Room-temperature superconductivity?

[Teemu]

Of course it is not located in the clock, it's not like in large enough acceleration in a certain direction a pendulum clock getting stuck. Physical reality is four dimensional.

It appears therefore more natural to think of physical reality as a four dimensional existence, instead of, as hitherto, the evolution of a three dimensional existence.
Albert Einstein

[ladajo]

An Ashby follower...

http://sciencewithoutfiction.com/upload ... ct_4th.PDF

[DeltaV]

Of course it is not located in the clock, it's not like in large enough acceleration in a certain direction a pendulum clock getting stuck. Physical reality is four dimensional.

It appears therefore more natural to think of physical reality as a four dimensional existence, instead of, as hitherto, the evolution of a three dimensional existence.
Albert Einstein

A. Einstein, Autobiographical Notes, in Albert Einstein--Philosopher-Scientist, P. A. Schitpp, ed.
(The Open Court Publishing Co., LaSatte, Illinois, 1970), p. 59.

If one did not wish to forego a physical interpretation of the coordinates in
general,.., it was better to permit such inconsistency---with the obligation,
however, of eliminating it at a later stage of the theory.

[DeltaV]

http://www.sciencenews.org/view/generic ... ght_secret

[ladajo]

http://tycho.usno.navy.mil/ptti/1987/Vol%2019_30.pdf

[ladajo]

http://www.dtic.mil/cgi-bin/GetTRDoc?Lo ... =ADA485085

[tomclarke]

Well that was easier than I thought...

Relativistic effects in GPS and LEO
Mikkjal Gulklett
October 8, 2003
University of Copenhagen, Denmark
Department of Geophysics
The Niels Bohr Institute for Physics, Astronomy and Geophysics
Supervisors: Carl Christian Tscherning and Poul Olesen

http://www.gfy.ku.dk/~cct/thesis/Speciale1.pdf

From Chapter 4:

SR time dilation: 2.5E-10
GPS clock accuracy 1E-14.

25,000X larger than clock errors.

I just want to know when DeltaV & Johan will stop making obviously absurd assertions about this.

From page 12 of the same document (emphasis mine):

At this point an observation regarding the time dilation may be useful. Very
often it is described in a way, which suggests that we are dealing with a physical
effect upon the moving clock. This is misleading, because clocks always
measure proper time. It is not a physical effect in the clock the time measures
appear to slow down as its velocity increases relative to the observer. It is
merely a metric effect due to the transformation from one system to another.
The same clock will appear to tick at different rates if seen from different
reference frames. Thus the effect is not located in the clock, but is purely a
metric effect due to the relative motion of the chosen reference frames..

Which is what Mendel Sachs, Johan and I have been trying to tell you.

So simple logic (if you can handle that) means that if two initially synchronized, perfectly accurate satellite and ground clocks were both brought to rest in the same frame, then they would show equal elapsed times (excluding GR effects due to a changing gravitational potential, which do cause an elapsed time difference, but SR does not).

I just want to know when Tom & GIT will stop making obviously absurd assertions about this.

To be fair DeltaV, it is subtle. OTOH, I've stated it here 3 times already, and you don't pay attention, or engage with the argument.

Time dilation in SR between inertail frames is indeed a relationship between coordinates. It has no reality. It cannot be measured, because the two clocks cannot be synchronised in any absoilute sense. It it did were real it would be inconsistent, because both the twins cannot "really" be aging slower.

Got it? So I agree with the author of the thesis, and have stated this many times above.

Now, time dilation between non-inertial frames, where the clocks return and can be synchronised, is different. It is real, because it can be measured. Of course from the POV of the clocks it is true they tick no differently, in their frames they keep good time. But the overall effect (elapsed time of one is greater than the other) can be clearly measured. And the reason is that acceleration bend the path in spacetime in such a way as to reduce total time along path.

For example, if a GPS clock loses 250ps/s, every second, while staying in the same orbit relative to an earth clock, it is not a coordinate system effect. It is a real difference in elapsed time which can be measured, and is measured, to an accuracy of 0.01ps/s. (That is quoting 1E-14 acuracy for GPS clocks from the thesis).

