One way speed of light measurement proposal

[lugita15]

ghwellsjr, that sounds like Einstein synchronization, not slow clock transport.

 

[ghwellsjr]

ghwellsjr, that sounds like Einstein synchronization, not slow clock transport.

Well then, let's tell the guy he's all wet and actually build a second identical light clock next to the first one making sure the two A counters increment in lock step and then slowly move the second one so that it's A counter and mirror are adjacent to the B counter and mirror of the first one. Will the B counter of the first setup be in lock step with the A counter of the second one?

 

[lugita15]

Well then, let's tell the guy he's all wet and actually build a second identical light clock next to the first one making sure the two A counters increment in lock step and then slowly move the second one so that it's A counter and mirror are adjacent to the B counter and mirror of the first one. Will the B counter of the first setup be in lock step with the A counter of the second one?

Yes in our universe, but not in all possible universes.

 

[ghwellsjr]

Yes in our universe, but not in all possible universes.

Then we shouldn't have told the guy he was all wet?

 

[lugita15]

Then we shouldn't have told the guy he was all wet?

Well, we should have told the guy he was all wet when he was originally performing Einstein synchronization but claiming it was slow transport synchronization. But then, now that he slowly moved one of the light clocks past the other, he has managed to genuinely slowly transport the A counter of one clock to the B counter of the other clock. Now if he happens to live in a universe like ours in which the two synchronization schemes give the same result, then he will find that the two counters he has now aligned are perfectly in sync. But if he lives in another universe in which special relativity is not true, like the universe that Newton believed that he lived in, then he will find that the A counter of one and the B counter of the other are not in sync at all.

Let me make my point another way. Suppose we synchronized two clocks using a method analogous to Einstein synchronization, except using sound other than light. Then we will find that "sound synchronization" yields very different results than slow transport synchronization, unless you happen to be in a frame that is at rest with respect to the air. And Newton would have agreed with this fact. But Newton would be flabbergasted to learn that slow transport synchronization and Einstein synchronization yield the same results.

 

[ghwellsjr]

Even in Newton's universe where Special Relativity is not true, and by that, I assume you mean there is no time dilation or length contraction, the two synchronization schemes will give the same result. In fact, in Newton's universe, they are both the same no matter what speed the clock is moved at. This is true even if you are not at rest with respect to the medium, whether it be air or ether. Even in our universe, the two synchronization schemes give the same result even if you are moving in the assigned reference frame or even if you assume LET to be the way the universe works and you are moving with respect to the ether.

So Newton would not be flabbergasted that slow transport synchronization and Einstein synchronization yield the same results but he might be flabbergasted to learn that fast transport synchronization yields a different result than slow transport synchronization (and Einstein synchronization) in our real universe.

In fact, slow transport and Einstein synchronization are exactly the same. Neither one validates the other and neither one is an experimental verification of the other. There is no difference between them except the common misconception that they are different.

One thing that needs to be made clear is that even if the time it takes for light to propagate from A to B is different than the time it takes for light to propagate from B to A, then Einstein will call these unequal times equal and the slow clock transport will also end up with the clock being "out of sync" with the stationary clock by exactly the same amount, but we make the claim that they are in sync and we simply define the time to be equal and the clocks to be in sync.

I urge you to analyze what actually happens with slow transport of a light clock and see that what I say is true before you react negatively.

 

[Alfie]

Just a thought about slow transport synchronisation.

What if, instead of moving one of the clocks away very slowly, each clock underwent acceleration programs, equal in all respects other than direction, so that they could be moved apart at arbitrarily high velocities, before being brought to rest with respect to each other? Would this qualify as a valid way of synchronising clocks?

 

[nitsuj]

sure would but the challanges remain the same.

 

[ghwellsjr]

Just a thought about slow transport synchronisation.

What if, instead of moving one of the clocks away very slowly, each clock underwent acceleration programs, equal in all respects other than direction, so that they could be moved apart at arbitrarily high velocities, before being brought to rest with respect to each other? Would this qualify as a valid way of synchronising clocks?

