Sorry Mac, I am not aware of a HTML version of the article, although I would think there should be one. I believe it appeared in the March 2003 Issue, Physics Today.org. It is very slow to open on my computer, but I did once last night and again today. When I say slow, click the link, go make yourself a sandwich and eat it, ha! Then come back and check. Really, there are some graphics on the link and pdf is always slow on my connection anyway. One I have been trying to access has crashed my computer twice. This one worked, it was just sloooow. As far as the GPS system is concerned, Mac I keep saying, there is no way to get accurate figures for relativity effects. The prelaunch offset is just a prelude, a simple artifical frame of reference (ECI) is used as a baseline to synchronize clocks, as they cannot be synchronized in a rotating frame. But a rotating frame is also used and that is where most of the relativist effects are accounted for before the code is sent by the satellite to the ground reciever. Each individual sat clock has its own frequency changes and those changes even differ in one orbit of the satellite, based on modelling. Even the Earth's difference in gravitational effects at various points is incorperated into the satellite's signal it broadcast. Some recievers for fast moving objects such as jet aircraft even take the first-order Doppler shift into account, in addition to the second-order Doppler shift due to satellite velocity relative to an Earth-based reciever. The prelaunch offset is just the bare beginnings of the frequency adjustments that are made to the clocks, a common reference point.
2Inquisitive, If you accessed the site via Google, if there is an HTML it will show it as an option. I agree with the difficulty of prcise calculation. My concern is actually more the description of the reference frames. It does seem none are relative velocity between the clocks but relative velocity (absolute local) velocity to some rest frame. The indication of the earth's surface velocity in the same pole frame is such that it has no impact on the data. Even if some other frame is used for the surface it still apears it will be the comparision of two frames each using some rest frame as a reference which keeps the orbiting clock as always having the higher velocity and the assumed rest position of surface or orbit clocks cannot be interchanged in accordance with the SRT view.
Two reference frames are used in all circumstances where the satellite communicates with the ground reciever. The pole based non-rotating one is a simple frame where all clocks are synchronized to keep exactly synchronous time (ECI). The ECEF frame is a rotating non-inertial frame where relativistic and environmental effects are calculated, it is far from a simple rest frame. And I am sure you have read many times where the military can pinpoint a nuclear explosion anywhere on the face of the Earth using the GPS system. Actually, in the GPS network, the surface of the Earth is not an inertial rest frame, it is a non-inertial frame in which General Relativity rules, taken into account when the ECEF frame is added to the underlying ECI frame.
2Inquisitive, Yes, I'm particularily intersted in Ashby's comments in section 2: ********************* Extract ************** Almost all users of GPS are at fixed locations on the rotating earth, or else are moving very slowly over earth's surface. This led to an early design decision to broadcast the satellite ephemerides in a model earth-centered, earth-fixed, reference frame (ECEF frame), in which the model earth rotates about a fixed axis with a defined rotation rate, . This reference frame is designated by the symbol WGS-84(G873) [19, 3]. For discussions of relativity, the particular choice of ECEF frame is immaterial. I shall simply regard the ECEF frame of GPS as closely related to, or determined by, the International Terrestrial Reference Frame established by the BIPM. ************************************************** I believe the ECEF frame is closely related to the ECI in that its frame is the center of mass which deviates only slightly from the center of rotation. That is this is a geoid affect and is not looking for any subsequent velocity affects leaving the predominant time dilation due to velocity as being the orbit velocity. As stated this is primarily a GR non-inertial frame and does not impact the SRT issue. To summarize my view at this time. I read somewhere there were something like 15 things processed to bringing about the current accuracy of the system. Something like a half dozen were relavistic affects. However, I think in terms of primary considerations what it boils down to is in general principle two considerations. The gravity affect and about +46 seconds tick rate increase and absolute orbit velocity reference the local rest preferred pole frame yielding the -7.2 microsecond time (clock) dilation affect. Sagnac and other considerations are getting into the minutiae details of improving accuracy and being able to apply the data generated in a useful manner on and relative to the surface.
