The Death of Relativity

[MacM]

I guess they just skipped straight to GR, which includes all the same effects, plus the other ones which are important.

I have already shown your flip-flop regarding the use of SR in GPS and pinned to the carpet you have finally admitted what I said a year ago when this all started "SR is not used in GPS".

So now that you were defeated on this issue you want to slip over to some bogus GR is the same thing arguement.

You are impossible, unbelievable and unworthy of any further discussion.

[KitNyx]

MacM - The currently accepted and best/most tested theory is SR and QED (which is SR applied to quantum theory). Therfore the burden of proof logically lies with you if you want to convince anyone of another theory. In my opinion James R is stating known fact or as close to it as we (society, including modern scientists and mathematicians) know, you on the otherhand are the one spouting illogical and unproven nonsense. I think James R deserves a bit of gratitude for actually trying to help people who come to this site to learn something about science instead of pseudoscience or as you put it - rhetoric...once again it is my opinion but I think you should stick to the perpetual motion machines...

- KitNyx

[James R]

Tell us how you propose to cause two physical clocks to accumulate less time than each other in the same test period.

How many times do I have to tell you: THEY CAN'T!

Write it down on your hand with a black marker, and look at it next time you lose your memory again.

[KitNyx]

I want to say something, but I can not quite laughing about that damn alien lander...-rolls out of chair-

- KitNyx

[MacM]

How many times do I have to tell you: THEY CAN'T!

Write it down on your hand with a black marker, and look at it next time you lose your memory again.

Then stop claiming reciprocity exists. You just did so claiming earth surface clocks run slow (due to velocity) when viewed from orbit even though they are synchronized to earth clocks. They do not and cannot.

[KitNyx]

Reciprocity? I do not think you are using that word correctly. Reciprocity describes an interdependant relationship...more like what you are describing. I am fairly certain that James R is advocating two INDEPENDANT frames of reference...

- KitNyx

[MacM]

Reciprocity? I do not think you are using that word correctly. Reciprocity describes an interdependant relationship...more like what you are describing.

Care to qualify this. "Not using correctly" and "more like you are describing", seem contridictory.

I am fairly certain that James R is advocating two INDEPENDANT frames of reference...

- KitNyx

James R has stipulated in very specific detail and described cases that reciprocity between relavistic affects of two observers in moton exists. He even claims today that earth's surface clocks are running slower due to relative velocity with the orbiting clock from the orbit's view - Even though the orbit clocks have been prelaunch calibrated and are in tick/tick synch with earth.

I am using the term reciprocity just as it is stipulated in texts regarding its appplication to SRT.

[MacM]

MacM - The currently accepted and best/most tested theory is SR and QED (which is SR applied to quantum theory). Therfore the burden of proof logically lies with you if you want to convince anyone of another theory. In my opinion James R is stating known fact or as close to it as we (society, including modern scientists and mathematicians) know, you on the otherhand are the one spouting illogical and unproven nonsense. I think James R deserves a bit of gratitude for actually trying to help people who come to this site to learn something about science instead of pseudoscience or as you put it - rhetoric...once again it is my opinion but I think you should stick to the perpetual motion machines...

- KitNyx

You are intitled to your opinion. I'll only note that your preferance seems to be the rhetoric and leaving valid physics issues unanswered infavor of appeals to authority, etc.

These are valid issues and they are not being asnwered with physics responses but only I say or Einstein said or SRT states. We can all read and likely have read all these claims. That is why we ask the questions in terms of physics. The theory is only partially demonstrated by test data and observation. That does not justify supporting those aspects of the theory that are simply and clearly false.

It would be one thing if he or others merely said well theory says this. But they don't, instead they make unsupported statements as matters of fact and attack us claiming we are ignorant, liars, etc. That doesn't cut it and it is not a physics discussion at that point.

[MacM]

They won't and never will. Next question?

You have already indicated that you accept that reciprocity is false, James R has not.

[funkstar]

You guys, it is all very simple where relativity of simultaneity comes from. I know you
must have seen this on your own. It comes from the act of always placing the observer in a frame of rest and the 'other' frame in motion. Let the observer on the
airplane consider himself in motion and the two events on the ground in a rest frame.
There is no loss of simultaneity in this situation, only time of transit delays of information (light). The constancy of the speed of light and symmetry between frames
is also tossed by doing this.

