Val Fitch

It’s the birthday of Val Fitch, who was born in 1923 in Merriman, Nebraska. Fitch’s undergraduate career was interrupted by World War II, but he was assigned to Los Alamos to work on the Manhattan Project where he learned experimental physics. He applied those techniques and others to investigate the decay of the neutral K meson, which was known to transform into an antiK0, suggesting that it’s made up of two more elementary states, dubbed K1 and K2. In 1964 Fitch and his student James Cronin used the Alternating Gradient Synchrotron at Brookhaven National Laboratory to fire protons at a beryllium target. The resulting K1 and K2 mesons decayed at slightly but significantly different rates: Fitch and Cronin had discovered that the weak interaction does not respect CP symmetry -- that is, reversing both the charge and parity of a particle does not restore its original behavior. CP violation came as a shock to physicists, because it implies that matter and antimatter are not exact mirror images of each other. Fitch and Cronin were awarded the 1980 Nobel physics prize for their discovery, which remains a focus of experimental and theoretical studies.

Date in History: 10 March 1923