Darwin Among the Machines

by George B. Dyson

  Richardson, having managed an electrical laboratory before World War I, might have contributed more to the development of electronic computers had there been laboratory facilities not directly involved in military research. Working entirely on his own in the late 1920s in Paisley, Scotland, he produced an odd but insightful paper. “The Analogy Between Mental Images and Sparks” includes schematic diagrams of two simple electronic devices that Richardson constructed to illustrate his theories on the nature of synaptic function deep within the brain. One of these circuit diagrams is captioned “Electrical Model illustrating a Mind having a Will but capable of only Two Ideas.”30 Richardson had laid the foundations for massively parallel computing in the absence of any equipment except his own imagination; now, with nothing but a few bits of common electrical hardware, he gave bold hints as to the physical basis of mind. But he had no interest in elaborating on these principles or attempting to embody them on a wider scale. His ideas lay dormant in the pages of the Psychological Review.

  Von Neumann saw to it that the powers of the electronic computer brought Richardson’s dream (and, with the invention of the atomic bomb, his nightmares) to life. The first public announcement of von Neumann’s postwar computer project was made by the New York Times after a meeting between Zworykin, von Neumann, and Francis W. Reichelderfer, chief of the U.S. Weather Bureau in Washington, D.C. The “development of a new electronic calculator, reported to have astounding potentialities . . . might even make it possible to ‘do something about the weather,’” the Times reported. “Atomic energy might provide a means for diverting, by its explosive power, a hurricane before it could strike a populated place.”31 Stan Ulam hinted at the required scale: “To be used in ‘weather control,’ one will have to consider among other problems the interaction between several, perhaps nearly simultaneous, explosions.”32

  The ENIAC was still a military secret, leading the Times to conclude that “none of the existing [computing] machines, however, is as pretentious in scope as the von Neumann-Zworykin device.” It was true that no program as ambitious was in the works. Von Neumann and Zworykin were not proposing to build just a computer, but a network of computers that would span the world. “With enough of these machines (100 was mentioned as an arbitrary figure) area stations could be set up which would make it possible to forecast the weather all over the world.”33

  Richardson’s methods—breaking up a complex problem into a mosaic of computational cells—were equally adaptable to meteorology, fluid dynamics, and the peculiar shock-wave effects that governed both the construction of an atomic bomb and the physical destruction produced when one went off. Von Neumann took care of the bombs first. Later, when he developed his own computing center at the Institute for Advanced Study, he established a numerical meteorological group under Jule Charney that transformed Richardson’s proposal into a working operation, leading directly to the system of numerical weather forecasting that models our atmosphere today.

  The idea of building a general-purpose electronic digital computer had long been incubating in von Neumann’s mind. “Von Neumann was well aware of the fundamental importance of Turing’s paper of 1936 ‘On computable numbers’ which describes in principle the ‘Universal Computer’ of which every modern computer (perhaps not ENIAC as first completed but certainly all later ones) is a realization,” recalled Stan Frankel, who supervised numerical computation at Los Alamos during the war. “Von Neumann introduced me to that paper and at his urging I studied it with care. Many people have acclaimed von Neumann as the ‘father of the computer’ (in a modern sense of the term) but I am sure that he would never have made that mistake himself.”34 Separated by personality and style, Turing and von Neumann labored independently to bring digital computers to life. While Turing was at Princeton University in 1937, preparing his doctoral thesis under Alonzo Church, he worked in close proximity to von Neumann. But he declined the offer of a position as von Neumann’s assistant, choosing instead to return to England and his destiny as the mastermind of Bletchley Park.

  In contrast to the respectful distance that characterized his relations with Turing, von Neumann maintained a close friendship and long correspondence with Rudolf Ortvay, director of the Theoretical Physics Institute at the University of Budapest. There were two complementary approaches to digital computers. The first was to start from the most elementary beginnings, in the style of Leibniz or Turing, using nothing except 1s and 0s—or switches of some kind or another, which are 1s and 0s in physical form. The other approach, advocated by Ortvay, was to proceed in the opposite direction, taking as a starting point that most complicated known computer, the human brain.

  ‘I read through your paper on games, and it gave me hope that you might succeed in formulating the problem of switching of brain cells if I succeed in drawing your attention to it,” wrote Ortvay to von Neumann in 1941. Ortvay’s suggestions encouraged von Neumann’s efforts to develop a theory of automata general enough to apply both to the construction of digital computers and to the operation of the brain. “The brain can be conceived as a network with brain cells in its nodes. These are connected in a way that every individual cell can receive impulses from more than one other cell and can transmit impulses to several cells. Which of these impulses are received from or passed on to other cells may depend on the state of the cell, which in turn depends on the effects of anything that previously affected this particular cell. . . . The actual state of the cells (which I conceive as being numbered) would characterize the state of the brain. There would be a certain distribution corresponding to every spiritual state. . . . This model may resemble an automatic telephone switch-board; there is, however, a change in the connections after every communication.”35 The link between game theory and a theory of neural nets was never brought to fruition by von Neumann, although there are hints that his theory of automata was so inclined.

