The Scientist as Rebel

by Freeman J. Dyson

  Dark Hero of the Information Age5 is the third biography of Norbert Wiener, unless there are others of which I am ignorant. First came a joint biography of Wiener and the mathematician John von Neumann, John von Neumann and Norbert Wiener: From Mathematics to the Technologies of Life and Death, by Steve Heims in 1980.6 Then came Norbert Wiener, 1894–1964, by Pesi Masani in 1990.7 The main justification for a new biography is that the three biographies emphasize different aspects of Wiener’s life and character. The Heims biography emphasizes politics. It is mainly concerned with Wiener’s activities as a social critic in the last third of his life. It presents the parallel lives of von Neumann and Wiener as a simple struggle between black and white, with von Neumann as the evil genius of science in the service of war, and Wiener as the good genius of science in the service of peace.

  The authors of the new biography cite Heims frequently, but do not accept his judgments uncritically. They present the relationship between von Neumann and Wiener as it appears in the historical documents, a friendship based on common interests and deep mutual respect. The paths of von Neumann and Wiener diverged after World War II when von Neumann was willing to accept money from the United States government to support his research and Wiener was not. After that, they saw little of each other, but the mutual respect endured. When von Neumann started building a digital computer in Princeton in 1946, Wiener recommended his collaborator Julian Bigelow to be in charge of the hardware, and Bigelow became von Neumann’s chief engineer with Wiener’s blessing.

  Pesi Masani’s biography is from a scholarly point of view the best of the three. Masani was a professional mathematician, born in India and settled in the United States. He collaborated with Wiener and published several substantial papers with him in the 1950s. After Wiener died, Masani edited his collected papers for publication. Masani was intimately familiar with every detail of Wiener’s work. The Masani biography is the only one that portrays him as a working mathematician. Any biography that skips the mathematics can give only a vague impression of Wiener’s way of thinking. Masani states his purpose at the beginning of his book: “This book attempts to trace the interaction between mathematical genius and history that has led to the conception of a stochastic cosmos.”

  Masani explains Wiener’s mathematical ideas with admirable clarity, and he has found and reproduced many historical documents that the other biographers have missed. One particularly illuminating document that Masani reproduces in full is a long and friendly letter from von Neumann to Wiener, written in November 1946, discussing the mysteries of the human brain and the various ways in which the mysteries might be explored. “I am most anxious to have your reaction to these suggestions,” von Neumann writes. “I feel an intense need that we discuss the subject extensively with each other.” Von Neumann’s letter shows how far he had come in foreshadowing the era of molecular biology that he never lived to see. Von Neumann and Wiener shared a passionate interest in biology. Both of them saw a deeper understanding of biology as the ultimate goal of their explorations of the science of computing and information.

  After Heims has described Wiener’s politics and Masani has described his mathematics, what is there left for a third biography to do? This third biography gives us a new and intimate portrait of Wiener as a person, and describes his stormy relationships with his friends and family. Flo Conway and Jim Siegelman have done a thorough job of historical research, interviewing most of the surviving witnesses, and documenting the narrative with detailed references to published and unpublished papers, letters, and interviews. The title, Dark Hero of the Information Age, indicates their main preoccupation. Their aim is to explore the roots of Wiener’s lifelong malaise and often weird behavior. Their intimate portrait became possible because they enjoyed the cooperation of Wiener’s daughters, Barbara and Peggy, who gave them free access to Wiener’s private papers and family records. Peggy wrote in a letter, “Serious unanswered questions remain concerning Dad’s life and relations with his colleagues. It is very important to tell the whole story,” and Barbara agreed. The main obstacle to full disclosure disappeared with the death of Wiener’s wife, Margaret, at the age of ninety-five in 1989.

