Michelson experiment speed of light animation
From this point of view it is natural to suppose that, just like the electromagnetic forces, the molecular attractions and repulsions are somewhat modified by a translation imparted to the body, and this may very well result in a change of dimensions. The electrons themselves become flattened ellipsoids. This would enable us to predict that no experiment made with a terrestrial source of light will ever show us an influence of the Earth's motion. Hendrik Lorentz , His Einstein's results concerning electromagnetic and optical phenomena agree in the main with those which we have obtained in the preceding pages, the chief difference being that Einstein simply postulates what we have deduced from the fundamental equations of the electromagnetic field. By doing so, he may certainly take credit for making us see in the negative result of experiments like those of Michelson , Rayleigh and Brace, not a fortuitous compensation of opposing effects, but the manifestation of a general and fundamental principle.
The Famous Michelson & Morley Experiment
The Michelson—Morley experiment was an attempt to detect the existence of aether , a supposed medium permeating space that was thought to be the carrier of light waves. The experiment was performed between April and July by Albert A. Michelson and Edward W. The result was negative, in that Michelson and Morley found no significant difference between the speed of light in the direction of movement through the presumed aether, and the speed at right angles. This result is generally considered to be the first strong evidence against the then-prevalent aether theory , and initiated a line of research that eventually led to special relativity , which rules out a stationary aether. Michelson—Morley type experiments have been repeated many times with steadily increasing sensitivity. These include experiments from to , and a series of experiments in the s.
Michelson-Morley experiment , an attempt to detect the velocity of the Earth with respect to the hypothetical luminiferous ether , a medium in space proposed to carry light waves. First performed in Germany in —81 by the physicist A. Michelson , the test was later refined in by Michelson and Edward W. Morley in the United States. The procedure depended on a Michelson interferometer , a sensitive optical device that compares the optical path lengths for light moving in two mutually perpendicular directions. No difference was found.
In retrospect, it was indeed a cool experiment, but not in the way the experimenters thought. It is now considered as one of the most famous null results in history. In all of the different times and seasons, the orientation of the spectrometer failed to add or to subtract the putative motion of the lab through the aether. The simplest interpretation of the results is that light travelled at the same speed with respect to the lab, whether or not the arm of the spectrometer were travelling with the Earth through the aether or at right angles to it. One could also make explanations in which the speed of light varied, but the shape of the spectrometer changed according to its orientation, in such a way that it exactly cancelled the effect of the lab's motion.