John Clive Ward was perhaps one of the most brilliant British physicists of the post war era. A contributor to the Standard Model and the creator of the famed Ward Identities his contributions are discussed in several well-known books dealing with theoretical and particle physics.

The Ward Identities have their origin in a 1950 paper published in Physical Review. This was a succinct master piece authored by J. C. Ward and entitled An identity in quantum electrodynamics. Building on previous work by Dyson this elegant letter proved in seven steps one of the most important and celebrated results of renormalization theory. In a following paper, published in 1951, Ward extended the initial result to a set of identities. Today, the Ward Identity or Ward Identities, are standard teachings in theoretical physics and continue to be the focus of considerable research activity. Some four thousand journal physics papers have been published with Ward Identity or Ward Identities either in their titles or abstracts. A much larger number of web sites refer to this subject.

In addition to his profound influence in field theory, and quantum electrodynamics, he made significant and fundamental contributions to quantum mechanics, elementary particle physics, quantum solid-state physics, and quantum statistics. However, his contributions have not yet received the widespread recognition they deserve. It has been said that for decades physicists have made use of his principles and developments "often without knowing it, and generally without quoting him." In this regard, it was Ward whom, in 1947, derived the equation for the quantum entanglement of orthogonal polarizations for two particles propagating in different directions ( | x, y > - | y, x > ).

Born in London, the 1st of August of 1924, John Ward was educated at Oxford. His doctoral advisor was M. H. L. Pryce who, like P. A. M. Dirac, was a student of R. H. Fowler. Following a series of appointments John Ward arrived to Australia in 1967, via Princeton and Johns Hopkins, and played a major role in creating a high-class physics program at Macquarie University . This physics curriculum was based on the now famous Feynman Lectures on Physics and included a superb experimental physics program. Under his influence, and with the assistance of several colleagues (including R. A. Aitchison, C. E. Curnow, E. Laisk, and R. E. B. Makinson), the foundations of a Macquarie physics education became a combination of courses in electromagnetism, quantum physics, solid state physics, advanced electronics, and experimental physics in addition to courses in applied mathematics. At Macquarie he became known for his forceful defense of science, high academic standards, and for his uncompromising honesty. In this regard, he openly and vigorously supported the student science reform movement that permanently changed the degree structure of the university. This transformative innovation strengthened significantly the structure of the sciences at Macquarie and Ward considered it a "most important accomplishment."

Although himself a gifted theoretician John Ward always held a deep rooted respect for experimental physics and engineering. This well balanced and utilitarian philosophy was well reflected in the nature of the Macquarie physics degree.

John Ward was a Fellow of The Royal Society and received several coveted physics awards including the Heinaman Prize, the Hughes Medal, and the Guthrie Medal. His contributions to theoretical physics inspired admiration among his most illustrious peers. In this regard, Sakharov classified him as one of the titans of quantum electrodynamics alongside Dyson, Feynman, Schwinger, and Tomonaga. In 1988 one of his former students met Julian Schwinger at a conference reception in Lake Tahoe. Once Schwinger knew that the young physicist was from Macquarie, he smiled and immediately proceeded to focus the conversation on one topic alone: John Ward.

In an informative and interesting magazine article he was described as a "restrained rather distant Englishman." Distance apart, he was the epitome of a physicist and a scholar,a man who exerted a distinct influence in the education of those physicists who knew him. An accomplished pianist, and french horn player, he spent the last years of his life in Vancouver Island, Canada. During this period, his time was devoted to his physics, wine making, and traveling to places like Europe, Mexico, and the south of South America.

I shared the last couple of days of 1999 and the first day of 2000, with John, in Santiago de Chile, at the foot of the majestic Andes. We discussed a litany of topics from physics to geopolitics. We laughed hard, tasted wine, and celebrated our iconic achievement at Macquarie. He was looking forward to get back to work on his physics and he suggested teaching jointly a refreshing physics course, for high school teachers in Santiago, similar to a course he had taught back at Macquarie. However, it would not be. John passed away following a trip to the South Pacific on the 6th of May of 2000.

Frank Duarte

• M. H. L. Pryce and J. C. Ward, Angular correlation effects with annhilation radiation, Nature 160, 435 (1947).
• F. J. Duarte and M. Brandt, Science notes, Arena 12(6), 7 (1979).
• F. J. Duarte and M. Brandt, Science notes, Arena 12(7), 5 (1979).
• G. Sheridan, Australian physicist wins Guthrie Medal, The Bulletin 101(5239), 49-50 (1980).
• G. Hooft, Gauge theories of the forces between elementary particles, Sci. Amer. 242, 104-138 (1980).
• A. Sakharov, Memoirs (Knopf, New York, 1990).
• P. W. Anderson, Is complexity physics?, Physics Today 44 (7), 9-11 (1991).
• N. Dombey and E. Grove, Britain's thermonuclear bluff, The London Review of Books, 22nd of October, 1992.
• M. Dunhill, Oxford note on the Hilary Term (1995).
• R. Delbourgo, The Nobel prize in physics 1999, The Physicist 36, 215-219 (1999).
• R. H. Dalitz and F. J. Duarte, John Clive Ward, Physics Today 53 (10), 99-100 (2000).
• F. J. Duarte, The origin of quantum entanglement experiments based on polarization measurements, The European Physical Journal H. 37, 311–318 (2012).

