SR/GR use absolute time to synchronize the GPS clocks with the ground clock.
in [Physics]
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From: kenseto on 5 May 2010 13:31 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....
From: kenseto on 5 May 2010 13:49 On May 4, 5:03 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) wrote: > kenseto <kens...(a)erinet.com> writes: > >On May 3, 6:54 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) > >wrote: > >> PD <thedraperfam...(a)gmail.com> writes: > >> >On May 3, 12:51 pm, kenseto <kens...(a)erinet.com> wrote: > >> >> In fact the GPS refute the mutual > >> >> time dilation concept: from the ground clock point of view the SR > >> >> effect on the GPS clock is 7 us/day running slow....and from the GPS > >> >> point of view the SR effect on the ground clock is ~7us/day rinng > >> >> fast. > >> >I've already told you, Ken, that the GPS satellite is not a case of > >> >relative *inertial* motion (within experimental precision), and so one > >> >does not expect mutual time dilation to apply. You seem to forget this > >> >within hours of it being told to you. Again. And again. > > >> To be fair to Ken, here he's only mentioning the SR effects (~7us/day) > >> and not the gravitational effects. He still gets it wrong, however, > >> by claiming the satellite sees the clock on the ground station as > >> running fast due to SR when in fact it'll see it as running slow. > > >> It's the gravitational well effects (~45uS/day) that reverse like that, > >> not the relative motion effects. > > >> Net effect: Ground clock sees satellite running ~45uS fast due to gravity > >> but ~7uS slow due to motion = ~38uS/day fast. > > >> Satellite sees ground clock running ~45uS slow due to gravity > >> and ~7uS slow due to motion = ~52uS/day slow. > >This is wrong and it has been explained to you many times. > > Nope, that's correct. SR effects of motion always cause the moving clock to run slow. "Nope, that's correct." ????? 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. > > > If the GPS > >clock sees the ground clock ~ 52 us/day slow then the GPS clock is not > >in synch with the ground clock. > > Congratulations! That's probably the first correct thing you've said > in this entire thread. You failed to understand what I said. I said that if from the GPS point of view the ground clock is running ~52 us/dau=y slow then the pre-launch setting for the GPS second of 4.15 more periods of Cs 133 radiation will not make the GPS clock to be continuously in synch with the ground clock. The redefined GPS second is designed to correct the GPS view point that the ground clock is ~38us/day slow....not 52 us/ day slow as you claimed. Ken Seto >The GPS clock is *not* in synch with the ground > clocks, because 1) it's moving at a non-trivial rate and 2) it's in a > different position in the gravity well. However, since the satellites > are in a circular orbit, the altitude (position in the gravity well) and > the orbital speed are both pretty much constant, so the onboard GPS clock > can produce a second pseudo-second signal that runs just slightly slower > than the actual second signal. This signal, when "sped up" by GR effects > when it reaches Earth, will correspond exactly* to a ground-based 1 second > signal. Just like the train, if the train moves at just the right speed, > an A-flat whistle will be heard on the platform as a perfectly tuned "A". > Same effect, different cause (Doppler vs. GR). > > Of course when going the other way, the gravitational and motion effects > of an earth-originated signal both decrease its frequency, so the > satellite will see an earth signal as ~52uS/day slow. The ground > transmitter will need the same modification as the satellite one, it needs > to have its clock running 52uS/day fast for the satellite to get the > correct timing from it. > > * to within limits of measuring/setting its speed and altitude.- Hide quoted text - > > - Show quoted text -
