Fitch, Val Logsdon, 1923–, American nuclear physicist, b. Merriman, Neb., Ph.D. Columbia Univ., 1954. Fitch and co-researcher James Watson Cronin 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 K-mesons, that a reaction run in reverse does not merely retrace the path of the original reaction, which showed that the reactions of subatomic particles are not indifferent to time.
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