Which, of course, is why this particular view doesn't match reality: The constancy of the speed of light and isotropic propagation regardless of frame has tremendous experimental basis. Your (Newtonian) view is, like SR, perfectly selfconsistent (it's just R^4 with a Euclidian metric), but it isn't as good a description of nature as SR.

The photon bouncing back and forth tracing a 'V' path in
the moving frame will always be in same moving frame, never happens to the 'other'
frame if ONE FRAME ONLY retains the rest frame status. A light clock always beats
slowly in ONE FRAME ONLY, whichever one is assumed to be moving, always.

Again, this is not how nature works.

[everneo]

And in the example James uses the phrase "exact moment" as to distinguish a single point in time, As in the instant James starts to type and MacM starts to sip. James is saying that while James starting typing and MacM starting to sip happen at the same "exact moment" for them, they do not happen in the same "exact moment" for the plane observer.

He also says :

The other person will be sipping their drink either a little before or a little after I typed the word "computer", according to the observer in the plane (the before or after depends on the direction of travel of the plane).

The implications :

If they are the next room from each other the non-simultaneity as seen from the plane will be on the order of nano-seconds, Not even enough time for EM to cross the distance between them.

..but enough for completing typing the word 'computer' within the order of nano-seconds clearly ahead of 'sipping'?!

Yes, you are trying to force it, by making the non-simultaneity larger than it would be if they were in the next room from each other (such that it is large enough to encompass the whole of the typing of "computer").

If simultaneity breaks down in the order of nano-seconds such that not even for 'EM waves to cross the distance between them', but somehow the typing was completed within the order of nano-seconds, great.

My question was simple. While typing, James was also talking, grinning, groaning
in response to some information he received through the head phone. If the plane observer distinguishes 'typing' act ( that accompanies his other acts detailed earlier ) and clearly ahead of 'sipping' then breakdown of simultaneity means breakdown of causality here.

[2inquisitive]

James R, I would like to discuss this issue of GPS clock synchronization if
you have time. I don't know all the answers, but I do have an understanding
of the synchronization process and some information you might not be familiar with.

To begin with, I won't go into detail of the GPS clock pre-set before launch,
just that it is said to be -38 microseconds/day according to Dr. Ashby and as stated on many university websites. This is arrived at by calculating the satellite clock will beat 45 u/s day fast due to location in the gravitational well and 7 u/s day slow due to relative velocity, leaving a needed adjustment
of -38 microseconds per day to synchronize the orbiting clock with a hypothetical clock at the center of the Earth. This adjustment does not synchronize the orbiting clock with a surface clock, but with a clock at the center of the Earth. I have gained more information about further adjustments. This information comes from the U. S. Naval Observatory's
website of published papers in pdf format. This particular paper was presented
by ITT, a GPS satellite contractor (not receiver). It was presented at the
33rd annual Precise Time and Time Interval Conference. The title of the paper
is 'Management Of Phase And Frequency For GPS 11R Satellites'. I mention all
this so you won't dismiss it as a crank paper before reading it, if you do choose to read it. I had read a few months ago, and not on a crank site, that
the pre-launch adjustment is done primarily because some physicists, presumably including Dr. Ashby, insisted it was done. This pre-launch adjustment doesn't seem to be necessary as the atomic clocks, both cesium
and rebidium, are turned on and synchronized in orbit. The first synchronization is called a 'cold injection' synchronization. The atomic clocks,
especially the rebidium, are not stable when first placed in orbit. They have quite a bit of drift for up to a month or two. After the clocks 'settle down',
a second synchronization is done. Here is an initial description:

