Room-temperature superconductivity?

[johanfprins]

Johan, it comes down to whether you think the "travelling twin" (or, if you like, GPS satellite) clock measures a shorted elapsed time than the earth-centered one as determined by synchronisation at two different times.

Tom, I just do not have the time to teach you elementary physics since I have more important issues to attend to. Read my manuscript and tell me where you differ from me.

The fact is that Galileo stated that the physics within all inertial reference frames must be the same same, Newton affirmed this in his first law, and Einstein expandeded this to include electromagnetism. Thus it is not possible for any clock within ANY inertial refrence frame to keep time at a different rate than any other clock within any other inertial reference frame. Thus, a radio-active material moving at a speed near the speed of light relative to another piece of the SAME radio-active material, will decay at the SAME rate. It is only when you transform what happens within an inertial reference frame into another inertial reference frame that the transformed simultaneous events within an inertial reference frame occur at different times and positions within the refrence frame into which they are being transformed: The actual time is the same on all moving clocks since they are ALL stationary within their own inertial reference frames.

Within any inertial refrence frame the time at every coordinate position is exactly the same. Only when you look in from outside do simultaneous events in one reference frame occur at different times within your reference frame. This does NOT mean that the time on the clocks within your or any other inertial reference frame show different times at different positions. Neither does it mean that the time at different positions within a passing reference frame is different at different positions within that inertial reference frame.

If all the natural clocks have been synchronised at the Bg Bang as they must have been, then they all are keeping the same time within their respective inertial refrence frames. Time is absolute in this sense. Only gravity affects the rate at which a clock keeps time, and this effect is not caused by the equivalence principle of Einstein, but by the fact that both light and matter consist of wave-energy: i.e. electromagnetic energy.

So I am not interested in your diagrams since I know all these diagrams better than a lightweight like you does. I also now know that they have been wrongly interpreted for over 100 years. So this is now definitely my last post for at least four weeks. Cheers!

[tomclarke]

Johan, it comes down to whether you think the "travelling twin" (or, if you like, GPS satellite) clock measures a shorted elapsed time than the earth-centered one as determined by synchronisation at two different times.

Tom, I just do not have the time to teach you elementary physics since I have more important issues to attend to. Read my manuscript and tell me where you differ from me.

The fact is that Galileo stated that the physics within all inertial reference frames must be the same same, Newton affirmed this in his first law, and Einstein expandeded this to include electromagnetism. Thus it is not possible for any clock within ANY inertial refrence frame to keep time at a different rate than any other clock within any other inertial reference frame. Thus, a radio-active material moving at a speed near the speed of light relative to another piece of the SAME radio-active material, will decay at the SAME rate. It is only when you transform what happens within an inertial reference frame into another inertial reference frame that the transformed simultaneous events within an inertial reference frame occur at different times and positions within the refrence frame into which they are being transformed: The actual time is the same on all moving clocks since they are ALL stationary within their own inertial reference frames.

Within any inertial refrence frame the time at every coordinate position is exactly the same. Only when you look in from outside do simultaneous events in one reference frame occur at different times within your reference frame. This does NOT mean that the time on the clocks within your or any other inertial reference frame show different times at different positions. Neither does it mean that the time at different positions within a passing reference frame is different at different positions within that inertial reference frame.

If all the natural clocks have been synchronised at the Bg Bang as they must have been, then they all are keeping the same time within their respective inertial refrence frames. Time is absolute in this sense. Only gravity affects the rate at which a clock keeps time, and this effect is not caused by the equivalence principle of Einstein, but by the fact that both light and matter consist of wave-energy: i.e. electromagnetic energy.

So I am not interested in your diagrams since I know all these diagrams better than a lightweight like you does. I also now know that they have been wrongly interpreted for over 100 years. So this is now definitely my last post for at least four weeks. Cheers!

Other than the mild insults, and reinterpretation of gravity, Johan does not say anything here I would disagree with. But it seems he does not understand the limitations (clocks must remain in a single reference frame) of what he says, because he applies the same logic to situations such as in my diagram.

The diagram makes this clearer.

Johan: I have told you many times in this thread where I disagree with you.

[GIThruster]

The fact is that Galileo stated that the physics within all inertial reference frames must be the same same, Newton affirmed this in his first law, and Einstein expandeded this to include electromagnetism. Thus it is not possible for any clock within ANY inertial refrence frame to keep time at a different rate than any other clock within any other inertial reference frame.

