SR/GR use absolute time to synchronize the GPS clocks with the ground clock.
in [Relativity]
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From: PD on 6 May 2010 10:06 On May 6, 8:47 am, kenseto <kens...(a)erinet.com> wrote: > On May 5, 4:43 pm, Sam Wormley <sworml...(a)gmail.com> wrote: > > > > > On 5/5/10 12:31 PM, kenseto wrote: > > > > On May 4, 5:14 pm, Sam Wormley<sworml...(a)gmail.com> wrote: > > >> On 5/4/10 8:30 AM, kenseto wrote: > > > >>> This is wrong and it has been explained to you many times. If the GPS > > >>> clock sees the ground clock ~ 52 us/day slow then the GPS clock is not > > >>> in synch with the ground clock. > > > >>> Ken Seto > > > >> http://www.facebook.com/profile.php?id=100000102086824&ref=pymk > > > >> The seconds on satellites are the same as the seconds everywhere else > > >> in the universe. Gravitation and relative velocity can cause time > > >> dilation of an observer. > > > > No wormy...the second on the eGPS clock is redefined to have 4.15 more > > > periods of Cs133 radiation.This redefinition of the GPS second make > > > the GPS clock in synch with the ground clock continuously. > > > >> Here is the detail of calculating the time dilation of satellite > > >> clocks:http://relativity.livingreviews.org/open?pubNo=lrr-2003-1&page=node5.... > > > You should learn relativity theory, Seto. No second redefinitions > > required. > > Wormy you should learn relativity...the GPS second was redefined to > have 9,192,631,770+4.15 periods of Cs 133 radiation. Where did you read such claptrap, Seto? It's factually, historically wrong. The entire design of the GPS system is available for public inspection on the internet. Surely you can correct yourself by checking your own blind assertions. > > Ken Seto > > - Hide quoted text - > > > > > - Show quoted text - > >
From: Sam Wormley on 6 May 2010 10:28 On 5/6/10 8:50 AM, kenseto wrote: > The you should go and argue with your SR brother Moroney...he said > that from the ground clock point of view the sr effect is 7us/day slow > and from the GPS point of view the SR effect on the ground clock is > also 7us/day slow. > > Ken Seto Why are you giving an ear to Moroney, Seto? I give you an excellent reference on the relativistic effects on satellite clocks which you either totally ignore, or more likely, can't follow. Try again. http://relativity.livingreviews.org/open?pubNo=lrr-2003-1&page=node5.html
From: Michael Moroney on 7 May 2010 11:32 Sam Wormley <swormley1(a)gmail.com> writes: > Why are you giving an ear to Moroney, Seto? I give you an excellent > reference on the relativistic effects on satellite clocks which you > either totally ignore, or more likely, can't follow. If I am posting anything incorrect, let me know (by email if necessary, remove the "spaamtrap"). My posts are made on the assumption that all GR effects on the GPS satellites can be simplified to the gravitational well effect of ~45uS/day and the motion effects of ~7uS/day.
From: Michael Moroney on 7 May 2010 11:51 kenseto <kenseto(a)erinet.com> writes: >On May 5, 4:23 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >wrote: >> kenseto <kens...(a)erinet.com> writes: >> >On May 4, 5:03 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >> >wrote: >> >> Nope, that's correct. SR effects of motion always cause the moving clock to run slow. >> >"Nope, that's correct." ????? >> >> "That" refers to the statement "Satellite sees ground clock running ~45uS >> slow due to gravity and ~7uS slow due to motion = ~52uS/day slow.". >> It is correct. >No that's not correct....how come the gravity effect is not >reversible...that is the ground clock sees the GPS 45us/day fast and >the GPS sees the ground clock ~45 us/day slow..... That's because no matter which frame you view it from, the ground observer is closer to a gravitating object (the Earth) than the GPS satellite. >and yet when it >comes to the SR effect you claimed that the velocity effect is >reversible....that is the gorund clock sees the SR effect on the GPS >is 7 us/day slow and the GPS sees the SR effect on the ground clock >also ~7us/day slow? That is because which object is in motion does depend on your frame of reference. Someone on the ground sees the GPS satellites as moving, so will see their clock as running slow (SR effects only). Someone riding a GPS satellite will see the satellite as stationary, but will see anyone fixed to the Earth as moving rapidly, so will see the Earth person's clock as running slow. PD is correct. You need to learn SR! >> >No to your statement....the SR effect of motion depends on who is >> >doing the moving. For example if you accelerated away from me you are >> >the one who is doing the moving....so your clock is running slower >> >than my clock. From your point of view my clock is running faster than >> >your clock. >> >> When you said "accelerated" did you really want to write "accelerated"? >> In that case there is non-inertial motion and SR does not apply. If >> you really did mean constant motion (no acceleration), then there is >> RELATIVE motion. I see you as moving away from me, you see me as moving >> away from you. We are both correct for our own frames, one co-moving >> with you, the other co-moving with me. I see your clock as slowed, you >> see my clock as slowed. >Hey idiot the GPS was accelerated from the ground clock.... So are you now saying the satellite clock "remembers" that it was once accelerated into space, and will therefore run at a different rate from then on? What if, I took some cesium, accelerated it to near c in a particle accelerator, then stopped it and mixed it with cesium that was never accelerated, and used it in a cesium clock? Will the two "kinds" of cesium atom try to make the clock tick at two different rates? >so why did >you claim that from the GPS point of view the SR effect on the ground >clock is also 7 us/day slow? Please learn some SR. An observer observes a clock moving relative to him as running slow. >> >The redefined GPS second >> >> THERE IS NO SUCH THING!!!! >Answer me this question: When the GPS want to signal the passage of a >second to the gorund clock does it sends the signal after >9,192,631,770 periods of Cs 133 radiation or does it sends the signal >after the passage of (9,192,631,770 + 4.15) periods of Cs 133 >radiation? The onboard clock will tick at 9,192,631,770 periods of Cs 133 radiation per second, exactly (by definition). A GPS satellite clock will also generate a signal that ticks at one pulse per 9,192,631,774.15 periods of Cs 133, which will be received on the ground as a highly accurate 1 pulse per second clock. No "redefinition" of a second.
From: Michael Moroney on 7 May 2010 13:56
Sam Wormley <swormley1(a)gmail.com> writes: >On 5/7/10 10:32 AM, Michael Moroney wrote: >> My posts are made on the assumption that all GR effects on the GPS >> satellites can be simplified to the gravitational well effect of >> ~45uS/day and the motion effects of ~7uS/day. > GTR covers everything! SR may be more convenient for some calculations > but GTR encompasses SR. Both theories need not be applied separately. I know that. But the satellite in orbit is constantly accelerating, its motion as seen from earth is curved and there are probably several effects I haven't considered. I'm assuming for this discussion the major effects are the gravity well effect and the orbital velocity effect, and others are minor in comparison. Also, for this discussion even know GR will have a single function that considers motion and gravity effects and everything else that will spit out a single time dilation value, the two effects can be considered as if independent and their contributions add. Remember, this discussion isn't exclusive to physics PhDs, the biggest contributor apparently doesn't understand SR but thinks he does. |