No, they would remain synchronized with each other but not with a clock that remained at their starting location. The whole idea of Einsteinian synchronization is to build a coordinate system where their is a synchronized clock at every location and the three fixed coordinates for that location plus the changing time on its coordinate clock becomes the four spacetime coordinates for that location.

 

[lugita15]

Even in Newton's universe where Special Relativity is not true, and by that, I assume you mean there is no time dilation or length contraction, the two synchronization schemes will give the same result.

No, they wouldn't. For instance, in a non-Lorentz ether theory like the one Maxwell believed in, they would give dramatically different results if you're not in the rest frame of the ether, just like in our universe slow transport synchronization and sound synchronization (Einstein synchronization with sound rather than light) give dramatically different results if you're not in the rest frame of air.

Even in our universe, the two synchronization schemes give the same result even if you are moving in the assigned reference frame or even if you assume LET to be the way the universe works and you are moving with respect to the ether.

Yes, Lorentz ether theory also says that the two synchronization methods give the same results, because LET and SR make the same experimental predictions. But other aether theories of light, and emitter theories of light, will not make the two methods equivalent.

So Newton would not be flabbergasted that slow transport synchronization and Einstein synchronization yield the same results but he might be flabbergasted to learn that fast transport synchronization yields a different result than slow transport synchronization (and Einstein synchronization) in our real universe.

I definitely agree that Newton would have expected slow transport synchronization and "fast transport" synchronization to produce the same, "correct" result. But he would have believed that both Einstein synchronization and sound synchronization produce "incorrect" results.

In fact, slow transport and Einstein synchronization are exactly the same. Neither one validates the other and neither one is an experimental verification of the other. There is no difference between them except the common misconception that they are different.

Do you disagree with the proof given in the Mansouri and Sexl paper DrGreg referred to in the old thread? (For your convenience, I've attached the relevant pages.) They say "We thus arrive at the important result that Einstein proceudre in general differs from synchronization by clock transport. The equality of both procedures is neither trivial nor logically cogent." And then they say "Thus clock synchronization by clock transport and by the Einstein procedure agree if and only if the time dilatation factor is given exactly by the special relativistic value." In other words, the procedures are not logically equivalent, but special relativity makes them equivalent.

One thing that needs to be made clear is that even if the time it takes for light to propagate from A to B is different than the time it takes for light to propagate from B to A, then Einstein will call these unequal times equal and the slow clock transport will also end up with the clock being "out of sync" with the stationary clock by exactly the same amount, but we make the claim that they are in sync and we simply define the time to be equal and the clocks to be in sync.

I'm not sure what you're saying here.

I urge you to analyze what actually happens with slow transport of a light clock and see that what I say is true before you react negatively.

I don't think what you say is true, and a very easy way to demonstrate that is, replace the red and green light beams with high-pitch and low-pitch sound waves. Then I think you should agree that if initially the A counters of the two "sound clocks" were in sync and the B counters were in sync, if we slowly transport one of the sound clocks so that the A counter of one clock is in sync with the B counter of the other, we'll find that they're not in sync as long as you're in a frame different than the rest frame of air.

 

[ghwellsjr]

I definitely agree that Newton would have expected slow transport synchronization and "fast transport" synchronization to produce the same, "correct" result.

I haven't got time to respond to all your points but let me just ask you right now, what is the difference between "fast transport" where we take the limit of the clock as it approaches the speed of light (just like we take the limit in slow transport as the speed approaches zero) and Einstein's synchronization?

EDIT: Just to make it clear: I'm talking about in Newton's world where Special Relativity is not true, that is, where there is no time dilation and no length contraction.

 

[lugita15]

I haven't got time to respond to all your points but let me just ask you right now, what is the difference between "fast transport" where we take the limit of the clock as it approaches the speed of light (just like we take the limit in slow transport as the speed approaches zero) and Einstein's synchronization?

EDIT: Just to make it clear: I'm talking about in Newton's world where Special Relativity is not true, that is, where there is no time dilation and no length contraction.

