Paul Dirac (full name: Paul Adrian Maurice Dirac, Paul Adrien Maurice Dirac, August 8, 1902 October 20, 1984), born in Bristol, England, is a theoretical physicist,quantum mechanicsOne of the founders,Royal SocietyAcademician, 1933Nobel Prize in PhysicsWinner:Florida State UniversityEmeritus professor[4]。
Paul Dirac graduated fromUniversity of BristolGraduation;In 1923, he graduated from Bristol University again with the first class honor and enteredUniversity of Cambridge[7]；In 1926, he received a doctor's degree in physics from Cambridge University and was invited to be a researcher of St. John's College in the same year;In 1927, he went to Gottingen, Germany, and was invited to participate in the fifth session in the same yearSolvay Conference [5]；In 1929, he was appointed as a senior lecturer in mathematical physics;In 1930, he was elected as an academician of the British Royal Society;In 1932, he served as Lucas Professor of Mathematics at Cambridge University;1933 Nobel Prize in Physics[1]；In 1961, he was elected as an academician of the Pontifical Academy of Sciences;In 1969, he resigned from Cambridge University and accepted the teaching position offered by Florida State University;Died in Tallahassee, Florida, on October 20, 1984, aged 82[12]。
Paul Dirac developed quantum mechanics and proposedDirac equationAnd theoretically predictedpositronThe existence of[1]。
One of the founders of quantum mechanics In 1930, he was elected as a member of the Royal Society 1933 Nobel Prize in Physics In 1961, he was elected as an academician of the Pontifical Academy of Sciences
In 1921, he graduated from Bristol University with the first class honours of Bachelor of Engineering, and then studied for the bachelor of mathematics degree of Bristol University free of charge. Because of the completed engineering degree, he was allowed to credit the first year of courses.
In 1923, he graduated from the University of Bristol again with first class honors and won a scholarship of 140 pounds.With 70 pounds from John College, this money is enough for him to live and study in Cambridge University.After entering Cambridge University, he began to contact atomic theory under the guidance of Ralph Fowler.
In 1926, he published a paper entitled "Quantum Mechanics" and obtained a doctor's degree in physics from Cambridge University;In the same year, he was invited to be a researcher of St. John's College;In September, at Fowler's suggestion, he went to CopenhagenNiels Bohr The Institute has conducted research for a period of time.
In 1927, he was invited to participate in the 5th Solvay Conference (Electronics and Photons)[5][19]；In the same year, he was elected as an academician of St. John's College.
In 1929, he was appointed as a senior lecturer in mathematical physics.
In 1930, he was elected as a member of the Royal Society.
In 1931, he was invited to Princeton University by Van Buren, who was then a professor of Princeton University[2][17]。
In 1932, he succeeded Joseph Lamore as Lucas Professor of Mathematics at Cambridge University.
1933, andErwin Schrodinger Jointly won the Nobel Prize in Physics[1]；On December 12, he delivered a Nobel Prize winning speech in Stockholm, entitled "Theory of Electron and Positron".
In 1961, he was elected as a member of the Zongzuo Academy of Sciences.
In 1969, in order to live closer to his daughter Mary, he resigned from Cambridge University and accepted the teaching position offered by Florida State University[7]。
In 1982, health began to deteriorate.
