The Most Successful Failed Experiment in History (Michelson–Morley)

In 1887, in Cleveland, Ohio, Albert Michelson and Edward Morley set out to measure how fast the Earth moves through the luminiferous aether, the invisible medium that light waves were supposed to travel in. Their interferometer sat on a stone slab floating on mercury; the light went back and forth along two arms at right angles, about eleven metres each way. The aether wind should have shifted the interference fringes by 0.4 of a fringe. The shift was certainly less than a twentieth of that. In 1889 George FitzGerald suggested that moving bodies shrink; in 1905 Einstein's relativity made the aether "superfluous". How much the experiment itself guided Einstein is still argued over, and Einstein's own accounts disagree. This is the story of the most famous null result in physics, told from the 1887 paper. 📖 The story behind this video: https://physics.stemlores.com/stories... ▶ Next in this series: The Day a Plane Outran Its Own Sound (Yeager, 1947)    • The Day a Plane Outran Its Own Sound (Yeag...   Chapters 0:00 The Most Successful Failed Experiment 1:15 A Wind Nobody Could Feel 3:12 A Stone on Mercury 5:16 Less Than a Fortieth 7:08 What Einstein Said Sources A. A. Michelson and E. W. Morley, On the Relative Motion of the Earth and the Luminiferous Ether, American Journal of Science 34, 333–345 (1887): https://en.wikisource.org/wiki/On_the... A. A. Michelson, The Relative Motion of the Earth and the Luminiferous Ether, American Journal of Science 22, 120–129 (1881): https://en.wikisource.org/wiki/The_Re... G. F. FitzGerald, The Ether and the Earth's Atmosphere, Science 13, 390 (1889): https://en.wikisource.org/wiki/The_Et... A. Einstein, On the Electrodynamics of Moving Bodies (1905), translated by W. Perrett and G. B. Jeffery: https://www.fourmilab.ch/etexts/einst... J. van Dongen, On the role of the Michelson-Morley experiment: Einstein in Chicago, Archive for History of Exact Sciences 63, 655–663 (2009): https://arxiv.org/abs/0908.1545 G. Holton, Einstein, Michelson, and the 'Crucial' Experiment, Isis 60, 133–197 (1969) The Nobel Prize in Physics 1907, Albert A. Michelson: https://www.nobelprize.org/prizes/phy... Nobel Prize in Physics 1907, presentation speech: https://www.nobelprize.org/prizes/phy... Encyclopedia of Cleveland History (Case Western Reserve University), Michelson-Morley Experiment: https://case.edu/ech/articles/m/miche... S. Herrmann et al., Rotating optical cavity experiment testing Lorentz invariance at the 10^-17 level, Physical Review D 80, 105011 (2009): https://arxiv.org/abs/1002.1284 NASA Earth Fact Sheet: https://nssdc.gsfc.nasa.gov/planetary... Michelson–Morley experiment, Wikipedia: https://en.wikipedia.org/wiki/Michels... Narration is synthetic (text-to-speech); animation made with code. Music: Machina by Scott Buckley – released under CC-BY 4.0. www.scottbuckley.com.au #physics #science #historyofscience