Life's Greatest Secret (13 page)

The word

in this theory, is used in a special sense that must not be confused with its ordinary usage. In particular,

must not be confused with meaning.

Unlike Wiener’s vision, Shannon’s approach had no place for feedback – this was a linear transmission system with no connection between the reception of the message and the source. It was not a model that could explain the flow of control in a behavioural or mechanical system; it did no more than what it claimed – it explained how a single message can pass from a transmitter to a receiver despite the presence of noise in a system. For Shannon, the critical process was encoding and decoding: ‘the function of the transmitter is to
encode,
and that of the receiver to
decode,
the message’.
¹⁷

Shannon showed that information could be conceptualised mathematically, as a measure of freedom of choice between all possible messages. The simplest such choice occurs when there are two options, as in a binary system. ‘This unit of information,’ wrote Shannon, ‘is called a “bit,” this word, first suggested by John W. Tukey, being a condensation of “binary digit.”’ Shannon’s formal mathematical description of information was essentially identical to that of Wiener, except that the two mathematicians approached the question from different sides: whereas Wiener saw information as negative entropy, for Shannon information was the same as entropy.
¹⁸

The two men were well aware of this difference; in October 1948 Shannon wrote to Wiener:

I consider how much information is produced when a choice is made from a set – the larger the set the more information. You consider the larger uncertainty in the case of a larger set to mean less knowledge and hence less information. The difference in viewpoint is partially a mathematical pun. We would obtain the same numerical answers in any particular question.

The explanation for these apparently opposite approaches, and the source of what Shannon called a pun was that whereas he was strictly focused on the relatively narrow issue of communication, Wiener wanted to create a grander, broader theory, which integrated communication, control, organisation and the nature of life itself. Wiener’s model therefore had to include meaning, something that Shannon opposed. This contrast between the two formulations was therefore far more than a mathematical pun – it reflected differences in the two men’s ambitions.

*

Wiener and Shannon’s ideas had an important influence on the scientific community. Information came to be seen as a characteristic of matter that could be quantified, preferably in terms of binary coding, while control and negative feedback seemed to be fundamental features of organic and engineered systems. One of the ways in which these ideas came to influence biologists was through the promise of creating automata and thereby testing models of how organisms function and reproduce.
²⁰
These links were explored at a symposium on Cerebral Mechanisms in Behavior that was held at the California Institute of Technology (Caltech) a month before the publication of
Cybernetics,
at the end of September 1948. The symposium was a small affair – only fourteen speakers, with a further five participants, one of whom was the Caltech chemist Linus Pauling.

1. Claude Shannon’s model of communication. From Shannon and Weaver (1949).

Von Neumann gave the opening talk, entitled ‘General and logical theory of automata’, and explored one of the defining features of life: its ability to reproduce. Von Neumann’s starting point was Alan Turing’s prewar theory of a universal machine that carried out its operations by reading and writing on a paper tape. But this was too simple for von Neumann: he wanted to imagine ‘an automaton whose output is other automata’.

Von Neumann argued that such a machine needed instructions to construct its component parts, and that these instructions would be ‘roughly effecting the functions of a gene’; a change in the instruction would be like a mutation. Von Neumann explained that a real gene ‘probably does not contain a complete description of the object whose construction its presence stimulates. It probably contains only general pointers, general cues.’ In contrast, the ‘fundamental act of reproduction, the duplication of genetic material’ could be conceptualised in terms of the copying of a paper tape – von Neumann was implicitly arguing that a gene was like one of Turing’s instruction-containing tapes.
²¹
Although von Neumann did not make the link, this was a computer version of Schrödinger’s aperiodic crystal that contained a code-script.

Scientists who were not at the meeting were also becoming interested in the links between cybernetics and genetics. Wiener was in contact with the British geneticist J. B. S. Haldane, who had been following Wiener’s work with close attention. In mid-November 1948, Haldane wrote to Wiener as he struggled to apply the new concepts to his field:

I am gradually learning to think in terms of messages and noise. … I suspect that a large amount of an animal or plant is redundant because it has to take some trouble to get accurately reproduced, and there is a lot of noise around. A mutation seems to be a bit of noise which gets incorporated into a message. If I could see heredity in terms of message and noise I could get somewhere.

Similar ideas were being developed by the University of Illinois physicist Sydney Dancoff, together with his colleague, the Austrian-born radiologist Henry Quastler. In July 1950, Dancoff wrote a letter to Quastler summarising the two men’s thinking on the links between genetics and information. The chromosome, wrote Dancoff, could be seen as a ‘linear coded tape of instructions.’ He went on:

The entire thread constitutes a ‘message’. This message can be broken down into sub-units which may be called ‘paragraphs,’ ‘words,’ etc. The smallest message unit is perhaps some flip-flop which can make a yes-no decision. If the result of this yes-no decision is evident in the grown organism, we can call this smallest message unit a ‘gene’.

Dancoff and Quastler were forcing genetics into a binary mode, viewing organisms as an example of the automata imagined by Turing and von Neumann.

