Must-read science book: Dirac

April 1, 2010 • 7:15 am

Biographies of scientists are often deadly dull.  Most famous scientists lived rather uninteresting lives apart from their work, and biographers often fail to convey the excitement of that work.  A notable exception to the dull-existence rule was evolutionary geneticist J.B.S. Haldane,  a real character (check out the poem he wrote about his rectal cancer) who had a terribly exciting life; but his biography, JBS by Ronald Clark, doesn’t really lay out why he’s famous.  Or, when biographers try to do that, the writing is turgid.  I’ve dutifully endured many deadly scientific biographies, including the acclaimed Subtle is the Lord: the Science and Life of Albert Einstein, by Abraham Pais. I even had trouble finishing the Pulitzer-winning biography of J. Robert Oppenheimer, American Prometheus, by Kai Bird and Martin J. Sherwin.

Until now, the only biography that I thought combined great writing and a full and accurate account of scientific achievement was Janet Browne’s magisterial two-volume life of Darwin.  (This isn’t just my pro-evolution bias: it really is a scientific page-turner.)  But now I’ve found another.

I’m giving two thumbs up to a splendid new life of P. A. M. Dirac (1902-1984) by Graham Farmelo: The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom.  Yes, the title is a bit wonky, for Dirac was no mystic (he was in fact a militant atheist), but he was a strange and brilliant character who, along with Heisenberg, was a major architect of quantum physics.  Dirac’s life was hardly exciting: he was a laconic, antisocial man, and even his physics colleagues couldn’t pry more than a few words out of him.  He had a tyrannical father, a fawning mother, and his brother committed suicide, all of which may account for Dirac’s asociality.  His real life was in his head, but what a head!  Somehow Farmelo manages, without burdening the reader with equations, to convey the wonder of Dirac’s accomplishments and turn his life into a triumph of the ill.

For me, the high point of Farmelo’s tale is Dirac’s prediction, from first principles, of the existence of antimatter.  It turned out that one of his quantum-mechanical equations, the famous “Dirac equation,” predicted the existence of antimatter: particles the size of electrons but with a positive charge.  For several years Dirac’s colleagues poo-pooed this prediction, for there was no evidence of antimatter.  Dirac even thought that his equation might be wrong.  But cloud-chamber experiments conducted by Carl Anderson at Caltech finally confirmed the existence of the predicted “positrons.” In 1933, at the age of only 31, Dirac shared the Nobel Prize in Physics with Erwin Schrödinger.

Throughout his life, Dirac insisted that the truth about nature was approached better through equations than experiments, and it still amazes me—in fact, I find this unbelievable—that Dirac accepted the existence of antimatter simply because it was demanded by his equations.  The notion that, with minimal input from observation or experiment, equations themselves can tell us what is real about the universe is something completely alien to a biologist.

Get this book; you won’t be disappointed.

Below is one of my favorite science photos. It shows Dirac (left) having a “conversation” with Richard Feynman at a relativity meeting in Warsaw in 1962.  The lanky Dirac, with an impossibly small head atop a stretched-out frame, leans back as the garrulous Feynman gesticulates.

And a Dirac anecdote:

At the question period after a Dirac lecture at the University of Toronto, somebody in the audience remarked: “Professor Dirac, I do not understand how you derived the formula on the top left side of the blackboard.”

“This is not a question,” snapped Dirac, “it is a statement. Next question, please.”

I’ve read only a few biographies as engrossing as Farmelo’s, and none (except for Browne’s) dealing with scientists.  Just to note my favorite non-scientific biographies: two are by Robert Caro, The Power Broker: Robert Moses and the Fall of New York, and his still-in-progress biography of LBJ, The Years of Lyndon Johnson ( The Path to Power, Means of Ascent, and Master of the Senate).  And my all-time favorite biography is a real masterpiece, and, sadly, will always be unfinished: William Manchester’s The Last Lion: Winston Spencer Churchill.  There are two volumes, Visions of Glory, 1874-1932, and Alone, 1932-1940.  It’s a great tragedy that Manchester died before finishing the third (and probably not the last) volume, one that would have described Churchill’s greatest achievement, shepherding Britain through World War II.