THIS, is what you think all the world doesn't understand? Everyone on the planet has missed this for a century, and suddenly you have it right?

Are you mad?

[ScottL]

Quick question for Johan...

If there is no difference in time rate, barring delay in signal from orbit to earth, why do GPS satellites need to resync periodically?

I'm not asking out of sarcasm, but out of confusion as to how this could be a necessity and yet the time rate be the same.

[DeltaV]

If there is no difference in time rate, barring delay in signal from orbit to earth,

There is an actual difference in onboard and ground station time rates due to different gravitational potential. I think everyone agrees on that point.

why do GPS satellites need to resync periodically?

Engineers who actually worked on GPS state that relativity is not the reason for these resyncs (emphasis added below):

Long-Term Prediction of GPS Accuracy: Understanding the Fundamentals

Ted Driver is the Senior Navigation Engineer at
Analytical Graphics, Inc (AGI). Ted has worked on AGI’s
navigation capabilities for more than three years, having
previously been the technical lead for Navigation Tool Kit
development at Overlook Systems Technologies. He has
led the engineering team in developing the navigation
algorithms and data stream definitions and is currently
working on statistical prediction models for GPS
accuracy. He was previously the senior GPS Operations
Center analyst within the 2nd Space Operations Squadron
at Schriever Air Force Base. He has worked in the GPS
field for 10 years, previously designing the environment
and navigation models for the GPS High Fidelity
Simulator currently in use at Schriever Air Force Base.
Mr. Driver received his Bachelors Degree in Physics from
the University of California at San Diego and his Masters
Degree in Physics from the University of Colorado. He is
a former President, Vice President and Secretary of the
Rocky Mountain Section of the Institute of Navigation.

Signal-In-Space Range Error

The SIS ranging error consists of two primary pieces,
ephemeris error and clock error. The ephemeris errors are
errors between the actual GPS satellite position and the
satellite position broadcast to receivers. The clock error is
similar – it’s the difference between the actual clock
phase and the clock phase that’s calculated from
parameters sent to the receiver. These errors are typically
a few meters but can be much more, especially in the case
of the clock. Ephemeris errors result from unmodeled
perturbations on the satellite and are reduced to almost
zero when a new navigation upload is made to the
satellite. At this point, the age of data (AOD) is zero and
the broadcast ephemeris is at its most accurate. As time
progresses throughout the day, imperfections in the
ephemeris prediction slowly appear, leading to larger
ephemeris errors.
The clock errors act similarly. The clock errors arise from
quantum mechanical fluctuations in the atomic clock
itself, leading the clock phase to exhibit a random walk
behavior. This effect is difficult to predict and over days,
and over weeks and months would be impossible to
determine.
In this analysis, the job of having to predict the ephemeris
and clock errors is made simpler by the fact that these
errors are clamped. The 2nd Space Operations Squadron
(2SOPs) watches both the ephemeris and clock residuals
in near real time and ensures that they stay below certain
thresholds by uploading new navigation data predictions
to the satellites. Typical satellites are uploaded once per
day; some more often (usually the older satellites), some
less often. This clamping effect on the SIS errors makes
predicting long term behavior easier, in that we do not
need to be able to predict random clock behaviors for
weeks at a time.

GPS AND RELATIVITY: AN ENGINEERING OVERVIEW

Henry F. Fliegel and Raymond S. DiEsposti
GPS Joint Program Offlce
The Aerospace Corporation
El Segundo, California 09245, USA

The Operational Control System (OCS) of the Global Positioning System (GPS) does not include the rigorous transformations between coordinate systems that Einstein's general theory of relativity would seem to require - transformations to and from the individual space vehicles(SVs), the Monitor Stations (MSs), and the users on the surface of the rotating earth, and the geocentric Earth Centered Inertial System (ECI) in which the SV orbits are calculated. There is a very good reason for the omission: the effects of relativity, where they are different from the effects predicted by classical mechanics and electromagnetic theory, are too small to matter - less than one centimeter, for users on or near the earth.

...

Eminent scientists have been divided amongst themselves, wondering whether the OCS software does not need to be rewritten, expecially since the Department of Defense is now requiring that the current specifications - 6 meters in User Range Error (URE) - are to be tightened under the Accuracy Improvement Initiative (AII). In this paper, we compare the predictions of relativity to those of intuitive, classical, Newtonian physics; we show how large or small the differences are, and how and for what applications those difference are large enough to make it necessary to correct the formulas of classical physics.