The GPS satellite here has both gravitational and SR corrections. If you deny this you must explain why GPS clocks are programmed with the SR correction (in this case it is about 1/4 the size of the GR correction, and 25,000X larger than the accuracy of the clocks).

You have throughout this conversation avoided argument when the questions are difficult. As here. You don't like my argument so post something different. Whereas I have directly answered all your points.

I don't mind you being pig-headed and wrong. People often are. I think your inability to stick to the topic at hand shows either lack of mental ability, or lack of (mental) integrity.

[tomclarke]

An Ashby follower...

http://sciencewithoutfiction.com/upload ... ct_4th.PDF

The satellite clock experiences change of FOR. It is the change of FOR (or bent world-line in M spacetime) that means the elapsed time along the satellite path is less than along an earth centred path.

This is not a direct effect of acceleration (the GR arguments). It is geometric, a direct effect of the Minkowski metric applied to two different paths.

The author does not understand this.

But unlike DeltaV & Johan, he is at least not denying the facts.

[GIThruster]

So simple logic (if you can handle that) means that if two initially synchronized, perfectly accurate satellite and ground clocks were both brought to rest in the same frame, then they would show equal elapsed times (excluding GR effects due to a changing gravitational potential, which do cause an elapsed time difference, but SR does not).

I just want to know when Tom & GIT will stop making obviously absurd assertions about this.

DV, the fact of the matter is, the CLAIM by Einstein was and is, since 1905, that if you have two clocks that are synchronized, give one some velocity, then return it to rest in the frame with the other clock, the clocks will no longer be synchronized. That is the claim. That is the observed fact as well. Einstein used the simplest language necessary to make this astonishing claim, which has certainly changed the world, and he used very few words as well. There's no dickering about what he said, nor meant.

Now when someone like Mendel Sachs writes on the issue, he may use the term "scaling" or "metric" and be vague about what he's saying, but essentially, he and you are asserting that Einstein, SR and well documented observations are all wrong, and your intuition (as well as Sachs') is right. That is a convenient position to hold if you're suffering delusions of grandeur, but otherwise I'd think more humility is called for.

Now in this above, you're making a new claim. You're saying you agree time dilation occurs in the case of a gravity well, the larger dilation effect found in GPS sats. So you believe in time dilation due to gravity as described by GR, but you do not believe in time dilation due to inertia as described by SR.

Is that right?

[DeltaV]

To be fair DeltaV, it is subtle. OTOH, I've stated it here 3 times already, and you don't pay attention, or engage with the argument.

Time dilation in SR between inertail frames is indeed a relationship between coordinates. It has no reality. It cannot be measured, because the two clocks cannot be synchronised in any absoilute sense. It it did were real it would be inconsistent, because both the twins cannot "really" be aging slower.

Got it? So I agree with the author of the thesis, and have stated this many times above.

"Got it?"! Tom, I've stated it here umpteen times already, and you don't pay attention. This is clearly what I've been telling you from the beginning, that Lorentz transform kinematics does not produce differential aging dynamics.

You were, up to this point, vehemently arguing that it does. Glad to see you've finally crawfished over to sensibility.

Now, time dilation between non-inertial frames, where the clocks return and can be synchronised, is different. It is real, because it can be measured. Of course from the POV of the clocks it is true they tick no differently, in their frames they keep good time. But the overall effect (elapsed time of one is greater than the other) can be clearly measured. And the reason is that acceleration bend the path in spacetime in such a way as to reduce total time along path.

All of my posts on the present thread drift have been about Lorentz transforms in inertial frames (no acceleration). I have not addressed at all the issue of accelerating frames (I have mentioned in passing the clock effects expected when gravitational potential varies).

