12 Facts About Sagnac effect

Sagnac effect, called Sagnac interference, named after French physicist Georges Sagnac, is a phenomenon encountered in interferometry that is elicited by rotation.

Georges Sagnac effect set up this experiment in an attempt to prove the existence of the aether that Einstein's theory of special relativity had discarded.

Not aware of the Sagnac effect, Harress had realized the presence of an "unexpected bias" in his measurements, but was unable to explain its cause.

Sagnac effect concluded that this interferometer experiment would indeed produce the same positive result for both special relativity and the stationary aether .

Sagnac effect concluded that only complete-aether-drag models would give a negative result.

Sagnac effect believed that his results constituted proof of the existence of a stationary aether.

However, since the gravitational field would have to be significant, Laue concluded it is more likely that the Sagnac effect is a result of changing the distance of the path by its movement through space.

Sagnac effect has stimulated a century long debate on its meaning and interpretation, much of this debate being surprising since the effect is perfectly well understood in the context of special relativity.

At non-relativistic speeds, the Sagnac effect is a simple consequence of the source independence of the speed of light.

Sagnac effect is well understood in the context of special relativity where from the rotating light source's point of view the phase difference is due to the line of simultaneity along the light path not forming a closed loop in spacetime.

Sagnac effect topology was actually first described by Michelson in 1886, who employed an even-reflection variant of this interferometer in a repetition of the Fizeau experiment.

Sagnac effect interferometers are almost completely insensitive to displacements of the mirrors or beam-splitter.