...

As we have shown, introducing the γ factor makes a change of only 2 or 3 millimeters to the classical result. In short, there are no "missing relativity terms." They cancel out.

While certainly not a formal relativity experiment, one could interpret this as early signs of the crumbling of the "Twin Paradox" edifice.

[tomclarke]

If there is no difference in time rate, barring delay in signal from orbit to earth,

There is an actual difference in onboard and ground station time rates due to different gravitational potential. I think everyone agrees on that point.

why do GPS satellites need to resync periodically?

Engineers who actually worked on GPS state that relativity is not the reason for these resyncs (emphasis added below):

Long-Term Prediction of GPS Accuracy: Understanding the Fundamentals

Ted Driver is the Senior Navigation Engineer at
Analytical Graphics, Inc (AGI). Ted has worked on AGI’s
navigation capabilities for more than three years, having
previously been the technical lead for Navigation Tool Kit
development at Overlook Systems Technologies. He has
led the engineering team in developing the navigation
algorithms and data stream definitions and is currently
working on statistical prediction models for GPS
accuracy. He was previously the senior GPS Operations
Center analyst within the 2nd Space Operations Squadron
at Schriever Air Force Base. He has worked in the GPS
field for 10 years, previously designing the environment
and navigation models for the GPS High Fidelity
Simulator currently in use at Schriever Air Force Base.
Mr. Driver received his Bachelors Degree in Physics from
the University of California at San Diego and his Masters
Degree in Physics from the University of Colorado. He is
a former President, Vice President and Secretary of the
Rocky Mountain Section of the Institute of Navigation.

Signal-In-Space Range Error

The SIS ranging error consists of two primary pieces,
ephemeris error and clock error. The ephemeris errors are
errors between the actual GPS satellite position and the
satellite position broadcast to receivers. The clock error is
similar – it’s the difference between the actual clock
phase and the clock phase that’s calculated from
parameters sent to the receiver. These errors are typically
a few meters but can be much more, especially in the case
of the clock. Ephemeris errors result from unmodeled
perturbations on the satellite and are reduced to almost
zero when a new navigation upload is made to the
satellite. At this point, the age of data (AOD) is zero and
the broadcast ephemeris is at its most accurate. As time
progresses throughout the day, imperfections in the
ephemeris prediction slowly appear, leading to larger
ephemeris errors.
The clock errors act similarly. The clock errors arise from
quantum mechanical fluctuations in the atomic clock
itself, leading the clock phase to exhibit a random walk
behavior. This effect is difficult to predict and over days,
and over weeks and months would be impossible to
determine.
In this analysis, the job of having to predict the ephemeris
and clock errors is made simpler by the fact that these
errors are clamped. The 2nd Space Operations Squadron
(2SOPs) watches both the ephemeris and clock residuals
in near real time and ensures that they stay below certain
thresholds by uploading new navigation data predictions
to the satellites. Typical satellites are uploaded once per
day; some more often (usually the older satellites), some
less often. This clamping effect on the SIS errors makes
predicting long term behavior easier, in that we do not
need to be able to predict random clock behaviors for
weeks at a time.

GPS AND RELATIVITY: AN ENGINEERING OVERVIEW

Henry F. Fliegel and Raymond S. DiEsposti
GPS Joint Program Offlce
The Aerospace Corporation
El Segundo, California 09245, USA

The Operational Control System (OCS) of the Global Positioning System (GPS) does not include the rigorous transformations between coordinate systems that Einstein's general theory of relativity would seem to require - transformations to and from the individual space vehicles(SVs), the Monitor Stations (MSs), and the users on the surface of the rotating earth, and the geocentric Earth Centered Inertial System (ECI) in which the SV orbits are calculated. There is a very good reason for the omission: the effects of relativity, where they are different from the effects predicted by classical mechanics and electromagnetic theory, are too small to matter - less than one centimeter, for users on or near the earth.

...

Eminent scientists have been divided amongst themselves, wondering whether the OCS software does not need to be rewritten, expecially since the Department of Defense is now requiring that the current specifications - 6 meters in User Range Error (URE) - are to be tightened under the Accuracy Improvement Initiative (AII). In this paper, we compare the predictions of relativity to those of intuitive, classical, Newtonian physics; we show how large or small the differences are, and how and for what applications those difference are large enough to make it necessary to correct the formulas of classical physics.

