Page 440: In November 2011, an unexpected witness added a remarkable story to my picture of AT's life in 1951. This was the writer Alan Garner, who wrote a column 'My Hero: Alan Turing', in the
Alan Garner kindly expanded to me on his recollections, and I have included the following passage in the Preface to the 2014 editions of the book:
He had been Alan Turing's training partner; they had run perhaps a thousand miles together through Cheshire country lanes in 1951-52. Garner was seventeen in 1951, and a sixth-former at Manchester Grammar School, studying classics. The meeting arose in that year, as fellow athletes spotting each other on the road. From the start, Garner felt himself treated as an equal, something he could appreciate and cope with because of this school's distinctive ambience (a culture that yet another Alan has evoked in The History Boys). He was also just about to become a serious competitive young sprinter. Their disparate long- and short-distance strengths were compatible with an equal pace over a run of several miles. Equality also was found in banter full of word play and scurrilous humour. It came as no surprise to Garner when Turing asked him if he thought intelligent machinery was possible. After running silently for ten minutes, along Mottram Road, Alderley Edge, he said no. Turing did not argue. 'Why learn classical languages?' Turing asked, and Garner said, 'You have to learn to use your brain in a different way': the kind of answer that Turing would have appreciated.
Their chat kept away from the personal: it was focused on sustaining the six or seven miles of running. But once, probably late in 1951, Turing mentioned the story of Snow White. 'You too!' said Garner, amazed. For he connected immediately with a singular event from his childhood. It was his first cinema outing when five years old. Snow White and the Seven Dwarfs had terrified him with the image of the poisoned apple. Turing responded with immediate empathy. 'He
used to go over the scene in detail, dwelling on the ambiguity of the apple, red on one side, green on the other, one of which gave death.' Their shared trauma - as Garner saw it - remained a bond.
The training extended into 1952 and overlapped with the period of Turing's trial. Turing never spoke of what he was undergoing and somehow Garner only heard the news late in 1952, when he was warned by the police not to associate with Turing. Garner was very angry at this, and at what he learnt had happened, and he never had the least sense of having been approached in any predatory way.
And yet, inevitably, it ended sadly. Alan Garner painfully recalls seeing Turing for the last time in 1953, as a fellow passenger on the bus from Wilmslow to Manchester. Being with his girlfriend, Garner found it too difficult to say anything appropriate and so he pretended not to have noticed his presence. This incident, so redolent of the fiction and film of final teenage years, was soon followed by Garner's departure to National Service, during which he heard of Turing's death. Alan Garner revealed nothing of this for sixty years.
Alan Turing would naturally have delighted to see a lad from a very ordinary Cheshire village background showing such curiosity and intellectual ambition. But it is as though he also saw something extra in Garner, sensing a writer of the future who would combine modernity and mythology. The story of the apple is like a glimpse of the Jungian analysis he went in for after 1952, of which we know virtually nothing. It is also striking to know that when Turing saw Snow White at its Cambridge release in 1938 (p. 189) a five-year-old boy was reacting in parallel, and one day would share it.
Alan Garner is now best known for his youth fiction, particularly The Owl Service (1967).
Page 452: The tune AMT played to Arnold was Cockles and Mussels, the same as to the detectives (page 463). (The Irish tune was employed by the Pet Shop Boys in their work A Man from the Future in 2014.)
Page 453: I was struck by AMT's reference to quantum mechanics in his 1951 radio talk, but confined my comment to the way it harked back to his reading of 20 years before. Now, stimulated by Roger Penrose, I would give more attention to what AMT was saying about the connection between computability and physics in this one sentence.
AMT was actually questioning whether a quantum-mechanical system could be modelled by a universal Turing machine, i.e. whether it might fail to be computable. In fact, I think this sentence gives an important if tantalising link between his logical work and the late interest in the wave-function reduction process. which he developed in 1953-4 (see chapter 8). It is the reduction process, not the evolution of the wave function according to Schrödinger's equation, which introduces an unpredictable element. This sentence also gives a link between Turing's thought and the arguments Roger Penrose published from 1988 onwards, (see The Emperor's New Mind) although this is not to say that Turing would have thought there must be an uncomputable element in quantum mechanics. More likely he was trying to make quantum mechanics into a computable theory by finding a new account of the reduction process. I wrote a short piece for the last volume of the Turing Collected Works which includes these remarks as an aspect of Turing's relationship with physics; this is available on this site. I would also now comment that his reference to the 'Mathematical Objection' was in this talk less conclusive than his Mind article had been a year earlier. However Turing drew no connection between these two problematic areas, as Roger Penrose has done.
B. J. Copeland's 1999 preface to this 1951 talk (see the bibliography) also draws attention to this sentence of Turing's but interprets 'unpredictable' in the context of his claim (not based on anything in Turing's writing) about randomness having a connection with 'oracle-machines.' Copeland does not draw the connection with Turing's developing interest in fundamental physics.
There is further material in the Alan Turing Internet Scrapbook:
Machines and Men's Minds and
Growth, Form and Crisis