Paul Dirac

Paul Adrien Maurice Dirac
Born	August 8, 1902 Bristol, England
Died	October 20, 1984 Tallahassee, Florida, USA
Residence	UK USA
Nationality	English- Swiss (to 1919) English (after 1919)
Field	Physicist
Institution	Cambridge University Florida State University
Alma Mater	University of Bristol Cambridge University
Doctoral Advisor	Ralph Fowler
Doctoral Students	Homi Bhabha , Harish Chandra Mehrotra, , Dennis Sciama, Behram Kurşunoğlu, John Polkinghorne
Known for	Quantum physics
Notable Prizes	Nobel Prize in Physics (1933)
Religion	Atheist

Paul Adrien Maurice Dirac, OM, FRS (IPA: [dɪ'ræk]) (August 8, 1902 – October 20, 1984) was a British theoretical physicist and a founder of the field of quantum physics. He held the Lucasian Professorship of Mathematics at the University of Cambridge. Among other key discoveries, he formulated the so-called "Dirac equation," which describes the behavior of fermions and which led to the prediction of the existence of antimatter. Dirac shared the Nobel Prize in physics for 1933 with Erwin Schrödinger, "for the discovery of new productive forms of atomic theory." Image of Paul Dirac File links The following pages link to this file: Paul Dirac ... August 8 is the 220th day of the year in the Gregorian Calendar (221st in leap years), with 145 days remaining. ... 1902 (MCMII) was a common year starting on Wednesday (see link for calendar). ... Bristol (IPA: ) is a city, unitary authority and ceremonial county in South West England, 115 miles (185 km) west of London and located at With a population of 400,000, and metropolitan area of 550,000, it is Englands sixth, and the United Kingdoms ninth, most populous city... This article or section does not cite its references or sources. ... October 20 is the 293rd day of the year (294th in leap years) in the Gregorian Calendar, with 72 days remaining. ... 1984 (MCMLXXXIV) was a leap year starting on Sunday of the Gregorian calendar. ... Tallahassee is the capital of Florida, a state of the United States of America. ... This article or section does not cite its references or sources. ... Image File history File links Flag_of_the_United_Kingdom. ... Image File history File links Flag_of_the_United_States. ... Image File history File links Flag_of_the_United_Kingdom. ... This article or section does not cite its references or sources. ... Image File history File links Flag_of_Switzerland. ... Image File history File links Flag_of_the_United_Kingdom. ... This article or section does not cite its references or sources. ... Physicists working in a government lab A physicist is a scientist who studies or practices physics. ... The University of Cambridge, located in Cambridge, England, is the second-oldest university in the English-speaking world. ... Florida State University, also commonly referred to as FSU or Florida State, is the oldest continuous site of higher education in Florida. ... The University of Bristol is a university in Bristol, England. ... The University of Cambridge, located in Cambridge, England, is the second-oldest university in the English-speaking world. ... Ralph Howard Fowler (January 17, 1889 – July 28, 1944) was a British physicist and astronomer. ... This page is about the physicist, Homi J. Bhabha. ... See Harishchandra for the character in Hindu mythology Harish-Chandra (11 October 1923-16 October 1983) was an Indian mathematician, who did fundamental work in representation theory. ... Denis Sciama was a British cosmologist and a Fellow of the Royal Society. ... Behram KurÅŸunoÄŸlu (Turkey, 1922 - Miami, USA, 2003) was a Turkish physicist and one of the founders of the University of Miamis Center for Theoretical Studies. ... The Rev. ... Fig. ... Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ... For information about the band, see Atheist (band). ... For other Orders see Order of Merit (disambiguation). ... The premises of the Royal Society in London (first four properties only). ... This is a concise version of the International Phonetic Alphabet for English sounds. ... August 8 is the 220th day of the year in the Gregorian Calendar (221st in leap years), with 145 days remaining. ... 1902 (MCMII) was a common year starting on Wednesday (see link for calendar). ... October 20 is the 293rd day of the year (294th in leap years) in the Gregorian Calendar, with 72 days remaining. ... 1984 (MCMLXXXIV) was a leap year starting on Sunday of the Gregorian calendar. ... Theoretical physics attempts to understand the world by making a model of reality, used for rationalizing, explaining, predicting physical phenomena through a physical theory. There are three types of theories in physics; mainstream theories, proposed theories and fringe theories. ... Fig. ... The incumbent of the Lucasian Chair of Mathematics, the Lucasian Professor is the holder of a mathematical professorship at Cambridge University. ... The University of Cambridge, located in Cambridge, England, is the second-oldest university in the English-speaking world. ... In physics, the Dirac equation is a relativistic quantum mechanical wave equation formulated by Paul Dirac in 1928 and provides a description of elementary spin-½ particles, such as electrons, consistent with both the principles of quantum mechanics and the theory of special relativity. ... In particle physics, fermions are particles with half-integer spin. ... In particle physics, antimatter extends the concept of the antiparticle to matter, wherein if a particle and its antiparticle come into contact with each other, the two annihilate —that is, they may both be converted into other particles with equal energy in accordance with Einsteins equation E = mc2. ... Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ... 1933 (MCMXXXIII) was a common year starting on Sunday (link will take you to calendar). ... Erwin Rudolf Josef Alexander Schrödinger (August 12, 1887 – January 4, 1961) was an Austrian physicist who achieved fame for his contributions to quantum mechanics, especially the Schrödinger equation, for which he received the Nobel Prize in 1933. ... Properties For other uses, see Atom (disambiguation). ...

