December 4, 2020
In 1997 V. Ragulsky performed an experiment similar to Hoek's, with the difference that he used glass instead of water in one arm . In addition, Ragulsky was able to rotate the entire arrangement in any direction, whereas Hoek's apparatus was fixed . Ragulsky was not familiar with the Hoek experiment, so he performed calculations without taking Fresnel's drag coefficient into account, while the influence of movement on the refractive index was taken into account. Since the Hoek experiment did not yield any results, Hoek concluded that Fresnel's drag coefficient eliminates the effect. A simple derivation of Fresnel's drag coefficient was given by Michelson in a footnote in his 1886 paper , which shows that the result need not be exactly zero even without a dispersion term.