deodands

Acknowledgements

Twenty years ago, I saw pictures of spots and stripes in the Turing Archive. I have always wanted to know what the pictures were of, both narrowly (which equations, which parameter values?), and more broadly: which questions were being asked and why? I still don't know the answers, though we can begin to make some guesses. The archive is too fragmentary for much more to be possible, but I hope that making my own notes available will help others to have a go. I don't think that it's very likely that any answer will be very useful scientifically: in fact I disapprove of Turing's approach to biology. (Though the record does tend to suggest I am wrong there.)

Many people deserve thanks for their help with this project. Andrew Hodges started it all for me when he gave a talk in King's, and much more recently has been both helpful and encouraging. Michael Halls, then the Modern Archivist at King's, invited me to see the original Turing material: an experience I have never forgotten. I was doubly amazed first to find myself back near King's and secondly to find that I could contribute to understanding the pictures I saw then. His successors as Archivist, Jacqueline Cox and Ros Moad, have been efficient, friendly, and helpful. Christof Teuscher invited me to a meeting in Lausanne which made much of this material take shape. Rebecca Hoyle has been encouraging, and explained some useful material about lattices, and Nick Hoskin shared his insight. Jon Agar, at the Manchester National Archive for the History of Computing, helpfully provided photocopies. PN Furbank promptly and courteously gave permission to quote from Turing's unpublished work. I'm grateful to Lesley Robertson and DJ Mabberley for help with copyright issues.