But regarding your statement above, a link that you posted states clearly that acceleration and even higher derivatives have no effect on clock rates (which I have no problem with):
viewtopic.php?p=74369&highlight=&sid=61 ... e143#74369

The Clock Hypothesis

The clock hypothesis states that the tick rate of a clock when measured in an inertial frame depends only upon its velocity relative to that frame, and is independent of its acceleration or higher derivatives.

link: The Clock Hypothesis-->
Does a clock's acceleration affect its timing rate?
...
Although the clock postulate is just that, a postulate, it has been verified experimentally up to extraordinarily high accelerations, as much as 10^18 g in fact (see the faq What is the experimental basis of Special Relativity?). Of course, the postulate also speaks of more than acceleration, it speaks of all derivatives of v with respect to time. But still it can be shown to be a reasonable thing to assume, because it leads to something that has been tested in other ways, as we'll see in the next section.

Please try to be more consistent.

The GPS satellite here has both gravitational and SR corrections. If you deny this you must explain why GPS clocks are programmed with the SR correction (in this case it is about 1/4 the size of the GR correction, and 25,000X larger than the accuracy of the clocks).

Any such SR programming of GPS clocks has to do with what the observed values are. Just because corrections are included for observers does not mean the actual clock rate onboard the satellite changes due to SR (it does due to GR, and I have always believed that).

You have throughout this conversation avoided argument when the questions are difficult. As here. You don't like my argument so post something different. Whereas I have directly answered all your points.

I don't mind you being pig-headed and wrong. People often are. I think your inability to stick to the topic at hand shows either lack of mental ability, or lack of (mental) integrity.

What makes you think I have time or inclination to respond to your every comment? Especially when you don't read what I post, or even what you post in your own supporting links. Your insults are also duly noted.

[DeltaV]

DV, the fact of the matter is, the CLAIM by Einstein was and is, since 1905, that if you have two clocks that are synchronized, give one some velocity, then return it to rest in the frame with the other clock, the clocks will no longer be synchronized. That is the claim. That is the observed fact as well. Einstein used the simplest language necessary to make this astonishing claim, which has certainly changed the world, and he used very few words as well. There's no dickering about what he said, nor meant.

He clearly changed his mind later in life. He was allowed to do that. Good thing you weren't around.

Now when someone like Mendel Sachs writes on the issue, he may use the term "scaling" or "metric" and be vague about what he's saying, but essentially, he and you are asserting that Einstein, SR and well documented observations are all wrong, and your intuition (as well as Sachs') is right. That is a convenient position to hold if you're suffering delusions of grandeur, but otherwise I'd think more humility is called for.

You need to show more humility, instead of denigrating a tenured, peer-reviewed, published and respected relativity theorist, who has completed Einstein's quest for a Unified Field Theory by removing the unnecessary spacetime reflection symmetry from the equations of General Relativity, bringing them to full fruition. Sachs completely supports Einstein and SR, and has finished what Einstein was trying to do when he died.

Sachs will know more about relativity in his grave than you (or I) ever have.

Now in this above, you're making a new claim. You're saying you agree time dilation occurs in the case of a gravity well, the larger dilation effect found in GPS sats.

That's not a new claim. I have always believed that.

So you believe in time dilation due to gravity as described by GR, but you do not believe in time dilation due to inertia as described by SR.

Is that right?

What is time dilation due to inertia? That's not what SR describes.

I have stated many times that I believe time dilation occurs in SR for observed times, between moving inertial frames. That is a kinematic Lorentz transform effect and has nothing to do with physical aging rates, as you believe.

[tomclarke]

To be fair DeltaV, it is subtle. OTOH, I've stated it here 3 times already, and you don't pay attention, or engage with the argument.

Time dilation in SR between inertail frames is indeed a relationship between coordinates. It has no reality. It cannot be measured, because the two clocks cannot be synchronised in any absoilute sense. It it did were real it would be inconsistent, because both the twins cannot "really" be aging slower.

Got it? So I agree with the author of the thesis, and have stated this many times above.

"Got it?"! Tom, I've stated it here umpteen times already, and you don't pay attention. This is clearly what I've been telling you from the beginning, that Lorentz transform kinematics does not produce differential aging dynamics.

You were, up to this point, vehemently arguing that it does. Glad to see you've finally crawfished over to sensibility.

The phrase "liar, liar, pants on fire" comes to mind.

But maybe you just have not read any of my previous posts.

