The Information (38 page)

“They are growing with fearful speed,” declared
Time
in its year-end issue. “They started by solving mathematical equations with flash-of-lightning rapidity. Now they are beginning to act like genuine mechanical brains.”
^♦
Wiener encouraged the speculation, if not the wild imagery:

Much of the success of his book, abstruse and ungainly as it was, lay in Wiener’s always returning his focus to the human, not the machine. He was not as interested in shedding light on the rise of computing—to which, in any case, his connections were peripheral—as in how computing might shed light on humanity. He cared profoundly, it turned out, about understanding mental disorders; about mechanical prostheses; and about the social dislocations that might follow the rise of smart machinery. He worried that it would devalue the human brain as factory machinery had devalued the human hand.

He developed the human-machine parallels in a chapter titled “Computing Machines and the Nervous System.” First he laid out a distinction between two types of computing machines: analog and digital, though he did not yet use those words. The first type, like the Bush Differential Analyzer, represented numbers as measurements on a continuous scale; they were analogy machines. The other kind, which he called numerical machines, represented numbers directly and exactly, as desk calculators did. Ideally, these devices would use the binary number system for simplicity. For advanced calculations they would need to employ a form of logic. What form? Shannon had answered that question in his master’s thesis of 1937, and Wiener offered the same answer:

The brain, too, he argued, is at least partly a logical machine. Where computers employ relays—mechanical, or electromechanical, or purely electrical—the brain has neurons. These cells tend to be in one of two states at any given moment: active (firing) or at rest (in repose). So they may be considered relays with two states. They are connected to one another in vast arrays, at points of contact known as synapses. They transmit messages. To store the messages, brains have memory; computing machines, too, need physical storage that can be called memory. (He knew well that this was a simplified picture of a complex system, that other sorts of messages, more analog than digital, seemed to be carried chemically by hormones.) Wiener suggested, too, that functional disorders such as “nervous breakdowns” might have cousins in electronics. Designers of computing machines might need to plan for untimely floods of data—perhaps the equivalent of “traffic problems and overloading in the nervous system.”
^♦

Brains and electronic computers both use quantities of energy in performing their work of logic—“all of which is wasted and dissipated in heat,” to be carried away by the blood or by ventilating and cooling apparatus. But this is really beside the point, Wiener said. “Information is information, not matter or energy. No materialism which does not admit this can survive at the present day.”

Now came a time of excitement.

“We are again in one of those prodigious periods of scientific progress—in its own way like the pre-Socratic period,” declared the gnomic, white-bearded neurophysiologist Warren McCulloch to a meeting of British philosophers. He told them that listening to Wiener and von Neumann put him in mind of the debates of the ancients. A new physics of communication had been born, he said, and metaphysics would never be the same: “For the first time in the history of science we know how we know and hence are able to state it clearly.”
^♦
He offered them heresy: that the knower was a computing machine, the brain composed of relays,
perhaps ten billion of them, each receiving signals from other relays and sending them onward. The signals are quantized: they either happen or do not happen. So once again the stuff of the world, he said, turns out to be the atoms of Democritus—“indivisibles—leasts—which go batting about in the void.”

That these ideas were spilling across disciplinary borders was due in large part to McCulloch, a dynamo of eclecticism and cross-fertilization. Soon after the war he began organizing a series of conferences at the Beekman Hotel on Park Avenue in New York City, with money from the Josiah Macy Jr. Foundation, endowed in the nineteenth century by heirs of Nantucket whalers. A host of sciences were coming of age all at once—so-called social sciences, like anthropology and psychology, looking for new mathematical footing; medical offshoots with hybrid names, like neurophysiology; not-quite-sciences like psychoanalysis—and McCulloch invited experts in all these fields, as well as mathematics and electrical engineering. He instituted a Noah’s Ark rule, inviting two of each species so that speakers would always have someone present who could see through their jargon.
^♦
Among the core group were the already famous anthropologist Margaret Mead and her then-husband Gregory Bateson, the psychologists Lawrence K. Frank and Heinrich Klüver, and that formidable, sometimes rivalrous pair of mathematicians, Wiener and von Neumann.

Mead, recording the proceedings in a shorthand no one else could read, said she broke a tooth in the excitement of the first meeting and did not realize it till afterward. Wiener told them that all these sciences, the social sciences especially, were fundamentally the study of communication,
and that their unifying idea was the
message
.
^♦
The meetings began with the unwieldy name of Conferences for Circular Causal and Feedback Mechanisms in Biological and Social Systems and then, in deference to Wiener, whose new fame they enjoyed, changed that to Conference on Cybernetics. Throughout the conferences, it became habitual to use the new, awkward, and slightly suspect term
information theory
. Some of the disciplines were more comfortable than others. It was far from clear where information belonged in their respective worldviews.