• M. H. L. Pryce and J. C. Ward, Angular correlation effects with annhilation radiation, Nature 160, 435 (1947).
• J. C. Ward, The scattering of light by light, Phys. Rev. 77, 293 (1950).
• J. C. Ward, An identity in quantum electrodynamics, Phys. Rev. 78, 182 (1950).
• J. C. Ward, A convergent non-linear field theory, Phys. Rev. 79, 406 (1950).
• J. C. Ward, Quantum effects in the interaction of electrons with high frequency fields, Phys. Rev. 80, 119 - 119 (1950).
• J. C. Ward, Renormalization theory of the interaction of nucleons, mesons, and photons, Phys. Rev. 84, 897-901 (1951).
• J. C. Ward and J. Wilks, The velocity of second sound in liquid helium near the absolute zero, Phil. Mag. 42, 314-316 (1951).
• J. C. Ward and J. Wilks, Second sound and the thermo-mechanical effect, Phil. Mag. 43, 48-50 (1952).
• M. Kac and J. C. Ward, A combinatorial solution of the two- dimensional Ising model, Phys. Rev. 88, 1332-1337 (1952).
• R. B. Potts and J. C. Ward, The combinatrial method and the two-dimensional ising model, Prog. Theor. Phys. 13, 38-46 (1955).
• A. Salam and J. C. Ward, Weak and electromagnetic interactions, Nuovo Cimento 11, 568-577 (1959).
• E. W. Montroll and J. C. Ward, Quantum statistics of interacting particles; general theory and some remarks on properties of an electron gas, Phys. Fluids 1, 55-72 (1958).
• J. M. Luttinger and J. C. Ward, Ground-state energy and many- fermion system, Phys. Rev. 118, 1417-1427 (1960).
• A. Salam and J. C. Ward, Δl = ½ rule, Phys. Rev. Lett. 5, 390 (1960).
• A. Salam and J. C. Ward, On a gauge theory of elementary interactions, Nuovo Cimento 19, 166-170 (1961).
• E. W. Montroll, R. B. Potts, and J. C. Ward, Correlations and spontaneous magnetization of the two-dimensionaol Ising model, J. Math. Phys. 4, 308-322 (1963).
• A. Salam and J. C. Ward, Electromagnetic and weak interactions, Phys. Lett. 13, 168-171 (1964).
• A. Salam and J. C. Ward, Gauge theory of elementary interactions, Phys. Rev. 136 B, 763-768 (1964).
• J. C. Ward, General relativity, the Dirac equation, and higher symmetries, Proc. Natl. Acad. Sci. USA 75, 2568 (1978).

• R. Delbourgo, John Clive Ward 1924-2000, CERN Courier 40 (6) (2000).
• F. J. Duarte and J. A. Piper, John Clive Ward, FRS, The Physicist 37 (4), 145-146 (2000).
• F. J. Duarte, J. C. Ward: elegant physics and a practical perspective, Optics and Photonics News 11 (8), 62-63 (2000).^*
• R. H. Dalitz and F. J. Duarte, John Clive Ward, Physics Today 53 (10), 99-100 (2000).

• F. J. Duarte, The man behind an identity in quantum electrodynamics, Australian Physics 46 (6), 171-175 (2009).

• F. J. Duarte, Tunable lasers for atomic vapor laser isotope separation: the Australian contribution, Australian Physics 47(2), 38-40 (2010).
  

• F. J. Duarte, The probability amplitude equation of quantum entanglement: the Australian connection, Australian Physics 50 (1), 12-14 (2013).

Note 1: a biographical note on Australian Physicist Richard ("Dick") H. Dalitz, a long time friend of John C. Ward, is available from Physics at Oxford. A more extensive article including a listing of Dalitz's works is entitled The scientific heritage of Richard Henry Dalitz, FRS (1925-2006) (by I. J. R. Aitchison et al.).

Note 2: in a long series of conversations with Dick Dalitz, whilst preparing the article on John Ward for Physics Today, it became clear to me that Dick was convinced tha John's contribution to the Standard Model was more extensive than accepted by conventional wisdom. Dick also accepted John's relevance to Britain's H-Bomb efforts. This was made explicit in his contribution to the Physics Today article. Further, Dick was working on a book on John's papers and contributions to physics which was the focus of my last conversation with him (Frank Duarte).

Note 3: an article describing a little known idea of John Ward, in the isotope separation field, known in Australia as the Ward Process is described in:

• A. W. Pryor, Personal memories of two advanced uranium enrichment projects at Lucas Heights in the years 1972-1980, The Australian & New Zealand Physicist 33 (3-4), 53-58 (1997).
• N. Dombey, John Clive Ward, Biogr. Mems. Fell. R. Soc. 60 (2021) .

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• F. Close, The Infinity Puzzle: Quantum Field Theory and the Hunt for an Orderly Universe (Oxford University, Oxford, 2011).
  
  

• F. J. Duarte, Laser Physicist (Optics Journal, New York, 2012).
  
  

• N. Dombey, John Clive Ward, Biog. Mems. Fell. R. Soc. 70, 419-440 (2021).
  
  

^*This paper was published in Optics and Photonics News and is made available as an electronic reprint with the permission of OSA. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. Copyright OSA (www.osa.org/pubs/osajournals.org).