Beschreibung:

TURING, Alan Mathison (1912-1954) 'The chemical basis of morphogenesis.' Offprint from: Philosophical Transactions of the Royal Society of London, ser. B, Biological Sciences, no. 641, vol. 237. London: 1952. Alan Turing and the secret of life – Claude Shannon’s copy of the extremely rare offprint of Turing's last major published work; a remarkable association copy linking two of the greatest pioneers of the digital age. At a time when Crick and Watson were using x-ray diffraction to establish the structure of DNA, Turing was grappling with a theoretical understanding of how information might be spread and diffused at a chemical level. In a classic statement of the scientific method Turing wrote: '"a mathematical model of the growing embryo will be described. This model will be a simplification and an idealisation, and consequently a falsification. It is to be hoped that the features retained for discussion are those of greatest importance in the present state of knowledge". The result was applied mathematics par excellence. Just as the simple idea of the Turing machine had sent him into fields beyond the boundaries of Cambridge mathematics, so now this simple idea in physical chemistry took him into a region of new mathematical problems' (Hodges p.434). This offprint is differentiated from the journal issue by the ommission of the price of 8 shillings printed from the front wrapper and its repetition in the signature line of the first leaf. Claude Shannon (1916-2001) is considered the founder of information theory for his landmark paper A mathematical theory of communication (1948), and for his thesis, A symbolic analysis of relay and switching circuits (1936), which established the theory of digital circuit design on the basis of Boolean algebra. Shannon and Turing met in 1943, when Turing was posted to Washington DC to share his cryptanalytic methods with the Americans. Post war, Shannon considered the problem of finding the smallest possible universal Turing machine, and demonstrated that a universal Turing machine can be constructed with a single tape and only two internal states, provided that enough tape symbols are used; and, conversely, that two tape symbols are sufficient provided there are enough internal states. Quarto (300 x 230mm), 36pp. comprising pp.37-72. Original printed buff wrappers (faint stain to upper wrapper just transferring onto blank area of first text leaf, light central horizontal creasefold from where the offprint has sometime been folded). Provenance: [Claude Shannon (1916-2001; acquired from his library by the present owner].