Well, let me ask you a question back. What's the difference between sound synchronization (Einstein synchronization with sound waves) and fast transport if we take the the clock's speed approaches the speed of sound? I'm asking this in either Newton's world, or our world where the speed of sound is small relative to the speed of light. It's kind of ambiguous, because the speed of sound is different in opposite directions, just like in Maxwell's aether theory the speed of light is different in opposite directions.

Anyway, I look forward to your response to the rest of my post.

 

[nitsuj]

No, they would remain synchronized with each other but not with a clock that remained at their starting location.

The whole idea of Einsteinian synchronization is to build a coordinate system where their is a synchronized clock at every location and the three fixed coordinates for that location plus the changing time on its coordinate clock becomes the four spacetime coordinates for that location.

If the topic of the thread is still the context (measure one way speed of light), Yes this method of "symmetricaly" seperating the clocks would work equally to slow clock transport. It acheives the same goal of keeping the two clocks syncronized.

But maybe I am jumping in the middle and the detail was important

 

[ValenceE]

Indeed it has veered off from my original question about a one way speed of light test setup validation using only one clock… and unfortunately, although my belief is that the one way speed of light is the same in all directions, the proposed experiment can’t distinguish between same or different speeds.

However, even if it's not the main subject of these other exchanges, there is mention of aether and that is interesting to me, but there are plenty other threads about it, so I don't mind reading on and don't mind it being locked as it doesn’t add any more to my enquiry for the moment…


Regards,

VE

 

[ghwellsjr]

No, they wouldn't. For instance, in a non-Lorentz ether theory like the one Maxwell believed in, they would give dramatically different results if you're not in the rest frame of the ether, just like in our universe slow transport synchronization and sound synchronization (Einstein synchronization with sound rather than light) give dramatically different results if you're not in the rest frame of air.

Keep in mind, I have been talking about comparing the synchronization via Einstein and slow transport for a particular instance of a large light clock and I maintain that as long as there is no time dilation and no length contraction and the speed of the light waves (or water waves or air waves) is a constant with respect to some fixed frame, then those two synchronization schemes are identical, even if the light clock is moving with respect to the fixed frame, not just in their outcome, but they physically are carrying out the same process with either synchronization scheme. I'm not saying that this could be used to synchronize all clocks in all orientations because the tick rate of one of these clocks could be different than another one at right angles to it, except in a universe like ours where SR is in effect.

Yes, Lorentz ether theory also says that the two synchronization methods give the same results, because LET and SR make the same experimental predictions. But other aether theories of light, and emitter theories of light, will not make the two methods equivalent.I definitely agree that Newton would have expected slow transport synchronization and "fast transport" synchronization to produce the same, "correct" result.

With the stipulations that I presented above, even emitter theories, as long as the light has constant speeds in each direction, will be the same synchronization process for both schemes.

But he would have believed that both Einstein synchronization and sound synchronization produce "incorrect" results.

Whether you call the results "correct" or "incorrect" they will be identical for any given instance of the type of clock I described.

Do you disagree with the proof given in the Mansouri and Sexl paper DrGreg referred to in the old thread? (For your convenience, I've attached the relevant pages.) They say "We thus arrive at the important result that Einstein proceudre in general differs from synchronization by clock transport. The equality of both procedures is neither trivial nor logically cogent." And then they say "Thus clock synchronization by clock transport and by the Einstein procedure agree if and only if the time dilatation factor is given exactly by the special relativistic value." In other words, the procedures are not logically equivalent, but special relativity makes them equivalent.

Yes, but like I said, they are covering a broader ground than I am. I'm simply pointing out that for a given instance of a light clock in a particular orientation, Einstein's synchronization is the same process as slow transport.