...

As we have shown, introducing the γ factor makes a change of only 2 or 3 millimeters to the classical result. In short, there are no "missing relativity terms." They cancel out.

While certainly not a formal relativity experiment, one could interpret this as early signs of the crumbling of the "Twin Paradox" edifice.

DeltaV, I am sure you could interpret anything in this way, and equally sure that on the internet you will find fuel.

The first quote shows that the corrections considered here are orbit periodic. Not systematic. The twins paradox relativity correction is inserted before the satellites are flown, by setting the clocks to a different rate from earth time.

This one-off rate correction has two components:
gravitational & SR. It is precise.

If it were wrong periodic errors would build up.

Of course the GPS clocks can be resynchronised with earth time, since the continually exchange signals and have known orbits. Your quote your does not say how often this happens.

[tomclarke]

Tom Van Flanders (now dead) is my favourite writer on Twins paradoc etc. His background is as a respected & published physicist (astronomer). He has some slightly weird ideas on LET as a non-standard alternative to SR, but he does not let these obscure the observational evidence (all of which is compatible with SR).

http://metaresearch.org/cosmology/gps-relativity.asp

He states that clock instability makes 1ns/day variation in GPS time.

Therefore, we can assert with confidence that the predictions of relativity are confirmed to high accuracy over time periods of many days. In ground solutions with the data, new corrections for epoch offset and rate for each clock are determined anew typically once each day. These corrections differ by a few ns and a few ns/day, respectively, from similar corrections for other days in the same week. At much later times, unpredictable errors in the clocks build up with time squared, so comparisons with predictions become increasingly uncertain unless these empirical corrections are used. But within each day, the clock corrections remain stable to within about 1 ns in epoch and 1 ns/day in rate.

The initial clock rate errors just after launch would give the best indication of the absolute accuracy of the predictions of relativity because they would be least affected by accumulated random errors in clock rates over time. Unfortunately, these have not yet been studied. But if the errors were significantly greater than the rate variance among the 24 GPS satellites, which is less than 200 ns/day under normal circumstances, it would have been noticed even without a study. So we can state that the clock rate effect predicted by GR is confirmed to within no worse than ±200 / 45,900 or about 0.7%, and that predicted by SR is confirmed to within ±200 / 7,200 or about 3%. This is a very conservative estimate. In an actual study, most of that maximum 200 ns/day variance would almost certainly be accounted for by differences between planned and achieved orbits, and the predictions of relativity would be confirmed with much better precision.

[ladajo]

There are many things that cause error in GPS Bird clocks. And as we fly more advanced birds with more capable clocks, previously ignorable errors are having to be accounted for.

In the case of the pre-launch correction for GR and SR it has been done since day one of GPS operations.

I believe that all are ok with the GR component, and the SR component is still questioned. Currently, the SR component, based on the flight profiles of the birds is about a 15% counter correction in regards to GR.

The birds are currently "corrected" (re-synched) to master time on about a daily basis, depending on the model of the bird. The primary reasons for this are orbital error (ephmeris), radiation induced errors and quantum error (the non-perfect cycling of the atoms).

One of the current initiatives in GPS capability is driven by military smart weapons and systems. This initiative is driving up the accuracy requirements in accordance with user system demands. This is manifesting two ways, one is that the running corrections algorythms be updated, the other is fielding ever more capable clocks, and "Paper clock" methodology.

Every operating bird is in a unique orbit, and is influenced by external factors due to this. These differences require constant monitoring and generate corrections by the three segments.

I personally feel that there is some merit to continue the discussion about the SR correction component, and also feel that we all can learn some things from it. Especially when considering the recent "finalized" results from the Gravity-B experiment and how they might apply to GPS corrections as well as SR. I also think that some consideration should be given to the Gravity-B project and a follow-on one for an orbit around the the sun, and then compare the two sets of data. Gravity-B was in a polar sun synch orbit, and as such should have had some component of frame dragging from the sun itself in its variance. I did not catch in the write up where this was considered, but I am sure it must have been.

The bottom line is that the GPS system works, and works REALLY WELL. Whether or not it works properly based on what we think we know and do about issues, verses what we have wrong, or misunderstand, and in that come up with a working correction based on incorrect ideas seems to be the core of the discussion.

