Paul Dirac, anomalous dude
The Strangest Man : The Hidden Life of Paul Dirac, Quantum Genius
Schrödinger has his cat, and Heisenberg his uncertainty principle. Thanks to these misleadingly everyday tags, the names of two of the founding fathers of quantum mechanics have somehow made it into our collective cultural consciousness. But Dirac? He has only his equation, and so remains mired in unwarranted obscurity.
In 1933, aged only 31, Paul Dirac shared the Nobel prize for physics with Erwin Schrödinger, "for their discovery of new productive forms of atomic theory", while Werner Heisenberg made the trip to Stockholm the same year to collect the prize deferred from 1932. Quantum mechanics grew in the powerhouses of theoretical physics in Berlin, Copenhagen and Göttingen. Many therefore assume, on hearing the foreign-sounding name Dirac, that he was born into the same central European ferment of new ideas as the others. But although his father was Swiss, Dirac's mother was Cornish and he himself was born a Bristolian who retained a West Country burr until he died in 1984. He spent most of his scientific career in Cambridge, holding the Lucasian chair of mathematics that had previously been Isaac Newton's and is now Stephen Hawking's.
Graham Farmelo succeeds brilliantly in bringing this shadowy figure into three dimensions. Dirac's life was dedicated to exploring the basis of physical reality through mathematics: he endlessly sought "beautiful" equations that would generate predictions about how the world must be. His greatest triumph, the Dirac equation of 1928, made Heisenberg's and Schrödinger's descriptions of the movement of the electron compatible with Einstein's theory of relativity, and predicted the existence of positrons - positive electrons, a form of antimatter - four years before they were actually observed. Farmelo describes the history of this discovery, and what followed, without using a single equation (other than E=mc2): indeed, the full Dirac equation appears nowhere in the book. For the general reader this is a blessing - and Farmelo no doubt heeded the well-publicised advice to Hawking that every equation would halve his sales. Physicists (they read biographies too) might wish for a mathematical appendix: if so they should keep beside them a copy of Dirac's own 1930 classic, The Principles of Quantum Mechanics, still in print.
In many ways Dirac matched the hackneyed stereotype of the lone genius all too well, but Farmelo has been scrupulous in balancing his originality with the scientific debts he owed to others. Indeed, he shows theoretical physics to have been a surprisingly sociable field, with all the key players on a merry-go-round of visits to try out their theories on each other. The personalities of the fatherly Niels Bohr, the irascible Wolfgang Pauli, the politically compromised Peter Kapitsa and many others populate a colourful community united only by their passion for physics. Farmelo excels in embedding the flowering of ideas about elementary particles in the troubled history of 20th-century Europe and America: no physicist, however unworldly, could remain unaffected by the rise of Nazism and communism, the second world war, the development of the atom bomb and the cold war.
It is clear from the outset - flagged unambiguously in the book's title and subtitle - that though he does justice to the history and the science, Farmelo's real interest is in Dirac the man. Dirac was famous among his colleagues for his peculiar literal-mindedness, his unwillingness to speak except in answer to a direct question, his devotion to strict routines and his lack of emotional responsiveness. With no dress-sense and a passion for Mickey Mouse cartoons and cheap comics, he was the archetypal geek: so odd that even Bohr, head of an institute of theoretical physics, called him "the strangest man [he] ever met". Using private family papers and countless interviews, Farmelo has gone after the roots of his strangeness. He reveals heartbreakingly unhappy relationships with a mean, tyrannical father and a pitiful, needy mother, who remained trapped in a nightmare of a marriage until long after Dirac had left home.
In discussion with an expert in autistic spectrum disorders, Farmelo concludes that Dirac was in all likelihood a high-functioning autistic, and that his father too may have had autistic traits. It is hard to see how he could have survived his loveless upbringing entirely unscathed, but the evidence of a genetically-acquired neurological basis to his personality also seems strong.
The surprising twist to the story is that having previously shown no interest in sexual relationships of any description, at 34 Dirac married the widowed sister of a Hungarian colleague and fathered two daughters. While the marriage to emotional and demonstrative Manci widened his horizons, he ultimately faced his own private tragedy: the failure, as he saw it, to refine the theory of quantum mechanics so that the calculations did not produce troublesome infinities. No matter that others saw him as the greatest theoretician since Einstein. Emotional satisfaction depended on finding the most beautiful equation of all, and it had eluded him.
