Acoustic Michelson-Morley Experiment with an Ultrasonic Range Finder
Norbert Feist
An ultrasonic range finder was mounted on a horizontally rotatable rail at fixed distance, s, to a reflector on the top of a car. The change of the distance reading, s, served to determine the two-way velocity of sound as a function of [car] velocity and direction. Result: the out- and back velocity c2 was isotropic as in the optical case of the Michelson-Morley experiment. Within the experimental error it was found to vary as c2 = (c2 - v2) / c.