When you fly a clock in orbit, and then compare it to a ground based clock, the clock rates will have been different. And these findings are also for different types of clocks, for example some using Cs and some Rb. This has been done many many times, and is being done as we speak. The rate difference is a proven fact. What it means, and why it is what it is are under discussion, with a dominance saying that the two clocks have a predictable different rate because of a combined GR and SR effect. I have been looking for evidence where the GR and SR components have been split out under similar circumstances, but have not found much to date in the orbital science realm.

I think Johan's point about a gravity free linear run is a good one. Maybe we will learn something.

[tomclarke]

ladajo,

Are the error estimates above reasonable? In which case they prove that eiter SR time dilation is correct, to within the given tolerance, or else some other combo SR/GR new theory makes a substantial correction to what is currently understood?

Tom

[ladajo]

Tom,
The SR component is what I have been thinking on. Unlike GR, which enjoys support and significant accuracy, SR is a little more wild with up to three magnitudes of error depending on what set of data you are looking at.

The SR counter correction made for GPS clocks is old school and included in every clock flown. So at least the math is good to produce the correction factor. The why of the math seems to be the argument here.

But, the fact remains, what is attributed to SR induced rate differences, is predicted and controlled everyday. We may not be right to call it SR correction, but the correction is required and does work. It is a neccessary fudge factor to adjust clock rate.

Unfortunately the PARCS and RACE concepts have run afoul of funding, and thus further insight into SR is delayed as we will not in the near future fly a "super clock" on ISS.

I think it is telling that different types of clocks experience the same rate issues. So what ever is going on is independant of the type of mechanism.

I would also argue that the correction factors for rate do indicate an "aging" difference. Flown clocks require rate corrections, these rate corrections are an offset of the atomic count rate, and thus the same matter, say Cs-133, experiences a different life rate. We define that 9,192,631,770 oscillations of Cs-133 is an atomic second. And then we go and adjust that number of reported oscillations with a combined SR & GR fudge factor to account for the fact that the Cs-133 flying in MEO does not in fact take 1 ground based (Master Station) second to make 9,192,631,770 oscillations. I would argue that is also an indication of difference in its "existence" time. That said, there are on-going arguments over isotope decay rates. Some have produced evidence that decay rates vary with distance to the sun, others have shown that outer system probes do not show a difference with decay rates compared to solar distance. it is a question to ask and test. Because if atomic oscillations do vary rate (as shown in orbital clocks), but atomic decay rates do not change in orbit, then we remain with questions. Like, is dilation seperate from matter's existence? Or is atomic oscillation releasing photons completely un-related to particle decay?

Here is a discussion talking about decays...

http://www.geo.cornell.edu/geology/clas ... ture02.pdf

[DeltaV]

Are the error estimates above reasonable? In which case they prove that eiter SR time dilation is correct, to within the given tolerance, or else some other combo SR/GR new theory makes a substantial correction to what is currently understood?

The clock errors arise from quantum mechanical fluctuations in the atomic clock itself, leading the clock phase to exhibit a random walk behavior.

Get the picture?

[ladajo]

The diagram does not show which birds are which types and how long they have been on orbit.. That also affects the stability of the clocks. Some of the birds are also in more eccentric orbits, which also induces a higher error accumulation rate.

Also note that long term error correction verses short term are an important difference. The graph you have shown is short term error, The GR (46us) /SR (7us) corrective factors are long term. Without them the entire chart is depicted would skew over time as the rate error accumulated.

I do understand your point, but I think that you miss the part about the long term correction. Some birds in fact are more stable over the longer run and track well within the daily limits (200ns if I recall) and do not require the short term adjusts. Those would be the ones tracking down the center of the axis. There are birds that go long periods without corrections, and they tend to be the ones in the most stable least eccentric orbits with newer clocks. Although, I believe there is an older bird that was orbit adjusted, and has behaved very nicely for a number of years since that.

edit: corrected SR/GR units to usec vice nsec.

[tomclarke]

It is 7us/day, not 7ns/day for SR correction.

That is 2100m/day correction.



DeltaV - I sometimes think that you just don't pay attention to numbers.

Your picture, which I get better than you it seems, shows max 10m/day typical 1m/day.

How can all those clock errors be significant?

[ladajo]

Sorry Tom, my typo. I did mean usec.

I am curious about decay rates. I did some searching, but still nothing definitive on SR effects on isotope decay rates.

[DeltaV]

Are you certain that the SR correction hasn't, by this time, random-walked away from its "factory offset" value?