32 thoughts on “Must-read science book: Dirac

  1. You are not serious, are you: “Most famous scientists lived rather uninteresting lives apart from their work…”?

  2. I’m surprised that Sylvia Nasar’s voluminous, meticulously researched, and deservedly well-known biography of John Nash, Jr. is not mentioned here on the positive side. There also exists a very good, unabridged audio version of that book.

    Frustratingly for me, the Paul Dirac bio is off-limits to Europeans at the Audible store. They always have those regional copyright barriers; it is such a pain (and only some audiobooks can be downloaded frm certain other sources which I shall not describe here).

    Professor Coyne might be pleased to hear, however, that features “Why Evolution is True” under the Dirac volume, in the “Customer who liked this also liked…” category.

    1. Would you not include Andrew Hodges’ “Alan Turing: the Enigma of Intelligence”?

      The JBSH poem may have been OCR’d – or just transcribed by someone innocent of anatomy. The line
      “One set is in my perineum
      Where I can feel, but can’t yet see ‘em.”
      appears as “…perineurn…” – which would rhyme only with “tea-urn”. I’m glad he didn’t.

      Comic verse needs good feminine rhymes, which this has in abundance, but I don’t know where “theatre” rhymes with “better”.

  3. Dirac’s prediction of the positron wasn’t quite as elegant as that. He was disturbed by the fact that the mathematically predicted antiparticle of the electron had never been observed, so he suggested that it might in fact be the proton. This was of course incorrect because the antiparticle predicted by his theory has exactly the same mass as the electron. Too bad he didn’t just stick to his guns and wait for experimental confirmation. (Easy to say in hindsight, but it must have been tough with that prediction hanging out there and no evidence forthcoming.)

    The reason why he was confident in the existence of antimatter is that his equation already resolved a host of other experimental issues (fine structure of the hydrogen atom, magnetic moment of the electron) based on very simple and elegant principles. It was too good to abandon just because it made a few weird predictions no one had ever seen before.

  4. I read Farmelo’s book about Dirac The Strangest Man a few months ago and found it to be a very interesting book about a fascinating man. I rated it 4 out of 5.

    1. I felt two things were missing to make it a 5 star book. The first issue is that the writing, good in most places, got to be a bit tedious occasionally. The second issue is that I finished the book still puzzled about Dirac, the man. Yes, there was a lot about his childhood, etc, but I felt something was missing. It could be that more research and interviews could find more or maybe the man is just too much of a puzzle and the information is not available.

  5. Good book, indeed. Although Dirac was an atheist, he was a mystic. He was a beauty mystic. He refused throughout his life to accept renormalization despite its smashing empirical success because “it wasn’t beautiful”.

  6. Dirac: the Dirac “delta function” (which is really a distribution and not a function) was one of his contributions to mathematics.

    It is a “function” f(x) where f(x) = 0 for all x not equal to zero but if you integrate f from -infinity to infinity you get 1!

    The Dirac delta can be thought as of a strange limit of functions:

    fk(x) = k for x between -1/k and 1/k and 0 elsewhere.

    Love it!

  7. Genius about Richard Feynman was quite good, I though. Been meaning to find The Strangest Man for a while – I think it was mentioned on the Guardian Science Weekly podcast as well.

    There are plenty of Dirac anecdotes around. George Gamow for one was fond of them.

    Pauli: “I think our good colleagues can be summed up thus: ‘There is no God, and Dirac is his prophet.'”

  8. It’s an even greater tragedy that Manchester realized well before his death that he would not be able to complete volume 3, because of his deteriorated mental abilities.

    Otherwise I highly recommend Paul Berg & Maxine Singer’s biography of George Beadle (of Beadle & Tatum): George Beadle: an Uncommon Farmer. Included are descriptions of TH Morgan & his lab, Barbara McClintock and others.