Biography

Early years

Paul Dirac grew up in Bishopston, in the English city of Bristol. His father, Charles Dirac, was an immigrant from Saint-Maurice in the Canton of Valais, Switzerland and taught French for a living. His mother was originally from Cornwall and the daughter of a mariner. Paul had an elder brother, Felix, who committed suicide in March 1925, and a younger sister, Beatrice. His early family life appears to have been unhappy on account of his father's unusually strict and authoritarian nature. He was educated first at Bishop Road Primary School and then at Merchant Venturers' Technical College (later Cotham Grammar School), where his father was a teacher. The latter was an institution, attached to the University of Bristol, that emphasized scientific subjects and modern languages. This was an unusual arrangement at a time when secondary education in Britain was still dedicated largely to the classics, and something for which Dirac would later express gratitude. Map sources for Bishopston at grid reference ST586755 Bishopston is an inner-suburb in north Bristol, England, situated on the Gloucester Road, the main northern arterial road in the city. ... This article or section does not cite its references or sources. ... Bristol (IPA: ) is a city, unitary authority and ceremonial county in South West England, 115 miles (185 km) west of London and located at With a population of 400,000, and metropolitan area of 550,000, it is Englands sixth, and the United Kingdoms ninth, most populous city... Roman Agaunum, the modern Saint Maurice (46°12′50″N, 7°0′15″E) in the canton Valais in southwesternmost Switzerland, was a minor post confined between the Rhone and the mountains along the well-travelled road that led from Roman Genava, modern Geneva, over the Alps by the Great... The Valais (German:  ) is one of the 26 cantons of Switzerland in the south-western part of the country, in the Pennine Alps around the valley of the Rhone River from its springs to Lake Geneva. ... Cornwall (Cornish: Kernow) is a county in South West England on the peninsula that lies to the west of the River Tamar. ... The Society of Merchant Venturers (or just the Merchant Venturers) is a private charitable organisation in the English city of Bristol, which dates back to the 13th century. ... The University of Bristol is a university in Bristol, England. ... Classics, particularly within the Western University tradition, when used as a singular noun, means the study of the language, literature, history, art, and other aspects of Greek and Roman culture during the time frame known as classical antiquity. ...

Dirac studied electrical engineering at the University of Bristol, completing his degree in 1921. He then decided that his true calling lay in the mathematical sciences and, after completing a degree in mathematics at Bristol in 1923, he received a grant to conduct research at St. John's College, Cambridge, where he would remain for most of his career. At Cambridge, Dirac pursued his interests in the theory of general relativity (an interest he gained earlier as a student in Bristol) and in the nascent field of quantum physics, working under the supervision of Ralph Fowler. Electrical Engineers design power systems… … and complex electronic circuits. ... The University of Bristol is a university in Bristol, England. ... Euclid, Greek mathematician, 3rd century BC, known today as the father of geometry; shown here in a detail of The School of Athens by Raphael. ... Full name The College of Saint John the Evangelist of the University of Cambridge Motto - Named after The Hospital of Saint John the Evangelist, Cambridge, named after John the Evangelist Previous names - Established 1511 Sister College Balliol College Master Prof. ... The University of Cambridge, located in Cambridge, England, is the second-oldest university in the English-speaking world. ... General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915. ... Fig. ... Ralph Howard Fowler (January 17, 1889 – July 28, 1944) was a British physicist and astronomer. ...

