James Chadwick discovered that the energy of beta radiation varied from one measurement to the next. To solve the problem, Wolfgang Pauli soon suggested that the energy was shared between two particles: one visible (the electron) and the other invisible (later discovered to be the neutrino), with one particle sometimes taking all the energy. Pauli thus did what he had always abhorred: postulating the existence of something unmeasurable to solve a physics problem. Pauli offered a case of fine champagne to anyone who could see the missing particle. After 42 years, he had to keep his promise and drink champagne with Clyde Cowan and Fred Reines.
