The Scientist as Rebel

by Freeman J. Dyson

  The same mutual admiration of experimenter and theorist was shown three years later when Einstein happened to be visiting Cambridge a few days after the triumph of Cockcroft and Walton. Einstein insisted on seeing the accelerator that had split the atom. Walton spent a morning showing him the apparatus and explaining the details of its operation. Einstein wrote a letter afterward, expressing “astonishment and admiration” for what he had seen. “He seems a very nice sort of man,” wrote the imperturbable Walton to his fiancée in Ireland.

  How is it that this mutual admiration and easy mixing of theory with experiment, which seemed natural and necessary in the 1930s, is absent from Lightman’s view of physics? Somehow it happened that the successors of Rutherford and Einstein drifted apart in the second half of the twentieth century. This was not the physicists’ fault. It resulted from the enormous growth of accelerators and the enormous proliferation of theories. Accelerators and the accompanying apparatus for detecting particles became so huge and complicated that each experiment was like a military operation. Hundreds of people with highly specialized skills were required to carry out a program planned many years in advance. Theorists became similarly specialized, some of them expert in accelerator design, some in particle interactions, some in general relativity, and some in string theory. It became difficult for theorists in different specialties to communicate with one another, let alone with experimenters. At the end of the century, accelerator physics was slowing down. Each experiment required about a decade to design and prepare. Lightman, an imaginative theorist who liked to avoid narrow specialization, found such experiments unattractive. It was natural for him, following his sense of the beautiful, to move away from experimental physics and toward astronomy.

  Astronomers have so far escaped the extreme specialization that has overtaken physicists. Telescopes are big, but they are not as complicated as accelerators. Observations with a big telescope can be carried out in hours rather than years. Astronomers can be skilled observers and also expert in the theory of what they are observing. That is why the astronomer Vera Rubin has a place of honor in Lightman’s book. She started her professional career as a student of George Gamow after Gamow moved to America. She spent the rest of her professional life observing galaxies and studying their dynamics. She found that the visible matter in galaxies is not heavy enough to explain the speed of their internal motions. She deduced from her observations that galaxies are pervaded by dark matter, invisible to our telescopes. Nobody knows what dark matter is. It is another deep mystery remaining to be explored. We know only that it is there, and that it weighs more than all the stuff that we can see.

  Besides discovering and exploring dark matter, Rubin raised four children and crusaded publicly for the advancement of women in science. I was recently chairman of a committee that organized a scientific conference with a list of distinguished scientists as members. I received a blistering letter from Rubin, asking why we had no women on our list. She supplied me with another list of women who should have been invited. I wrote back to apologize and to thank her for her list, which I shall certainly use in the unlikely event that I ever become chairman of another such committee.

  Lightman’s chapter on Edward Teller is a review of Teller’s memoirs. Lightman considers Teller to be on the whole an evil character, in sharp contrast to his sympathetic portrayals of Einstein and Feynman. The title of the Teller chapter is “Megaton Man,” emphasizing the obsession with hydrogen bombs which made Teller famous. Lightman admits that there were two Tellers. He writes, “There is a warm, vulnerable, honestly conflicted, idealistic Teller, and there is a maniacal, dangerous, and devious Teller.” But his portrait of Teller shows us mostly the dark side. I knew Teller well and worked with him joyfully for three months on the design of a safe nuclear reactor. The Teller that I knew was the warm, idealistic Teller. We disagreed fiercely about almost everything and remained friends. He was the best scientific collaborator I ever had. I consider Lightman’s portrayal of him to be unjust. My own review of Teller’s memoirs explains why.3

  Putting together the portrait of Rutherford in Cathcart’s book with my own recollections of Teller, I find striking similarities. Rutherford and Teller were both immigrants who became fiercely patriotic in defense of their adopted countries. Both often behaved like overgrown children, losing their tempers over trivialities and then regaining their equilibrium with a friendly smile. Both were father figures to their students, taking care of students’ personal problems as well as their professional education. Both were more interested in the strategy of science than in the tactics. Rutherford made the decision to explore nuclei with an accelerator, and then left the details of the accelerator to Cockcroft and Walton. Teller made the decision to build a hydrogen bomb or a safe reactor and then left the details to others. Both had a lifelong dedication to science, but spent more time helping younger people than doing research themselves. Teller published his version of the hydrogen bomb story under the title The Work of Many People. The names of Cockcroft and Walton appear on the letter to Nature announcing their discovery but Rutherford’s does not. My name appears on the patent for the safe reactor but Teller’s does not.

  The most concise and original chapter in Lightman’s book is “Metaphor in Science,” an essay originally published in 1988 in The American Scholar. Illustrating his thesis with quotations from great physicists from Isaac Newton to Niels Bohr, Lightman traces the powerful influence of metaphors on their thinking. As science has become more abstract and remote from everyday experience, the role of metaphor in our descriptions of the world has become more central. The language that nature speaks, as Galileo long ago pointed out, is mathematics. The language that ordinary human beings speak, especially those of us who are not fluent in mathematics, is metaphor. Lightman ends his discussion with another metaphor: “We are blind men, imagining what we don’t see.” That is a good description of theoretical physics.