Middle years

Dirac noticed an analogy between the old Poisson brackets of classical mechanics and the recently-proposed quantization rules in Werner Heisenberg's matrix formulation of quantum mechanics. This observation allowed Dirac to obtain the quantization rules in a novel and more illuminating manner. For this work, published in 1926, he received a Ph.D. from Cambridge. In mathematics and classical mechanics, the Poisson bracket is an important operator in Hamiltonian mechanics, playing a central role in the definition of the time-evolution of a dynamical system in the Hamiltonian formulation. ... Classical mechanics is a branch of physics which studies the deterministic motion of objects. ... Werner Karl Heisenberg (December 5, 1901 – February 1, 1976) was a celebrated German physicist and Nobel laureate, one of the founders of quantum mechanics, and acknowledged to be one of the most important physicists of the twentieth century. ... Matrix mechanics is a formulation of quantum mechanics created by Werner Heisenberg in 1925. ... In physics, quantization is a procedure for constructing a quantum field theory starting from a classical field theory. ... In physics, canonical quantization is one of many procedures for quantizing a classical theory. ... 1926 (MCMXXVI) was a common year starting on Friday (link will take you to calendar). ... This article or section does not cite its references or sources. ... The University of Cambridge, located in Cambridge, England, is the second-oldest university in the English-speaking world. ...

In 1928, building on Wolfgang Pauli's work on non-relativistic spin systems, he proposed the Dirac equation as a relativistic equation of motion for the wavefunction of the electron. This work led Dirac to predict the existence of the positron, the electron's antiparticle, which he interpreted in terms of what came to be called the Dirac sea. The positron was subsequently observed by Carl Anderson in 1932. Dirac's equation also contributed to explaining the origin of quantum spin as a relativistic phenomenon. 1928 (MCMXXVIII) was a leap year starting on Sunday (link will take you to calendar). ... This article is about Austrian-Swiss physicist Wolfgang Pauli. ... In physics, spin refers to the angular momentum intrinsic to a body, as opposed to orbital angular momentum, which is the motion of its center of mass about an external point. ... In physics, the Dirac equation is a relativistic quantum mechanical wave equation formulated by Paul Dirac in 1928 and provides a description of elementary spin-½ particles, such as electrons, consistent with both the principles of quantum mechanics and the theory of special relativity. ... The special theory of relativity was proposed in 1905 by Albert Einstein in his article On the Electrodynamics of Moving Bodies. Some three centuries earlier, Galileos principle of relativity had stated that all uniform motion was relative, and that there was no absolute and well-defined state of rest... In physics, equations of motion are equations that describe the behavior of a system (e. ... This article discusses the concept of a wavefunction as it relates to quantum mechanics. ... The electron is a fundamental subatomic particle that carries an electric charge. ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... The Dirac sea is a theoretical model of the vacuum as an infinite sea of particles possessing negative energy. ... Carl David Anderson (3 September 1905 – 11 January 1991) was a U.S. experimental physicist. ... 1932 (MCMXXXII) was a leap year starting on Friday (the link will take you to a full 1932 calendar). ... In physics, spin refers to the angular momentum intrinsic to a body, as opposed to orbital angular momentum, which is the motion of its center of mass about an external point. ...

