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  • The Strangest Man - Dirac

    John Anderson

    The Academy Class “The Ghost Particle”

     mi 

    His view that fundamental

    physics could be gleaned

    from elegant mathematics

    now permeates a whole

    field of inquiry into the

    reality of nature, string

    theory.

  • •Swiss father, Charles, taught French at

    English School - well regarded teacher

    •Mother, Flo, was English - 12 years

    younger (and Methodist)

    •Father wanted Paul to speak only

    French (Paul would stay silent)

    •One sister, Betty, one brother, Felix

    • Father a bit of a charlatan

    X - Lied on resume

    X - Hid large amounts of income

    X - Had long term secret affair

    X - Lied to Paul about financial aid

    Early Life

    Paul

    Family in 1907

    Charles later on.

  • •Rivalry between older brothers - would

    pass in streets without speaking

    •Wanted to go into medicine. No money

    so mech. eng. at local tech college

    •Took a dull job as draftsman in

    Wolverhampton

    •Took up Buddhism, found a guru, had a

    girlfriend (family split on meeting her)

    •Suicide 1925, two months after quitting

    •Ravaged family, especially father

    •Paul resolved never to take his own life

    Brother Felix

    Felix

    1921

    “My parents were terribly distressed. I

    didn’t know they cared so much…

    I never knew that parents ought to care

    for their children, but from then on I

    knew.” P. Dirac

  • •Extrovert from Hungary. Wigner’s sister

    •Divorced with 2 children. (Judith,

    Gabriel)

    •Met in Princeton lunch counter, 1934

    •They had 2 daughters (Mary Elizabeth

    and Florence Monica)

    Wife - Margit Wigner

    Manci 1963

    When asked by Manci what

    he would say if she left, the

    sweet-talking Paul said “I

    would say good-bye dear.” Judy, MIA

    http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=otqQvmLu7y--pM&tbnid=yG4icTUrWuCE1M:&ved=0CAcQjRw&url=http://en.wikipedia.org/wiki/Paul_Dirac&ei=RYk4VNKcKYOeyASrpoDgDg&bvm=bv.77161500,d.aWw&psig=AFQjCNGAzAXNNMeNz9gi0gxIuvz_55YpsA&ust=1413077784856665

  • •Honeymoon at the shore, conventional Brighton.

    Family Photos

  • Education

    • Starts out slow. Scholarship exam

    success at Bishop Road School

    • Outshines brother in high school,

    college, relationship strained

    • Completes degree at Bristol, only bad

    mark in OJT internship at factory

    •Studies general relativity

    •J.S. Mill’s philosophy of science

    • Applies to Cambridge - Needs money

    • More study at Bristol - Projective

    geometry, Q.M., Hamiltonian mechanics

    • British citizenship in 1919

    • Cambridge - Re-applies. Gets

    money

    • In the big time now

  • Education Bristol

    • Merchant Venturers’ Technical

    College in Bristol

    • Grade school with Archibald Leach

  • Cambridge Education

    •Terse cards home to mother

    •Cavendish Lab connections

    •Patrick Blackett - (cosmic rays,

    cloud chambers, Nobel 1948)

    •Pyotr Kapitza (Soviet Ideology,

    super-fluidity, Nobel 1978)

    • Dirac is a passive listener

    • Ralph Fowler urges Dirac to

    publish

    •Dirac stories begin in earnest.

    •“It is not now raining.”

    • Brother Felix commits suicide

    •Paul sees parents grief (Paul’s

    emotional blindness)

    • Heisenberg, Bohr speak at Kapitza

    club

    •Early work: 5 good papers, and then,

  • • Kapitsa at Cambridge educates Dirac on

    Soviet ideology

    • Kapitsa club at Cambridge (Bohr guest)

    • Climbed Mt. Elbrus in Caucasus mountains

    • Attended conferences in Soviet Union

    • Gets roughed up at border, held 3 days

    • No MI-5 file

    Russian Affinity

    Peter Kapitsa

    1894-1984 Nobel 1978

    Mt. Elbrus, 18,510 ft. Tough climb.

    Igor Tamm

    1895-1971 Nobel 1958

  • Making a Name

    •First Really Major Paper - 1925

    •Born astonished:

    “This was -- I remember well -- one of the

    greatest surprises of my scientific life. For the

    name Dirac was completely unknown to me, the

    author appeared to be a youngster, yet

    everything was perfect in its way and admirable.”

