Like I was saying last time, the electron was discovered by JJ Thomson in 1897, the proton was discovered by his student Ernest Rutherford in 1917, and the neutron was discovered by his student  James Chadwick in 1932: Chadwick neutron discovery image from Goodfellow.com The positron was discovered by Carl Anderson in the same year. Then the muon was discovered by Carl Anderson and Seth Neddermayer in 1936. After a hiatus due to World War II, the charged pion was discovered in 1947, as was the…

The history of particle physics starts with the concept of the atom. The word is derived from atomos, which means indivisible. It goes way back to the Greek philosopher Leucippus in the 5th century BC. His student Democritus promoted the idea, but Aristotle was dead against it. The Christian Church sided with Aristotle, and it wasn’t until the 17th century that atoms were resurrected. See the Philosophy Institute article Evolution of the Atomic Theory for more. Things really picked up in 1808 when John Dalton published…