The necessity of electron matter being created and destroyed in Enrico Fermi's 1934 theory of beta decay, however, led to a reinterpretation of Dirac's equation as a "classical" field equation for any point matter of spin ħ/2, itself subject to quantization conditions involving anti-commutators. Thus reinterpreted, the Dirac equation is as central to theoretical physics as the Maxwell, Yang-Mills and Einstein field equations. Dirac is regarded as the founder of quantum electrodynamics, being the first to use that term. He also introduced the idea of vacuum polarization in the early 1930s. Enrico Fermi (September 29, 1901–November 28, 1954) was an Italian physicist most noted for his work on beta decay, the development of the first nuclear reactor, and for the development of quantum theory. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... A field equation is an equation in a physical theory that describes how a fundamental force (or a combination of such forces) interacts with matter. ... In mathematics, the commutator gives an indication of how poorly a certain binary operation fails to be commutative. ... Maxwells equations are the set of four equations, attributed to James Clerk Maxwell, that describe the behavior of both the electric and magnetic fields, as well as their interactions with matter. ... Gauge theories are a class of physical theories based on the idea that symmetry transformations can be performed locally as well as globally. ... General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915. ... Quantum electrodynamics (QED) is a relativistic quantum field theory of electromagnetism. ... In quantum physics, if we expand about the Fock vacuum, the true vacuum contains short-lived virtual particle-antiparticle pairs which are created in pairs out of the Fock vacuum and then annihilate each other. ...

Dirac's Principles of Quantum Mechanics, published in 1930, is a landmark in the history of science. It quickly became one of the standard textbooks on the subject and is still used today. In that book, Dirac incorporated the previous work of Werner Heisenberg on “Matrix Mechanics” and of Erwin Schrödinger on “Wave Mechanics” into a single mathematical formalism that associates measurable quantities to operators acting on the Hilbert space of vectors that describe the state of a physical system. The book also introduced the bra-ket notation and the delta function, which are now universally used. 1930 (MCMXXX) was a common year starting on Wednesday (link is to a full 1930 calendar). ... The history of science investigates the historical record of human events that are pertinent to the cultural context and the secular development of what is currently called science, namely, a body of empirical and theoretical knowledge, produced by a global community of researchers, making use of specific techniques for the... Werner Karl Heisenberg (December 5, 1901 – February 1, 1976) was a celebrated German physicist and Nobel laureate, one of the founders of quantum mechanics, and acknowledged to be one of the most important physicists of the twentieth century. ... Erwin Rudolf Josef Alexander Schrödinger (August 12, 1887 – January 4, 1961) was an Austrian physicist who achieved fame for his contributions to quantum mechanics, especially the Schrödinger equation, for which he received the Nobel Prize in 1933. ... In mathematics, a Hilbert space is a real or complex vector space with a positive definite sesquilinear form, that is complete under its norm. ... Bra-ket notation is the standard notation for describing quantum states in the theory of quantum mechanics. ... The Dirac delta function, often referred to as the unit impulse function and introduced by the British theoretical physicist Paul Dirac, can usually be informally thought of as a function δ(x) that has the value of infinity for x = 0, the value zero elsewhere. ...

Guided by a comment in Dirac's textbook and by Dirac's 1933 article "The Lagrangian in quantum mechanics" (published in the Soviet journal Physikalische Zeitschrift der Sowjet Union), Richard Feynman developed the path integral formulation of quantum mechanics in 1948. This work would prove exceedingly useful in relativistic quantum field theory, in part because it is based on the Lagrangian, whose relativistic invariance is explicit, while the invariance is only implicit in the Hamiltonian formulation. A Lagrangian of a dynamical system, named after Joseph Louis Lagrange, is a function of the dynamical variables and concisely describes the equations of motion of the system. ... Motto: Пролетарии всех стран, соединяйтесь! (Transliterated: Proletarii vsekh stran, soedinyaytes!) (Russian: Workers of the world, unite!) Anthem: The Internationale (1922-1944) Hymn of the Soviet Union (1944-1991) Capital (largest city) Moscow None; Russian de facto Government Federation of Soviet Republics  - Last President Mikhail Gorbachev  - Last Premier Ivan Silayev Establishment October Revolution   - Declared 30... Richard Phillips Feynman (May 11, 1918 in Queens, New York – February 15, 1988 in Los Angeles, California) (surname pronounced FINE-man; in IPA) was an influential American physicist known for expanding greatly on the theory of quantum electrodynamics, particle theory, and the physics of the superfluidity of supercooled liquid helium. ... This article or section is in need of attention from an expert on the subject. ... 1948 (MCMXLVIII) was a leap year starting on Thursday (the link is to a full 1948 calendar). ... Quantum field theory (QFT) is the application of quantum mechanics to fields. ... Lagrangian mechanics is a re-formulation of classical mechanics introduced by Joseph Louis Lagrange in 1788. ... Hamiltonian mechanics is a re-formulation of classical mechanics that was invented in 1833 by William Rowan Hamilton. ...