"In all current generations of GPS SVs (Block Ivrww), phase and frequency are adjustable from the
ground. A nominal GPS Block IVHA cesium clock has a frequency drift that is on the order of
l~lO-'~/day. Thus, a nominal cesium atomic standard, whose phase and frequency has been initially set to
zero, would require zero or maybe one phase correction in its lifetime to keep the phase within the
broadcast navigation message limits.
GPS Block IIAA rubidium atomic standards have much higher frequency drift than cesium atomic
standards. The GPS Block II/IIA rubidium atomic standards can have frequency drift on the order of
20~10-'~/day. Because of the high frequency drift, a nominal II/IIA rubidium atomic standard, whose
phase and frequency has been initially set to zero, would require a correction to phase and/or frequency
once or twice a year to keep the phase within the broadcast navigation message limits.
GPS Block IIR rubidium atomic standards, after a year of operation, have a frequency drift in the range of
1 to S~lO-'~/day. In addition, GPS Block W has an adjustable frequency drift that allows the Master
Control Station to use a new frequency drift correction approach for Block IIR satellites to keep the phase
within the broadcast navigation message limits. This approach has led to a much closer control of phase
and frequency, so that frequency drift corrections are required, on the average, once every 1 or 2 years.
There is a further benefit for the new approach in that a frequency drift correction can be applied to an
operational satellite without any outage, while a satellite outage is needed for a phase and/or frequency
correction."

Here is a description of the clock adjustment procedures:

"The initial operation phase starts when the cold injection procedure is completed and ends with the first
frequency drift correction. In the initial operation phase, there are no corrections made to the clock, but
there are changes in the phase, frequency, and frequency drift of the clock. The phase is driven from -100
microseconds toward zero, because the frequency is positive, which causes the phase to increase
algebraically. The frequency is driven from +15~10”~ to zero, because the frequency drift is negative,
which causes the frequency to decrease algebraically. The clock frequency drift starts off with a very large
value such as -20x10-I4/day and decays rapidly toward zero and, at the same time, stabilizes. The
frequency error becomes a cue as to when to make the first frequency drift correction to begin the next
phase. When the frequency error is in the vicinity of zero, a frequency drift correction is made to cancel
out most of the frequency drift of the RAFS. This leaves the broadcast 10.23 MHz signal with a negative
net frequency drift, but much reduced in magnitude from the frequency drift of the RAFS. The initial
operation period is on the order of 6 months long. At the end of the initial operation period, the frequency
error is essentially zero, the phase is close to zero and the frequency drift is much reduced in magnitude
from its initial large negative value and is much more predictable. The initial operation period is clearly
shown in Figure 3, where clocks start off with large positive frequency and decay toward zero.
The normal operation phase starts off with the first frequency drift correction and continues for the rest of
the life of the clock. During this time, frequency drift corrections are used to keep the clock frequency
error between some limits such as k4~1O-l~. Because the frequency drift of the clock varies, it is not
possible to have the clock frequency drift correction exactly cancel the clock frequency drift. If the net
frequency drift is positive, then the clock frequency error will go toward +4~10-’~; if it is negative then the
frequency error will go toward -4~10-’~. When the net frequency drift reaches a limit, a frequency drift
adjustment is made so that the net frequency drift changes sign and the frequency error moves toward the
other frequency limit. Typically, the frequency will have a zigzag curve between the frequency limits. It is
expected that the average time between frequency drijl corrections will be between 1 and 2 years.
The increase in phase error is fairly small because the frequency errors are kept to low values and because
the zigzag frequency course tends to integrate into keeping phase low. The following heuristic argument
illustrates this process."
http://tycho.usno.navy.mil/ptti/ptti2001/paper49.pdf

I post this again to illustrate that the 'pre-launch' adjustments are calculations from theory and not the final or actual adjustment used after the
clocks are in orbit. The final, actual adjustments are done after the clocks are
placed in orbit. Why do I think this is important? Because the clocks are
synchronized with EARTH SURFACE CLOCKS. GPS time and UTC time only differs because leap seconds are not incorporated into GPS time, but are
included in the 'message' broadcast from the satellites. The Russian GLONASS
system does update their clocks when leap seconds are added in UTC time.
They are in perfect synchronization with UTC time.

