The Information (37 page)

♦
Toward the end of his life Gödel wrote, “It was only by Turing’s work that it became completely clear, that my proof is applicable to every formal system containing arithmetic.”

♦
“not considering statistical structure over greater distances than about eight letters.”

It is probably dangerous to use this theory of information in fields for which it was not designed, but I think the danger will not keep people from using it.

—J. C. R. Licklider (1950)
^♦

MOST MATHEMATICAL THEORIES
take shape slowly; Shannon’s information theory sprang forth like Athena, fully formed. Yet the little book of Shannon and Weaver drew scant public attention when it appeared in 1949. The first review came from a mathematician, Joseph L. Doob, who complained that it was more “suggestive” than mathematical—“and it is not always clear that the author’s mathematical intentions are honorable.”
^♦
A biology journal said, “At first glance, it might appear that this is primarily an engineering monograph with little or no application to human problems. Actually, the theory has some rather exciting implications.”
^♦
The Philosophical Review
said it would be a mistake for philosophers to overlook this book: “Shannon develops a concept of
information
which, surprisingly enough, turns out to be an extension of the thermodynamic concept of
entropy
.”
^♦
The strangest review was barely a review at all: five paragraphs in
Physics Today
, September 1950, signed by Norbert Wiener, Massachusetts Institute of Technology.

Wiener began with a faintly patronizing anecdote:

In the present book (Wiener continued), Shannon, along with Warren Weaver, “has summed up his views on communication engineering.”

The fundamental idea developed by Shannon, said Wiener, “is that of the amount of information as negative entropy.” He added that he himself—“the author of the present review”—had developed the same idea at about the same time.

Wiener declared the book to be work “whose origins were independent of my own work, but which has been bound from the beginning to my investigations by cross influences spreading in both directions.” He mentioned “those of us who have tried to pursue this analogy into the study of Maxwell’s demon” and added that much work remained to be done.

Then he suggested that the treatment of language was incomplete without greater emphasis on the human nervous system: “nervous reception and the transmission of language into the brain. I say these things not as a hostile criticism.”

Finally, Wiener concluded with a paragraph devoted to another new book: “my own
Cybernetics
.” Both books, he said, represent opening salvos in a field that promises to grow rapidly.

He saluted his colleagues for their well-worked and independent approach—to cybernetics.

Shannon, meanwhile, had already contributed a short review of Wiener’s book to the
Proceedings of the Institute of Radio Engineers
, offering praise that could be described as faint. It is “an excellent introduction,” he said.
^♦
There was a little tension between these men. It could be felt
weighing down the long footnote that anchored the opening page of Weaver’s portion of
The Mathematical Theory of Communication
:

Shannon’s colleague John Pierce wrote later: “Wiener’s head was full of his own work.… Competent people have told me that Wiener, under the misapprehension that he already knew what Shannon had done, never actually found out.”
^♦

Cybernetics
was a coinage, future buzzword, proposed field of study, would-be philosophical movement entirely conceived by this brilliant and prickly thinker. The word he took from the Greek for
steersman
: κυβερνιτησ,
kubernites
, from which comes also (not coincidentally) the word
governor
.
^♦
He meant cybernetics to be a field that would synthesize the study of communication and control, also the study of human and machine. Norbert Wiener had first become known to the world as a curiosity: a sport, a prodigy, driven and promoted by his father, a professor at Harvard. “A lad who has been proudly termed by his friends the brightest boy in the world,”
The New York Times
reported on page 1 when he was fourteen years old, “will graduate next month from Tufts College.… Aside from the fact that Norbert Wiener’s capacity for learning is phenomenal, he is as other boys.… His intense black eyes are his most striking feature.”
^♦
When he wrote his memoirs, he always used the word
prodigy
in the titles:
Ex-Prodigy: My Childhood and Youth
and
I Am a Mathematician: The Later Life of a Prodigy
.

After Tufts (mathematics), Harvard graduate school (zoology), Cornell (philosophy), and Harvard again, Wiener left for Cambridge, England, where he studied symbolic logic and
Principia Mathematica
with Bertrand Russell himself. Russell was not entirely charmed. “An infant prodigy named Wiener, Ph.D. (Harvard), aged 18, turned up,” he wrote a friend. “The youth has been flattered, and thinks himself God Almighty—there is a perpetual contest between him and me as to which is to do the teaching.”
^♦
For his part, Wiener detested Russell: “He is an iceberg. His mind impresses one as a keen, cold, narrow logical machine, that cuts the universe into neat little packets, that measure, as it were, just three inches each way.”
^♦
On his return to the United States, Wiener joined the faculty of MIT in 1919, the same year as Vannevar Bush. When Shannon got there in 1936, he took one of Wiener’s mathematics courses. When war loomed, Wiener was one of the first to join the hidden, scattered teams of mathematicians working on antiaircraft fire control.

