Edward W. Morley and Albert A. Michelson tested whether the orientation of an interferometer revealed motion through the proposed luminiferous aether. Perpendicular optical paths were recombined to form interference fringes; rotating the instrument tested for the predicted change in their relative travel times. The measured shift was much smaller than the prediction based on a stationary luminiferous aether and the Earth's orbital motion. The experiment constrained that model through a differential optical measurement, rather than directly timing a single light pulse.[ref]
On the Relative Motion of the Earth and the Luminiferous Ether by Albert Abraham Michelson and Edward W. Morley. 1887 report, perpendicular paths, rotation and comparison of measured with predicted fringe displacements
Portrait of Edward W. Morley
. Photographer not identified; portrait of Edward Williams Morley in 1887; source University of Maryland aether-drift page. Public domain in the United States as asserted by Commons. Source usage terms, via Wikimedia Commons. Source. Articles by others on the same topic
Edward W. Morley (1838–1923) was an American chemist and physicist best known for his contributions to the field of science, particularly in relation to the study of light and the measurement of the speed of light. He is most famously associated with the Michelson-Morley experiment, conducted in 1887 in collaboration with physicist Albert A. Michelson.