SR/GR use absolute time to synchronize the GPS clocks with the ground clock.
in [Relativity]
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From: Michael Moroney on 23 Mar 2010 12:57 kenseto <kenseto(a)erinet.com> writes: >Let me expain to you once again: In SR the rate of a clock moving wrt >you is 1/gamma at all time. The GPS clock sends sends a signal to the >ground clock after the passage of N+4.15 periods of Cs 133 >radiation....when the ground clock receives this signal it will know >that the passage of N periods of Cs 133 radiation on its clock have >taken place. Yes, just like the train horn. The approaching train has to sound at a frequency lower than 440 Hz to be heard at the station as 440 Hz, while a departing train has to sound at a higher frequency to be heard as 440 Hz. Same effect, different causes.
From: Androcles on 23 Mar 2010 14:02 "Michael Moroney" <moroney(a)world.std.spaamtrap.com> wrote in message news:hoarit$alc$1(a)pcls6.std.com... > kenseto <kenseto(a)erinet.com> writes: > >>Hey idiot time dilation got nothing to do with this discussion. > > Time dilation has *everything* to do with this discussion. Time dilation > would cause the GPS satellite to "transmit" at the wrong frequency (as > far as a terrestial receiver is concerned), so they adjusted the frequency > before launch so it would at the correct frequency on Earth. Bullshitting fuckwit!
From: kenseto on 24 Mar 2010 09:27 On Mar 23, 12:51 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) wrote: > kenseto <kens...(a)erinet.com> writes: > >Hey idiot time dilation got nothing to do with this discussion. > > Time dilation has *everything* to do with this discussion. Time dilation > would cause the GPS satellite to "transmit" at the wrong frequency (as > far as a terrestial receiver is concerned), so they adjusted the frequency > before launch so it would at the correct frequency on Earth. Sigh...the discussion was about whether observed doppler shift will effect the rate of a clock. The answer is no. The rate of a moving clock is 1/gamma at all time. Ken Seto
From: kenseto on 24 Mar 2010 09:37 On Mar 23, 12:57 pm, moro...(a)world.std.spaamtrap.com (Michael Moroney) wrote: > kenseto <kens...(a)erinet.com> writes: > >Let me expain to you once again: In SR the rate of a clock moving wrt > >you is 1/gamma at all time. The GPS clock sends sends a signal to the > >ground clock after the passage of N+4.15 periods of Cs 133 > >radiation....when the ground clock receives this signal it will know > >that the passage of N periods of Cs 133 radiation on its clock have > >taken place. > > Yes, just like the train horn. The approaching train has to sound at a > frequency lower than 440 Hz to be heard at the station as 440 Hz, while a > departing train has to sound at a higher frequency to be heard as 440 Hz. No it's not the same. The GPS sends a signal after N+4.15 perods of Cs 133 radiation elapsed....no matter if it is approaching the ground clock or receding away from the ground clock. The ground clock will know N periods of cs 133 radiation have elapsed on the ground clock. With your situation the audience at the platform will hear 440 Hz when the train is approaching but they will hear a different frequency when the train is receding away from the platform. Ken Seto > > Same effect, different causes.
From: Sam Wormley on 24 Mar 2010 11:14
On 3/24/10 8:27 AM, kenseto wrote: > Sigh...the discussion was about whether observed doppler shift will > effect the rate of a clock. The answer is no. The rate of a moving > clock is 1/gamma at all time. > > Ken Seto Let the clock be a distant pulsar with radial velocity v with respect to the observer. The relativistic formula for the Doppler shift in pulse arrival time due to an arbitrary velocity is given by t' = (1 + v/c) γ t where v represents the velocity along the line of sight between source and observer and t' and t represent the time between pulses at the observer and at the source, respectively. |