John Clive Ward
Encyclopedia
John Clive Ward was a British
-Australia
n physicist
. His most famous creation was the Ward-Takahashi identity, originally known as "Ward Identity" (or "Ward Identities"). This celebrated result, in quantum electrodynamics
, was inspired by a conjecture of Dyson
and was disclosed in a one-half page letter typical of Ward's succinct style. In their recent book entitled Quantum Electrodynamics, Greiner and Reinhardt state in their discussion of charge renormalization
: "Yet the Ward Identity has a much more fundamental significance: it ensures the universality of the electromagnetic interaction."
Andrei Sakharov
classified Ward as one of the "titans" of quantum electrodynamics
alongside Dyson
, Feynman
, Schwinger
, and Tomonaga
. In this regard, it has been said that physicists have made use of his principles and developments "often without knowing it, and generally without quoting him."
(with Maurice Pryce), Ward was the first to calculate the correlation of the quantum polarizations of two photons propagating in opposite directions. This prediction was experimentally confirmed by Wu
and Shaknov in 1950. In current terminology this result corresponds to a pair of entangled photons and is directly relevant to a typical Einstein-Podolsky-Rosen (EPR) paradox
, or situation.
He is also one of the creators of the Standard Model
. His contributions were published in a series of papers co-authored with A. Salam
An insightful and well documented discussion on Ward's contribution to the physics of the Standard Model is given in the recent book Cosmic Anger.
In addition, he made important contributions to quantum mechanics
, fermion theory, quantum solid-state physics
, and statistical mechanics
. He is further credited with being an early pioneer in the use of Feynman diagrams.
In 1955-1956 Ward worked, at Aldermaston, on British atomic weapons and has been portrayed as the "creator of the British hydrogen bomb". This topic is discussed by historian Lorna Arnold
while Ward's own account is given in his memoirs. An additional analysis on this issue is provided by one of Ward's colleagues, and friend, Richard Dalitz
.
, Ward worked in several places in the United States
and eventually he moved to Sydney, Australia, via New Zealand
. In 1964 he created the physics program of Macquarie University
using the Feynman Lectures on Physics as primary textbooks. This program had a strong experimental emphasis and Ward himself (whom originally was trained as an engineer) "had great admiration for anything practical". In the late 1970s he participated, with Frank Duarte
, in the Macquarie science reform movement
.
Besides his physics, Ward was an accomplished pianist and French horn player. He has an Erdős number of 2.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
-Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
. His most famous creation was the Ward-Takahashi identity, originally known as "Ward Identity" (or "Ward Identities"). This celebrated result, in quantum electrodynamics
Quantum electrodynamics
Quantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...
, was inspired by a conjecture of Dyson
Freeman Dyson
Freeman John Dyson FRS is a British-born American theoretical physicist and mathematician, famous for his work in quantum field theory, solid-state physics, astronomy and nuclear engineering. Dyson is a member of the Board of Sponsors of the Bulletin of the Atomic Scientists...
and was disclosed in a one-half page letter typical of Ward's succinct style. In their recent book entitled Quantum Electrodynamics, Greiner and Reinhardt state in their discussion of charge renormalization
Renormalization
In quantum field theory, the statistical mechanics of fields, and the theory of self-similar geometric structures, renormalization is any of a collection of techniques used to treat infinities arising in calculated quantities....
: "Yet the Ward Identity has a much more fundamental significance: it ensures the universality of the electromagnetic interaction."
Andrei Sakharov
Andrei Sakharov
Andrei Dmitrievich Sakharov was a Soviet nuclear physicist, dissident and human rights activist. He earned renown as the designer of the Soviet Union's Third Idea, a codename for Soviet development of thermonuclear weapons. Sakharov was an advocate of civil liberties and civil reforms in the...
classified Ward as one of the "titans" of quantum electrodynamics
Quantum electrodynamics
Quantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...
alongside Dyson
Freeman Dyson
Freeman John Dyson FRS is a British-born American theoretical physicist and mathematician, famous for his work in quantum field theory, solid-state physics, astronomy and nuclear engineering. Dyson is a member of the Board of Sponsors of the Bulletin of the Atomic Scientists...
, Feynman
Richard Feynman
Richard Phillips Feynman was an American physicist known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as in particle physics...
