, which is how I have arrived at my understanding. It is the proper time of each body or observer that is important.

Originally Posted by MacM

Speaking of confusion: Your assertion that "Proper" time is the same and that clocks are not ticking at different rates is frankly an unbelievable comment.

Why?

Originally Posted by MacM

Like I said you have not read the thread or fail to comprehend the issue.

I see that you have not read or commented on my analogy about automobiles traversing different distances depending on the route taken. It is the key to understanding how elapsed time can differ depending on the world-line taken. It is you that fail to comprehend.

Originally Posted by MacM

Doppler or any other illusion of motion measurement IS NOT time dilation of the sort which results in the Twin being younger.

No, but it is what you are going to see if you actually OBSERVE signals being sent among the various spacecraft in your "experiment". Again, the twin is younger because he travelled a world-line with less proper time. Clocks B and C in your experiment really do experience only 18,000 seconds of proper time because you have chosen a trajectory where only 18,000 seconds of proper time will elapse. End of story.

Originally Posted by MacM

Only physical actual change in time can do that and that must be evidenced by actual comparative accumulated time over a common test period. Which BTW will be consistant with the dilated tick rate of the clock. Think again. You are in error.

And what exactly do you mean by "physical actual change in time"? How have your clocks "accumulated time over a common test period"? Relative to whom?

Originally Posted by MacM

This is the only correct thing you have posted. It is also why SR is flawed. It mandates it and it is not possible.

SR mandates no such thing.

Originally Posted by MacM

For your information "Proper Time" of moving frames are not the same tick for tick otherwise there would never be any recorded change of time..

Now what on earth does that mean?

Originally Posted by MacM

For those that don't know here is a refresher link regarding clock tick rates: http://www.physics.nus.edu.sg/~phyte.../dilation.html

The Secret to Longevity: Time Dilation

The solution can be found in Einstein's theory of Special Relativity. When travelling at speed v, time actually slows down according to the equation:

t' = t / (1 - v^2/c^2)^1/2

What is meant by time dilation is that a moving clock will tick more slowly than when it is at rest.

The author of this site does not understand special relativity any better than you do. If they think that someone traveling at a good fraction of the speed of light will somehow live longer, the joke's on them.

You ought to start consulting more reputable sources than Herbert Dingle and the web site you referenced above.

[Nereid]

Originally Posted by MacM

[snip]

The point is all clocks are recording time at their proper rate while in an inertial (rest) state. The space station and each shuttle is equipped with several clocks.

The capital letter designates in which frame the clock is mounted, followed by "m" means it is the master clock ticking at the proper time rate for that frame. Followed by "a", "b" or "c" means it has been calibrated to reflect the time of the master clock of the frame designated by the small letter. Followed by a "p" means the time is what is predicted by relativity for observers of the frame designated by the capital letter or followed by a "c" means it is calibrated to tick in synch with clock Am for control purposes.

All of these calibrations can be made via precalculation of Special Relativity predictions.

Since the time dilation is precalculated based on the planned flight schedule it is known that (assuming Special Relativity is valid) the proper shuttle clocks, Bm and Cm, will be ticking at one half the rate of Am. Control monitoring clocks have been precalibrated and installed in each shuttle to run at two ticks per each tick of clocks Bm and Cm. They are labled Bac and Cac.

The space stations shuttle prediction monitoring clocks are labled Abp and Acp and are calibrated to tick at one half the rate of Am so as to allow the station operators to know what time has accumulated aboard the shuttles.

The monitors Bac and Cac allow the pilots of the shuttles to see and operate in accordance with the rate that time is passing back at the space station clock Am.

[snip]

Here's a part I don't get MacM: there are only 3 clocks, one on each of A, B, and C. All the other clocks are just gears or software - they're slightly more complicated versions of the many clocks you see showing 'time now in Sydney' and 'time now in Tokyo' and 'time now in Montreal' - without a videolink to a clock in Sydney, a clock in Tokyo, etc, this nice display (say, in the departure hall at Heathrow airport) is just a fiction.

And to get the 'videolink' in your Gedankenexperiment, don't you need to address all those simultaneity issues you otherwise avoid?

[worzel]

Originally Posted by Mac

4 - Special Relativity requires that clocks B and C both tick at a rate of 0.5 / 1 to the space station clock. That is B and C are ticking at a common rate inspite of the fact that they have a relative velocity to each other which also requires them to tick at rates of about 1 tick to 7 ticks of the other. Impossible reciprocity and impossible ticking conditions for all views.

I think this statement is central to your misunderstanding and central to the problem with your attempted demonstration of SR's inconsistency.

Clocks B and C only tick at a common rate according to A because they both have the same relative velocity to A. Neither B nor C has the same relative velocity to the other as it does to itself (obviously) and so there is no requirement that their clocks tick at the same rate as each others in their own frames.

Your reasoning is begging for an absolute frame in which to account for all clock rates and then attempting to use that absolutists analysis to refute the relativity of their clock rates depending of the frame of reference.

The interesting thing is that this does all seem inconsistent at first, but when you work out what happens should the clocks ever reunite so that a comparison of their elapsed time can be agreed upon by both clock carriers then which ever [ correct ] way you work it out gives the same answer - i.e. SR is consistent afterall (unsuprisingly, given the attention it has received over the years).

