Which 1887 experiment is famous for failing to detect an aether wind?

The 1887 Michelson–Morley experiment is famous for failing to detect an “aether wind.” Albert A. Michelson and Edward W. Morley compared light traveling in perpendicular directions, looking for a difference caused by Earth moving through the hypothetical luminiferous aether.

Their interferometer produced a null result: the expected shift in the interference pattern was not observed at a significant level. The experiment was performed between April and July 1887 in Cleveland, Ohio, and published later that year.

The result challenged 19th-century theories that treated aether as the medium carrying light. It did not by itself prove special relativity, but it became an important part of the evidence leading to the abandonment of stationary-aether theories and the development of Lorentz transformations and Einstein’s 1905 theory.

A common mix-up is calling the experiment an outright failure. It failed to detect the predicted effect, but experimentally it was highly influential. Later, more sensitive Michelson–Morley-type experiments also found no convincing aether wind.