He was short and rotund, with heavy glasses and a Mephistophelian goatee. Where Shannon’s fire-control work drilled down to the signal amid the noise, Wiener stayed with the noise: swarming fluctuations
in the radar receiver, unpredictable deviations in flight paths. The noise behaved statistically, he understood, like Brownian motion, the “extremely lively and wholly haphazard movement” that van Leeuwenhoek had observed through his microscope in the seventeenth century. Wiener had undertaken a thoroughgoing mathematical treatment of Brownian motion in the 1920s. The very discontinuity appealed to him—not just the particle trajectories but the mathematical functions, too, seemed to misbehave. This was, as he wrote, discrete chaos, a term that would not be well understood for several generations. On the fire-control project, where Shannon made a modest contribution to the Bell Labs team, Wiener and his colleague Julian Bigelow produced a legendary 120-page monograph, classified and known to the several dozen people allowed to see it as the Yellow Peril because of the color of its binder and the difficulty of its treatment. The formal title was
Extrapolation, Interpolation, and Smoothing of Stationary Time Series
. In it Wiener developed a statistical method for predicting the future from noisy, uncertain, and corrupted data about the past. It was too ambitious for the existing gun machinery, but he tested it on Vannevar Bush’s Differential Analyzer. Both the antiaircraft gun, with its operator, and the target airplane, with its pilot, were hybrids of machine and human. One had to predict the behavior of the other.

Wiener was as worldly as Shannon was reticent. He was well traveled and polyglot, ambitious and socially aware; he took science personally and passionately. His expression of the second law of thermodynamics, for example, was a cry of the heart:

He was concerned for his place in intellectual history, and he aimed high. Cybernetics, he wrote in his memoirs, amounted to “a new interpretation of man, of man’s knowledge of the universe, and of society.”
^♦
Where Shannon saw himself as a mathematician and an engineer, Wiener considered himself foremost a philosopher, and from his fire-control work he drew philosophical lessons about purpose and behavior. If one defines behavior cleverly—“any change of an entity with respect to its surroundings”
^♦
—then the word can apply to machines as well as animals. Behavior directed toward a goal is purposeful, and the purpose can sometimes be imputed to the machine rather than a human operator: for example, in the case of a target-seeking mechanism. “The term servomechanisms has been coined precisely to designate machines with an intrinsic purposeful behavior.” The key was control, or self-regulation.

To analyze it properly he borrowed an obscure term from electrical engineering: “feed-back,” the return of energy from a circuit’s output back to its input. When feedback is positive, as when the sound from loudspeakers is re-amplified through a microphone, it grows wildly out of control. But when feedback is negative—as in the original mechanical governor of steam engines, first analyzed by James Clerk Maxwell—it can guide a system toward equilibrium; it serves as an agent of stability. Feedback can be mechanical: the faster Maxwell’s governor spins, the wider its arms extend, and the wider its arms extend, the slower it must spin. Or it can be electrical. Either way, the key to the process is information. What governs the antiaircraft gun, for example, is information about the plane’s coordinates and about the previous position of the gun itself. Wiener’s friend Bigelow emphasized this: “that it was not some particular physical thing such as energy or length or voltage, but only information (conveyed by any means).”
^♦

Negative feedback must be ubiquitous, Wiener felt. He could see it at work in the coordination of eye and hand, guiding the nervous system of a person performing an action as ordinary as picking up a pencil. He focused especially on neurological disorders, maladies that disrupted physical coordination or language. He saw them quite specifically as
cases of information feedback gone awry: varieties of ataxia, for example, where sense messages are either interrupted in the spinal cord or misinterpreted in the cerebellum. His analysis was detailed and mathematical, with equations—almost unheard of in neurology. Meanwhile, feedback control systems were creeping into factory assembly lines, because a mechanical system, too, can modify its own behavior. Feedback is the governor, the steersman.

So
Cybernetics
became the title of Wiener’s first book, published in the fall of 1948 in both the United States and France. Subtitle:
Control and Communication in the Animal and the Machine
. The book is a hodgepodge of notions and analysis, and, to the astonishment of its publishers, it became the year’s unexpected bestseller. The popular American news magazines,
Time
and
Newsweek
, both featured it. Wiener and cybernetics were identified with a phenomenon that was bursting into public consciousness just at that moment: computing machines. With the end of the war, a veil had been lifted from the first urgent projects in electronic calculation, particularly the ENIAC, a thirty-ton monster of vacuum tubes, relays, and hand-soldered wires stretching across eighty feet at the University of Pennsylvania’s electrical engineering school. It could store and multiply up to twenty numbers of ten decimal digits; the army used it to calculate artillery firing tables. The International Business Machines company, IBM, which provided punched card machines for the army projects, also built a giant calculating machine at Harvard, the Mark I. In Britain, still secret, the code breakers at Bletchley Park had gone on to build a vacuum-tube computing machine called the Colossus. Alan Turing was beginning work on another, at the University of Manchester. When the public learned about these machines, they were naturally thought of as “brains.” Everyone asked the same question: Can machines think?