In 1931 Dirac showed that the existence of a single magnetic monopole in the universe would suffice to explain the observed quantization of electrical charge. This proposal received much attention, but there is to date no convincing evidence for the existence of magnetic monopoles. 1931 (MCMXXXI) was a common year starting on Thursday (link is to a full 1931 calendar). ... In physics, a magnetic monopole is a hypothetical particle that may be loosely described as a magnet with only one pole (see electromagnetic theory for more on magnetic poles). ... Electric charge is a fundamental property of some subatomic particles, which determines their electromagnetic interactions. ...

He married Eugene Wigner's sister, Margit, in 1937. He adopted Margit's two children, Judith and Gabriel. Paul and Margit Dirac had two natural children together, daughters Mary Elizabeth and Florence Monica. Eugene Wigner Eugene Paul Wigner (Hungarian Wigner Pál Jenő) (November 17, 1902 – January 1, 1995) was a Hungarian physicist and mathematician who received the Nobel Prize in Physics in 1963 for his contributions to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and... 1937 (MCMXXXVII) was a common year starting on Friday (link will take you to calendar). ... Gabriel Andrew Dirac (1925-1984) was a mathematician. ...

Later years

Dirac was the Lucasian Professor of Mathematics at Cambridge from 1932 to 1969. During World War II, he conducted important theoretical and experimental research on uranium enrichment by gas centrifuge. In 1937, he proposed a speculative cosmological model based on the so called "large numbers hypothesis." Dirac would write, "I am very disturbed by the situation because the so-called good theory [quantum theory] does involve neglecting infinities in an arbitrary way.This is not sensible. Sensible Mathematics involves neglecting a quantity when it's small not because it's infinitely great and we do not want it" ^[1] Dirac became unsatisfied with the renormalization approach to dealing with these infinities in quantum field theory and his work on the subject moved increasingly out of the mainstream. After having relocated to Florida in order to be near his elder daughter, Mary, Dirac spent his last ten years (both of life and as a physicist) at Florida State University (FSU) in Tallahassee, Florida. The incumbent of the Lucasian Chair of Mathematics, the Lucasian Professor is the holder of a mathematical professorship at Cambridge University. ... 1932 (MCMXXXII) was a leap year starting on Friday (the link will take you to a full 1932 calendar). ... 1969 (MCMLXIX) was a common year starting on Wednesday (the link is to a full 1969 calendar). ... Combatants Major Allied powers: United Kingdom Soviet Union United States Republic of China and others Major Axis powers: Nazi Germany Italy Japan and others Commanders Winston Churchill Joseph Stalin Franklin Roosevelt Harry Truman Chiang Kai-Shek Adolf Hitler Benito Mussolini Hideki Tojo Casualties Military dead: 17,000,000 Civilian dead... Enriched uranium is uranium whose uranium-235 content has been increased through the process of isotope separation. ... The gas centrifuge is a hyper-centrifuge used to produce enriched uranium. ... 1937 (MCMXXXVII) was a common year starting on Friday (link will take you to calendar). ... Cosmology, as a branch of astrophysics, is the study of the large-scale structure of the universe and is concerned with fundamental questions about its formation and evolution. ... The Dirac large numbers hypothesis refers to an observation made by Paul Dirac in 1937 relating ratios of size scales in the universe to that of force scales. ... Figure 1. ... Florida State University, also commonly referred to as FSU or Florida State, is the oldest continuous site of higher education in Florida. ... Location Location in Leon County and the state of Florida. ...

Amongst his many students was John Polkinghorne who recalls that Dirac, "was once asked what was his fundamental belief. he strode to a blackboard and wrote that the laws of nature should be expressed in beautiful equations"^[2] The Rev. ...