I'm not sure what you're saying here. I don't think what you say is true, and a very easy way to demonstrate that is, replace the red and green light beams with high-pitch and low-pitch sound waves. Then I think you should agree that if initially the A counters of the two "sound clocks" were in sync and the B counters were in sync, if we slowly transport one of the sound clocks so that the A counter of one clock is [STRIKE]in sync with[/STRIKE] adjacent to the B counter of the other, we'll find that they're not in sync as long as you're in a frame different than the rest frame of air.

[I edited your response to fit what I think you meant.]

It depends on what you mean by "in sync". If you mean that someone looking at the counters via light sees if they count synchronously, then of course the slowly transported A counter will not be in sync with the stationary B counter. But if we could synchronize clocks with some higher speed communication than light provides, we'd have a whole different world.

But if by "in sync" you mean that the stationary B counter increments to an odd count when the low frequency signal bounces off it (while the stationary A counter increments to an odd count when the high frequency signal bounces off it), then, yes, the slow transport will result in its A counter in sync with the stationary B counter when they get together.

Since you disagree, I would suggest that you work through how the sound waves propagate at two different speeds in each direction and yet the slow transport of the sound clock will produce the same synchronization as the method I described which you called Einsteinian synchronization (and I agree, it is).

 

[lugita15]

ghwellsjr, if you have some arguments or calculations to show that for this particular large light clock slow transport synchronization and Einstein synchronization are the exact same process, I would be happy to take a look at them. But tell me this, how does this example get around the general result in the paper I attached, which says that regardless of the kind of clock used, in a world where a(v) is equal to something other than what special relativity predicts, like the world of Maxwell's theory of light, the two synchronization methods MUST give different results?

Also, do you agree that in our universe, Einstein synchronization using light gives a different simultaneity than sound synchronization? And do you agree that if Earth was pervaded by two different media, say air and water, which did not interact with each other, then Einstein-like synchronization using these two different media would produce different simultaneities? And that this would be true regardless of the kinds of clocks synchronized?

Finally, do you agree that if slow transport synchronization gave the same result as, say, synchronization by sound waves in air, then it could not give the same result as synchronization by sound waves in water?

 

[DrGreg]

You can't use a light clock in a universe where the speed of light is in question. Light clocks measure the cumulative distance traveled by a photon bouncing between two mirrors, then divide by c to get a time. So if you are performing an experiment to determine the speed of light, you can't use a clock that requires prior knowledge of the speed of light.

If, instead, we assume we are using a clock that works accurately in a hypothetical Galilean universe -- one in which all accurate clocks tick at the same rate relative to each other regardless of their motion -- then synchronisation by slow-transport is the same as synchronisation by faster-transport and keeps all clocks absolutely synced to each other. This behaviour is incompatible with Einstein synchronisation (which always gives rise to relativity of simultaneity). Absolutely synced clocks will measure the 1-way speeds of light to be c ± v (in a frame moving at an absolute speed of v parallel to the light) whereas Einstein synced clocks will measure the 1-way speed of light to be the same in both directions.

 

[ghwellsjr]

ghwellsjr, if you have some arguments or calculations to show that for this particular large light clock slow transport synchronization and Einstein synchronization are the exact same process, I would be happy to take a look at them.

I'm going to present an analogy to Einstein's synchronization and extend it to slow transport. Bear with me:

Imagine a very long ski slope, many miles long and perfectly smooth. There are two rope lifts, a few yards apart, also of many miles that allow skiers to grab on to which take them up the slope at 12 miles per hour. The skiers come down the slope between the two rope lifts at exactly 60 miles per hour. That means that it will take a skier 1 minute to travel one mile down the slope, instantly stop and grab a rope lift and then take 5 minutes to traverse the one mile back to his starting point for a total round-trip time of 6 minutes.

Oh, and the mountain is shrouded in thick clouds so that they can barely see the hand in front of their face. And the skiers have no clocks, watches, cell phones, radios, GPS devices, etc. I will note the times that certain things happen but the skiers are completely unaware of these timings.