  1. Brian Cathcart, The Fly in the Cathedral: How a Group of Cambridge Scientists Won the International Race to Split the Atom (Farrar, Straus and Giroux, 2004).

  2. Pantheon, 2005.

  3. See Chapter 15. Edward Teller describes in his memoirs the only time he met Rutherford. Rutherford gave in 1934 a lecture denouncing as a lunatic anyone who imagined that nuclear energy might ever be put to practical use. The lecture was given in London, soon after Teller arrived in England as a refugee. Teller was in the audience and was not favorably impressed. He afterward learned that the lunatic who had aroused Rutherford’s anger was his friend Leo Szilard. Szilard had tried unsuccessfully to persuade Rutherford that a neutron chain reaction was a practical and dangerous possibility. It is interesting to speculate how different the history of the last century might have been if Rutherford had taken Szilard’s warning seriously.

  22

  THE TRAGIC TALE OF A GENIUS

  NORBERT WIENER WAS famous at the beginning of his life and at the end. For thirty years in the middle during which he did his best work, he was comparatively unknown. He was famous at the beginning as a child prodigy. His father, Leo Wiener, the first Jew to be appointed a professor at Harvard, was a specialist in Slavic languages. Leo was also an extreme example of a pushy parent. He drove Norbert unmercifully, schooling him at home in Greek, Latin, mathematics, physics, and chemistry. Fifty years later Norbert described, in his autobiography, Ex-prodigy: My Childhood and Youth,1 how the prodigy was nurtured:

  He would begin the discussion in an easy, conversational tone. This lasted exactly until I made the first mathematical mistake. Then the gentle and loving father was replaced by the avenger of the blood.… Father was raging, I was weeping, and my mother did her best to defend me, although hers was a losing battle.

  At age eleven, Leo enrolled Norbert as a student at Tufts University, where he graduated with a degree in mathematics at age fourteen. Norbert then moved to Harvard as a graduate student and emerged with a Ph.D. in mathematical logic at age eighteen. While he was growing up and t
rying to escape from his notoriety as a prodigy at Tufts and Harvard, Leo was making matters worse by trumpeting Norbert’s accomplishments in newspapers and popular magazines. Leo was emphatic in claiming that his son was not unusually gifted, that any advantage that Norbert had gained over other children was due to his better training. “When this was written down in ineffaceable printer’s ink,” said Norbert in Ex-prodigy, “it declared to the public that my failures were my own but my successes were my father’s.”

  Miraculously, after ten years of Leo’s training and seven years of tortured adolescence, Norbert settled down to adult life as an instructor at the Massachusetts Institute of Technology and became a productive mathematician. He climbed the academic ladder at MIT until he was a full professor, and stayed there for the rest of his life. For thirty years, roughly from age twenty to age fifty, he faded from public view. He remained famous in the MIT community for his personal eccentricities. He liked to think aloud and needed listeners to hear what he was thinking. He made a habit of wandering around the campus and talking at great length to any colleague or student that he encountered. Most of the time, the listeners had only a vague idea of what he was talking about. Colleagues and students who valued their time learned to hide when they saw him coming. At the same time, they respected him for his achievements and for his encyclopedic knowledge of many subjects.

  Wiener was unusual among mathematicians in being equally at home in pure and applied mathematics. He made his reputation as a pure mathematician by inventing concepts such as “Wiener measure” that have passed into the mainstream of mathematics. Wiener measure gave mathematicians for the first time a rigorous way to talk about the collective behavior of wiggly curves or flexible surfaces. While continuing to publish papers in the abstract realms of mathematical logic and analysis, he loved to talk with the engineers and neurophysiologists who were his neighbors at MIT and Harvard. He became deeply immersed in their cultures, and enjoyed translating problems from the languages of engineering and neurophysiology into the language of mathematics.

  Unlike most pure mathematicians, he did not consider it beneath his dignity to apply his skills to the messy practical problems of the real world. He became a successful applied mathematician, helping to design machines and communication systems for use in war and peace. He understood, more clearly than anyone else, that the messiness of the real world was precisely the point at which his mathematics should be aimed. As an applied mathematician, he worked out a general theory of control systems and feedback mechanisms, a theory which he called “cybernetics.” Cybernetics was a theory of messiness, a theory that allowed people to find an optimum way to deal with a world full of poorly known agents and unpredictable events. The word “cybernetics” comes from the Greek word for steersman, the man who steers a frail ship through stormy seas between treacherous rocks.

