1887Reputable sourceWell documented
The Michelson–Morley Experiment
On the timeline · around 1887 ·
What happened
Physicists believed light waves travelled through an invisible medium filling all space, the 'ether.' In 1887 Albert Michelson, working with Edward Morley, used the exquisitely sensitive interferometer he had invented to measure the speed of light as the Earth moved through this supposed ether. They found the speed of light unchanged by the Earth's motion — no sign of the ether at all.
Why it matters
This 'failed' experiment was one of the most important in the history of physics. Its null result undermined the idea of the ether and set the stage for Einstein's relativity. Michelson won the 1907 Nobel Prize, the first American to win a Nobel in the sciences.