Does motion affect the operation of clocks or not ?

Hi everybody

In his paper - "The Confrontation between General Relativity and
Experiment: A 1998 Update" - http://xxx.lanl.gov/abs/gr-qc/9811036
Clifford M. Will wrote on page 12 that
the Global Positioning System (GPS) provides absolute
accuracies of around 15 m (even better in its military mode)
anywhere on Earth, which corresponds to 50 nanoseconds in
time accuracy at all times. Yet the difference in rate between
satellite and ground clocks as a result of special and general
relativistic effects is a whopping 40 microseconds per day
(60micros. from the gravitational redshift, and -20micros. from
time dilation). If these effects were not accurately accounted
for, GPS would fail to function at its stated accuracy.

This seems to indicate that the GPS clocks are really affected by
motion. However, in their book "Spacetime Physics - Introduction to
Special Relativity" (W. H. Freeman and Company - 1992) Edwin F.
Taylor and John Archibald Wheeler write on page 77:
We conclude that free-float motion does not affect the
structure or operation of clocks.

I'm not sure what to believe now. Does motion affect the operation of
clocks or not? Can anybody enlighten me on this?

Thanks,

Andrew A. Harland

.

Relevant Pages

  • Re: Myth of GPS Employing the Nonsense of SR and GR
    ... I wouldn't have thought GR was relevant to GPS? ... People often ask me "What good is Relativity?" ... GPS satellites are not in geosynchronous or geostationary orbits). ... their clocks ticking more slowly (see the Special Relativity ...
    (sci.physics.relativity)
  • Re: to sam
    ... Real-World Relativity: The GPS Navigation System ... GPS satellites are not in geosynchronous or geostationary orbits). ... their clocks ticking more slowly (see the Special Relativity ...
    (sci.physics)
  • Re: to sam
    ... Einstein's Relativity and Everyday Life ... But GPS is an exception. ... twice per day, much faster than clocks on the surface of the Earth, ... The net result is that time on a GPS satellite clock advances ...
    (sci.physics)
  • Re: to sam
    ... Real-World Relativity: The GPS Navigation System ... GPS satellites are not in geosynchronous or geostationary orbits). ... their clocks ticking more slowly (see the Special Relativity ...
    (sci.physics)
  • Real-World Relativity: The GPS Navigation System
    ... Real-World Relativity: The GPS Navigation System ... GPS satellites are not in geosynchronous or geostationary orbits). ... their clocks ticking more slowly (see the Special Relativity ...
    (sci.geo.satellite-nav)
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