On October 20, 1984, he died in Tallahassee, Florida at the age of 82[12]。Buried in the local Rosland Cemetery after death[30]。
Key achievements
Announce
edit
Scientific research achievements
Dirac equation
Paul Dirac was originally engaged in the study of relativistic dynamics, since 1925Werner Heisenberg After visiting Cambridge University, under its influence, he turned to the research of quantum mechanics.In 1928, he introduced relativity into quantum mechanics and established theSchrodinger equationDirac equation.This equation has two characteristics: one is that it meets all the requirements of relativity and is applicable to electrons moving no matter how fast;Second, it can automatically derive the conclusion that the electron has spin.The solution of this equation is very special, including both positive and negative energy states.Paul Dirac thus predicted the existence of positrons, believing that positrons are a mirror image of electrons, and they have exactly the same mass, but the charge sign is opposite.According to this picture, he also predicted that there would be a process in which an electron and a positron annihilate each other and emit photons;On the contrary, the reverse process of this process, that is, the process of photon annihilation to produce an electron and a positron, may also exist.In 1932, American physicistCarl David AndersonWhen studying the high-energy electron track in the cosmic ray shower, it was found that half of the electrons in the strong magnetic field deflected in one direction and the other half deflected in the opposite direction. After careful identification, this was the positron predicted by Paul Dirac.Later, it was soon discovered that gamma rays produced electron pairs, and positive and negative electrons collided and "annihilated" into photons, which fully confirmed the correctness of Paul Dirac's prediction.Paul Dirac's work initiated theoretical and experimental research on antiparticles and antimatter[1]。
Fermi Dirac statistics
Paul Dirac is the founder of quantum radiation theoryEnrico Fermi Fermi Dirac statistics were independently discovered[13]。
Cosmology
Paul Dirac has published papers on cosmology at Florida State University in the United States, promoting the development of cosmology research[14]。
Magnetic monopole
In 1931, Paul Dirac discussed the idea of magnetic monopole in his article "Singularities in quantized electromagnetic fields".In 1933, his paper, which continued from 1931, proved that the existence of a single magnetic monopole was enough to explain the quantization of charges.In 1975, 1982 and 2009, some research results pointed out that there might be a magnetic monopole, and his magnetic monopole was the first time to use the concept of topology to deal with physical problems[15]。
electrodynamics
Paul Dirac in quantum field theory, especiallyQuantum electrodynamicsThey also made groundbreaking work[18]。
Large number hypothesis
In 1937, Paul Dirac proposedLarge number hypothesis。He compared two dimensionless quantities: the ratio of the basic force (in this case, gravity and electromagnetic force) and the scale of the age of the universe, and found that both fall in about 39 orders of magnitude.He speculated that this might not be a coincidence, and that there might be some correlation between the two.With reference to Edward Arthur Milne's theory, the gravitational constant is allowed to change with time.Based on these assumptions, he designed his own cosmological model[1]。
In 1930, Paul Dirac published the quantum mechanics work "Principles of Quantum Mechanics", in which he integrated Heisenberg's work in matrix mechanics and Schrodinger's work in wave dynamics into a mathematical system, connecting the relationship between observable measurement and the actors in Hilbert space.The book also introduces Dirac δ function, which is widely used in quantum mechanics.Continuing Dirac's article in 1939, he added his mathematical symbol system - Dirac symbol to the third edition of the book in 1939[1]。
In 1966, "Lectures on Quantum Mechanics" laid the foundation of quantum field theory in the form of Hamiltonian mechanics, in which many quantum mechanics in curved space-time were discussed.
In 1974, the book Spinor in Hilbert Space was published in 1969University of MiamiBased on the lecture notes of, starting from a real Hilbert space, we deal with the basic level of spinor.
In 1975, General Relativity summarized Einstein's general theory of relativity in 68 pages.
In 1978, The Direction of Physics was assembled by Dirac in a series of speeches at the University of New South Wales[21]。
academic exchange
In 1955, Paul Dirac was asked about his personal philosophy of physics when he gave a speech in the Department of Physics of Moscow University. He replied: "A physical law must have mathematical beauty". The blackboard with this sentence is still preserved[16]。
In 1975, Paul Dirac gave a series of five speeches at the University of New South Wales.This series of lectures was later published as The Direction of Physics (1978).He donated the royalties of this book to the University of New South Wales to set up a series of Dirac lectures[1]。
personnel training
Instruct students
