Life's Greatest Secret by Matthew Cobb Read Free Book Online Page B

constructing in Princeton.
    Seven months later, in October 1946, the New York Academy of Sciences held a special meeting on ‘Teleological mechanisms’ at which Wiener spoke, outlining the ideas in the Yellow Peril that had been withheld from public view the year before. 25 Wiener explained that underlying all examples of negative feedback control there was a single unifying idea, which he called the message – all control systems involved communication, and could be understood using the same conceptual framework. Inspired by Schrödinger’s
What is Life?,
Wiener made a link between information and entropy, going even further than Szilárd’s discussion of Maxwell’s Demon, in that he defined entropy as ‘the negative of the amount of information contained in the message’. This was ‘not surprising’, Wiener went on, because ‘Information measures order and entropy measures disorder. It is indeed possible to conceive all order in terms of message.’ The laws governing communication, he argued, were ‘really identical’ with the second law of thermodynamics. So, for example, once a message has been created, subsequent operations can degrade it but cannot add information. The arrow of entropy points only one way, and all that life can do is to temporarily halt the process; it cannot truly reverse it. One of the main explanatory frameworks used by postwar science – the role of information in biology – was emerging and was now connected with the fundamental measure of order on a cosmic scale.
    A month later, von Neumann took a step towards linking the study of control systems with visions of how life reproduces itself. He was increasingly convinced that Wiener’s focus on modelling human behaviour was a mistake: the human brain was far too complex. At the end of November 1946, von Neumann wrote a long letter to Wiener outlining a startlingly different approach, which dominated science for decades to come. 26 He began with a self-criticism, pointing out that through their shared enthusiasm for studying the human central nervous system, ‘we selected … the most complicated object under the sun – literally.’ But the problem was even greater than the mere complexity of the brain, argued von Neumann. He felt they had first to understand the underlying molecular mechanisms before they could hope to understand higher level activity:
    nothing that we may know or learn about the functioning of the organism can give, without ‘microscopic’, cytological work any clues regarding the further details of the neural mechanism.
    Von Neumann’s solution was radical. He concluded that they should focus on what he termed
    the less-than-cellular organisms of the virus or bacteriophage type … They are self-reproductive and they are able to orient themselves in an unorganized milieu, to move towards food, to appropriate it and to use it. Consequently, a ‘true’ understanding of these organisms may be the first relevant step forward and possible the greatest step that may at all be required.
    Von Neumann’s grasp of virus biology was flimsy – he told Wiener that a virus was ‘definitely an animal, with something like a head and a tail’ (in fact viruses are not even alive by most definitions). Despite being a poor biologist, von Neumann’s suggestion that simple systems can reveal principles that apply to more complex forms of organisation was absolutely right. He calculated that each virus consisted of around 6,000,000 atoms, and ‘only … a few hundred thousand “mechanical elements”.’ Von Neumann explained to Wiener that it should be possible to understand the interaction of these components, although he recognised that even this proposal was challenging:
    Even if the complexity of the organisms of molecular weight 10
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    is not too much for us, do we not possess such means now, can we at least conceive them, and could they be acquired by developments of which we can already foresee the