John Clive Ward

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John Clive Ward (born August 1, 1924 in London , † May 6, 2000 ) was a British physicist.

Ward studied at Oxford , where he did his PhD with Maurice Pryce . He was in the USA a. a. at Princeton University , Carnegie Institute of Technology and Johns Hopkins University , before immigrating to Australia in 1967 and becoming a professor at Macquarie University .

Ward is best known today because of two essays in Physical Review from 1950 in which he identified an identity named after him (" Ward identity ", today "Ward-Takahashi identity" additionally after Yasushi Takahashi ) between the momentum derivative of the electron Propagators and the effective electron-photon interaction vertex. With such identities he was able to prove the equality or the disappearance of different renormalization constants and thus closed a gap in the proof of the renormalizability of quantum electrodynamics by Freeman Dyson . Similar identities are used today to prove the renormalizability of other gauge theories .

Ward was also a pioneer of the Standard Model . In an article Abdus Salam of 1964 he examined a unified theory of the electro-weak interaction with gauge group SU (2) x U (1) (as well as later Steven Weinberg ), with Weak Mixing angle between the photon and the neutral Z-gauge boson , but without spontaneous symmetry breaking .

In the early 1950s he also worked on superfluids , quantum mechanical many-body theory (with JM Luttinger , Renfrey Potts , Elliott Montroll ) and the Ising model (e.g. he developed a combinatorial solution of the Ising model with Mark Kac in 1952).

Ward was also involved in work for the British hydrogen bomb in 1955 and worked on ideas for uranium enrichment (Ward process) in Australia. His involvement in the development of the British hydrogen bomb, which was first tested in 1957 (Operation Grapple) is also described in his memoirs, but according to the historian Lorna Arnold there is no indication in the archives of who the successful design was due to. The direction of development at the Atomic Weapons Establishment in Aldermaston was William Penney . William Richard Joseph Cook , Henry Hulme , Keith V. Roberts and John Bryan Taylor were also named as major contributors (and Ken Allen in the Grapple V design). Development began in July 1954 and the last test of the development phase was near Christmas Island in September 1958.

Ward last lived in Vancouver and died after returning from a trip to the South Seas. Ward became a Fellow of the Royal Society in 1965. In 1980 he received the Guthrie Medal of the Institute of Physics, 1982 the Dannie Heineman Prize for Mathematical Physics and 1983 the Hughes Medal of the Royal Society.

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Remarks

  1. ↑ Ward “The Scattering of Light by Light”, Physical Review Vol. 77, 1950, p. 293, “An identity in QED”, Physical Review Vol. 78, 1950, p. 406
  2. ↑ More precisely, in his first work he showed the disappearance of the photon-photon scattering amplitude and thus that a separate four-photon vertex component is not necessary in the renormalized Lagrangian function. Shortly afterwards he proved with his identity that the renormalization constant of the electron wave function is equal to that of the electron-photon vertex.
  3. ↑ Renormalizable roughly means that the infinities occurring when calculating loop diagrams can be "hidden" by redefining (renormalizing) a finite number of constants in the Lagrangian
  4. ↑ Salam, Ward “Weak and electromagnetic interactions”, Physics Letters, Vol. 13, 1964, p. 168, and “Gauge theory of elementary interactions”, Physical Review B 136, 1964, p. 763. As early as 1961, both published “On a gauge theory of elementary interactions ", Nuovo Cimento Vol. 19, p. 166
  5. ↑ Kac, Ward, Physical Review Vol. 88, 1952, p. 1332
  6. ↑ See also Renfrey Potts , Ward, Progr. Theor. Phys., Vol. 13, 1955, p. 38. Spontaneous magnetization has been discussed by Elliott Montroll , Potts, Ward, J. Math. Phys., Vol. 4, 1963, p. 308.
  7. ↑ Dalitz, Duarte "John Clive Ward", Physics Today, Vol. 53, 2000, Issue 10, p. 99
  8. ^ Ward, Memoirs of a Theoretical Physicist, Optics Journal, Rochester, New York, 2004
  9. ^ Lorna Arnold, Britain and the H-Bomb, Palgrave, 2001. On the Fathers of Development, p. 224. She could not speak or receive written contact with Penney, Cook, Hulme and Roberts, but with Ward, Bryan Taylor, John Corner u. a.
personal data
SURNAME Ward, John Clive
BRIEF DESCRIPTION British physicist
DATE OF BIRTH August 1, 1924
PLACE OF BIRTH London
DATE OF DEATH May 6, 2000