Now to the issue of whether or not an observer on a GPS satellite will 'see' the Earth clock as beating slower. Of course the observer sees the Earth
clock beating slower because of gravitational potential differencies. That is
not in dispute. What you and I don't seem to agree on is whether satellite
clocks can be synchronized in both frames of reference. This is not a problem
if time dilation is one way only, such as the GR redshift adjustment. If the relative
velocity component is two way, where each reference frame 'sees' the other
reference frame as dilated (slow) then synchronization is impossible as viewed
from BOTH frames, i.e. surface-to-satellite and satellite-to-surface. But, James R, the surface clock DOES NOT beat slower than the synchronized
satellite clock. After years of operation, the satellite clock is still in synch
with the EARTH SURFACE clock, not a clock at the center of the Earth.
You say the clocks are only synchronized in the Earth frame of reference.
They ARE synchronized in the Earth frame because that is where the users
are located. But synchronizing in the Earth frame is not possible if the satellite
clocks are gaining time on the surface clocks in the satellite clocks frame of
reference. They would have to be adjusted to beat faster relative to the Earth clock to keep them in synch in the Earth frame. But viewed from the
satellite frame, they would be gaining time twice as fast as the Earth clock
if the two-way time dilation of STR were true. That doesn't happen, the satellite clocks keep in synch with the surface clocks in the satellite clock's
frame of reference also, for years. Time dilation due to relative velocity HAS
to be a one-way affect, at least in orbiting frames of reference, or it has to
be non-existant. There is much evidence that supports a slower beating clock
for high velocity particles. I believe gravitational fields are the key, but that is not the point of this post. Synchronization of clocks is the point. Can you
offer a detailed rebuttal to show where I am mistaken in my conclusions above? Perhaps I am misunderstanding something, but I need that shown before I can change my conclusions.

[john smith]

why dont you rite a book fo sho? im mean thts not a discussion, its a fucking synopsys my fizzy shin dig

[funkstar]

2inq: Let me see if I understand you correctly.

What you're saying is that synchronization is only possible wrt the gravitational redshift, because that's absolute, and not velocity time dilation, because that's relative. Since the GPS clocks are synched to Earth clock time, the velocity time dilation cannot be in effect.

Now, that the GPS clocks are set to to synchronize with the earth center clock is (I believe) not a problem, because the effects of velocity time dilation of standing still on the surface (that is, rotating) and the change in gravitational redshift when going from a pole to the equator cancel each other out at sea level (IIRC). So earth surface time ticks the same everywhere, and has a trivial relation with earth center time (I think).

Ok, that takes care of the earth center/earth surface part, but the GPS clocks still have a velocity wrt. the earth (right?), and there's gravitational redshift to factor in.

Now, we can easily factor out the gravitational redshift by making the GPS clock slightly slower than the earth clock (counting more hyperfine transitions pr. GPS "second"). Also, as viewed from the earth, we can cancel out the velocity time dilation easily by making it just a tad faster than were we only cancelling out the redshift part, summing to the making a "day" 38,000 nanoseconds longer for the GPS clock.

So the GPS second (let's call it a gps ) is actually

1 gps = (1 - (gamma_v - 1) + (gamma_g - 1)) proper seconds
= (1 - gamma_v + gamma_g) proper seconds

where gamma_v is the velocity time dilation, gamma_g is the gravitational redshift (both > 1).

Now, you're saying that since the GPS stays in synch with the Earth clocks, as it was designed to do, it must be the case that there are only non-symmetric effects like redshift in effect, if the earth clocks stay in in synch with the GPS clock. Let's examine this, so we know what we're talking about.

Now, when we compare the timestamp of a satellite with our own time on earth, we know for a fact that if they match up then for the satellite more proper time has elapsed than the timestamp reads because the GPS clock is designed to tick slower than standard time. And they will match up because the system is designed that way. In other words receiving a timestamp matching local conclusively proves that the GPS clock is ticking "too fast", as viewed from earth.

Now, imagine a synchronization event where the satellite compares a timestamp it has received from earth with its GPS clock. Now, you're saying that if these timestamps match up then GPS time is directly propertional to earth time, and that therefore it cannot see earth time as slowed down by both velocity and gravitational time dilation. I believe that is correct. Let's see why:

The GPS clock is ticking a bit slower than a proper second by design, so the relationship between a proper time second for and the GPS clock second (gps) is

1 proper second = (1 + gamma_v - gamma_g) gps

(Just manipulate the above previous equation)

Hence, when the GPS clock reads t, then actually (1 - gamma_v + gamma_g)*t proper seconds has elapsed. But now you receive a timestamp that says that on earth only t seconds has elapsed. But the satellite knows and has experienced t(1 - (gamma_v-1) + (gamma_g-1)) seconds so the earth's clock is definitely slowed down. Now, since velocity time dilation is symmetric, we have that viewed from the satellite, time on earth should slowed by a factor of 1 + (gamma_v-1) + (gamma_g-1). This implies that gamma_v is 1, or that velocity time dilation is anti-symmetric.