  A Turing machine assembles a complex computation from a sequence of atomistic steps, whereas, as Ortvay suggested, the brain represents a computational process by a network of intercommunicating components, the chain of events being spatially distributed and not necessarily restricted to one computational step at a time. In 1943, neuropsychiatrist Warren S. McCulloch and mathematician Walter Pitts published their “Logical Calculus of the Ideas Immanent in Nervous Activity,” showing that in principle (and for extremely simplified theoretical neurons) the computational behavior of any neural net can be duplicated exactly by an equivalent Turing machine.36 This paper was widely cited in support of analogies between digital computers and brains. When von Neumann compiled the First Draft of a Report on the EDVAC, a document that launched the breed of stored-program computers that surround us today, he adopted the McCulloch-Pitts symbolism in diagramming the logical structure of the proposed computer and introduced terms such as organ, neuron, and memory, which were more common among biologists than among electrical engineers.

  The EDVAC (Electronic Discrete Variable Automatic Computer) was conceived while the ENIAC was being built. The ability to modify its own instructions gained the EDVAC a distinction as the first full-fledged stored-program computer design. Beset by a series of technical and administrative delays, the original EDVAC did not become operational until late 1951, preceded and outperformed by its own more nimble offspring in both England and the United States. The EDVAC was nonetheless immortalized as the conceptual nucleus around which successive generations of computers formed. The project was initiated by Mauchly, Eckert, Goldstine, Arthur Burks, and others at the Moore School, but it was von Neumann’s involvement that ignited the chain reaction that spread computers around the world. The EDVAC stored both data and instructions in mercury delay-line memory, as binary code. As in Turing’s universal machine, long strings of bits defined not only numbers to be operated on but the sequence and potentially dynamic structure of the operations to be performed. The EDVAC thus embodied Turing’s principle that complexity and adaptability could be more profitably assigned to the coding than
to the machine.

  Von Neumann consulted extensively with the EDVAC group in late 1944 and early 1945 and then, in a virtuoso performance, wrote up a detailed treatment of the engineering principles, logical architecture, and programming language (“order code”) of the proposed computer, submitting the manuscript to the Moore School for review. Herman Goldstine had the incomplete draft (dated 30 June 1945) typed up, with von Neumann listed as sole author, and distributed it widely, with controversial results. On the one hand, the release of the EDVAC report parted the veil of secrecy that had obscured the ENIAC and Colossus projects during the war. The explicit instructions provided in the EDVAC report inspired a flurry of computer building and coding around the world—especially in England, where the Bletchley Park alumni remained handicapped by a prohibition against discussing their own existing work. On the other hand, the attribution of sole authorship to von Neumann embittered Eckert and Mauchly, who left the Moore School to found the Eckert-Mauchly Computer Company, producer of the BINAC and UNIVAC and ultimately acquired by Sperry-Rand. They believed, with some justification, that von Neumann’s report had undermined their interest in future patents by placing the EDVAC design in the public domain. Insult was added to injury by von Neumann’s eagerness to propagate the technology as widely and freely as possible, not only in conjunction with the government and academia, but also in cooperation with Eckert and Mauchly’s competitors, such as RCA and IBM.

  Von Neumann’s computer project at the Institute for Advanced Study, launched at the end of 1945, received the bulk of its support not from industry but from the army, the navy, and the Atomic Energy Commission (AEC). Commercial benefits flowed mainly in reverse, with IBM and other organizations partaking freely of the IAS design and IAS-trained personnel. The Institute shied away from industrial contracts but had no qualms about accepting the support of Army Ordnance, the Office of Naval Research, and the AEC. Of some $772,000 of support for the IAS computer project between its inception in 1946 and June 1950, only $82,000 (excluding von Neumann’s salary) was contributed by the IAS.37

  Lewis Strauss, J. Robert Oppenheimer, and von Neumann all held influential positions at both the Institute and the AEC. Eventually this surfeit of influence presented a problem, because, as Herman Goldstine, administrative director of the computer project, explained, “when the Atomic Energy Commission up [and] decided one day that it was wrong for the Atomic Energy Commission to engage in research on electronic computers, we had nobody we could go to without all this fear of conflict of interest.”38 By the time AEC support of the IAS computer project wavered, the IAS design was being replicated widely and a derivative version (first known as the defense calculator) was being developed commercially by IBM. Originally targeted at defense contractors who were building new weapons systems, IBM renamed it the model 701 when they discovered the extent of the demand. Von Neumann was hired as a consultant, officially working thirty days a year for IBM.

  Von Neumann’s computer bore the paternity of war but, like the jet airplane or the Jeep, it did not remain exclusively a war machine for long. The defense industry employed the brightest minds of the time, individuals who commanded both a clear vision of the future of computers and the resources to bring this future about. “Over the years, the constant and most reliable support of computer science—and of science generally—has been the defense establishment,” concluded Nicholas Metropolis and Gian-Carlo Rota in introducing a symposium on the history of digital computers at Los Alamos in 1976. “While old men in congresses and parliaments would debate the allocation of a few thousand dollars, farsighted generals and admirals would not hesitate to divert substantial sums to help oddballs in Princeton, Cambridge, and Los Alamos.”39 The oddballs turned out to be right.