The meeting in 1950, on March 22 and 23, began self-consciously. “The subject and the group have provoked a tremendous amount of external interest,” said Ralph Gerard, a neuroscientist from the University of Chicago’s medical school, “almost to the extent of a national fad. They have prompted extensive articles in such well known scientific magazines as
Time, News-Week
, and
Life
.”
^♦
He was referring, among others, to
Time
’s cover story earlier that winter titled “The Thinking Machine” and featuring Wiener:

It was true, Gerard said, that his field was being profoundly affected by new ways of thought from communications engineering—helping them think of a nerve impulse not just as a “physical-chemical event” but as a sign or a signal. So it was helpful to take lessons from “calculating machines and communications systems,” but it was dangerous, too.

Wiener felt he had to respond. “I have not been able to prevent these reports,” he said, “but I have tried to make the publications exercise restraint. I still do not believe that the use of the word ‘thinking’ in them is entirely to be reprehended.”
^♦
♦
♦

Gerard’s main purpose was to talk about whether the brain, with its mysterious architecture of neurons, branching dendrite trees, and complex interconnections alive within a chemical soup, could properly be described as analog or digital.
^♦
Gregory Bateson instantly interrupted: he still found this distinction confusing. It was a basic question. Gerard owed his own understanding to “the expert tutelage that I have received here, primarily from John von Neumann”—who was sitting right there—but Gerard took a stab at it anyway. Analog is a slide rule, where number is represented as distance; digital is an abacus, where you either count a bead or you do not; there’s nothing in between. A rheostat—light dimmer—is analog; a wall switch that snaps on or off, digital. Brain waves and neural chemistry, said Gerard, are analog.

Discussion ensued. Von Neumann had plenty to say. He had lately been developing a “game theory,” which he viewed effectively as a mathematics of incomplete information. And he was taking the lead in designing an architecture for the new electronic computers. He wanted the more analog-minded of the group to think more abstractly—to recognize that digital processes take place in a messy, continuous world but are digital nonetheless. When a neuron snaps between two possible states—“the state of the nerve cell with no message in it and the state of the cell with a message in it”
^♦
—the chemistry of this transition may
have intermediate shadings, but for theoretical purposes the shadings may be ignored. In the brain, he suggested, just as in a computer made of vacuum tubes, “these discrete actions are in reality simulated on the background of continuous processes.” McCulloch had just put this neatly in a new paper called “Of Digital Computers Called Brains”: “In this world it seems best to handle even apparent continuities as some numbers of some little steps.”
^♦
Remaining quiet in the audience was the new man in the group, Claude Shannon.

The next speaker was J. C. R. Licklider, an expert on speech and sound from the new Psycho-Acoustic Laboratory at Harvard, known to everyone as Lick. He was another young scientist with his feet in two different worlds—part psychologist and part electrical engineer. Later that year he moved to MIT, where he established a new psychology department within the department of electrical engineering. He was working on an idea for quantizing speech—taking speech waves and reducing them to the smallest quantities that could be reproduced by a “flip-flop circuit,” a homemade gadget made from twenty-five dollars of vacuum tubes, resistors, and capacitors.
^♦
It was surprising—even to people used to the crackling and hissing of telephones—how far speech could be reduced and still remain intelligible. Shannon listened closely, not just because he knew about the relevant telephone engineering but because he had dealt with the issues in his secret war work on audio scrambling. Wiener perked up, too, in part because of a special interest in prosthetic hearing aids.

When Licklider described some distortion as neither linear nor logarithmic but “halfway between,” Wiener interrupted.

“What does ‘halfway’ mean?
X
plus
S
over
N
?”

Licklider sighed. “Mathematicians are always doing that, taking me up on inexact statements.”
^♦
But he had no problem with the math and later offered an estimate for how much information—using Shannon’s new terminology—could be sent down a transmission line, given a certain bandwidth (5,000 cycles) and a certain signal-to-noise ratio (33 decibels), numbers that were realistic for commercial radio. “I think it
appears that 100,000 bits of information can be transmitted through such a communication channel”—bits per second, he meant. That was a staggering number; by comparison, he calculated the rate of ordinary human speech this way: 10 phonemes per second, chosen from a vocabulary of 64 phonemes (2
⁶
, “to make it easy”—the logarithm of the number of choices is 6), so a rate of 60 bits per second. “This assumes that the phonemes are all equally probable—”

“Yes!” interrupted Wiener.
^♦

“—and of course they are not.”

Wiener wondered whether anyone had tried a similar calculation for “compression for the eye,” for television. How much “real information” is necessary for intelligibility? Though he added, by the way: “I often wonder why people try to look at television.”

Margaret Mead had a different issue to raise. She did not want the group to forget that meaning can exist quite apart from phonemes and dictionary definitions. “If you talk about another kind of information,” she said, “if you are trying to communicate the fact that somebody is angry, what order of distortion might be introduced to take the anger out of a message that otherwise will carry exactly the same words?”
^♦