  9. That IS a great photo of Dirac and Feynman!

    Feynman’s right leg and foot are in a very strange position… it almost looks like he is dancing the Macarena. Or stomping on Dirac’s toes, maybe.

    I’ll be reading this book soon.

    1. I think that Feynman’s foot is simply turned outwards (towards his right), but Dirac’s shoe makes it look as though Feynman’s foot is twisted in.
      Their feet are almost touching, though–I suspect Dirac is leaning back to avoid having his personal space invaded!

      1. or not… I have seen that standing talking foot geometry among many, not from US though. I have no visual proof. Maybe Dr Feymann picked it up in one of his travels. P Dirac looks scared.

        1. Curious, I found this (bookofbodylanguage!!!): “Paintings done during the Middle Ages often show high status men standing in the Foot-Forward Position (RF) as it allowed them to display their fine hosiery, shoes and breeches” It is not evident that Dr Feynmann is wearing any fine hosiery.

  10. Thanks for the recommendation—one fascinating aspect that Farmelo explores his his Dirac’s autism, an explanation which is consistent with your funny but strange anecdote.

    Armchair diagnoses are to be avoided, but where appropriate it is necessary (and quite often very easy!) to explain how an influential person’s life is shaped by psychological or personality disorders.

    Certainly a strong case can be made for the role of autism in Dirac’s contributions—I’m curious what you thought of this important part of Farmelo’s biography.

    Another example of a disorder having widespread influence is Princess Diana’s borderline personality disorder. It’s good that many biographers no longer shy away from this key aspect of their subjects.

  11. PAM Dirac fans might enjoy this video. It includes, toward the end, a snippet of Dirac as an old man lecturing at FSU.

  12. Thanks, I’ll look for that book. I don’t know what context that quote by Dirac was made in, but it is certainly not true. At the start you may have blind experiments (if you really know absolutely nothing), then you create your mathematical models. What Dirac (and many others for that matter) was exceptional at was understanding the implications of the proposed mathematical models. Rather than “A fits the data gathered from B very nicely”, Dirac would say “If A were correct, then C must be observable” (the infamous prediction). The predictions are really nothing more than testing the consistency of the mathematical model. However, without experimental data you can neither demonstrate nor disprove any assertions based on a model.

    I agree that biographies are dreadfully dull; I have always been frustrated by biographies of J.R. Oppenheimer in particular. It seems that people either adore him and merely write a sycophantic story or they hate him and the biography is nothing but an anti-Oppenheimer rant. None I’ve read even explain what’s so special about him as the top scientist managing the Manhattan Project or what contributions he had made to science when he was not managing the bomb project. Nor does anyone seem to want to discuss the scandals at the end of the war (which I can only guess arose from some actions of his brother Frank and John’s attempts to protect his brother). Frank Oppenheimer is another very interesting person, but history seems to have forgotten him (though some might know him as the guy who started the San Francisco Exploratorium – but that’s just a small part of his life).

    1. Well, in fact, there is now a new biography out of Frank Oppenheimer, by K.C. Cole. It has received some good reviews. So perhaps he’s not so forgotten.

  13. I have read the book and yes it is a good book but I have a minor issue with you using the word antisocial instead of introverted. This happens quite a lot because people regard me as antisocial too whereas I am just extremely introverted like Dirac, there is a big difference.

    1. Sorry, I meant “asocial” (as I used it below) rather than “antisocial,” meaning that Dirac did not have an abiding need for human company.

  14. An excellent, well-written and learned book that had me gripped throughout. I would quibble about the term ‘Militant,’ atheist. Atheist, certainly, but I am not sure he was very militant.

    I am a non-scientist but the author successfully conveyed to me the monumental nature of Dirac’s achievements. Highly recommended.

  15. Dirac was quite plainly a high-functioning autistic chap.
    Thus the laconic social brusqueness coupled with chronic genius.

  16. Ordered it. Another good and somewhat gripping biography (of a mathematician, however) is Robert Kanigel’s “The Man Who Knew Infinity”(i.e. Ramanujan). Though I would have liked a little more math (and elaborations of the charms of number theory), it is still very well told.

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