  The drama of Wiener’s personal life begins with his years as an infant prodigy, tormented by his brilliant but tyrannical father. Either as a result of his father’s training or from genetic predisposition, he suffered from violent swings of mood that continued throughout his life. If he had been seen by a modern psychiatrist he would probably have been diagnosed as manic-depressive. He sank periodically into deep depressions that continued for several months, and then emerged into intervals of restless and creative activity. The depressions tended to come more often when he stayed at home, and that was one of the reasons why he spent so much of his time traveling. Away from home, the distractions of public lectures and ceaseless conversation with friends and admirers kept his spirits high.

  Another major theme of this biography is Wiener’s marriage. His wife, Margaret, was a student of his father, and the marriage was arranged by his parents. Margaret was chosen to take over from his parents the job of caring for him and organizing his life. This job she performed well, running a frugal household and providing a comfortable home for him and the children. She said to a friend in the early days of the marriage, “Norbert does the math and I do the arithmetic.” She coped with his moods and raised his daughters.

  But Margaret was in some respects even crazier than Wiener. She had emigrated from Germany to America at the age of fourteen. She was a fervent admirer of Adolf Hitler and kept two copies of Mein Kampf displayed prominently in her bedroom, one in German and one in English. She made no secret of her political views, to the intense annoyance of Wiener, who was himself Jewish and had many friends who were victims of Nazi persecution. When the daughters were teenagers and began to acquire boyfriends, she made their lives miserable by accusing them of nonexistent sexual delinquencies. When they once went out with a girlfriend and came home with their ears pierced, Margaret was furious and accused them of trying to seduce their father. As a result of her paranoid accusations, both daughters escaped from home as soon as they could and thereafter had little contact with her or with Wiener.

  The most tragic episode of Wiener’s life happened in 1951 when he was fifty-seven years old and passionately involved in a collaboration with his friend Warren McCullough and a group of young colleagues that he called “the boys.” McCullough was a neurophysiologist who had moved from Illinois to MIT to work with Wiener. They planned to explore the connections between Wiener’s theory of feedback control and the functioning of living neurons and brains. “The boys” were a brilliant team, including Jerome Lettvin, who later became a leading experimental biologist. Margaret was insanely jealous of McCullough and his boys, and resolved to break up their friendship with Wiener. At a dinner with some colleagues in Mexico, who reported the episode to Lettvin many years later, she informed Wiener that McCullough’s boys had seduced his daughter Barbara when she was a teenager staying at McCullough’s house.

  This story had no basis in fact, but Wiener believed it. He made no attempt to verify the accusation, and immediately wrote an angry letter to the president of MIT dissolving all connection between himself and the McCullough team. From that day until the end of Wiener’s life, the contact remained broken. McCullough never knew why. The effect of the breach on McCullough and his boys was devastating. The effect on Wiener was also profound. His foray into biology, and his hopes for unifying cybernetics with biology, were at an end. Margaret achieved her objective, to cut him off from his friends and have him for herself.

  The personal drama of the breach between Wiener and McCullough is the centerpiece of this biography, the event around which the rest of the narrative revolves. Perhaps the authors’ main purpose was to exorcise the Wiener family curse by exposing the family secrets to the light of day. Wiener is the dark hero, and Margaret is the dark villain. The book reads more like a novel than a conventional b
iography. And inevitably the reviewer wonders whether the story is true. Margaret is now the one who is accused and will never have a chance to answer her accusers. She never spoke with the authors, and left no friend behind to speak for her. The evidence against her is well documented and seems convincing. And still, the reviewer wonders. The evidence that Margaret claimed a seduction had taken place comes from a single informant, the late Arturo Rosenblueth, who told the story to Lettvin and others, ten years after the event. This is not the sort of evidence that would convict a murderer in a court of law. It is not likely, but possible, that Rosenblueth, who died in 1970, might have had ulterior motives for concocting the story.