  During World War II, Wiener worked with his engineer friend Julian Bigelow designing an optimum control system for antiaircraft guns. The design of the control system was an elementary exercise in cybernetics. Like his colleagues at MIT, Wiener was happy to be engaged in work that could help to win the war. To shoot down an airplane, it was necessary to predict the future position of the airplane at the time of arrival of the shell, knowing only the past track of the airplane up to the moment when the prediction was made. During the interval between prediction and arrival, the pilot of the airplane would be taking evasive action, changing his course in a way that could only be estimated statistically. To maximize the chance of destroying the airplane, the control system must take into account the multitude of wiggly paths that the airplane might follow. The concept of Wiener measure was the tool that allowed him to translate the problem of finding an optimum prediction into precise mathematical language. He worked hard with Bigelow to translate the mathematical solution of the problem back into electrical and mechanical hardware. Unfortunately, the United States Army could not wait for the Wiener-Bigelow hardware to be manufactured and tested. The army needed an antiaircraft control system that could be mass-produced and deployed on the battlefield as soon as possible. The army chose a less sophisticated control system that would be available sooner, designed by a rival group of engineers at the Bell Laboratories.

  The Bell system became operational and the Wiener-Bigelow system never saw combat. In the end, the choice of the Bell system probably had little effect on the course of the war. The big breakthrough in antiaircraft technology was the invention of the proximity fuse, a radar-controlled fuse that enabled a shell to explode and destroy an airplane nearby without directly hitting it. Without proximity fuses, neither the Bell system nor the Wiener-Bigelow system was accurate enough to shoot down airplanes reliably. After proximity fuses became available in 1944, the Bell system was good enough.

  When the war ended with the nuclear attacks on Hiroshima and Nagasaki in 1945, Wiener was outraged. In his eyes, the government had committed a crime against humanity, and the scientists who had created the bomb were to blame for allowing the government to exploit their skills for evil purposes. The nuclear attacks confirmed a belief that had been growing in his mind for many years, that the technology of communication and control which he had helped to create was fundamentally dangerous. He saw the nuclear attacks as a glaring example of the disasters that could result from science and technology when scientists were working in secrecy for military and industrial authorities. He feared that the nascent technology of computers and automatic machinery could lead to even greater disasters if it remained in the hands of secret military and industrial organizations. He decided from that moment on to have nothing to do either with government or with industry. He decided to devote a major part of his time to educating the public, to helping it deal wisely with new technologies.

  In January 1947, Wiener published in The Atlantic Monthly an article with the title “A Scientist Rebels,” an eloquent statement of his refusal to cooperate with the government. “I do not expect to publish any future work,” he wrote, “which may do damage in the hands of irresponsible militarists.” This article immediately made him as famous at the age of fifty-two as he had been as a child prodigy. For the rest of his life, he continued to be well known as a political activist, writing articles and books that were widely read, traveling to many countries to meet with political leaders and concerned citizens. As he explained in his second autobiography, I Am a Mathematician: The Later Life of a Prodigy,2 “I thus decided that I would have to turn from a position of the greatest secrecy to a position of the greatest publicity, and bring to the attention of all the possibilities and dangers of the new developments.”

  For the last decade of his life, Wiener was a prophet who spoke and wrote eloquently about the displacement of human beings by automatic machinery. He saw this displacement as a likely consequence of his own inventions. But he spoke and wrote with equal eloquence of the good that automatic machinery could do, if it were used intelligently to make poor societies rich, to enable poor countries to jump from an agricultural economy to an industrial economy without enduring the horrors of nineteenth-century industrialization. He published two books that became best sellers, Cybernetics; or, Control and Communication in the Animal and the Machine, in 1948,3 and The Human Use of Human Beings: Cybernetics and Society, in 1950.4 Before modern electronic computers existed, these books predicted with some degree of accuracy the economic and political effects of computer technology on human societies. “We were here,” he wrote,

  in the presence of another social potentiality of unheard-of importance for good and for evil.… It gives the human race a new and most effective collection of mechanical slaves to perform its labor.… However, any labor that accepts the conditions of competition with slave labor accepts the conditions of slave labor, and is essentially slave labor.… The answer, of course, is to have a society based on human values other than buying or selling.

  He concluded his sermon with a sentence borrowed from the medieval poet Bernard of Cluny, “The hour is ver
y late, and the choice of good and evil knocks at our door.”

  Wiener shared the fate of other major prophets, being honored abroad more than at home. He was honored most spectacularly in India and Russia. He traveled several times to India and was welcomed personally by Nehru and other Indian leaders. He went on lecture tours, and gave advice about industrial policy to the Indian government. He advocated the founding of technical institutes and the encouragement of homegrown technical industries. His advice is bearing fruit fifty years later, as India emerges as a major center of information technology and American business is outsourced to Indian firms. He also traveled to Russia, where he received equally strong official adulation but felt less at home. He told the Russians that science must be free from the restraints of political ideology. He found the ideology of Marxism as destructive of human values as the ideology of free-market capitalism. The Soviet government ignored his plea for scientific freedom but enthusiastically supported cybernetics.

  The cult of cybernetics in Russia was more philosophical than practical, but it may have had some lasting effects. Perhaps it contributed to the recent emergence of a computer-literate society and a homegrown software industry. In 1964, at the age of sixty-nine, Wiener was invited to give lectures about cybernetics in Sweden, where his ideas also had a wide following. The day after his arrival, he died suddenly of a pulmonary embolism on the steps of the Royal Institute of Technology in Stockholm.