On Jon Butterworth’s Life and Physics blog, Mark Lancaster gives a history of the muon beyond the snappy quote I named this scrapbook after. He makes clear that discovering and understanding this particle took much more work than those three words suggest.
The particle was originally given the name the “mesotron”. As is often the case in science, there was not a “Eureka moment” of discovery, but a gradual dawning of a new paradigm through the work of many people, both theoretical and experimental. Anderson got the credit (having already bagged a Nobel Prize for observing the positron, it was probably an easier sell..) but there was a considerable dramatis personae —- Bethe, Heitler, Rossi, Neddermeyer, Street, Stevenson, Carlson and Oppenheimer —- without whose contributions the “mesotron” would not have been discovered. The “mesotron” was quickly renamed the muon, and it became clear that the muon wasn’t a red or green electron, since if it were just a heavy or a more energetic electron it should decay to an electron and a photon, and this was not observed. The muon appeared to be its own distinct particle and so the muon (after the electron) was the second fundamental particle (i.e. one that doesn’t seem to be made of other particles) to be discovered. Its discovery thus heralded the start of particle physics as a subject.