2Inquisitive, Read Muller on SR vs LR and also GPS. http://itis.volta.alessandria.it/episteme/ep6/ep6-mull.htm
by Muller: "1 - The GPS community, for example, must use a reference frame fixed to the earth and not rotating with it, in order to account for the Sagnac effect that takes place between the GPS satellites and the terrestrial stations. This is an example of a preferred frame of reference, breaking all reciprocities and symmetries" =============================================================== I am not impressed in the least with Meller's article. Too many mistakes and incorrect assumptions as far as I am concerned. In the sentence above, he is only referring to ONE frame of reference. Tell me Mac, is it the ECI frame or the ECEF frame? Give me your answer and I will tell you why it is incorrect, because what he said does not apply to either frame. The ECI frame is an INERTIAL frame in which the Sagnac effect doesn't apply and the Sagnac effect IS accounted for in the ECEF rotating NON-INERTIAL frame. Don't forget Mac, I am not a supporter of SR. I am not a supporter of Lorentz Relativity. I believe both have problems. The closest theory I have seen to my viewpoint is Ronald Hatch's Ether Guage Theory. It is referred to as a modified Lorentz ether theory, of course. His paper "The Scandalous Clock" was very interesting. http://www.egtphysics.net/index.htm Don't forget the point I challenged in my opening post here. Something about -7.2 micro-second offset proving LR vs. SR. I am not defending SR. The SR velocity correction is 6 microseconds after BOTH FOR's are considered, as I pointed out by Dr. Ashby's statement already.
My inital reaction would be he is refering to the ECI. On this we are in complete agreement. My position has been that LR is preferred over SR but that LR is not entirely correct either. I also like Hatch and find his credentials give him considerable credability. (Noting here that as being used "m" is not milli but micro, also that m/s is not time units) The experimentally verified magnitude of GPS being 7.2 m*s does not prove LR it disproves SR. Both LR and SR use the same Gamma calculation and taken in the limited view (which is what Muller and I also are referring to) you get the same answer. However it is the extension of SR into claims which involve complete reciprocity which cause it to fail. (Also why I posted Muller is his use of the term reciprocity in discussing relativity. Something I have been assaulted for and told that term is never used; which is as false as SRT itself) Please Register or Log in to view the hidden image! My view of the universe would seem to be a mixture, combination of amalgamation of the following: 1 - Hatch: LET http://www.egtphysics.net/scandclock.pdf ****************** 2 - Renshaw: RCM http://renshaw.teleinc.com/papers/german1/german1.doc http://renshaw.teleinc.com/ (antimations) ***************** 3 - Tyron: ex-nihilo http://www.angelfire.com/scifi2/zpt/chapter5.html ***************** 4 - Lindner: Flowing Space http://home.earthlink.net/~hhlindner/Writings/Space/Physics.htm ***************** 5 - Barwacz: Unification Theory http://members.triton.net/daveb ***************** That is I see our observed physics along the lines of LET (as 'c' limited domains) within an RCM hidden physical system; which affords explanations for the invariance of light, particle entanglement, tunneling and FTL gravity affects via Lindner and existance under Tyron. Which I hope makes it understandable why my view is a bit difficult to express in a straight forward presentation. Please Register or Log in to view the hidden image! But they do all merge generally into a comprehensive concept that seems to follow the ideas of Barwacz.
2inquisitive,, You said: Briefly what is this all about? It seems you are making a statement that the speed of light is not indepenedent of the motion of the source of the light. I thought this was a postulate of light cast in steel? Any references easily available? Thnx Geistkiesel.
Yuriy, You should check your logic very closely in this question. You say that the satellite velocity has a velocity in regard to the points of the earth, so what? The question is what are the relative velocity of the satellite and the points of the earth? You seem to think that the mathemtical statement R/Re = V / Ve means the satellite has a velocity > 0 with respect to points on the earth. The statement has no physical meaning. The expression says merely that one entity has one velocity and another entity has another velocity. This is similar to the statement C' = C - V, or C'' = C +V, where C is the speed of light and V he velocity if an ertial frame. The statement says no more that C' is smaller than C by the amount subtracted, aor that the C'' is larger than C by the amount added. When you measure the rate of change of the distance between satellite and ground clocks designated by V and Ve what you get? If you use any model that results in a dx/dt > 0 then you are saying the distance between the satellite and earth clocks is not constant. Which is entirely different from saying the speeds of the satellite and ground clocks is different. When you inlcude that the satellite and ground clocks are moving in a circle you remove the ambiguity in your statements. Your definition and discussion seems to be redefining relativity and the relative motion between uniformly moving reference frames. You are making an attempt to make the satellite and earth clocks inertial frames in reagrd to SRT. Obviously velocity of the satellite is greater than the velocity of the earth clocks wrt the earth axis for instance. This would contradict the deinition of geosynchronous orbit as you, MacM and et al have been using the term. The distance between the satellite and earth clocks is invariant as seen here. The relative motion of the satellite and ground clocks is zero. The frames of reference for both is identical, neither the satlelite nor the ground clocks, but the earth axis is the common and prefered frame for both entities, What is so difficult to see about this? Is not relativity founded on the postulate that the absolute motion of inertial frames moving uniformly cannot be detected? Is not this why SRT can assume one frame at rest wrt to the other, because the absolute motion of he individual frames cannot be measured? Is not this gut root SRT? You seem to be skirting around SRT here in your zealous approach to the problem of SRT. which is admirable, by the way. It appears to me that you are screaming that the absolute velocity of the frames are tied to the imperatives of SRT wrt the satlelite and the ground clocks. For a committed ho hum nonrelativistic theorist like myself I am kind of proud at having discovered a flaw in the rhetoric of a great champion of SRT. A flaw discovered by reading through the pssts until I was able to understand your differences. I am starting to understand you much better Yuriy. Where x is the distance betyween satellite and ground clock the expression dx/dt is not equal to V and Ve and the following is not true: V + Ve = dx/dt because the dx/dt = 0 a velocity, and here a relative velocity. Finally, I am only expressing an obseravtion here. Geistkiesel
geistkiesel, did you ever heard that velocity V is a vector, that there are a radial Vr and an angular Vφ components of velocity, that V = Vr + Vφ? That at rotation on the geostationar orbit (by the definition) Vr = 0 (and that is why R = constant) so that: V = Vφ? You can even imagine how idiotic your "observations" look like! And all this stuff is read in whole World! Definitely, there goes on the parade of Stupidity in our Forum!
