In carrying out the experiment, Michelson and Morley oriented the apparatus so that the line was nearly parallel to the earth’s motion in its orbit (at certain times of the day and night). This orbital speed is about miles per second, and any “ether drift” should be at least that much at some time of the day or night and at some time during the year. The apparatus was amply sensitive to observe such an effect, but no time difference was found—the velocity of the earth through the ether could not be detected. The result of the experiment was null.