So, the question I ask is: How do the clocks synchronize? What frame are they synchronised to? What are their velocities in that frame?

[Anomalous]

...
Anomalous:
To meet, one or both of them needs to accelerate. During acceleration, other time dilation effects occur which are different from constant-velocity affects.

I am asking what will decide whoes clock will race ahead ?

[2inquisitive]

OK, funkstar, I'll see if I can summarize this a bit. The information you read at university websites and such only mention the pre-launch adjustment, in which the
satellite clocks are supposed to be adjusted to a clock at the center of the Earth,
therefore eliminating Earth surface velocity from consideration. By doing that, you don't have to worry whether the ground receiver is located at the equator or the north pole.
The surface velocity of the Earth is different at different latitudes, making accurate
synchronization impossible in a frame of reference where the surface is moving relative
to the satellites, if two-way time dilation due to relative velocity is true in a rotating
frame of reference. The U S Naval observatory is the enity that operates the GPS system. ITT works as a contractor for them. The paper presented by ITT describes how they handle the synchronization process while the satellite clocks are in orbit.
Read carefully and you will see the satellite clocks are synchronized with clocks on
the surface of the Earth, not with the hypothetical clock at the center of the Earth.
This is evidenced by the fact that GPS satellites broadcast very accurate time to
Earth surface clocks all over the Earth, equal to most any atomic clock on the surface, except perhaps hydrogen masers. If you like, I can give you a link a new website, Aerospace corp., that has designed a new laser cooled cesium clock for GPS satellites that is equal to even the hydrogen maser clocks. I mention this because time delivered by GPS signals is extremely precise both in time and time interval.
This time is kept on the satellite clock, in orbit. Synchronizing the orbiting clock
to beat in synch with a surface clock would keep clocks synchronized from an observer
on Earth's point of view, but if two-way time dilation were true, the clocks would still not be synchronized in the satellites frame. The clock in the satellite frame would still see the Earth clock as beating slower than itself, now off by twice as much. But this
doesn't happen, the satellite clock, especially cesium clocks, can beat for many years
without needing any further adjustment to its tick rate. There are minor adjustments made to the phase and frequency generated by the crystal oscillators and frequency
generators that send the signals, but that is due to varying gravitational potentials
and delays in the signal while it is in transit through the ionosphere and troposphere, the Sagnac effect, etc. Remember, not only does the satellite clock have to count time at the same rate as a surface clock, the time interval has to synchronize with
the time interval on the surface clock. It cannot do that if the Earth clock is ticking
more slowly than it. Synchronize the satellite clock with the surface clock in the orbital frame of reference and the Earth clocks will see the orbital clock as beating much too slowly if time dilation due to relative velocity is as described by STR in LINEAR
inertial frames. Yes, velocity time dilation is anti-symmetric in the GPS and GLONASS
systems, but I don't know if that applies to a linear inertial frame as described by STR.
But don't forget, the muon-in-atmosphere example happens in the rotating frame of the Earth's atmosphere and gravitational field also. Particles in particle accelerators are in rotating frames
in the Earth's gravitational field. I see little evidence to support 'mutually observed
time dilation', but realize this post does not refute that it might be possible in deep space, for example.

[qb3]

alright guys!! excellent wordthoughts, and many thanks of appreciation from here.
tinq, funk, hold up now.. lets take a substantive look at this issue;
if we leave the nominal issue of clocksynch suspended for a moment,
perhaps we might recognize a deeper, more interesting issue at play here
with the substance of s/g rt 'foundations' !
-check it out:
fine to suggest that the special-relativistic effect is one-way,
more interesting to realize that relativity DEMANDS reciprocality -but not equivalency- in reference-frame dynamics.
Bingo!
i.e. - does absolute relativity of motion imply absolute equivalency of frame-referential coordinate-systems ?
-of course not!
-missing pieces?
-questions? answers?
-
so what governs the precedence?

=b

[funkstar]

Ok, I've been thinking a bit more about the synchronization bit, and (besides discovering more than a few errors in my post above) I think I've resolved it. This post might get a bit long, but bear with me.