From: Michael Moroney on 5 May 2010 16:23 kenseto <kenseto(a)erinet.com> writes: >On May 4, 5:03 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) >wrote: >> kenseto <kens...(a)erinet.com> writes: >> >> >> Net effect: Ground clock sees satellite running ~45uS fast due to gravity >> >> but ~7uS slow due to motion = ~38uS/day fast. >> >> >> Satellite sees ground clock running ~45uS slow due to gravity >> >> and ~7uS slow due to motion = ~52uS/day slow. >> >This is wrong and it has been explained to you many times. >> >> 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 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. >> > If the GPS >> >clock sees the ground clock ~ 52 us/day slow then the GPS clock is not >> >in synch with the ground clock. >> >> Congratulations! That's probably the first correct thing you've said >> in this entire thread. >You failed to understand what I said. I understood you fine. The satellite clock isn't synched with the ground clock. It is pseudo-synchronized by having a predetermined correction in frequency applied to the signal used by the GPS. > I said that if from the GPS >point of view the ground clock is running ~52 us/dau=y slow then the >pre-launch setting for the GPS second of 4.15 more periods of Cs 133 >radiation will not make the GPS clock to be continuously in synch with >the ground clock. It will tick at the same rate since the ~38uS/day preset slowdown exactly cancels the ~38uS/day combined GR speedup as far as the ground clock sees. >The redefined GPS second THERE IS NO SUCH THING!!!! > is designed to correct the >GPS view point that the ground clock is ~38us/day slow....not 52 us/ >day slow as you claimed. The ~52 us slowdown is going the other way - the GPS clock will see an Earth-based clock as running ~52us/day slow. If there is a need for a GPS signal to be received exactly on frequency X, the ground based transmitter needs to be set fast by ~52uS/day. Remember this: Earth to satellite: seen as ~52uS/day slow. Satellite to earth: ~38uS/day fast. And before you ask, yes it does mean if you transmit a signal at frequency A to a GPS satellite, it will see it as frequency B, and if it retransmits (or just reflects) it back to Earth, the received frequency will be C, and A != B != C. Yes it's kind of hard to wrap your mind around it, but just because you can't wrap your mind around it doesn't mean it's not true.
From: Sam Wormley on 5 May 2010 16:43 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.
From: kenseto on 6 May 2010 09:33
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: > >> kenseto <kens...(a)erinet.com> writes: > > >> >> Net effect: Ground clock sees satellite running ~45uS fast due to gravity > >> >> but ~7uS slow due to motion = ~38uS/day fast. > > >> >> Satellite sees ground clock running ~45uS slow due to gravity > >> >> and ~7uS slow due to motion = ~52uS/day slow. > >> >This is wrong and it has been explained to you many times. > > >> 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.....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? > > >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 why did you claim that from the GPS point of view the SR effect on the ground clock is also 7 us/day slow? > > >> > If the GPS > >> >clock sees the ground clock ~ 52 us/day slow then the GPS clock is not > >> >in synch with the ground clock. > > >> Congratulations! That's probably the first correct thing you've said > >> in this entire thread. > >You failed to understand what I said. > > I understood you fine. The satellite clock isn't synched with the ground > clock. It is pseudo-synchronized by having a predetermined correction > in frequency applied to the signal used by the GPS. > > > I said that if from the GPS > >point of view the ground clock is running ~52 us/dau=y slow then the > >pre-launch setting for the GPS second of 4.15 more periods of Cs 133 > >radiation will not make the GPS clock to be continuously in synch with > >the ground clock. > > It will tick at the same rate since the ~38uS/day preset slowdown exactly > cancels the ~38uS/day combined GR speedup as far as the ground clock sees.. > > >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? Ken Seto > > > is designed to correct the > >GPS view point that the ground clock is ~38us/day slow....not 52 us/ > >day slow as you claimed. > > The ~52 us slowdown is going the other way - the GPS clock will see an > Earth-based clock as running ~52us/day slow. If there is a need for a > GPS signal to be received exactly on frequency X, the ground based > transmitter needs to be set fast by ~52uS/day. > > Remember this: Earth to satellite: seen as ~52uS/day slow. Satellite to > earth: ~38uS/day fast. > > And before you ask, yes it does mean if you transmit a signal at frequency > A to a GPS satellite, it will see it as frequency B, and if it retransmits > (or just reflects) it back to Earth, the received frequency will be C, > and A != B != C. > > Yes it's kind of hard to wrap your mind around it, but just because you > can't wrap your mind around it doesn't mean it's not true. |