According to the data of the website of the Mathematics Pedigree Project in September 2023, Paul Dirac has instructed 8 students in Cambridge University, with the details as follows[8]：
time
full name
school
1935
Bhabha, Homi
University of Cambridge
1937
Lees, A
University of Cambridge
1945
Eliezer, Christie
University of Cambridge
1947
Harish Chandra
University of Cambridge
1951
Eden, Richard
University of Cambridge
1953
Sciama, Dennis
University of Cambridge
1955
Polkinghorn, John
University of Cambridge
Hoyle, Fred
University of Cambridge
Honor recognition
time
Honor recognition
Awarding unit
1930
Fellow of the Royal Society[6]
Royal Society
1933
Nobel prize in Physics[1]
Royal Swedish Academy of Sciences
1939
Royal Medal
1948
Honorary Fellow of the American Physical Society[9]
A family portrait of Dirac (second from the right) in 1907
Charles Dirac, Paul Dirac's father, was born in Monty, Wallace, Switzerland (a French speaking state) in 1866. He did not become a British citizen until 1919.At the age of 20, Charles Dirac betrayed his family and left for Geneva University to study.He came to England in 1890 and settled in Bristol, where he taught French for a living.In 1896, he got a teaching position in Bristol Commercial Vocational and Technical School, and met Florence Holten (the daughter of a captain, 12 years younger than Charles) in Bristol. He married her in 1899.One year after their marriage, their first child, Reginald Dirac, was born.On August 8, 1902, their second child Paul Dirac was born. Their family lived in Monk Street at that time.Four years later, the third child, Beatrice Marguerite Dirac, was born.Like his brother and sister, Paul Dirac joined Swiss nationality at birth, and did not acquire British nationality until he was 17 years old in 1919[1]。
1963 Dirac and his wife
Paul Dirac's brother committed suicide. He attributed his brother's death to his father's fault.When Paul Dirac won two scholarships at Cambridge University, he only needed 5 pounds to leave the place.His father gave the money to his son, making him think it was his father who let him start his own business.Only later did Dirac realize the truth.After his father died in 1936, he found that the important 5 pounds was not given by his father, but by a local educational institution. But his father saved 7500 pounds, which is 15 times his annual salary[1]。
marriage and family
In the autumn of 1934, Paul Dirac began his first one-year vacation in the InstituteEugene Wigner (Eugene Wigner) introduced his sister Manci Balazs to him, and later they got married[2]。
Refuse to be canonized
Paul Dirac refused to be knighted because he didn't want to change his name[10]。
Character characteristics
Paul Dirac is famous for his silence. He seldom speaks. He is unwilling to argue with others.He is emotionally withdrawn and has no interest in anything other than mathematics[11]。
Character evaluation
Announce
edit
Paul Dirac was an outstanding theoretical physicist in the 20th century, whose work was fundamental to the development of quantum mechanics and quantum electrodynamics[3]。(National Magnetic Laboratory Assessment)
Throughout his career he made numerous contributions to the fields of quantum mechanics and quantum electrodynamics[7]。(Cambridge St. John's College Review)
Commemoration for future generations
Announce
edit
Paul Dirac's Hometown
The house where Paul Dirac lived in Bristol as a child was hung with a blue plaque, and the road where the house was located was also named Dirac Way to show his connection with this area.When the landlord Jiaolu Primary School hung a sign on the wall showing the Dirac equation[25]。
Paul Dirac Memorial Stone
On August 1, 1991, Paul Dirac's father's hometown St. Morris Garden erected a memorial stone.
On November 13, 1995, a commemorative slate made of Burlington green slate and engraved with Dirac equation was placed in theWestminster AbbeyFirst appearance[22]。
Dirac Medal and Bonus
Tomb of Dirac and his wife
In 1987, the British Physical Society awarded Dirac a medal and a prize for his "outstanding contribution to theoretical (including mathematical and computational methods) physics".The first three winners wereStephen Hawking(1987)John Stewart Bell (1988) andRoger Penrose (1989)[23]。
ICTP Dirac Medal
International Centre for Theoretical Physics(International Centre for Theoretical Physics, referred to as ICTP) issues ICTP Dirac Medal on August 8 every year (Dirac's birthday)[24]。
Dirac Tower
The publishing headquarters of the British Physical Society in Bristol is named Dirac House[29]。
Dirac Herman Award
In 1997, Bruce Herman, the last doctoral student of Paul Dirac, set up the Dirac Herman Award at Florida State University to reward the outstanding performance of theoretical physics researchers in the university[29]。
Paul Dirac Science Library
In 1989, Manchi founded the Paul Dirac Science Library, which is located in Florida State University. Dirac's papers were collected here before his death, and there is a bronze statue of him outside the library[26]。
Paul Dirac Road
The road where the Tallahassee National Strong Magnetic Laboratory is located is named "Paul Dirac Drive"[27]。
Image compression format
The BBC named a video compression format it developed after Dirac[28]。
