Nobel laureate and former physics professor James Cronin died Aug. 25 in St. Paul, Minn. He was 84. Cronin and former professor Val Fitch were awarded the 1980 Nobel Prize in physics for their 1964 discovery of violations of fundamental symmetry principles in the decay of particles called “K-mesons,” showing that the laws of physics are not the same for particles and anti-particles. The finding offered an explanation of why matter survived the Big Bang. Cronin taught at Princeton for 13 years before joining the University of Chicago faculty.