Michelson talked Alexander Graham Bell, newly enriched inventor of the telephone, into providing the funds to build an ingenious and sensitive instrument of Michelson's own devising called an interferometer, which could measure the velocity of light with great precision.

As Caltech astrophysicist Kip S. Thorne has written: "The speed of light turned out to be the same in all directions and at all seasons."It was the first hint in two hundred years—in exactly two hundred years, in fact—that Newton’s laws might not apply all the time everywhere. The Michelson-Morley outcome became, in the words of William H. Cropper, "probably the most famous negative result in the history of physics." Michelson was awarded Nobel Prize in physics for the work—the first American so honored—but not for twenty years. Meanwhile, the Michelson-Morley experiments would hover unpleasantly, like a musty smell, in the background of scientific thought.