OR - maybe you have a conceptual problem which means you don't understand what is an interial frame.

We were debating the twins paradox, as measured by planes flying. You claimed there could be no SR correction to time in this case.

But that is a non-inertial frame. Because in order to return the plane must change velocity. As are GPS satellites.

So make up your mind. Are you now saying your objection only applies to inertial frames? In which case ALL the experiments deal with a case you do not consider. So why argue so strongly against them?

Now, time dilation between non-inertial frames, where the clocks return and can be synchronised, is different. It is real, because it can be measured. Of course from the POV of the clocks it is true they tick no differently, in their frames they keep good time. But the overall effect (elapsed time of one is greater than the other) can be clearly measured. And the reason is that acceleration bend the path in spacetime in such a way as to reduce total time along path.

All of my posts on the present thread drift have been about Lorentz transforms in inertial frames (no acceleration). I have not addressed at all the issue of accelerating frames (I have mentioned in passing the clock effects expected when gravitational potential varies).

But regarding your statement above, a link that you posted states clearly that acceleration and even higher derivatives have no effect on clock rates (which I have no problem with):
viewtopic.php?p=74369&highlight=&sid=61 ... e143#74369

The Clock Hypothesis

The clock hypothesis states that the tick rate of a clock when measured in an inertial frame depends only upon its velocity relative to that frame, and is independent of its acceleration or higher derivatives.

link: The Clock Hypothesis-->
Does a clock's acceleration affect its timing rate?
...
Although the clock postulate is just that, a postulate, it has been verified experimentally up to extraordinarily high accelerations, as much as 10^18 g in fact (see the faq What is the experimental basis of Special Relativity?). Of course, the postulate also speaks of more than acceleration, it speaks of all derivatives of v with respect to time. But still it can be shown to be a reasonable thing to assume, because it leads to something that has been tested in other ways, as we'll see in the next section.

Please try to be more consistent.

DeltaV. I am losing my patience with you, because you misunderstand key concepts which i have restated several times, and then fire these accusations at me which are untrue.

YES - acceleration does not cause time dilation (I've never said it does, in fact I've many times said it is not significant).

NO - the effects of acceleration (change in velocity) are highly significant, because they allow clocks to move apart and then back together again. In this situation (only) is it possible unambiguously to synchronise clock times, and so determine whether or not time dilation happens. In this situation, if one clock is inertial, and the other chnages velocity, the one that changes velocity will have smaller elapsed time.

The GPS satellite here has both gravitational and SR corrections. If you deny this you must explain why GPS clocks are programmed with the SR correction (in this case it is about 1/4 the size of the GR correction, and 25,000X larger than the accuracy of the clocks).

Any such SR programming of GPS clocks has to do with what the observed values are. Just because corrections are included for observers does not mean the actual clock rate onboard the satellite changes due to SR (it does due to GR, and I have always believed that).

That is not true, because the position & velocity of the satellite relative to earth does not change from one orbit to the next, whereas the time error does change. Because the satellite is always in the same relative position, it is easy to devise two-way synchronisation which is accurate and does not suffer variable doppler effects. Sure, the synchronisation is not unique, but it does not matter. The SR time dilation continuously changes the relative times. Whereas synchronisation error remains fixed (because the satellite position & velocity relative to earth do not change). So the effect must be real, if it exists.

In a thought experiment you could wait enough time for the SR time error to be >> the lightspeed time between satellite and earth. This time is an upper limit on any synchronisation. But of course you can do better than that because the satellite position and velocity are fixed.

Or, you could bring the satellite back to earth after the clock has got 1s out of synch. Are you telling me it would suddenly run faster and gain 1s due to this?

You have throughout this conversation avoided argument when the questions are difficult. As here. You don't like my argument so post something different. Whereas I have directly answered all your points.

I don't mind you being pig-headed and wrong. People often are. I think your inability to stick to the topic at hand shows either lack of mental ability, or lack of (mental) integrity.

What makes you think I have time or inclination to respond to your every comment? Especially when you don't read what I post, or even what you post in your own supporting links. Your insults are also duly noted.