Now some skiers decide to do a little experiment. They are located somewhere in the middle of the ski slope, several miles up. They take a steel cable, one mile long and one of them holds on to one end and let's the other end dangle down the slope. They have attached two flags onto the cable, a yellow one at the half-way point and an orange one at the bottom end. The skier holding on to the top end of the cable doesn't move and since he will be counting, we'll call him Counter A. Another skier goes down to the bottom end of the cable, where the orange flag is and stays there. We'll call him Counter B.

After this initial setup, two more skiers, one wearing a red outfit and one wearing a green outfit start together down the slope at 60 mph. A half minute after they start, the skiers get to the yellow flag and the green skier stops and grabs the rope lift on his right. It will take him 2 and a half minutes to get to the top. Meanwhile, the red skier continues down. When he gets to the orange flag at the bottom of the cable, he stops and grabs the rope lift on his right. 60 seconds have gone by since the start. It will take him 5 more minutes to get to the top.

When the green skier gets back to the top at 3 minutes, the stationary skier called Counter A shouts out "1" and the green skier immediately heads back down the slope. This time he continues all the way to the bottom and he tells the skier called Counter B to shout out "2" because it is 1 more than the number he heard when he arrived at the top. It is now 4 minutes into the experiment. When the red skier gets back to the top it is 6 minutes into the experiment and Counter A calls out "2" while the red skier heads back down.

Now it should be easy to list the times and the counts that are being shouted out picking up at time 6:

Time=6, red arrives at top, counter A shouts 2
Time=7, red arrives at bottom, counter B shouts 3
Time=9, green arrives at top, counter A shouts 3
Time=10, green arrives at bottom, counter B shouts 4
Time=12, red arrives at top, counter A shouts 4
Time=13, red arrives at bottom, counter B shouts 5
Time=15, green arrives at top, counter A shouts 5
Time=16, green arrives at bottom, counter B shouts 6
Time=18, red arrives at top, counter A shouts 6
Time=19, red arrives at bottom, counter B shouts 7
Time=21, green arrives at top, counter A shouts 7
Time=22, green arrives at bottom, counter B shouts 8

Notice the patterns: it takes each skier one minute to go down the slope and five minutes to go up the slope. Each counter shouts a new number every 3 minutes. The two counters shout at different times but they don't know that because they can't hear or see each other. As far as they are concerned, they are shouting at exactly the same time, because they have defined time according to Einstein's synchronization process.

And what is that process? Einstein said you note the time on a clock at a light source when you start a pulse of light down to a mirror and reflect it back to the light source where you note the time again. You take the difference in the two times and this is the round-trip time. You divide it in half. You add that to the time on the clock at the light source the moment the next light pulse occurs and when the pulse gets to the clock at the mirror, that is the time you set on that remote clock.

So let's see how that works in our analogy with the skiers. First we note how long it takes for one of the skiers to make the round trip. Remember, they don't know about the actual times in the list above, all they know about is the numbers that the Counters shout out and if you look at either skier's round trip, you will see that it takes 2 counts for both Counter A and Counter B. So Einstein says we divide that by 2 which gives 1. So when a skier leaves a Counter, he adds 1 to that count and when he gets to the other end of the cable, if that is the number the other Counter shouts out, then the two Counters are synchronized. Note that this is what happens in all four cases: red going down, green going down, red going up and green going up.

But one bright skier says he knows how to prove that the Counters are in fact shouting out the same numbers at the same time by another synchronization process called slow transport.

He sets up the identical experiment with the other rope lift on the other side of where the skiers are with a different set of skiers and another one-mile long cable with the flags. After they get everything going, they get the second set synchronized with the first set and the counters counting the same numbers so the both Counter A's are in sync, (they are close enough to hear each other) and both Counter B's are in sync.

The plan is to slowly move the entire setup with the one-mile long cable, Counter A skier at the top and Counter B skier at the bottom, while the second set of red and green skiers are doing their skiing down the slope and coming back up with the second rope lift. The whole apparatus will go down the hill one mile, stopping when the second Counter A reaches the first Counter B.

And so they do it. And what do they find? Yes, indeed, the second Counter A is in sync with the first Counter B, even though they didn't do anything special to make this happen, like in the first setup. So the bright skier feels that he has proved something significant.

