Kennedy-Thorndike experiment

The Kennedy-Thorndike experiment, first conducted in 1932, is a modified form of the Michelson-Morley experimental procedure. This experiment tests whether c, the speed of light, depends on the velocity of the laboratory. Special relativity states that the speed of light is the same no matter how fast an observer is travelling. The Kennedy-Thorndike experiment tests this prediction by monitoring the oscillations of a light source as it accelerates and decelerates. In this experiment, the path lengths of a split beam are made unequal. If correct, the Fitzgerald-Lorentz contraction hypothesis would then be unable to explain the null result from this experiment.

Current (as of 2003) Michelson-Morley experiments' precision is higher than the current Kennedy-Thorndike experiments' precisions.