Answer:
calculated the speed of light over a short distance
Step-by-step explanation:
Albert Michelson was an American physicist who conducted an experiment regarding the speed of light in the air 1880s. He believed in the existence of "aether," a field of space that is deemed necessary for transporting electromagnetic forces. In order to do this, he setup a device in order to accurately measure the speed of light in in aether. His device is now known as "Michelson interferometer." The result was actually negative.
In order to make his experiment even more accurate, he collaborated with Edward Morley, a famous American scientist. Although the result failed, together, they were able to improve and come with the a standard length of light. This calculated the speed of light over a short distance, which was the significant result of Michelson's experiment.
Thus, this explains the answer.