But another smart skier says, "wait a minute, you did no such thing, you did exactly what the first set of skiers did and let me explain why." And his explanation went like this:

It should be immediately obvious that while the one-mile long cable is in motion down the hill, the red and green skiers will travel farther downhill than they will travel uphill using the rope lift on each round trip. In fact, they will have added in exactly one additional downhill trip at the expense of one uphill trip. So both the Counters on the second setup will be counting later by the time of one downhill trip than they were before they started moving. And that is exactly what the first setup did to synchronize their two Counters.

But tell me this, how does this example get around the general result in the paper I attached, which says that regardless of the kind of clock used, in a world where a(v) is equal to something other than what special relativity predicts, like the world of Maxwell's theory of light, the two synchronization methods MUST give different results?

As I said before, as long as there is no length contraction and the propagation speed for one direction remains constant during the slow transport while the propagation speed for the opposite direction remains constant, then the two synchronization processes are identical for any given instance. But also like I said before, if you rotate the entire apparatus so that round-trip time for the signal propagations is not the same as it was before, then that means that the light clock itself is not dependable in that universe but the two synchronization methods will still be identical to each other in that rotated configuration.

Also, do you agree that in our universe, Einstein synchronization using light gives a different simultaneity than sound synchronization? And do you agree that if Earth was pervaded by two different media, say air and water, which did not interact with each other, then Einstein-like synchronization using these two different media would produce different simultaneities? And that this would be true regardless of the kinds of clocks synchronized?

Finally, do you agree that if slow transport synchronization gave the same result as, say, synchronization by sound waves in air, then it could not give the same result as synchronization by sound waves in water?

Again, I'm not saying that two different light clocks will even tick at the same rate (based on the round-trip signal propagation) in all universes or in all media or in all orientations, let alone be capable of being used as a dependable clock but in every one of those situations, as long as the criteria that I outlined are true, then the two synchronization methods are identical in process and in outcome for a given setup of the type that Einstein described in section 1 of his 1905 paper.

But what is really important is that the paper also affirmed that the two synchronization methods agree in our universe. And it's your insistence that slow transport is better than Einstein's synchronization because, for example, it provides experimental proof, as evidenced by your posts #15, #23, #42, #44, #56, etc.

You seem to overlook the fact that slow transport assumes that the clock remains synchronized while being transported and that oversight allow you to think that it has some intrinsic experimental value over Einstein's method.

 

[DrGreg]

ghwellsjr, re post #53

I haven't time to go through your post in detail, but I gather you are asserting that synchronisation by slow light-clock transport is the same as Einstein synchronisation. I haven't checked the maths but I'm quite prepared to accept that assertion may well be correct.

But that wasn't what Mansouri & Sexl, were talking about. The proposal there was for slow clock transport. not slow light-"clock" transport. As I pointed out in post #52, you are not entitled to assume that a "light-clock" is a clock unless you already know that light-speed is invariant. Mansouri & Sexl's result applies to real clocks (i.e. devices that accurately measure proper time under the conditions you are using them), not devices that may or may not be clocks depending on factors yet to be determined.

You seem to overlook the fact that slow transport assumes that the clock remains synchronized while being transported...

Actually that's not what Mansouri & Sexl assume. Even in an Einsteinian universe, the clocks do not remain Einstein-synchronised when moved, but only in the mathematical limit as the speed of transport tends to zero. Mansouri & Sexl's argument exploits that fact; it matters what the dilation factor is, not just that it tends to 1.

... and that oversight allow you to think that it has some intrinsic experimental value over Einstein's method.

It's not that one method is better than the other. It's just that the two methods could give different results if relativity were not true. So experimentally comparing both methods (using accurate clocks, not light-clocks) is one way of confirming (or falsifying) relativity.

