Darwin Among the Machines (28 page)

Coaching the U.S. team was a nonprofit organization known as RAND. Incorporated in 1948 “to further and promote scientific, educational, and charitable purposes, all for the public welfare and security of the United States of America,”
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RAND (Research And Development) was the successor to U.S. Air Force Project RAND, established by a contract of 2 March 1946 specifying that “the Contractor will perform a program of study and research on the broad subject of intercontinental warfare, other than surface, with the object of recommending to the Army Air Forces preferred techniques and instrumentalities for this purpose.”
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Headquartered in Santa Monica, California, RAND was constituted as a refuge for the free-thinking academic approach to military problems that had thrived during the war but risked being extinguished by the peace.

Although operating on principles similar to those of the Institute for Advanced Study, RAND went about the business of creative thinking in reverse. The Institute, established for the pursuit of pure research, quietly facilitated military work. RAND was openly targeted at military objectives, while quietly facilitating pure science and advancing scientific careers. Cross-fertilization between pure and applied mathematics flourished at RAND as nowhere else. In 1955, RAND published
A Million Random Digits with 100,000 Normal Deviates
, whose introduction notes that “because of the very nature of the tables, it did not seem necessary to proofread every page of the final manuscript in order to catch random errors.”
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In the 1950s there was a serious shortage of random numbers, and RAND's random numbers were widely distributed and used for solving problems in many fields. RAND researchers were responsible for writing and defending their own reports. The resulting publications, aimed at air force generals, not academic colleagues, were distinguished by a clarity, economy, and self-contained documentation rarely seen in academic work.

RAND's first published study was the 324-page
Preliminary Design of an Experimental Earth-Circling Spaceship
, issued on 2 May 1946. The report advised the government that “the achievement of a satellite craft by the United States would inflame the imagination of mankind, and would probably produce repercussions in the world comparable to the explosion of the atomic bomb. . . . Whose imagination is not fired by the possibility of voyaging out beyond the limits of
our earth, traveling to the Moon, to Venus and Mars?”
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When the Soviets launched the first
Sputnik
, on 4 October 1957, the American public was taken by surprise, but it was no surprise to RAND, whose analysts had predicted the appearance of a Soviet satellite on 17 September 1957, the centenary of the birth of Konstantin Tsiolkovsky, the great Russian rocket pioneer. In November 1957, after
Sputnik II
had circled the earth with a payload of 1,120 pounds (including the dog Laika), there was no longer any doubt that the Soviets were thinking about launching not only dogs, but bombs as well. U.S. spending on the Atlas ICBM program jumped from $3 million in 1953 to $161 million in 1955 and $1,300 million in 1957. RAND studies led the way. “By 1953 RAND's knowledge of the missile and weapon fields indicated that nuclear warheads could be carried by rockets, and could produce a wide enough zone of destruction to more than compensate for their aiming errors,” reported a RAND history in 1963.
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With weapons multiplying on both sides, RAND sought to identify stable nuclear strategies, hosting a renaissance of mathematical game theory beginning where von Neumann and Morgenstern had left off. The titles of some published reports convey the general drift:
The noisy duel, one bullet each, arbitrary nonmonotone accuracy
(D. H. Blackwell, March 1949);
A generalization of the silent duel, two opponents, one bullet each, arbitrary accuracy
(M. A. Girshick, August 1949);
A loud duel with equal accuracy where each duelist has only a probability of possessing a bullet
(M. A. Girshick and D. H. Blackwell, August 1949);
The silent duel, one bullet versus two, equal accuracy
(L. S. Shapley, September 1950);
Noisy duel, one bullet each, with simultaneous fire and unequal worths
(I. L. Glicksberg, October 1950).

The Distant Early Warning (DEW Line) system constructed in 1953 offered a two- or three-hour warning of Soviet bomber attack. By the time the Ballistic Missile Early Warning system came on-line in 1960, the United States was reduced to fifteen or thirty minutes' warning of an incoming missile attack. Nuclear stability depended on mutual deterrence, either by threatening to launch missiles at the first sign of enemy attack or by preserving the ability to retaliate after a strike. Launch-on-warning, serviceable as a bluff, would be suicidal in practice, since sooner or later an erroneous warning would arise. So the best way to prevent a nuclear nightmare appeared to be to construct a retaliatory system designed to survive attack. To hide, disperse, or harden missiles was comparatively easy; the difficulty was how to construct a robust system of control.

“Throughout history successful generals make their plans based upon enemy capabilities and not intent,” recalled Paul Baran, an
electrical engineer who arrived at RAND at age thirty-three in 1959. “This period was the height of the cold war. Both the U.S. and USSR were building hair-trigger nuclear ballistic missile systems. The early missile-control systems were not physically robust. Thus, there was a dangerous temptation for either party to misunderstand the actions of the other and fire first. . . . If we could wait until after attack rather than having to respond too quickly under pressure then the world would be a more stable place.” Although use of the word
surrender
was forbidden by act of Congress, RAND officials recognized that “a survivable communications network is needed to stop, as well as to help avoid, a war.”
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A 1960 RAND study, Cost
of a Hardened, Nationwide Buried Cable Network
, estimated the cost of providing two hundred facilities with communication links hardened against 100-psi blast pressure at $2.4 billion, with protection to 1,000 psi available for about $1 billion additional cost.
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Baran was assigned the job of analyzing whether it was possible to do as well or better for less. Retaliatory ability could be met by an extremely low bandwidth channel, or “minimal essential communications”—official terminology for the president's (or his successor's) ability to issue the order “Fire your missiles” or “Stop.”