Death and afterwards

In 1984 Dirac died in Tallahassee, Florida where he is buried. The Dirac-Hellman Award at FSU was endowed by Dr Bruce Hellman (Dirac's last doctoral student) in 1997 to reward outstanding work in theoretical physics by FSU researchers. The Dirac Prize is also awarded by the International Centre for Theoretical Physics in his memory. In 1995, a plaque in his honour bearing his equation was unveiled at Westminster Abbey in London with a speech from Stephen Hawking. A commemorative garden, in his honour, has been established opposite the railway station in Saint-Maurice, Switzerland, the town of origin of his father's family. Tallahassee is the capital of Florida, a state of the United States of America. ... This article or section does not cite its references or sources. ... 1997 (MCMXCVII) was a common year starting on Wednesday of the Gregorian calendar. ... Confusingly, there are two prominent awards in the field of theoretical physics and mathematics commonly known as the Dirac Prize, awarded by different organizations. ... The Abdus Salam International Centre for Theoretical Physics operates under a tripartite agreement among the Italian Government, UNESCO and International Atomic Energy Agency (IAEA) (both agencies of the United Nations) to foster advanced studies and research, especially in developing countries. ... 1995 (MCMXCV) was a common year starting on Sunday of the Gregorian calendar. ... In physics, the Dirac equation is a relativistic quantum mechanical wave equation formulated by Paul Dirac in 1928 and provides a description of elementary spin-½ particles, such as electrons, consistent with both the principles of quantum mechanics and the theory of special relativity. ... The Abbeys western façade The Collegiate Church of St Peter, Westminster, which is almost always referred to as Westminster Abbey, is a mainly Gothic church, on the scale of a cathedral (and indeed often considered one), in Westminster, London, just to the west of the Palace of Westminster. ... London (pronounced ) is the capital city of England and the United Kingdom. ... Stephen William Hawking, CH, CBE, FRS (born 8 January 1942) is a theoretical physicist. ... Roman Agaunum, the modern Saint Maurice (46°12′50″N, 7°0′15″E) in the canton Valais in southwesternmost Switzerland, was a minor post confined between the Rhone and the mountains along the well-travelled road that led from Roman Genava, modern Geneva, over the Alps by the Great...

Honours and tributes

Paul Dirac shared the 1933 Nobel Prize for physics in with Erwin Schrödinger "for the discovery of new productive forms of atomic theory." ^{[citation needed]} Dirac was also awarded the Royal Medal in 1939 and both the Copley Medal and the Max Planck Medal in 1952. 1933 (MCMXXXIII) was a common year starting on Sunday (link will take you to calendar). ... Nobel Prize medal. ... Erwin Rudolf Josef Alexander Schrödinger (August 12, 1887 – January 4, 1961) was an Austrian physicist who achieved fame for his contributions to quantum mechanics, especially the Schrödinger equation, for which he received the Nobel Prize in 1933. ... The Royal Medals of the Royal Society of London were established by King George IV. They were further supported with certain changes to their conditions, by King William IV and Queen Victoria. ... 1939 (MCMXXXIX) was a common year starting on Sunday (link will take you to calendar). ... The Copley Medal is a scientific award for work in any field of science, the highest award granted by the Royal Society of London. ... 1952 (MCMLII) was a Leap year starting on Tuesday (link will take you to calendar). ...

He was elected a Fellow of the Royal Society in 1930, and of the American Physical Society in 1948. The premises of the Royal Society in London (first four properties only). ... 1930 (MCMXXX) was a common year starting on Wednesday (link is to a full 1930 calendar). ... The American Physical Society was founded in 1899 and is the worlds second largest organization of physicists. ... 1948 (MCMXLVIII) was a leap year starting on Thursday (the link is to a full 1948 calendar). ...

Immediately after his death, two organizations of professional physicists established annual awards in Dirac's memory. The Institute of Physics, the United Kingdom's professional body for physicists, awards the Paul Dirac Medal and Prize for "outstanding contributions to theoretical (including mathematical and computational) physics". The first three recipients were Stephen Hawking (1987), John Bell (1988), and Roger Penrose (1989). The Abdus Salam International Centre for Theoretical Physics (ICTP) awards the Dirac Medal of the ICTP each year on Dirac's birthday (August 8). Confusingly, there are two prominent awards in the field of theoretical physics and mathematics commonly known as the Dirac Prize, awarded by different organizations. ... The Institute of Physics (IOP) is the United Kingdoms professional body for physicists. ... Stephen William Hawking, CH, CBE, FRS (born 8 January 1942) is a theoretical physicist. ... John Bell is a common name. ... Sir Roger Penrose, OM, FRS (born 8 August 1931) is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the University of Oxford and Emeritus Fellow of Wadham College. ... Founded in 1964, the Abdus Salam International Centre for Theoretical Physics (ICTP) operates under a tripartite agreement between the Government of Italy and two UN agencies, the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the International Atomic Energy Agency (IAEA). ...

