James Cronin
Facts
Photo from the Nobel Foundation archive.
James Watson Cronin
The Nobel Prize in Physics 1980
Born: 29 September 1931, Chicago, IL, USA
Died: 25 August 2016, St. Paul, MN, USA
Affiliation at the time of the award: University of Chicago, Chicago, IL, USA
Prize motivation: “for the discovery of violations of fundamental symmetry principles in the decay of neutral K-mesons”
Prize share: 1/2
Work
For a long time, physicists assumed that various symmetries characterized nature. In a kind of “mirror world” where right and left were reversed and matter was replaced by antimatter, the same physical laws would apply, they posited. The left-right symmetry had already been proven violated when, in 1964, James Cronin and Val Fitch discovered that the matter-antimatter symmetry is violated when the neutral K-meson decays. Their experiment also proved that symmetry does not apply during time reversal: reactions going backward in time are not identical to those going forward.
Nobel Prizes and laureates
Six prizes were awarded for achievements that have conferred the greatest benefit to humankind. The 12 laureates' work and discoveries range from proteins' structures and machine learning to fighting for a world free of nuclear weapons.
See them all presented here.