To all: (Yuiry, please correct immediately if I am wrong.) Look at Yuriy's picture closely: http://www.sciforums.com/attachment.php?attachmentid=3699&stc=1 At any given time the instantaneous velocities of objects through spacetime are all that matter for SRT calculations. Look at V and Ve at a given point. If gravity were to cease at that point, we wouldn't be having this discussion. The objects would move in straight lines with a relative velocity difference of |V-Ve|. We would all easily agree on the time dilation factor. However, since they are moving in concentric circles, we seem to be disposing of the fact that the relative velocity between the objects is still |V-Ve|, just because there is no relative displacement between them. Also, I have found many sources of info that describe how SR and GR effects are correctly accounted for (to the limits of measurement) in GPS systems (Google you way through them). Specifically, this Van Flandern guy seems to have gotten through the BS detectors at Physics Letters: This seems pretty straightforward to me. How can we still be arguing this?!?
Note: I am sitting here, under an acceleration of 9.8m/s/s yet I am not displacing along the line of acceleration.
There is nothing to be corrected. You asked: "How can we still be arguing this?!?" Because of a very simple reason - because of our foolishness. (In Russia people use to say: "If somebody is born a fool - it is for a long time. It is forever"... )
The reason for argueing this is simple (Vo - Ve) yields an incorrect time dilation figure. The correct figure is (gamma at Vo dilation - gamma at Ve dilation). That procedure is not relative velocity but differential dilation of absolute velocities. I calculated both ways and showed clearly that Yuriy's choice and the one you now advocate (Vo - Ve) is invalid. Best reason in the world to continue to argue. That is not SRT. It is LRT. Another case of Gamma being validated and SRT invalidated. Yuriy. In America we have another saying "Ignorance is bliss". Considering that I have (even by your own admission) provided correct calculations, your continued resistance to the fact is simple ignorance or blatant stuborness. Neither is a sign of superior intelligence.
Ok. Could you tell me what you think of this article? Maybe you've seen it. http://math.ucr.edu/home/baez/RelWWW/wrong.html#gps
AND? Yes, I have seen it and much more. In fact I am a member of Tom's MetaResearch Forum, although I rarely post there anymore. I disagree with Tom on many points but I also find he has a lot of things in proper perspective. Now to this eye wash you give us. Note: 1 - It is actually "Precisely 11 hours and 58 minutes". 2 - How casually they pass off the fact that "Relative Velocity to earth surface clocks is not used. Further that they distort the issue by referring to the stars and not the earth's pole which is the actual local preferred rest referance frame used. Reading further after lambasting Tom they admit that they have merely glazed over the true operation and that they have not shown the relavistic calculations and how they are done but simply assert that "Relativity" is taken into account. Yes relativity is taken into account "GR and Absolute Velocities" but NOT SRT and relative velocity damnit. I have made the point numerous times LR and SR both use the same mathematics to compute one way dilation affects due to velocity. So of course one will get the same answer but that does not support SRT. It supports only gamma. The true test is the referance point used and the fact that it does not allow for the SRT view of reciprocity or mutual reversable dilation from the other observers view point by changing who is deemed at rest. That is GPS disproves SRT and favors LRT. You are being hood winked by those that argue only the resulting calculation for gamma as being SRT. That is not the whole of SRT.
