James Cronin  James Watson Cronin (September 29, 1931 – August 25, 2016) was an American particle physicist. Cronin was born in Chicago, Illinois, and attended Southern Methodist University in Dallas, Texas. He and co-researcher Val Logsdon Fitch were awarded the 1980 Nobel Prize in Physics for a 1964 experiment that proved that certain subatomic reactions do not adhere to fundamental symmetry principles. Specifically, they proved, by examining the decay of kaons, that a reaction run in reverse does not merely retrace the path of the original reaction, which showed that the interactions of subatomic particles are not invariant under time reversal. Thus the phenomenon of CP violation was discovered. Cronin received the Ernest Orlando Lawrence Award in 1976 for major experimental contributions to particle physics including fundamental work on weak interactions culminating in the discovery of asymmetry under time reversal. In 1999, he was awarded the National Medal of Science. Cronin was Professor Emeritus at the University of Chicago winning the prestigious Quantrell Award and a spokesperson emeritus for the Auger project. He was a member of the Board of Sponsors of the Bulletin of the Atomic Scientists. James Cronin was born on September 29, 1931. His father, James Farley Cronin, was a graduate student of classical languages at the University of Chicago. After his father had obtained his doctorate the family first moved to Alabama, and later in 1939 to Dallas, Texas, where his father became a professor of Latin and Greek at Southern Methodist University. After high school Cronin stayed in Dallas and obtained an undergraduate degree at Southern Methodist University in physics and mathematics in 1951. For graduate school Cronin moved back to Illinois to attend the University of Chicago. His teachers there included Nobel Prize laureates Enrico Fermi, Maria Mayer, Murray Gell-Mann and Subrahmanyan Chandrasekhar. He wrote his thesis on experimental nuclear physics under supervision of Samuel K. Allison. After obtaining his doctorate in 1955, Cronin joined the group of Rodney L. Cool and Oreste Piccioni at Brookhaven National Laboratory, where the new Cosmotron particle accelerator had just been completed. There he started to study parity violation in the decay of hyperon particles. During that time he also met Val Fitch, who brought him to Princeton University in Fall 1958. After Cosmotron underwent magnet failure, Cronin and the Brookhaven group moved to Bevatron at the University of California, Berkeley during the first half of 1958.