Hammar Experiment - Overview

Overview

Experiments such as the Michelson-Morley experiment of 1887 (and later other experiments such as the Trouton-Noble experiment in 1903 or the Trouton-Rankine experiment in 1908), presented evidence against the theory of a medium for light propagation known as the Luminiferous aether; a theory that had been an established part of science for nearly one hundred years at the time. These results cast doubts on what was then a very central assumption of modern science, and later led to the development of special relativity. In an attempt to explain the results of the Michelson-Morley experiment in the context of the assumed medium, aether, many new hypotheses were examined. One of the proposals was that instead of passing through a static and unmoving aether, massive objects at the Earth's surface may drag some of the aether along with them, making it impossible to detect a "wind". Oliver Lodge (1893-1897) was one of the first to perform a test of this theory by using rotating and massive lead blocks in an experiment that attempted to cause an asymmetrical aether wind. His tests yielded no appreciable results differing from previous tests for the aether wind.

In the 1920s, Dayton Miller conducted repetitions of the Michelson–Morley experiments, which allegedly gave a positive result. However, several experiments conducted afterwards by others gave negative results. Miller claimed that this is due to entrainment of the aether, because the other experiments used heavily enclosed equipment. To test Miller's assertion, Hammar conducted the following experiment using a common path interferometer in 1935.