The author now gets to the heart of the matter regarding the Sagnac effect:

One of the most confusing relativistic effects – the Sagnac effect – appears in rotating reference frames. The Sagnac effect is the basis of ring-laser gyroscopes now commonly used in aircraft navigation. In the GPS, the Sagnac effect can produce discrepancies amounting to hundreds of nanoseconds.

It is only “confusing” to Relativists because they can’t explain Sagnac’s effects without resorting to obtuse tensor calculus and the invoking of “conditions” they have no way of proving true, invariably resorting to circular reasoning. In other words, they have no physical explanation for why one beam in Sagnac’s interferometer traveled slower than the other beam; rather, they only account for Sagnac’s effect (and they must or else their GPS satellites will be off by “hundreds of nanoseconds”) by creating “relativistic” mathematical equations. But mathematical equations explain very little about the causes for a particular phenomenon. Equations only make one side equal to the other, but with integers on either side that do not necessarily represent the physical processes taking place. In regard to the “fixed-earth” concept, the author reminds his readers that:

Observers in the non-rotating ECI inertial frame would not see a Sagnac effect. Instead, they would see that receivers are moving while a signal is propagating. Receivers at rest are moving quite rapidly (465 m/s at the equator) through the ECI frame. Correcting for the Sagnac effect in the Earth-fixed frame is equivalent to correcting for such receiver motion in the ECI frame.

Here the author is admitting that if the system is not rotating, there would be no Sagnac effect, yet it would appear as another effect (i.e., “receiver motion”). He still hasn’t explained why a Sagnac effect exists in a rotating system (except to point out the anomaly of Relativity theory that light doesn’t behave the same when it is not moving in straight lines). What he has failed to consider is that these anomalies are not “relativistic” effects, but physical effects caused by the medium through which light must travel, the very thing that Sagnac demonstrated by his 1913 experiment. Sagnac’s experiment did not prove “time dilation” or “rotational effects” but, through a device showing that when light came up against a medium or a force that impeded its speed and made it arrive at the destination in more time than expected, it demonstrated none other than the presence of absolute motion in a space, a motion that Einstein dismissed as “relativistic.” Answering this by appealing to “time dilation” is merely an attempt to paint the phenomenon by the phenomenon itself, which doesn’t explain anything, except one’s biased perceptions. In another paragraph, Ashby tries to cover over the inadequacies of Relativity to answer the GPS anomalies:

The Sagnac effect is particularly important when GPS signals are used to compare times of primary reference cesium clocks at national standards laboratories far from each other….A Sagnac correction is needed to account for the diurnal motion
of each receiver during signal propagation. In fact, one can use the GPS to observe the Sagnac effect. Of course, if one works entirely in the nonrotating ECI frame, there is no Sagnac effect.

[CONTINUED]