Quick Summary

Also known as the Sagnac effect, the results are an uncontested fact, the interpretation is far from it. This experiment was formulated to prove the existence of Aether and though the results are positive relativists just try to make it fit into relativity. Once again, the problem is that relatvists will throw in a universal frame of reference any time it's convienient but patently deny its existance when questioned. The explanations are actually correct but incompatible with relativity

Think about this. If you split a laser to travel opposite directions around a square of mirrors, the beam will arrive back at the same point at precisely the same time correct? If light travels the same speed in all frames of reference then will spinning the whole room -changing the speed of the emitter or listener- do anything to the arrival time of the two beams? No, right?

Unfortunately for relativity, experiments show that it does... (Though the tests are not set up to compare the arrival of the first wave, the results and the explanations bear out that there is a difference.)

The Aether based explanation of this effect and the Relativity explanation are suspiciously similar:

Relativity: Though we know there is no universal frame of reference and therefore never any need for more than two frames of reference for an experiment, for the explanation of this experiment, we're going to add a third frame of reference outside of the emitter and receiver and call it "proper time". In regard to this third frame of reference the light beam is traveling a different distance so that is why it is out of sync.

Aether:  Because the light traveled further in one direction than the other in regard to an absolute reference frame(the medium through which it traveled), the two signals are out of sync.

Here is a link to a project apparently in New Zealand to more precisely gauge the Earth's rotation using the Sagnac Effect. The funny part is that their indoctrination into relativity is so deep that they talk about proofs of Aether without even realizing that they are doing so. They do also mention that the Sagnac Effect does cause a Doppler shift in frequency which it should not if relativity were true. Overview

I'll give you a Link to a page with a very lengthy explanation of why I'm wrong and relativity is right. I'll let him have 20 Pages to my 2 and let you decide what is logical. Pay close attention to the automatic hostility towards anyone not on the writers side. The opposing side is painted with the broad brush of "Anti-Scientific","Crack-Pots". Whereas a historian can tell you that there were Nobel Prize winning scientists of that day and current day he just painted with that brush. Also notice his erroneous proclamation of no Doppler in Sagnac it's a very important aspect.

My contention with his explanation is not that it's incorrect exactly. I'm saying that the method he's using excludes relativity from the equation. I have no doubt that his math is impeccable and that it reflects test results and reality. However the problem is not with the math but with the logic. Any argument of relativity that includes a third frame of reference other than the emitter and the detector is inferring a universal frame of reference. Logically he's contradicting relativity in his explanation of how it fits with relativity. He does a great job of explaining what is really going on because the truth is that it really does travel through more space (more Aether)

This guy is actually explaining that the light is having to travel further in regard to an outside reference frame. So, in other words, he's saying that if three equidistant planets are all traveling in one direction with light emitted from the middle one, the light traveling to the lead planet is having to go through more space than the light going to the trailing planet when we add an outside reference point. This is implying a universal frame of reference. This is implying an Aether. If there is no Aether then there is no "Proper Time" and the motion of the three planet system should not affect how long it takes for light to get to the two outer planets according to relativity.