  The hydrogen bomb is a three-stage device. Thermonuclear fusion is triggered by a nuclear fission explosion, which is triggered by a high-explosive charge. With no room for trial and error, simulations executed by high-speed computers were as essential to successful bomb building as any of the other ingredients consumed—and transformed—along the way. Perhaps because of this close association from birth with bombs, electronic digital computers acquired an aura of explosiveness that lingers to this day. While computers were being used to catalyze this three-stage process, a series of repercussions was being reflected the other way. From one perspective, computers were testing bombs. From another perspective, bombs were testing computers, unleashing equally powerful results.

  For fifty years, the bombs have remained under control. Our worst nightmare has become less of a nightmare as the century draws to a close. Of von Neumann’s two creations, it is the computers that exploded, not the bombs.

  6

  RATS IN A CATHEDRAL

  There is one further order that the control needs to execute. There should be some means by which the computer can signal to the operator when a computation has been concluded, or when the computation has reached a previously determined point. Hence an order is needed which will tell the computer to stop and to flash a light or ring a bell.

  —BURKS, GOLDSTINE, AND VON NEUMANN1

  I was eight years old, in 1961, when I stumbled on some relics of John von Neumann’s electronic computer project left to molder away in an old barn. The barn was itself a relic, predating the establishment of the Institute for Advanced Study amid the Princeton, New Jersey, fields of Olden Farm. Littered with bales of hay, spring-toothed harrows, and other remnants of its working life, the barn now served as auxiliary storage to the Institute’s physical plant and, on weekends, as a way station to a small band of boys who hunted frogs and turtles in the swamps and slow-moving streams that bordered the Institute woods. Ancient instincts drew us toward capturing small animals and dismantling machines. Our eyes adjusted to the darkness as a few rays of sunlight perforating the roof traced downward through the dust raised by the pigeons that fluttered away from us overhead. When we stopped talking, absolute silence reigned.

  The old barn was a refuge to an extended family of ghosts. Something about abandoned machines—the suspension of life without immediate decay—evokes a mix of fear and hope. When the machine stops, we face whatever it is that separates death from life.

  Our fathers were field theorists. At the Institute it was easier to find an expert in celestial mechanics than to find someone who worked on his or her own car. Agricultural implements were as foreign to us as were the mysterious contents of a series of heavy wooden crates piled in the center of the barn, filled with thick wood-and-metal plates of Mediterranean antiquities, the work of one of the Institute’s classical scholars awaiting a second printing that never came. After determining that the plates were the imprints of treasures and not treasures themselves, we scavenged on. Like so many grave robbers before us, we discovered that someone else had gotten to the good stuff first. At one end of the barn was a stockpile of war-surplus electronic equipment that had been selectively cannibalized for vacuum tubes and other vital parts. Partially eviscerated carcasses were distributed like livestock among the abandoned stalls.

  We inspected cautiously; then we grew bold and returned with borrowed crescent wrenches and screwdrivers tucked under our belts. First we dismantled relays, making off with small electromagnets that we hooked up to battery power or doorbell transformers at home. Later we discovered microswitches: micro not in size but in the hair-trigger mechanism that shifted their internal state between off and on. Embedded within a maze of wiring and armored in Bakelite, they became the prized trophies of our hunt. Relays, solenoids, and microswitches were thoroughly intertwined. Relays were wired to solenoids wired to microswitches connected to other relays in turn, or sometimes back to the same relays once again. We blindly dissected the fossilized traces of electromechanical logic out of which the age of digital computers first took form. The primitive hardwired architecture, so accessible to our screwdrivers, remained impenetrable to our minds.

  The square mile of fields and woodland surrounding the Institute for Advanced
Study was cultivated, in lieu of forestry or agriculture, as a sanctuary for ideas. Its founders, in 1930, envisioned their educational utopia as a refuge from the mind-numbing bureaucracy of U.S. universities; they did not imagine the international upheaval from which their enclave would shortly offer an escape. “The Institute was a beacon in the descending darkness,” wrote Director Harry Woolf in 1980, reflecting on the first fifty years, “a gateway to a new life, and for a very few a final place within which to continue to work and transmit to others the style and the techniques of great learning from the other shore.”2

  After the war the Institute became a permanent home to Albert Einstein, Kurt Gödel, John von Neumann, George Kennan, and other scholars equally distinguished if less well known. J. Robert Oppenheimer reigned as director from 1947 to 1966, presiding over what he described as an “intellectual hotel.” He maintained the Institute’s lead in mathematical physics while hosting transient scholars as diverse as child psychologist Jean Piaget and poet T. S. Eliot, a visiting member for the fall term of 1948 who listed The Cocktail Party (1950) as his only “publication related to IAS residence.”3 The Institute woods, bordered by the meandering bends of Stony Brook, offered sanctuary to indigenous wildlife as well, a refuge against the suburban fringe that was metastasizing up and down the eastern seaboard as inexorably as Dutch elm disease, consuming farmland as well as forest and leaving two-car garages in its wake.