In Europe, too, the scientific community discussed the new ideas about information and control, with each country taking a slightly different approach to the question. In September 1950, the Royal Society of London organised a three-day conference on ‘information theory’ – this was not a term used by Shannon or Wiener, although it has since become widespread. Around 130 attendees crowded into the small lecture theatre in Burlington House on Piccadilly to discuss the mathematical and electronic aspects of the field. Shannon gave three talks at the meeting, but there was little exploration of Wiener’s cybernetic approach. There were no geneticists to be seen. The only person to speak about genes was Alan Turing, and he was more interested in how natural selection alters the shape of organisms than in thinking about how heredity works.
²⁴

The degree to which information had inserted itself into scientific thinking and ordinary language was revealed at the end of 1950, when the British zoologist J. Z. Young gave the prestigious Reith Lectures on the BBC, under the title ‘Doubt and certainty in science’. The first three radio lectures were about how biologists study brain function, and they teemed with the word ‘information’.
²⁵
Listeners were presented with this new vision as though it were the only way of understanding how nervous systems work. What it really showed was that the way that biologists thought about life had been transformed.*

In France the Nobel Prize-winning physicist Louis de Broglie gave a lecture series in spring 1950 under the general title ‘Cybernetics’, and in 1951 a congress was held in Paris, funded by the Rockefeller Foundation, that was attended by over 300 people including Wiener and McCulloch. After the congress was over, Wiener remained in Paris to give several talks on the subject at the prestigious Collège de France. There were also articles in French journals such as
Esprit
and the
Nouvelle Revue Française
while, for the general public, science journalist Pierre de Latil wrote a lively book called
La Pensée Artificielle,
which explained the nature and genesis of cybernetics, full of useful diagrams and photos, but focusing on feedback and showing how French engineers had come up with the concept in the fifteenth and nineteenth centuries.
²⁶
De Latil’s book embodied the contrast between the French and British approaches to cybernetics: whereas the British focused on information, the French emphasised the control and robotics aspects of the subject. Strikingly, de Latil’s book did not refer to Shannon at all. In the UK and the US ‘information’ was widely discussed in popular science magazines such as
The Times Science Review
and
Scientific American,
both as an abstract concept and in Shannon’s mathematised version.
²⁷

Whatever the contrasts between different subject areas and different countries, in Britain, America and France, everyone in science knew that a conceptual revolution was taking place. Not everyone was impressed, however. In 1948 Max Delbrück was invited to one of the cybernetics conferences. It was the only such meeting he attended. Not a man to mince his words, Delbrück later recalled that he found the discussion ‘too diffuse for my taste. It was vacuous in the extreme and positively inane.’
²⁸

*

In 1950, public interest in cybernetics was cranked up even further when Wiener published a second book – this time without a single equation – in which he outlined the potential changes that society would have to face as a result of increased automation. With the unwieldy title
On the Human Use of Human Beings,
Wiener’s new book explained how society should respond to the looming cultural and economic developments that would follow the introduction of automation and the development of computers in the second half of the twentieth century. It spanned a wide range of culture in a free-wheeling style, dealing with language, law and individuality, exploring their changing meaning in the context of machines that could apparently embody aspects of purposeful behaviour. Wiener was concerned that top-down social control was becoming typical of all economic and political systems across the planet. As he explained: ‘I wish to devote this book to a protest against this inhuman use of human beings.’
²⁹
Professor Cyril Joad, the BBC’s favourite philosopher, hated the book. His review in the
Times Literary Supplement
was scathing, criticising Wiener’s ‘incoherent and slovenly language’ and branding the book as ‘highly dangerous’.
³⁰

Despite Joad’s fears, Wiener’s remarkable book had a lasting influence because it showed that everything – including humans – could ultimately be reduced to mere patterns of information. Wiener again emphasised the links between the latest technological developments and the way in which organisms behave and function: ‘It is my thesis that the operation of the living individual and the operation of some of the newer communication machines are precisely parallel.’
³¹
If humans were essentially machines in both form and function, then it should be possible to define a human being in terms of the information they contained, by calculating ‘the amount of hereditary information,’ he claimed. If that information could be represented in some way, then it would even be possible to transmit it by electronic means, preserving the identity of the individual, argued Wiener.
³²
Although he realised that such a procedure would remain in the realms of science fiction for the foreseeable future, Wiener had made his point: a human being was fundamentally no different from any other form of organised matter. In the end, it was information.

Wiener was not the only person to be thinking along these lines. In July 1949, Shannon sketched a list of different items and their ‘storage capacities’. He considered that a ‘phono record’ contained about 300,000 bits of information, one hour of broadcast TV contained 10
¹¹
bits, and the ‘genetic constitution of man’ was a mere 80,000 bits.
³³
Nothing became of these wildly inaccurate guesstimates – the sketch remained in the Shannon archives until it was recently discovered by James Gleick – but they show how the concept of information could be applied to virtually anything. In May 1952, J. B. S. Haldane wrote a letter to Wiener in which he announced that he had ‘worked out the total amount of control (= information = instruction) in a fertilized egg’.
³⁴
It is not known what number Haldane came up with, nor on what basis he made his calculation – he never published his answer to this conundrum.

Henry Quastler was bolder. In March 1952 he organised a symposium on Information Theory in Biology, which was held in his Control Systems Laboratory at the University of Illinois. The rising star of bacterial genetics, Joshua Lederberg, had been invited to attend, but he was wary because the meeting was funded by the US Office of Naval Research. Lederberg was concerned that the discussions were to be recorded and might involve matters that could be the subject of a future security classification.
³⁵
Lederberg was not being paranoid – the McCarthyite witch-hunts were getting into their stride, leading to US academics having to swear ‘loyalty oaths’ or risk losing their jobs; one ill-judged comment could lead to disaster.