Yuriy, Now lets see what you are made of. Are you man enough and have sufficient integrity to respond in specific technical terms or will you once again simply cast innuendo and make fiat and slanderous personal attacks? Question #1: Given Vo is velocity of orbit, Ve is velocity of the earth's surface in consideration and te is earth clock tick rate and to is orbit tick rate. Which formula will provide the correct GPS velocity time dilation prelaunch adjustment (PLA)calculation? (A) - Gamma = 1/(1 - (Vo - Ve)<sup>2</sup>/c<sup>2</sup>)<sup>1/2</sup> PLA = te/gamma or (B) - Gamma1 = 1/(1 - Vo<sup>2</sup>/c<sup>2</sup>)<sup>1/2</sup> Gamma2 =1/(1 - Ve<sup>2</sup>/c<sup>2</sup>)<sup>1/2</sup> PLA = te * (Gamma1/Gamma2) Question # 2: Which theory does each calculation process belong to LR or SR? A is____________ B is ___________ NOTE: Readers be advised that (A) above results in 5.58 micro-seconds per day loss adjustment and (B) results in 7.2 micro-seconds per day loss adjustment. BTW: GPS makes a 7.2 micro-second per day loss adjustment for velocity affects. Please Register or Log in to view the hidden image! Using the earth's pole as a local preferred rest frame (prohibited by SRT) Vo is always larger than Ve (that is it cannot be reversed per SRT).
aha, you are exactly the one who has a right to appeal to ...manhood! But anyway, for sake of others I will answer on your questions, although I already did it... Question #1. Formula Gamma1 = 1/(1 - Vo^2/c^2)^1/2 Earth located clocks do not experience any physical adjustments: they readings simply are corrected by right calculations. Such parameter as "PLA = te * (Gamma1/Gamma2)" is created by people like you: it never is used in real practice of consumers of GPS. Question #2. Term "LR" is created by people like you. Such term in Physics does not exist, same as it does not exist any of its content that you try to appeal. Now about your statement after questions. Nobody is using North Pole as any reference frame in GPS, except people like you. Notion "local preferred frame" is created by people like you and never is used in Science. Statement like some "reference frame is prohibited by SRT" is absolutely stupid accusation of SRT, which never "prohibits" or "allows" any RF. SRT never "reverses" any relative velocities. Conclusion: your statement is ignorant and full of stupid terms, accusations and assertions. But there is nothing unusual: the most your posts here are full of such statement... This is why UniKEF is an honorable exhibit of crank-Museum...
superluminal, link you provided contains all scientific proves that crank-Museum members wanted to be produced. You can never be wary about bringing on any of other responses on their screams: "Give as a single proof!" Simply repeat this link...
Well, your post clearly shows who knows GPS and who doesn't. It is pathetic indeed when so much has been posted from official sources which show with absolute clarity that they openly state they use the earth's pole as a rest referance point. Based on this outrageous denial by you of even the most basic facts regarding the functioning of GPS the balance of your ill prepared and presented falsehoods deserve no response. You are either totally lost or a deliberate prevaricator. However, for the benefit of other readers learning the truth I will tolerate your abuse and continue to post the facts. Above you chose once again to not answer technically but to distort and generate negative innuendo. Of course you do not see PLA used. I was trying to put the process used into terms that can not be misinterpreted or distorted and wrote the formulas myself. In the event you cannot interprete simple mathematics I guess I will now write it out verbally and ask again for you to respond technically. Question where Vo is velocity of orbit and Ve is velocity of the earths surface at the equator (or any other location under consideration) and Vn = (Vo - Ve) does GPS use: Vn = Ve * ( 1 - (Vo - Ve)<sup>2</sup>/c<sup>2</sup>)<sup>1/2</sup> as its primary prelauch adjustment for velocity affects of the atomic clocks when such calculation yields a 5.58 micro-second/day loss? Yes or No. (This is process "A") OR If no, does GPS use a process where the pole of earth's axis is used as a local preferred rest frame which yields Vo and Ve above and it is the calculated gammas of each (Vo and Ve) that are proportioned as to = te *G1/G2 or differentiated as losses from respective gammas where: tlo is time loss in orbit and tle is time loss on earth based on absolute velocities relative to the pole such that to = (tlo - tle). Which provide a general calculation of 7.2 micro-seconds/day loss? (This is process "B") Which calculation is used A (5.58 micro-second/day loss) or B (7.2 micro-seconds/day loss)? Which theory does each represent SR or LR. A _____________ B _____________ Lets see if you once more try to avoid answering factually.