Baran began with Frank Collbohm's suggestion that by installing a minimal amount of digital logic throughout the existing nationwide network of AM radio stations, a decentralized and highly redundant communication channel could be engaged in the event of an attack. The strategy was to flood the network with a given message. No routing was required other than a procedure that ceased transmission of a specific message once copies of it started bouncing back. Analysis showed that even with widespread destruction of network nodes, with metropolitan broadcast facilities disappearing first, the overlapping nature of the system would allow messages to diffuse rapidly throughout the surviving stations on the net (an unstated conclusion being that American country music could survive even a worst-case Soviet attack). Baran took this proposal to the armed forces, which held out for more bandwidth, believing that real-time voice communication was required to fight a war. “Okay, back to the drawing board,” said Baran, “but this time I'm going to give them so much damn communication capacity they won't know what in hell to do with it all.”
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And he did.

Baran's first job had been with the Eckert-Mauchly Computer Company in 1949. The weaknesses of vacuum-tube-delay-line computers at that time suggested a tenuous future for such unwieldy and temperamental machines. In ten years everything had changed.
Witnessing this revolution encouraged Baran to question other assumptions as well. The creative approach to digital computing that had flourished in the early 1950s at the Institute for Advanced Study continued to flourish in the early 1960s at RAND. Baran's thesis advisor at UCLA was Gerald Estrin, who had been instrumental in disseminating the computer project at the IAS. JOHNNIAC, the RAND version of the IAS machine, incorporated several improvements, including a working Selectron memory, and was completed under the direction of Willis Ware, also an alumnus of the IAS. RAND had steadily acquired the latest machines from IBM. Working under the auspices of the computer department, not the communications department, Baran's analysis of communication problems was able to develop unencumbered by preconceived ideas. “Computers and communications,” he remarked, “were at that time two totally different fields.”
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Baran invented a new species of communications network, starting with clear-cut objectives and little else. “An
ideal
electrical communications system can be defined as one that permits any person or machine to reliably and instantaneously communicate with any combination of other people or machines, anywhere, anytime, and at zero cost,” he wrote. “It should effectively allow the illusion that those in communication with one another are all within the same soundproofed room—and that the door is locked.”
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He threw out all existing assumptions. “In most communication applications, silence is the
usual
message,” he later explained.
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By digitizing all communications and multiplexing across the entire network rather than over one channel at a time, Baran knew he could reduce most of the waste. Taking a cue from the store-and-forward torn-tape telegraph networks, he proposed relaying digital messages from node to node across the net, but with high-speed computers instead of telegraph equipment providing switching and storage at the nodes. He examined existing military communications switches and asked: “Why are these things so big? Why do these switching systems require rooms and rooms of stuff?” He concluded that there was far too much recording and storage of messages at the switching nodes, for no apparent reason other than a tradition “to be able to prove that lost traffic was someone else's fault.”
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Computers were already operating at multimegacycle rates, and Baran knew that the telecommunications infrastructure would eventually be forced to catch up. He proposed a system operating at up to 1.5 million bits per second over low-power, line-of-sight microwave links—ample bandwidth for real-time transmission of digitally encrypted voice. This
proposal secured the undivided enthusiasm of the military commanders, if guaranteeing stiff resistance from the managers of AT&T, which handled all military voice communications within the United States. They were not about to admit that their system was physically vulnerable, inefficient, or insecure.

In May 1960, RAND released the first official memorandum that provided an outline of Baran's design. “If war does not mean the end of the earth in a black and white manner, then it follows that we should do those things that make the shade of grey as light as possible,” wrote Baran in his introduction to
Reliable Digital Communications Systems Utilizing Unreliable Network Repeater Nodes
. “We are just beginning to design and lay out designs for the
digital
data transmission systems of the future . . . systems where computers speak to each other. . . . As there does not seem to be any fundamental technical problem that prohibits the operation of digital communication links at the clock rate of digital computers, the view is taken that it is only a matter of time before such design requirements become hardware . . . where the intelligence required to switch signals to surviving links is at the link nodes and
not
at one or a few centralized switching centers.”
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Baran then suggested how to evaluate the robustness of his design: “To better visualize the operation of the network, a hypothetical application is postulated: a congressional communications system where each congressman may vote from his home office. The success of such a network may be evaluated by examining the number of congressmen surviving an attack and comparing such number to the number of congressmen able to communicate with one another and vote via the communications network. Such an example is, of course, farfetched but not completely without utility.”
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The more alternative connection paths there are between the nodes of a communications net, the more resistant it is to damage from within or without. But there is a combinatorial explosion working the other way: the more you increase the connectivity, the more intelligence and memory is required to route messages efficiently through the net. In a conventional circuit-switched communications network, such as the telephone system, a central switching authority establishes an unbroken connection for every communication, mediating possible conflicts with other connections being made at the same time. “Such a central control node offers a single, very attractive target in the thermonuclear era,” warned Baran.
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The stroke of genius at the heart of Baran's proposal was to distribute the requisite intelligence and redundancy not only among the individual switching nodes, but also among the messages themselves.

Baran credited the ancestry of this approach to Theseus, a mechanical mouse constructed by information theorist Claude Shannon in 1950. Guided by the intelligence of seventy-two electromagnetic relays, Theseus was able to find its way around a 5 × 5 maze, in Warren McCulloch's words, “like a man who knows the town, so he can go from any place to any other place, but doesn't always remember how he went.”
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To adapt to changes in the layout of the maze and the location of the goal, Theseus had to be able not only to remember but to forget. Baran saw that the problem of routing a mouse through a maze was equivalent to the problem of routing messages through a communications net. “In a very short period of time—within the past decade, the research effort devoted to these ends has developed from analyses of how a mechanical mouse might find his way out of a maze, to suggestions of the design of an all-electronic world-wide communications system,” he wrote in 1964.
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