Phase and Frequency Shift in a Michelson Interferometer
Year: 2011 Pages: 9
Keywords: OCIS: Fundamental tests, Instruments, apparatus, and components common to the sciences, Interferometry , Phase measurement
Traditionally the outcome of Michelson's interference experiment has been interpreted as evidence against the existence of a luminiferous medium called ?ether?. Einstein, however, emphasized in 1920 that an ether must exist in spite of Michelson's null result. In this paper it is shown that a medium theory ? be it for light or for sound ? actually predicts the observed null result. Michelson expected a gradual fringe shift when his apparatus was turned in the ?ether wind?. Such a phase change would, however, require a temporary frequency change in one of the interferometer arms. Since wind does not alter the frequency in the interferometer, a phase shift cannot occur either.