  This biography belongs to a genre that has recently become fashionable, emphasizing the baring of family secrets and the exposure of human weaknesses. There has been a spate of books exposing the human weaknesses of Einstein, Madame Curie, and other scientific heroes. Such books are worth reading if they give us a balanced mixture of human drama with scientific substance. Many of them make no attempt at balance, giving us stories and scandals undiluted with science. The authors of this book have succeeded in bringing Wiener to life as a great figure in the world of science as well as a tragic hero in a domestic drama. They show him as he was, a mixture of Galileo and Othello. Because they are ignorant of mathematics, they cannot give the reader a detailed picture of what Wiener actually did. But they answer the crucial questions: what cybernetics was, what Wiener intended to do with it, and why it seems to have disappeared from the scene after Wiener’s death.

  Wiener defined cybernetics to be “the entire field of control and communication theory, whether in the machine or in the animal.” The languages of communication theory are mathematical. To understand the history of cybernetics, it is important to understand that mathematical communication has two languages, which we call analog and digital. Analog communication describes the world in terms of continuously variable quantities such as electrical voltages and currents that can be directly measured. Digital communication describes the world in terms of zeros and ones, each zero or one representing a logical choice between two discrete alternatives. Analog communication is the language of analysis. Digital communication is the language of logic.

  Wiener was fluent in both languages and intended cybernetics to include both. In 1940 he wrote a memorandum explaining in detail why digital language would be preferable for the computers whose existence he already foresaw. But his own contributions to communication theory happened to be written in analog language, for four reasons. First, his work as a pure mathematician had mostly been in analysis. Second, his practical experience with antiaircraft prediction was concerned with analog measurements and analog feedback mechanisms. Third, his conversations with neurophysiologists had convinced him that the language of sensory-motor feedback signals in the brains of humans and animals is analog. Fourth, the transmission of signals by chemical hormones is evidence that the action of the brain is at least partly analog. For all these reasons, Wiener’s book Cybernetics, which summarized his thinking in 1948, was written in analog language. And for the last ten years of his life, as he traveled from country to country preaching the gospel of cybernetics, he used analog language almost exclusively. In spite of his original intentions, cybernetics became a theory of analog processes.

  Meanwhile, also in 1948, Claude Shannon published his classic pair of papers with the title “A Mathematical Theory of Communication,” in The Bell System Technical Journal. Shannon’s theory was a theory of digital communication, using many of Wiener’s ideas but applying them in a new direction. Shannon’s theory was mathematically elegant, clear, and easy to apply to practical problems of communication. It was far more user-friendly than cybernetics. It became the basis of a new discipline called “information theory.” During the next ten years, digital computers began to operate all over the world, and analog computers rapidly became obsolete. Electronic engineers learned information theory, the gospel according to Shannon, as part of their basic training, and cybernetics was forgotten.

  Neither Wiener nor von Neumann nor Shannon, nor anyone else in the 1940s, foresaw the microprocessors that would make digital computers small and cheap and reliable and available to private citizens. Nobody foresaw the Internet or the ubiquitous cell phone. As a result of the proliferation of digital computers in private hands, Wiener’s nightmare vision of a few giant computers determining the fate of human societies never came to pass. But other aspects of Wiener’s vision of the future are coming true. We see, as he predicted, millions of skilled human workers displaced by machines and sinking into poverty. We see the basis of the wealth of nations moving from the manufacture of goods to the processing of information. We see the beginnings of an understanding of the mysteries of the human brain. We still have much to learn from Wiener’s vision.

  Postscript, 2006

  Each time I publish a review in The New York Review, I receive a bimodal set of responses. First come the responses from nonexpert readers who write to tell me how much they like the review. Second come the responses from expert readers who write to correct my mistakes. I am grateful for both categories of response, but I learn much more from the second category. It is inevitable that I make mistakes when writing about fields in which I am not an expert, and I rely on the experts to set the record straight.

  This review gave me an unusually rich collection of responses in both categories. I am especially grateful to those who wrote to correct my mistakes. I have responded to their criticisms by deleting some statements and judgments that were either untrue or unfair.

  1. Simon and Schuster, 1953.

  2. Doubleday, 1956.

  3. John Wiley.

  4. Houghton Mifflin.

  5. Flo Conway and Jim Siegelman, Dark Hero of the Information Age: In Search of Norbert Wiener, the Father of Cybernetics (Basic Books, 2005).

