A pool of mercury in a basement provided a nearly frictionless and vibration-free environment for rotating this experiment's apparatus. This experiment found a fringe shift of nearly zero, instead of the expected four-tenths of a fringe. The interference pattern discrepancy indicated that the speed 
A pool of mercury in a basement provided a nearly frictionless and vibration-free environment for rotating this experiment's apparatus. This experiment found a fringe shift of nearly zero, instead of the expected four-tenths of a fringe. The interference pattern discrepancy indicated that the speed of light did not vary with direction in this experiment, which used an interferometer named for one of its experimenters. For 10 points, name this experiment in which two scientists disproved the existence of luminiferous ether.
A pool of mercury in a basement provided a nearly frictionless and vibration-free environment for rotating this experiment's apparatus.
Michelson-Morley experiment [accept names in either order]