Schrödinger has his cat, and Heisenberg his uncertainty principle. Thanks to these misleadingly everyday tags, the names of two of the founding fathers of quantum mechanics have somehow made it into our collective cultural consciousness. But Dirac? He has only his equation, and so remains mired in unwarranted obscurity.
In 1933, aged only 31, Paul Dirac shared the Nobel prize for physics with Erwin Schrödinger, "for their discovery of new productive forms of atomic theory", while Werner Heisenberg made the trip to Stockholm the same year to collect the prize deferred from 1932. Quantum mechanics grew in the powerhouses of theoretical physics in Berlin, Copenhagen and Göttingen. Many therefore assume, on hearing the foreign-sounding name Dirac, that he was born into the same central European ferment of new ideas as the others. But although his father was Swiss, Dirac's mother was Cornish and he himself was born a Bristolian who retained a West Country burr until he died in 1984. He spent most of his scientific career in Cambridge, holding the Lucasian chair of mathematics that had previously been Isaac Newton's and is now Stephen Hawking's.
Graham Farmelo succeeds brilliantly in bringing this shadowy figure into three dimensions. Dirac's life was dedicated to exploring the basis of physical reality through mathematics: he endlessly sought "beautiful" equations that would generate predictions about how the world must be. His greatest triumph, the Dirac equation of 1928, made Heisenberg's and Schrödinger's descriptions of the movement of the electron compatible with Einstein's theory of relativity, and predicted the existence of positrons - positive electrons, a form of antimatter - four years before they were actually observed. Farmelo describes the history of this discovery, and what followed, without using a single equation (other than E=mc2): indeed, the full Dirac equation appears nowhere in the book. For the general reader this is a blessing - and Farmelo no doubt heeded the well-publicised advice to Hawking that every equation would halve his sales. Physicists (they read biographies too) might wish for a mathematical appendix: if so they should keep beside them a copy of Dirac's own 1930 classic, The Principles of Quantum Mechanics, still in print.
In many ways Dirac matched the hackneyed stereotype of the lone genius all too well, but Farmelo has been scrupulous in balancing his originality with the scientific debts he owed to others. Indeed, he shows theoretical physics to have been a surprisingly sociable field, with all the key players on a merry-go-round of visits to try out their theories on each other. The personalities of the fatherly Niels Bohr, the irascible Wolfgang Pauli, the politically compromised Peter Kapitsa and many others populate a colourful community united only by their passion for physics. Farmelo excels in embedding the flowering of ideas about elementary particles in the troubled history of 20th-century Europe and America: no physicist, however unworldly, could remain unaffected by the rise of Nazism and communism, the second world war, the development of the atom bomb and the cold war.
It is clear from the outset - flagged unambiguously in the book's title and subtitle - that though he does justice to the history and the science, Farmelo's real interest is in Dirac the man. Dirac was famous among his colleagues for his peculiar literal-mindedness, his unwillingness to speak except in answer to a direct question, his devotion to strict routines and his lack of emotional responsiveness. With no dress-sense and a passion for Mickey Mouse cartoons and cheap comics, he was the archetypal geek: so odd that even Bohr, head of an institute of theoretical physics, called him "the strangest man [he] ever met". Using private family papers and countless interviews, Farmelo has gone after the roots of his strangeness. He reveals heartbreakingly unhappy relationships with a mean, tyrannical father and a pitiful, needy mother, who remained trapped in a nightmare of a marriage until long after Dirac had left home.
In discussion with an expert in autistic spectrum disorders, Farmelo concludes that Dirac was in all likelihood a high-functioning autistic, and that his father too may have had autistic traits. It is hard to see how he could have survived his loveless upbringing entirely unscathed, but the evidence of a genetically-acquired neurological basis to his personality also seems strong.
The surprising twist to the story is that having previously shown no interest in sexual relationships of any description, at 34 Dirac married the widowed sister of a Hungarian colleague and fathered two daughters. While the marriage to emotional and demonstrative Manci widened his horizons, he ultimately faced his own private tragedy: the failure, as he saw it, to refine the theory of quantum mechanics so that the calculations did not produce troublesome infinities. No matter that others saw him as the greatest theoretician since Einstein. Emotional satisfaction depended on finding the most beautiful equation of all, and it had eluded him.