Read Life's Greatest Secret for Free Online Page A

apple will fall to the ground because its final cause is to go downwards. From the seventeenth century onwards, it was increasingly realised that this approach did not explain anything, and more powerful mechanistic explanations were sought. Wiener wanted to reinstate the idea of purpose by explaining it in mathematical terms.
    Wiener and Rosenblueth showed that purposeful, goal-directed behaviour can be seen in organisms and machines, and that it operates through what is known as negative feedback. Normal feedback leads to the uncontrolled amplification of the signal – this is the howl that is produced if a microphone is placed too close to a loudspeaker. Negative feedback means that a given activity ceases when a particular pre-defined state is achieved. In this way a signal can drive a machine or an organism to an end; if the goal is not attained, then continued signals will direct the behaviour towards the goal. For example, a torpedo that homes in on acoustic signals emitted by a battleship uses negative feedback to guide itself to its target – it stops altering its direction when the signal is strongest, as that indicates that the target is dead ahead. 8
    After the war, Warren Weaver finally got round to reading the Wiener, Rosenblueth and Bigelow paper. He was not impressed: ‘I want to read this article but so far I have not succeeded in getting beyond the first four paragraphs’, he told Wiener. 9 If Weaver had ploughed on, he might have found the rest of the document more rewarding, for it marked a shift in scientific thinking. It put all systems on the same level, be they mechanical, organic or hybrid human–machine (as in the case of the anti-aircraft guns), and suggested that behaviour could be interpreted using the same principles and analysed in terms of the same negative feedback loops. When the paper was read to the small New York audience, the effect was electric. Neurophysiologist Warren McCulloch was particularly excited, as it coincided with the models of brain function that he was developing with Walter Pitts, an odd but brilliant 20-year-old maths prodigy. 10 Even the anthropologist Margaret Mead was rapt: ‘I did not notice that I had broken one of my teeth until the Conference was over’, she later wrote. 11
    Although Wiener’s insight excited his academic colleagues, his attempt to build an anti-aircraft device that could be engineered into a battlefield version was upstaged by a rival top-secret project, which was jointly run by MIT and a private company, Bell Laboratories. Under the deliberately misleading title the Radiation Lab (known as the Rad Lab), the project involved more than thirty scientists and in its first year alone had a budget of more than $800,000. Although it used a highly unrealistic prediction method – it assumed that the aircraft would fly in a straight line – the device made up for its lack of accuracy by firing a hail of shells around the predicted location, some of which would get lucky. In 1942 the Rad Lab project passed a practical test and more than 1,200 units were ordered by the US military. Although Wiener and Bigelow’s statistical predictor was marginally more accurate than their Rad Lab rival, it soon became apparent that the improvement over the Rad Lab version would not be worth the effort and Wiener’s project was cancelled in November 1943. 12 The Rad Lab system, now called the M-9, incorporated some elements of Wiener’s predictive protocols and went into mass production. It eventually formed a central component of what was the first robot war – the clash between the German V-1 automatic rockets or doodlebugs and the Allies’ semi-automated defence systems, in the skies over southern England in 1944–45. 13
    Wiener wrote up his method for predicting the movement of objects and filtering out noise under the daunting title ‘Extrapolation, interpolation, and smoothing of stationary time series with engineering applications’. This duplicated