[Grey]

MacM, let me ask a question to clarify something. Are you claiming that special relativity is internally inconsistent, and that your thought experiment shows this, or are you claiming that special relativity is consistent, but leads to results that you just can't believe, so it must be false. In the first case, you'd presumably accept a valid calculation of the situation in question using special relativity, which shows the results to be consistent, as proof of your error. In the second case, you already accept that special relativity would give a valid result, you just think that result must be wrong, which you'd hopefully acknowledge is not a scientific view. Which is it?

[MacM]

Originally Posted by Grey

MacM, let me ask a question to clarify something. Are you claiming that special relativity is internally inconsistent, and that your thought experiment shows this, or are you claiming that special relativity is consistent, but leads to results that you just can't believe, so it must be false. In the first case, you'd presumably accept a valid calculation of the situation in question using special relativity, which shows the results to be consistent, as proof of your error. In the second case, you already accept that special relativity would give a valid result, you just think that result must be wrong, which you'd hopefully acknowledge is not a scientific view. Which is it?

To others. I'm not ignoring you but responding here in that this is the most appropriate post and addresses the issue in a form which can be discussed. Yours were fiat or rhetorical statements as fact which I dispute.

Now to this post. My contention is inconsistancy. Let me emphasize what I have already stated. That is the inclusion of simultanety can be used to actually generate the data you want and gives the appearance of consistancy; however, my arguement is that doing so destroys the test of the specific gamma claim being made.

That is that t' = t / (1 - v^2/c^2)^1/2. When you interject simultaniety you alter "t", that is the period for which data is accumulated at a specified tick rate.

That is I contend that the correct test is to insure a common standard "t". In this case the "Am " clock is used for all data.

The informational Start/Stop signals sent from the shuttles insures that the space station can compute the interval inbetween and thereby verify that the tick rates were as planned. That is that the 18,000 ticks occured in the same 36,000 seconds of Am, hence gamma=2.000, etc.

What others here are proposing is to include simultaneity shift such that clocks B and C alternately run 35 hours (126,000 seconds per Am) so as to come to the correct accumulated time to be consistant but then "t" is no longer "t" but t''.

My bottom line contention is that Relativity of Simultaneity is not a bonafide time dilation affect. It is a measurement illusion affect due to relative motion and does not affect the accumulated time on clocks when subsequently compared in a common frame.

Only gamma for a common test period can alter accumulated time in the manner which would make the twin younger upon being reunited with his brother.

Simulteneity or "Remote Viewing" do not change time locally.

[Ken G]

Originally Posted by MacM

I'm afraid your analysis is incorrect. All clocks stop after 36,000 seconds per clock Am, if the start/stop information signals from the shuttles compute that SR infact works as advocated.

It is you who are incorrect. The second statement above is correct, what is incorrect is any suggestion that there is a problem here. There is none. As I said before, the error in your analysis is a failure to account for differences in synchronization of the clocks. This is often the mistake made by people who don't understand special relativity. I will explain.

Instead of having clocks Bac and Cac on board the shuttles, it is actually more informative to let these clocks be spread out over the "stationary" frame of the space station. Let there be a bunch of such clocks, all synchronized to the space station in the station's frame, spread all over. Then the "flight plan" will be for the shuttles to stop their clocks when they reach the stationary clock that reads 36,000 seconds. This has the exact same spirit as your gedankin, but will reach no inconsistency and will therefore demonstrate the flaw in your reasoning.

When the shuttle reaches the stationary clock that says 36,000 seconds, its clock will of course say 18,000 seconds and will shut off its clock. At this point, it will also infer that the original space station clock reads 9,000 seconds (which it can tell by correcting for the time of flight of a light pulse that comes from the space station, so it can see that clock). So does this yield a contradiction between the number 9,000 and the number 36,000? No. The shuttle does not think that those clocks are properly synchronized, and they never were in that frame. If the shuttle carries its own Bac clock, it will conclude that the 36,000 second clock is it passing is also not synchronized with its Bac clock. Nevertheless, this is what the flight plan requires for the shutdown of the shuttle clock-- not when the Bac clock reads 36,000 seconds. You have done an incomplete transformation of how the shuttle will account for the passage of time in the space station frame. It is not enough to account for time dilation, it also necessary to account for differences in clock synchronizations. If the agreement is that the shuttle will turn its clock off when 36,000 seconds has passed for the space station, then the time dilation effect is simply not sufficient to make the transformation from the space station's concept of 36,000 seconds into the moving frame of the shuttle. The usual twin paradox does not meet with the second aspect of the problem because when you return to the same point, you needn't worry about synchronization issues.

Bottom line: the space shuttle will not agree that clock Bac is recording time in the same way as time elapses in the space station's frame, because it is not going to agree with the synchronized clocks we've laid out in the space station's frame.

So what have we learned? We have learned there is nothing wrong with special relativity, but this does not mean your gedankenexperiment is of no value. It is quite useful indeed, for demonstrating that passage of time in two different frames involves more than just time dilation, it also requires consideration of conventions for clock synchronization. It is indeed possible to get rid of reciprocity as a physical principle, if a different synchronization principle is applied. Special relativity, in contrast, quite purposefully applies a synchronization principle that assures reciprocity. This is not a physical principle, the way time dilation is, it is a convention of the theory, but it is nevertheless a crucial convention to be able to use the rest of special relativity, and it must be obeyed if one is trying to find flaws that don't actually exist.