Albert Abraham Michelson was born in Strelno, Prussia, in 1852. When he was two years old, his family emigrated to the United States, where they settled in San Francisco. Michelson graduated from the United States Naval Academy in 1873, and then served as science instructor at the academy from 1875 until 1879.
In 1878, Michelson began work on what was to be the focus of his life: the accurate measurement of the speed of light. He was able to obtain useful values with homemade apparatuses. Feeling the need to study optics before he could be qualified to make real progress, he traveled to Europe in 1880 and spent two years in Berlin, Heidelberg, and Paris, resigning from the U.S. Navy in 1881. Upon his return to the United States, he determined the velocity of light to be 299,853 kilometres (186,329 miles) per second, a value that remained the best for a generation, until Michelson himself improved on it.
While in Europe, Michelson began constructing an interferometer, a device designed to split a beam of light in two, send the parts along perpendicular paths, then bring them back together. If the light waves had, in the interim, fallen out of step, interference fringes of alternating light and dark bands would be obtained. From the width and number of those fringes, unprecedentedly delicate measurements could be made, comparing the velocity of light rays traveling at right angles to each other. From these investigations, Michelson was able to determine, in what came to be called the Michelson-Morley experiment, that there were no interference fringes and apparently no motion of the Earth relative to the "ether" (then thought to make up the basic substratum of the universe). To explain the result of the Michelson-Morley experiment, physics had to be recast on a new and more refined foundation, something that resulted, eventually, in Albert Einstein's formulation of the theory of relativity in 1905.
Information as of 1923