Remember, we're only concerned about the velocity time dilation - we're all in agreement that gravitational redshift is easy to factor out. So in the following I'll only assume a velocity time dilation of gamma. We'll also assume that the light propagation delay for timestamps flowing back and forth is factored out, so timestamps arrive at the time written in them, as viewed from the sender frame (this is in practice not as easy as it looks, as 2inq has explained above, but in principle it can be done.)

It's easy to factor out velocity dilation so that the clocks beat in synch as viewed from the earth clock: Just shorten the orbiter's second by gamma. Then, by the velocity time dilation of gamma, the shortening cancels out, and the clocks are in perfect synch. This is also not in dispute. Hence, in the earth frame, if we receive a timestamp st_gps, from the orbiter, at time t_e, and st_gps = t_e, then the clocks are ticking in synch in earth frame (and since we know that the GPS is calibrated to tick a little to fast, if we see it as ticking in synch with our own, the clock must be time dilated as predicted by SR).

Thus we have that in the earth frame, the following relation between time on earth and the time as seen ticking on the orbiter.

1 earth second : 1 gps second

That's all fine and dandy, and noone is any wiser. SR is working fine when viewed from this frame, the GPS clock is obviously ticking slower than the earth clock. This is actually a very important point.

From the orbiter frame, this relation between second lengths does not hold. Not only is the earth clock second longer than the gps second by a factor of gamma by design, it is also time dilated by a further factor of gamma by the velocity time dilation predicted by SR. That is

gamma^2 gps seconds : 1 earth second

What is being put forward into evidence by 2inq, your honour, is that apparently, time stamps from earth, st_e, are arriving at the satellite at time t_gps (i.e. what the orbiter clock reads) in the orbiter frame, and that st_e = t_gps.

The claim is now that this is incompatible with SR! The argument runs like this: The above relation of gamma^2 gps seconds to 1 earth second means that if st_e = t_gps at one particular time, then at any other given time , another time stamp st_e' cannot be equal to t_gps'. If the time stamps are sent once each earth second, then the gps clock will accumulate gamma^2 seconds between each time stamps arrival, and thus the time stamps can never again agree. Assuming that the time stamp st_e agreed with the gps clock at time 0 (also assumed synchronized between the frames), the relation ship between the time stamps and the gps clock must be

t_gps = gamma^2 * st_e

corresponding to the fact that that from the orbiter frame, the gps clock is continually gaining on the earth clock.


While this certainly seems reasonable, it is, however, wrong. Here's why, explained in two different ways:

1) Let's see what happen when we send time stamps from earth to the satellite as viewed from the earth frame. In this frame, the clocks are ticking synchronously, so a time stamp st_e, arriving at time t_e (with light propagation delays factored out so st_e is set to t_e), will arrive when the gps clock reads t_gps = t_e. This, that st_e was equal to t_gps, can be confirmed in any number of ways: the GPS satellite can flash a light bulb if, and only if, it receives a time stamp it the proper time (that is, at the time the time stamp says), for instance.

Now, it is well known that frames agree on which events happen. Therefore, since in the earth frame the light bulb keeps blinking, it must do so as well in the orbiter frame. Hence, the time stamps arrive at the right time, even though we know earth time to be dilated in this frame, and even though there's no one to one correspondence between the observed second length of the two clocks.

You might feel that this is cheating a bit, and so I'll explain once again, but this time from the orbiter frame.

2) The above argument against the time stamp agreeing with gps time was that in the orbiter frame we should have

gamma^2 * st_e = t_gps

and thus cannot have

st_e = t_gps

by the (valid) reasoning of the relationship of time between the frames. However, this fails, for the following reason: The time stamp is designed so as to reach the satellite such that st_e = t_e in the earth frame! The orbiter will not agree that the time stamp arrives at the time the earth clock reads st_e! And without that vital connection between st_e and the earth clock, the above relationship barring st_e from being equal to t_gps falls.

So when does the time stamp st_e arrive, then? Well, we can use the Lorentz transforms from the earth frame to the orbit frame to conclude that the st_e time stamp arrives at time gamma * st_e (the distance between the earth and the satellite is constant so no length contraction is involved.) Now, this gamma * st_e is in standard seconds and the gps second is shortened by a factor gamma, so st_e arrives a time t_gps = st_e.

So, in fact, had there not been this synchronicity, then it would have been strong evidence against SR.