The street on which the National High Magnetic Field Laboratory in Tallahassee, Florida, is located was named Paul Dirac Drive. The BBC named its video codec Dirac in his honour. And in the popular British television show Doctor Who, the character Adric was named after him (Adric is an anagram of Dirac). // Overview The National High Magnetic Field Laboratory (NHMFL) develops and operates high magnetic field facilities that scientists use for research in physics, biology, bioengineering, chemistry, geochemistry, biochemistry, materials science, and engineering. ... Tallahassee is the capital of Florida, a state of the United States of America. ... This article or section does not cite its references or sources. ... The British Broadcasting Corporation, invariably known as the BBC (and also informally known as the Beeb or Auntie) is the largest broadcasting corporation in the world, employing 26,000 staff in the UK alone and with a budget of £4 billion. ... A video codec is a device or software module that enables the use of data compression for digital video. ... Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video. ... Doctor Who is a long-running British science fiction television programme produced by the BBC about a mysterious time-travelling adventurer known as The Doctor, who explores time and space with his companions, fighting evil. ... Adric is a fictional character played by Matthew Waterhouse in the long-running British science fiction television series Doctor Who. ... An anagram (Greek ana- = back or again, and graphein = to write) is a type of word play, the result of rearranging the letters of a word or phrase to produce other words, using all the original letters exactly once. ...

Personality

Dirac was known among his colleagues for his precise and taciturn nature. When Niels Bohr complained that he didn't know how to finish a sentence in a scientific article he was writing, Dirac replied, "I was taught at school never to start a sentence without knowing the end of it." ^{[citation needed]} While visiting the U.S.S.R., he was invited to lecture on his philosophy of physics. He merely stood up and wrote on the board, "Physical laws should have mathematical beauty and simplicity". ^{[citation needed]} When asked about his views on poetry, he responded, "In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, it's the exact opposite". ^{[citation needed]} Niels (Henrik David) Bohr (October 7, 1885 – November 18, 1962) was a Danish physicist who made fundamental contributions to understanding atomic structure and quantum mechanics. ... Soviet redirects here. ... The Chinese poem Quatrain on Heavenly Mountain by Emperor Gaozong (Song Dynasty) Poetry (from the Greek , poesis, making or creating) is a form of art in which language is used for its aesthetic qualities in addition to, or in lieu of, its ostensible meaning. ...

Eugene Wigner, Dirac's brother-in-law, once described Richard Feynman as "another Dirac, only this time human". ^{[citation needed]} Richard Phillips Feynman (May 11, 1918 in Queens, New York – February 15, 1988 in Los Angeles, California) (surname pronounced FINE-man; in IPA) was an influential American physicist known for expanding greatly on the theory of quantum electrodynamics, particle theory, and the physics of the superfluidity of supercooled liquid helium. ...

Dirac was also noted for his personal modesty. He called the equation for the time-evolution of a quantum-mechanical operator, which Dirac was in fact the first to write down, the "Heisenberg equation of motion". Most physicists speak of Fermi-Dirac statistics for half-integer spin particles and Bose-Einstein statistics for integer spin particles. While lecturing later in life, Dirac always insisted on calling the former "Fermi statistics". He referred to the latter as "Einstein statistics" for reasons, he explained, of "symmetry". ^{[citation needed]} Fermi-Dirac distribution as a function of ε/μ plotted for 4 different temperatures. ... In statistical mechanics, Bose-Einstein statistics determines the statistical distribution of identical indistinguishable bosons over the energy states in thermal equilibrium. ...