    •Niels Bohr in Copenhagen - 1926

    • Next Born in Göttingen, then Leiden,

    then Brussels for Solvay Conference of

    1927.

    European Tour

  • Quantum Revolution Over - 1927

    First row: I. Langmuir, M. Planck, M. Curie, H. A. Lorentz, A. Einstein, P. Langevin, C. E. Guye, C. T. R. Wilson, O. W. Richardson.

    Second row, left to right: P. Debye, M. Knudsen, W. L. Bragg, H. A. Kramers, P. A. M. Dirac, A. H. Compton, L. V. de Broglie, M. Born, N. Bohr.

    Standing: A. Piccard, E. Henriot, P. Ehrenfest, E. Herzen, T. De Donder, E. Schroedinger, E. Verschaffelt, W. Pauli, W. Heisenberg, R. H. Fowler, L. Brillouin.

    Fifth Solvay Conference – Changing of the Guard

    P. A. M. Dirac

  • How to incorporate Special

    Relativity into Quantum Mechanics

    Dirac has recalled a conversation with Bohr during the 1927 Solvay

    conference.

    Bohr: ‘What are you working on?’

    Dirac: ‘I’m trying to get a relativistic theory of the electron.’

    Bohr: ‘But Klein has already solved that problem.’

    Dirac disagreed.

  • Ingredients to Build QFT

    Quantum Mechanics

    Strong Force

    Electroweak

    Force

    Einstein’s Relativity

    Principle Locality (no action at a

    distance – emission and

    absorption of particles)

    QFT

    Classical

    Field

    Theory

    Dirac

    merges

  • The Dirac Equation - 1928

        0

     

      

      

      

     

     xmxeA

    x i  

    Dirac gets first order equation

     mi  Feynman slash notation

    No electromagnetic field

    In Westminster Abbey Plaque

    Shorthand

    yields

    concise

    equation

    “Our

    equations

    are smarter

    than we are.”

    4x4 matrices,

    way to factor

    equations

    Electron matter field.

  • Special Relativity - Results

    •Dirac succeeds in adding Relativity to Quantum Mechanics.

    •Coefficients are really matrices not numbers.

    •Two positive energy solutions 

    •Correct magnetic moment  Wow!

    •Correct Thomas factor in Coulomb field

    •Ordinary Schrödinger Eq. if E

  • Golden Years Timeline

    Graduates High School - 1918 at 16

    Graduates Bristol Univ. 1921,

    Engineer

    Bristol Univ. for 2 More Years,1923

    • Advanced math and physics

    Enters Cambridge. PhD 1926.

    • Ceremony in Latin. Paul doesn’t

    understand.

    Lucasian Professor - 1932 - 1968

    • Finally earning some money

    Nobel Prize - 1933

    • Shared with Schrödinger

    Dirac, Heisenberg and Schrödinger

    in Stockholm

  • Early Builders of QFT

    Wolfgang Pauli

    1929- Team w/Heisenberg

    Lagrangian formulation of

    QFT.

    1928 – w/Jordan shows relativity compatible with

    QED time commutators.

    J. Robert Oppenheimer

    1929 – 3rd part of Heisenberg- Pauli paper (Coulomb Gauge

    precursor) in Göttingen,

    Germany.

    Werner Heisenberg

    1929- Team w/Pauli

    Lagrangian formulation of

    QFT.

    1932 – First to apply QM principles to nucleus.

  • Builders - Continuity Post War

    Feynman picked up Dirac’s Lagrangian

    approach and developed path integrals in PhD

    thesis (1942).

    In Warsaw, Poland 1962

    Relativity Conference

  • Particle and Field Concepts Evolve

    Phase I - Classical View

    “Your old fashioned ideas are no

    damn good.” Feynman

    Phase II – Quantum Mechanics

    1. Particle spreads like wave

    2. Particle impacts like classical particle

    3. It carries its own probability info about

    where it is likely to impact

    Phase III – Quantum Field Theory

    1. Particle is a quantum of the permanent field

    2. Forces via exchange of particles

    3. Fields are fundamental - particles

    secondary!!!

    “Duality”

    D

    i

    s

    t

    i

    n

    c

    t

    Quantum

    of Field

    Point Particle

    Wave/Field

    Field/P