The error, to summarize, was to mix frames: That t_gps = st_e has two entirely different meanings in the different frames, and doesn't rule out mutual time dilation. This was complicated by the fact that synchronicity in one frame seemed to suggest that time dilation wasn't taking place (when, in fact, it was) leading one to expect a sort of "double" time dilation in the other frame. Also, had I just used the fuckin' Lorentz transformation from the beginning I wouldn't have had to think about this all fucking day, because the error would have been apparent. I'm going to bed...

[2inquisitive]

by funkstar:


"It's easy to factor out velocity dilation so that the clocks beat in synch as viewed from the earth clock: Just shorten the orbiter's second by gamma. Then, by the velocity time dilation of gamma, the shortening cancels out, and the clocks are in perfect synch. This is also not in dispute."
================================================== ==============

This is your first error. You have to synchronize all SV clocks with all Earth surface clocks. Remember I mentioned latitude in my previous post? The Earth surface clock at
the equator has a different relative velocity wrt the constellation as a whole than a similar surface clock located at an Earth pole, for instance. You are synchronizing one
surface clock with one satellite clock. The gamma factor is different at different latitudes. All clocks in the Earth frame of reference must be synchronized with all clocks in the satellite constellation frame of reference. Also, to synchronize the SV clock in an Earth frame, the SV clock must be adjusted to beat faster, as the Earth clocks precieves the SV clock be be beating too slow wrt the Earth frame. SV = space
vehicle, the way the U S Naval Observatory (military) refers to a GPS satellite. It is also shorter to type.
-----------------------------------------------------------------------------------

by funkstar:
(and since we know that the GPS is calibrated to tick a little to fast, if we see it as ticking in synch with our own, the clock must be time dilated as predicted by SR).
================================================== ============

Actually we do not know this. The pre-launch calibration is to SLOW the tick of the SV
clock by 38 microseconds per day. University websites claim the -7 microseconds per
day difference between a SV clock and a CENTER-OF-EARTH clock is included in the
pre-launch adjustment. Regardless if it is or not, that will NOT synchronize the SV clock with an EARTH-SURFACE clock. The rotational speed of the Earth's surface is not included in the ECI frame, the frame where the pre-launch calibration is calculated.
You do understand the difference in synchronizing all the clocks in the orbital constellation with a single non-moving clock located at the center of the earth (this is
the ECI frame) where all orbital clocks have the same relative velocity wrt the Earth
center clock and synchronizing the moving constellation with moving clocks on the surface of the Earth, with different relative velocities wrt the constellation? By the way, the rotating Earth surface is modeled in the ECEF frame at the university websites.
--------------------------------------------------------------------------------

by funkstar:
"What is being put forward into evidence by 2inq, your honour, is that apparently, time stamps from earth, st_e, are arriving at the satellite at time t_gps (i.e. what the orbiter clock reads) in the orbiter frame, and that st_e = t_gps.

The claim is now that this is incompatible with SR! "
================================================== =============

No, that is not my claim. 'Time stamps from Earth (there are none, but that doesn't matter) arriving at the orbiter' is STILL from the Earth's frame of reference, not the
SV frame of reference. The SV frame of reference is a 'time stamp sent from the SV to
the Earth clock'. The satellite clocks are synchronized with Earth clocks in the Earth's
frame of reference, but the signals (time stamps) are broadcast from the GPS satellites
in the satellites frame of reference, and received on Earth in the same frame of reference, from the satellites' point of view. You are mixing frames. It seems you went
to considerable effort in your post, which is appreciated, but the post has mistakes. I
can go into much greater detail on any one point if you want further explaination. Thanks for posting, funkstar. Remember, GPS satellites orbit the Earth in six different orbital planes and the surface of the Earth is also rotating within these planes. A clock
on the surface of the Earth has to synchronize with the satellite constellation regardless if the surface clok has the rotational velocity at the equator or 0 rotational
velocity at a pole on Earth. As I have said, it is complicated. I am not a newcomer to
studing the GPS system.

[James R]

funkstar:

That's right, though I doubt any of the anti-relativists will understand.

Once again, the relativity of simultaneity rears its ugly head. Assume that the satellite receives time stamp t from earth exactly at the time the Earth clock displays time t in the Earth frame. Then, according to SR, the satellite WILL NOT receive the time stamp t at the same time in the satellite frame that it sees the Earth clock displaying time t.