Cronin, James Watson

▪ American physicist
born Sept. 29, 1931, Chicago, Ill., U.S.

      American particle physicist, corecipient with Val Logsdon Fitch (Fitch, Val Logsdon) (q.v.) of the 1980 Nobel Prize for Physics for an experiment that implied that reversing the direction of time would not precisely reverse the course of certain reactions of subatomic particles.

      Cronin graduated from Southern Methodist University at Dallas, Texas, in 1951 and received his Ph.D. from the University of Chicago in 1955. He then joined the staff of the Brookhaven National Laboratory, Upton, N.Y., and in 1958 became a professor at Princeton University.

      Cronin and his colleague Fitch played a role in modifying the long-held notion that the laws of symmetry and conservation are inviolable. One of these laws, the principle of time invariance (designated T), states that particle interactions should be indifferent to the direction of time. This symmetry and two others, those of charge conjugation (C) and parity conservation (P), were once thought to govern all the laws of physics. But in 1956 the physicists Chen Ning Yang and Tsung-Dao Lee suggested, correctly, that parity conservation could be violated by particle decays involving weak interactions. Physicists abandoned the view that C, P, and T are independently true for weak interactions, but saved the overall concept by proposing that any P violation must be offset by an equal C violation, a concept known as CP symmetry.

      In a series of experiments conducted at Brookhaven in 1964, Cronin and Fitch showed that in rare instances, subatomic particles called K mesons violate CP symmetry during their decay. (See CP violation.) In 1971 Cronin was appointed professor of physics at the University of Chicago.

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Universalium. 2010.

Look at other dictionaries:

  • Cronin , James Watson — (1931–) American physicist Cronin, who was born in Chicago, Illinois, was educated at the Southern Methodist University and at Chicago, where he obtained his PhD in 1955. After a period at the Brookhaven National Laboratory he moved to Princeton… …   Scientists

  • James Watson Cronin — James Cronin (2006) James Watson Cronin (* 29. September 1931 in Chicago) ist US amerikanischer Physiker. Cronin schloss 1951 seine Studien an der Southern Methodist University ab und ging für die weitere Ausbildung an die University of Chicago,… …   Deutsch Wikipedia

  • James Watson Cronin — Pour les articles homonymes, voir Cronin. James Watson Cronin en 2006. James Watson Cronin (29 septembre 1931 à Chicago …   Wikipédia en Français

  • James Watson — puede referirse a: James Dewey Watson, biólogo, premio Nobel estadounidense. James Watson Cronin, físico nuclear, premio Nobel estadounidense. Véase también James, (desambiguación). Watson, (desambiguación) …   Wikipedia Español

  • Physiknobelpreis 1980: James Watson Cronin — Val Logsdon Fitch —   Die amerikanischen Physiker wurden für die Entdeckung von Verletzungen fundamentaler Symmetrieprinzipien beim Zerfall der neutralen Kaonen ausgezeichnet.    Biografien   James Watson Cronin, * Chicago (Illinois) 29. 9. 1931; ab 1965 Professor… …   Universal-Lexikon

  • Cronin — James Watson …   Scientists

  • James Cronin — James Watson Cronin Pour les articles homonymes, voir Cronin. James Watson Cronin en 2006. James Watson Cronin, né à …   Wikipédia en Français

  • James Cronin — James Watson Cronin en una presentación en la Universidad Nacional de Vietnam el 4 de agosto de 2006. James Watson Cronin (Chicago, 29 de septiembre de 1931), es un físico nuclear estadounidense. Biografía Nació en Chicago, Illinois …   Wikipedia Español

  • James Cronin — (2006) James Watson Cronin (* 29. September 1931 in Chicago) ist US amerikanischer Physiker. Cronin schloss 1951 seine Studien an der Southern Methodist University ab und ging für die weitere Ausbildung an die University of Chicago, wo er 1955 …   Deutsch Wikipedia

  • Cronin —   [ krəʊnɪn],    1) Archibald Joseph, englischer Schriftsteller, * Cardross (bei Dumbarton) 19. 7. 1896, ✝ Montreux 6. 1. 1981; war Arzt (u. a. im Bergbaugebiet von Wales; später in London), dann freier Schriftsteller in den USA und in der… …   Universal-Lexikon

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