Sagnac Experiment

The Sagnac Experiment was first conducted by French physicist Georges Sagnac in 1913. The experiment is essentially the same experiment as the Michelson-Morley Experiment, except that it is on a horizontal rotating turn-table. The results of the Sagnac Experiment show that when the table is rotated around during the experiment the velocity of light indeed changes, to where c = +/- v, where v is the additional or subtracted velocity of the moving broadcasting device. This contradicts the Michelson-Morley Experiment that was designed to use the supposed movement of the Earth to change position, and which showed no change in light velocity.

From a paper on the Sagnac Effect one writer states:



Critics of the Sagnac Effect generally claim that the laws of Special Relativity do not apply to the Sagnac Experiment due to the rotational acceleration in the device. However, the same effect is seen in non-accelerating linear motion as well. See the Wang Experiment.

A Critical Analysis
In Theory of Relativity: A Critical Analysis (Archive) its author Dr. Roberto Monti (bio) describes in the abstract:

On the subject of the Sagnac Effect, Dr. Monti states:

Malcom Bowden
The geocentrist Malcom Bowden describes the Sagnac Experiment in the following video:

Video Description:

University of Geneva
The Sagnac effect and transformations of relative velocities between inertial frames J.H.Field, Département de Physique Nucléaire et Corpusculaire, Université de Genève Full Text Link (Archive)

From the Abstract:

From the Conclusion:

General Relativity Framework
On the assertion that the Sagnac Effect is explained under the framework of General Relativity theory, Professor Ramzi Suleiman of the University of Haifa writes the following:

The Sagnac Effect Falsifies Special Relativity Theory (Archive)

1942 Dufour-Prunier
The French duo, Dufour and Prunier, performed a variety of interesting variations on Sagnac's original experiment. They reported lightspeed is always observed to be c+v (where v is the speed of the rotor in Earth's frame) regardless of whether:

- the observer is co-rotating with the device

- the observer is sitting stationary in the lab (while the optical bench co-rotates with the rotor)

- some of the mirrors comprising the optical circuit are stationary in the lab while others co-rotate on the rotor (the light is diverted from a set of spinning mirrors up to a set of stationary mirrors suspended in the air over the rotor, then diverted back down to the spinning mirrors and observer)

They concluded that Relativity is "in complete disagreement" with the results.


 * Original 1942 Paper (Archive)


 * Recent Dufour & Prunier Analysis Article (Archive) by Robert Bennet, PhD (bio)

Wang Experiment
As stated previously, it has been claimed that Special Relativity does not apply to the Sagnac Effect because the Sagnac Experiment involves rotational acceleration. In 2004 Dr. Ruyong Wang demonstrated that a non-accelerating linearly moving observer can also measure a difference in light velocity.


 * 2004 Wang. Generalized Sagnac Effect (pdf) (Archive)
 * First experiment conducted by R. Wang (Archive)
 * Second experiment carried out by R. Wang (Archive)

Robert Bennett
Robert Bennett, Ph.D. (bio) writes:

See: A Landmark Experiment: The Linear Sagnac Test of Ruyong Wang (Archive)

Al Kelly
From Challenging Modern Physics: Questioning Einstein's Relativity Theories by Al Kelly (bio) we find:

José Croca
On p.306 of the book Unified Field Mechanics II we find a paper (Archive) by Physicist José R. Croca, Ph.D. (bio), where we see:

If, as is suggested by Dr. Croca above, the speed of light is actually c +/- v, where v is the speed of the moving broadcasting device, then it is quite curious that the Michelson-Morley Experiment did not experience this from the movement of the Earth on a horizontal plane.

In parting, Dr. Croca states:

Defeated, and with the ever need to have an 'explanation' to keep the model alive, relativists seem to hint that relativity might operate differently at different scales. One must remark that it is quite odd and remarkable that Special Relativity remains true despite a direct violation of its postulates with multiple experiments; apparently only applicable to certain situations involving the motion of the Earth as a heliocentric explanation for why the Earth has been tested to be horizontally motionless. Sagnac and Wang experiments have observed an inconsistency of light velocity for different speeds of a detector in motion, including light traveling faster than c, which is directly contradictory to Special Relativity's postulate of a speed consistency of light to all observers and the luminal speed limit of c.

Daniel Y. Gezari
Dr. Gezari (bio) in his Experimental Basis for Special Relativity in the Photon Sector (Archive) shows us that Special Relativity is a theory of limited experimental validity and casts doubt on the invariance of c postulate used to justify the Michelson-Morley Experiment. We are informed that the invariance of c (speed of light consistency) has never been demonstrated with a moving detector.