Re: General Relativity ?

[Gary Karshner <karshner@STMARYTX.EDU>]

Mark,
        The Sagnac effect is not the gravitational red shift, but due to the
fact that your in a rotating frame of reference.I believe it has both a
special and general relativistic component, and seems to be used by people
who really worry about synchronizing clocks.  You can organize the
relativistic effects as follows: Mass of Earth which is your G red shift
(both for the satellite clock and the observer), oblateness of the Earth,
altitude of clock, Spin of the Earth, ground speed of clock, sagnac effect
both on the observer and the propagation of the satellite's signal, orbital
motion of the satellite. All of this is corrected for by the GPS system and
your one hundred dollar GPS receiver!

Gary


> Is the Sagnac effect the same thing as the gravitational red/blueshift? I
> haven't come across this name and it isn't in the index of any of the
> several relativity books on the shelf next to me.


Gary Karshner

St. Mary's University
San Antonio, Texas
KARSHNER@STMARYTX.EDU