, Schwinger
Julian Schwinger
Julian Seymour Schwinger was an American theoretical physicist. He is best known for his work on the theory of quantum electrodynamics, in particular for developing a relativistically invariant perturbation theory, and for renormalizing QED to one loop order.Schwinger is recognized as one of the...
, and Tomonaga
Sin-Itiro Tomonaga
was a Japanese physicist, influential in the development of quantum electrodynamics, work for which he was jointly awarded the Nobel Prize in Physics in 1965 along with Richard Feynman and Julian Schwinger.-Biography:...
. In this regard, it has been said that physicists have made use of his principles and developments "often without knowing it, and generally without quoting him."
Additional contributions
In a 1947 paper, published in NatureNature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
(with Maurice Pryce), Ward was the first to calculate the correlation of the quantum polarizations of two photons propagating in opposite directions. This prediction was experimentally confirmed by Wu
Chien-Shiung Wu
Chien-Shiung Wu was a Chinese-American physicist with expertise in the techniques of experimental physics and radioactivity. Wu worked on the Manhattan Project...
and Shaknov in 1950. In current terminology this result corresponds to a pair of entangled photons and is directly relevant to a typical Einstein-Podolsky-Rosen (EPR) paradox
EPR paradox
The EPR paradox is a topic in quantum physics and the philosophy of science concerning the measurement and description of microscopic systems by the methods of quantum physics...
, or situation.
He is also one of the creators of the Standard Model
Standard Model
The Standard Model of particle physics is a theory concerning the electromagnetic, weak, and strong nuclear interactions, which mediate the dynamics of the known subatomic particles. Developed throughout the mid to late 20th century, the current formulation was finalized in the mid 1970s upon...
. His contributions were published in a series of papers co-authored with A. Salam
Abdus Salam
Mohammad Abdus Salam, NI, SPk Mohammad Abdus Salam, NI, SPk Mohammad Abdus Salam, NI, SPk (Urdu: محمد عبد السلام, pronounced , (January 29, 1926– November 21, 1996) was a Pakistani theoretical physicist and Nobel laureate in Physics for his work on the electroweak unification of the...
An insightful and well documented discussion on Ward's contribution to the physics of the Standard Model is given in the recent book Cosmic Anger.
In addition, he made important contributions to quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
, fermion theory, quantum solid-state physics
Solid-state physics
Solid-state physics is the study of rigid matter, or solids, through methods such as quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from...
, and statistical mechanics
Statistical mechanics
Statistical mechanics or statistical thermodynamicsThe terms statistical mechanics and statistical thermodynamics are used interchangeably...
. He is further credited with being an early pioneer in the use of Feynman diagrams.
In 1955-1956 Ward worked, at Aldermaston, on British atomic weapons and has been portrayed as the "creator of the British hydrogen bomb". This topic is discussed by historian Lorna Arnold
Lorna Arnold
Lorna Arnold is a historian who has written a number of books connected with the British nuclear weapons programmes.As the second official historian of the British nuclear weapons programmes, she has had access to previously secret documents and personally knew many of the people involved...
while Ward's own account is given in his memoirs. An additional analysis on this issue is provided by one of Ward's colleagues, and friend, Richard Dalitz
Richard Dalitz
Richard Henry Dalitz was an Australian physicist known for his work in particle physics.Born Dimboola, Victoria near Melbourne, Dalitz studied physics and mathematics at Melbourne University before moving to the United Kingdom in 1946, starting his PhD research at the University of Cambridge...
.
Macquarie University
After World War IIWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, Ward worked in several places in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and eventually he moved to Sydney, Australia, via New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. In 1964 he created the physics program of Macquarie University
Macquarie University
Macquarie University is an Australian public teaching and research university located in Sydney, with its main campus situated in Macquarie Park. Founded in 1964 by the New South Wales Government, it was the third university to be established in the metropolitan area of Sydney...
using the Feynman Lectures on Physics as primary textbooks. This program had a strong experimental emphasis and Ward himself (whom originally was trained as an engineer) "had great admiration for anything practical". In the late 1970s he participated, with Frank Duarte
F. J. Duarte
F. J. Duarte is a laser physicist and author/editor of several well-known books on tunable lasers. He introduced the generalized multiple-prism dispersion theory and has discovered various multiple-prism grating oscillator laser configurations...