  6. MIT Press.

  7. Birkhäuser.

  23

  WISE MAN

  GREAT SCIENTISTS COME in two varieties, which Isaiah Berlin, quoting the seventh-century-BC poet Archilochus, called foxes and hedgehogs. Foxes know many tricks, hedgehogs only one. Foxes are interested in everything, and move easily from one problem to another. Hedgehogs are interested only in a few problems which they consider fundamental, and stick with the same problems for years or decades. Most of the great discoveries are made by hedgehogs, most of the little discoveries by foxes. Science needs both hedgehogs and foxes for its healthy growth, hedgehogs to dig deep into the nature of things, foxes to explore the complicated details of our marvelous universe. Albert Einstein was a hedgehog; Richard Feynman was a fox.

  Many readers are more likely to have encountered Feynman as a storyteller, for example in his book Surely You’re Joking, Mr. Feynman!,1 than as a scientist. Not many are likely to have read his great textbook The Feynman Lectures on Physics,2 which was a best seller among physicists but was not intended for the general public. Now we have a collection of his letters, selected and edited by his daughter, Michelle.3 The letters do not tell us much about his science. For readers who are not scientists, it is important to understand that foxes may be as creative as hedgehogs. Feynman happened to be young at a time when there were great opportunities for foxes. The hedgehogs, Einstein and his followers at the beginning of the twentieth century, had dug deep and found new foundations for physics. When Feynman came onto the scene in the middle of the century, the foundations were firm and the universe was wide open for foxes to explore.

  One of the few letters in the collection that discusses Feynman’s science was written to his former student Koichi Mano. It describes the fox’s way of working:

  I have worked on innumerable problems that you would call humble, but which I enjoyed and felt very good about because I sometimes could partially succeed.… The development of shock waves in explosions. The design of a neutron counter.… General theory of how to fold paper to make a certain kind of child’s toy (called flexagons). The energy lev
els in the light nuclei. The theory of turbulence (I have spent several years on it without success). Plus all the “grander” problems of quantum theory.

  No problem is too small or too trivial if we can really do something about it.

  “The ‘grander’ problems of quantum theory” were only one item in a long list of Feynman’s activities.

  The phrase “the ‘grander’ problems of quantum theory” refers to the great work for which he received a Nobel Prize in 1965: inventing the pictorial view of nature which he called “the space-time approach.” This work began in 1947 as a modest enterprise, to calculate accurately the fine details of the hydrogen atom for comparison with the findings of some new experiments that had been done at Columbia University. To do the calculation, Feynman invented a new way of describing quantum processes, using pictorial diagrams instead of equations to represent interacting particles. The “Feynman diagrams” that he invented for a particular calculation caused a revolution in physics. The diagrams were not only a useful tool for calculation but a new way of understanding nature. Feynman’s basic idea was simple and general. If we want to calculate a quantum process, all we need to do is to draw stylized pictures of all the interactions that can happen, calculate a number corresponding to each picture by following some simple rules, and then add the numbers together. So a quantum process is just a bundle of pictures, each of them describing a possible way in which the process can happen.

  Feynman’s diagrams gave us a simple visual representation of quantum processes not only for hydrogen atoms but for everything else in the universe. Within twenty years after they were invented, these diagrams became the working language of particle physicists all over the world. It is difficult now to imagine how we used to think about fields and particles before we had this language. A new book by the MIT historian David Kaiser, Drawing Theories Apart: The Dispersion of Feynman Diagrams in Postwar Physics,4 gives a lively account of the spread of the diagrams, describing how they were transmitted around the world. The diagrams spread like a flu epidemic. Each new generation of young scientists became infected with the Feynman disease and then infected others with whom they came into personal contact. The Feynman epidemic lasted longer than a flu epidemic, because the incubation period was measured in years rather than in days. Many of the older scientists remained immune, but their influence waned as the new language became universal.