Wolfgang Pauli, when asked about Dirac's religious views, replied, "If I understand Dirac correctly, his meaning is this: there is no God, and Dirac is his Prophet," ^{[citation needed]} a wry reference to the Islamic profession of faith. Various religious symbols Religion is a system of social coherence based on a common group of beliefs or attitudes concerning an object, person, unseen being, or system of thought considered to be supernatural, sacred, divine or highest truth, and the moral codes, practices, values, institutions, traditions, and rituals associated with... The shahadah (Arabic:   translit: ) (Turkish: Åžehadet) is the Islamic creed. ...

Dirac once "re-invented" the purling stitch in knitting. While speaking with a collegue about physics, he saw the colleague's wife knitting. Afterward, he considered the topology involved and realized that there was another way to do it. He also concluded that the stitch that he saw and the alternative that he conceived were the only stitches possible.^{[citation needed]} Knit hat, yarn, and knitting needles. ... A Möbius strip, a surface with only one side and one edge; such shapes are an object of study in topology. ...

Selected bibliography

• Principles of Quantum Mechanics (1930): This book summarizes the ideas of quantum mechanics using the modern formalism that was largely developed by Dirac himself. Towards the end of the book, he also discusses the relativistic theory of the electron (see Dirac equation) which was also pioneered by him. This work does not refer to any other writings then available on quantum mechanics.
• Lectures on Quantum Mechanics (1966): Much of this book deals with quantum mechanics in curved space-time.
• General Theory of Relativity (1975): This 68 page work summarizes Einstein's general theory of relativity.

In physics, the Dirac equation is a relativistic quantum mechanical wave equation formulated by Paul Dirac in 1928 and provides a description of elementary spin-½ particles, such as electrons, consistent with both the principles of quantum mechanics and the theory of special relativity. ...

See also

• Dirac sea
• Dirac notation
• Dirac equation
• Dirac matrices
• Dirac delta function, Dirac comb
• Dirac large numbers hypothesis

The Dirac sea is a theoretical model of the vacuum as an infinite sea of particles possessing negative energy. ... Bra-ket notation is the standard notation for describing quantum states in the theory of quantum mechanics. ... In physics, the Dirac equation is a relativistic quantum mechanical wave equation formulated by Paul Dirac in 1928 and provides a description of elementary spin-½ particles, such as electrons, consistent with both the principles of quantum mechanics and the theory of special relativity. ... The Dirac equation is a relativistic quantum mechanical wave equation invented by Paul Dirac in 1928. ... The Dirac delta function, often referred to as the unit impulse function and introduced by the British theoretical physicist Paul Dirac, can usually be informally thought of as a function δ(x) that has the value of infinity for x = 0, the value zero elsewhere. ... In mathematics, a Dirac comb is a periodic Schwartz distribution constructed from Dirac delta functions for some given period T. Some authors, notably Bracewell, refer to it as the Shah function (probably because its graph resembles the shape of the cyrillic letter sha Ш). From the orthogonality of the Fourier series... The Dirac large numbers hypothesis refers to an observation made by Paul Dirac in 1937 relating ratios of size scales in the universe to that of force scales. ...

References

• The Second Creation: makers of the revolution in twentieth century physics by Robert P. Crease and Charles C. Mann, 1986 Macmillan Publishing, New York, 1996 (revised), Rutgers University Press. Entertaining personality-based history of particle physics/quantum mechanics in the twentieth century.
• QED and the men who made it: Dyson, Feynman, Schwinger, and Tomonaga by Silvan S. Schweber, Princeton University Press, 1994. Includes a chapter on Dirac as the founder of quantum electrodynamics.
• "Paul Adrien Maurice Dirac"

External links

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Paul Dirac

Wikiquote has a collection of quotations related to:

Paul Dirac

• Paul Dirac at the Notable Names Database
• Dirac Medal of the International Centre for Theoretical Physics
• O'Connor, John J., and Edmund F. Robertson. "Paul Dirac". MacTutor History of Mathematics archive.
• Paul Adrien Maurice Dirac Biography
• Dirac Medal of the World Association of Theoretically Oriented Chemists (WATOC)
• Photographs of Dirac
• The Paul Dirac Collection at Florida State University
• The Paul A. M. Dirac Collection Finding Aid at Florida State University
• discovery of new productive forms of atomic theory.
• Annotated bibliography for Paul Dirac from the Alsos Digital Library for Nuclear Issues