, in the Macquarie science reform movement
Macquarie science reform movement
Macquarie science reform movement refers to the successfultransformation of the degree system at Macquarie University in 1979which followed an academic and political campaign initiated in 1977.Macquarie University, founded in 1964, adopted a degree structure...
.
Besides his physics, Ward was an accomplished pianist and French horn player. He has an Erdős number of 2.
See also
- BRST quantizationBRST quantizationIn theoretical physics, BRST quantization is a relatively rigorous mathematical approach to quantizing a field theory with a gauge symmetry...
- Chiral anomalyChiral anomalyA chiral anomaly is the anomalous nonconservation of a chiral current. In some theories of fermions with chiral symmetry, the quantization may lead to the breaking of this chiral symmetry. In that case, the charge associated with the chiral symmetry is not conserved.The non-conservation happens...
- Feynman diagrams
- Gauge fixingGauge fixingIn the physics of gauge theories, gauge fixing denotes a mathematical procedure for coping with redundant degrees of freedom in field variables. By definition, a gauge theory represents each physically distinct configuration of the system as an equivalence class of detailed local field...
- Gauge theoryGauge theoryIn physics, gauge invariance is the property of a field theory in which different configurations of the underlying fundamental but unobservable fields result in identical observable quantities. A theory with such a property is called a gauge theory...
- Ising modelIsing modelThe Ising model is a mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables called spins that can be in one of two states . The spins are arranged in a graph , and each spin interacts with its nearest neighbors...
- Luttinger's theoremLuttinger's theoremIn condensed matter physics, Luttinger's theorem is a result derived by J. M. Luttinger and J. C. Ward in 1960 that has broad implications in the field of electron transport...
- Noether's theoremNoether's theoremNoether's theorem states that any differentiable symmetry of the action of a physical system has a corresponding conservation law. The theorem was proved by German mathematician Emmy Noether in 1915 and published in 1918...
- Path integral formulationPath integral formulationThe path integral formulation of quantum mechanics is a description of quantum theory which generalizes the action principle of classical mechanics...
(of quantum mechanics). - Quantum electrodynamicsQuantum electrodynamicsQuantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...
- RenormalizationRenormalizationIn quantum field theory, the statistical mechanics of fields, and the theory of self-similar geometric structures, renormalization is any of a collection of techniques used to treat infinities arising in calculated quantities....
- Standard modelStandard ModelThe Standard Model of particle physics is a theory concerning the electromagnetic, weak, and strong nuclear interactions, which mediate the dynamics of the known subatomic particles. Developed throughout the mid to late 20th century, the current formulation was finalized in the mid 1970s upon...
- Vacuum polarizationVacuum polarizationIn quantum field theory, and specifically quantum electrodynamics, vacuum polarization describes a process in which a background electromagnetic field produces virtual electron–positron pairs that change the distribution of charges and currents that generated the original electromagnetic...
- Vertex functionVertex functionIn quantum electrodynamics, the vertex function describes the coupling between a photon and an electron beyond the leading order of perturbation theory...
- Ward–Takahashi identityWard–Takahashi identityIn quantum field theory, a Ward-Takahashi identity is an identity between correlation functions that follows from the global or gauged symmetries of the theory, and which remains valid after renormalization....
(Includes a brief description of the Ward Identity).
External links
- Unfinished autobiography: J. C. Ward, Memoirs of a Theoretical Physicist (Optics Journal, Rochester, New York, 2004. (online).
- Biographical note (includes Ward's publications and picture).
- AIP biography (R. H. DalitzRichard DalitzRichard Henry Dalitz was an Australian physicist known for his work in particle physics.Born Dimboola, Victoria near Melbourne, Dalitz studied physics and mathematics at Melbourne University before moving to the United Kingdom in 1946, starting his PhD research at the University of Cambridge...
and F. J. DuarteF. J. DuarteF. J. Duarte is a laser physicist and author/editor of several well-known books on tunable lasers. He introduced the generalized multiple-prism dispersion theory and has discovered various multiple-prism grating oscillator laser configurations...
, Physics Today 53 (10), 99–100 (2000)).