(1) You are responding.
(2) I read what you post, because I have directly addressed all your arguments, even when repeated.
(3) Please address my arguments with the same assiduity. then the insults will not apply.

[tomclarke]

To move things on, here is a well-argued paper that explains precisely how & why time dilation works in the wins paradox case.

To provide context: the writer supports LR (Lorentzian relativity) not SR, and is actually arguing against SR because it is counterintuitive when compared with LR. (LR says that absolute space, time exists relative to local gravitational field, and that all electromagnetic phenomena go slower when at high velocity).

Therefore the writer agrees (unlike DeltaV) with all the experimental evidence that age difference in the twins paradox is real. One twin will age more than the other. He shows that it can be explained by either SR or LR equally, his objection to SR is that it seems more complex.

I'm not myself supporting LR over SR. Don't have any opinion except vaguely skeptical. But I have an important comment to make on the (interesting) argument against SR in this paper. And the paper is valuable because it shows more clearly what is going on throughout the twins paradox journery than is usual.

The key concept is that if you try to compare times between the two twins throughout the journey, there are two effects:
Time dilation (real, symmetric)
Time slippage (real, asymmetric)

He defines these by constructing sets of clocks stationary in each frame and located throughout space. These can in principle be synchronised exactly and unambiguously by exchange of light beams, since they have no relative motion.

Time slippage dominates over time dilation and is the inferred change in distant time when compared with local time. It depends on velocity and so changes dramatically at the moment that the twin velocity changes round. Acceleration has no part in this.

The paper works through the (SR) calculations from both twins and shows how they are consistent, and how the eventual asymmetry comes from the real asymmetry in the problem - the fact that the travelling twin changes velocity, whereas the stationary twin does not.

http://www.worldnpa.org/pdf/abstracts/abstracts_662.pdf

You need to be patient and read all through the paper to get to the meat.

Now, the argument here is that SR is implausible because the inferred times of the distant clock (which change radically on the travelling twin change of velocity) are given physical reality in SR, and this is counter-intuitive.

Here is where I diagree. SR does not say that any time synchronisation between different frames has (unique) physical reality. When the travelling twin changes velocity the synchronisation method used to determine inferred distant times changes, so therefore do the times. But one method is no better than another. SR makes clear that there is no absolute time, therefore such remote synchronisation is a matter of arbitrary choice, and not unique.

My view on this is to look at Minkowski space-time (the mathematical construct that "explains" SR) and see what this implies. It actually makes the twins paradox asymmetry trivially obvious, a property of bent paths which are therefore closer to the geodesic light cone paths than a straight path between any two points with timelike separation.

You'll have to forgive me if I therefore infer the precise meaning of all those famous axioms etc from my physical interpretation of MS. But not surprisingly this process seems compatible.

Best wishes, Tom

[krenshala]

All of the discussion up to date, with the exception of a few comments from Johan (and one or two others whose names I can't remember ... horrible with names), appear to assume that one of the twins is on the earth, and that the other goes off somewhere else in the system/universe, then returns and shows differential aging.

What about Johan's question asking whether you felt the "traveling" twin would show differential aging when both twins were in a zero-g environment, nowhere near any other celestial body? From what Johan was saying, which makes sense to me, it would be impossible to determine which of the twins was the one actually accelerating in such a scenario, as A would see B doing so, and B would see A doing so, so both FOR would be considered inertial ...

[tomclarke]

All of the discussion up to date, with the exception of a few comments from Johan (and one or two others whose names I can't remember ... horrible with names), appear to assume that one of the twins is on the earth, and that the other goes off somewhere else in the system/universe, then returns and shows differential aging.

What about Johan's question asking whether you felt the "traveling" twin would show differential aging when both twins were in a zero-g environment, nowhere near any other celestial body? From what Johan was saying, which makes sense to me, it would be impossible to determine which of the twins was the one actually accelerating in such a scenario, as A would see B doing so, and B would see A doing so, so both FOR would be considered inertial ...

In a zero-g environment the "stationary" twin would show no acceleration if instrumented with accelerometers, the travelling twin would show acceleration.

If they both accelerate equally then there is no difference in aging.