 

[lugita15]

It should be immediately obvious that while the one-mile long cable is in motion down the hill, the red and green skiers will travel farther downhill than they will travel uphill using the rope lift on each round trip. In fact, they will have added in exactly one additional downhill trip at the expense of one uphill trip. So both the Counters on the second setup will be counting later by the time of one downhill trip than they were before they started moving. And that is exactly what the first setup did to synchronize their two Counters.

I'm sorry, but this isn't immediately obvious. I don't really follow your logic. The issue is already complicated enough, and bringing in the skiers doesn't seem to make matters better. If it's not too much trouble, can you just phrase your argument in terms of plain old light clocks, preferably without even the wrinkle of two different light beams in the apparatus?

As I said before, as long as there is no length contraction and the propagation speed for one direction remains constant during the slow transport while the propagation speed for the opposite direction remains constant, then the two synchronization processes are identical for any given instance.

No, I don't think that's true, because Einstein synchronization makes measurements of the one-way propagation speeds automatically isotropic. But if you had something that traveled with different speeds in opposite directions, then a slow transport synchronization will tell you that there's a clear difference in the speeds in opposite direction.

Again, I'm not saying that two different light clocks will even tick at the same rate (based on the round-trip signal propagation) in all universes or in all media or in all orientations, let alone be capable of being used as a dependable clock but in every one of those situations, as long as the criteria that I outlined are true, then the two synchronization methods are identical in process and in outcome for a given setup of the type that Einstein described in section 1 of his 1905 paper.

But what is really important is that the paper also affirmed that the two synchronization methods agree in our universe.

And I've affirmed this as well.

And it's your insistence that slow transport is better than Einstein's synchronization because, for example, it provides experimental proof, as evidenced by your posts #15, #23, #42, #44, #56, etc.

Yes, I maintain that one-way speed of light measurements with Einstein synchronization are trivial or universe-independent, and one-way speed of light measurements with slow transport are nontrivial or universe-dependent.

You seem to overlook the fact that slow transport assumes that the clock remains synchronized while being transported and that oversight allow you to think that it has some intrinsic experimental value over Einstein's method.

No, I don't overlook this fact at all. I've said numerous times that slow transport synchronization, like all synchronization procedures, is just an arbitrary convention. We are not assuming that two clocks that are transported slowly away from each other are in sync in some deep metaphysical sense. Rather, we are defining the simultaneity convention by saying that two clocks that are transported slowly away from each other are said to be in sync.

 

[Austin0]

ghwellsjr, re post #53

I haven't time to go through your post in detail, but I gather you are asserting that synchronisation by slow light-clock transport is the same as Einstein synchronisation. I haven't checked the maths but I'm quite prepared to accept that assertion may well be correct.

But that wasn't what Mansouri & Sexl, were talking about. The proposal there was for slow clock transport. not slow light-"clock" transport. As I pointed out in post #52, you are not entitled to assume that a "light-clock" is a clock unless you already know that light-speed is invariant. Mansouri & Sexl's result applies to real clocks (i.e. devices that accurately measure proper time under the conditions you are using them), not devices that may or may not be clocks depending on factors yet to be determined.

Actually that's not what Mansouri & Sexl assume. Even in an Einsteinian universe, the clocks do not remain Einstein-synchronised when moved, but only in the mathematical limit as the speed of transport tends to zero. Mansouri & Sexl's argument exploits that fact; it matters what the dilation factor is, not just that it tends to 1.

It's not that one method is better than the other. It's just that the two methods could give different results if relativity were not true. So experimentally comparing both methods (using accurate clocks, not light-clocks) is one way of confirming (or falsifying) relativity.

Hi DrGreg
Are you saying that that if SR is valid then ideally slow transported clocks, initially synched with the central clock in a Conventionally synched system, would isotropically agree with all system clocks upon arrival at distant locations?

 

[DrGreg]

Hi DrGreg
Are you saying that that if SR is valid then ideally slow transported clocks, initially synched with the central clock in a Conventionally synched system, would isotropically agree with all system clocks upon arrival at distant locations?

On the understanding that "ideally slow transported clocks" means in the limit as the speed of transportation tends to zero, yes.