1 00:00:10,590 --> 00:00:16,200 Good evening. Welcome, everybody, to the showdown in theatre on a beautiful autumn evening in Oxford. 2 00:00:16,800 --> 00:00:17,730 My name's Mike Wooldridge. 3 00:00:17,740 --> 00:00:24,120 I'm the head of Department of Computer Science and it's my pleasure this evening to host our Michaelmas term Straight to Lecture, 4 00:00:24,120 --> 00:00:31,410 which is our distinguished lecture series. Before I do that, though, I should point out the Straight G lectures are a celebration. 5 00:00:31,680 --> 00:00:36,930 They're a celebration of science, sometimes obscure science, sometimes somewhat more accessible science. 6 00:00:36,930 --> 00:00:39,810 But we have another reason for celebration today. 7 00:00:40,320 --> 00:00:45,930 Some of you may have seen in the press last week that we were delighted to be able to welcome back to 8 00:00:45,930 --> 00:00:50,709 Oxford as a member of the Department of Computer Science and as a fellow at Christchurch College, 9 00:00:50,710 --> 00:00:54,960 Sir Tim Berners-Lee, and as you will all know, is the inventor of the World Wide Web. 10 00:00:55,380 --> 00:00:59,880 Tim is actually with us in the audience tonight with his with his wife, Rosemary and Tim. 11 00:00:59,880 --> 00:01:19,690 Rosemary. You are most welcome back to Oxford. So on to this evening's business lecture this evening is Andrew Hotchkiss. 12 00:01:20,380 --> 00:01:24,980 And I asked Andrew to give me some short biographical details, and this is what he actually told me to tell you. 13 00:01:25,450 --> 00:01:31,690 He's a senior research fellow in the Mathematical Institute. He's been a long time fellow and tutor in mathematics at Wadham College. 14 00:01:32,470 --> 00:01:38,110 His research was in mathematical physics, I think twist a theory under the supervision of Roger Penrose, 15 00:01:38,110 --> 00:01:46,450 with whom he has a close relationship to the present day. He was given an honorary doctor of Science at the University of Edinburgh in June last year, 16 00:01:46,630 --> 00:01:53,470 and he also tells me he appeared on stage with the Pet Shop Boys in the Albert Hall in July 2014. 17 00:01:54,190 --> 00:02:03,280 In all other respects, a distinguished but in some sense unremarkable career for an Oxford Don, 18 00:02:03,280 --> 00:02:06,730 the kind of career that you would expect an Oxford Don to have. 19 00:02:07,630 --> 00:02:14,140 But the reason that Andrew's here tonight is that in the late 1970s and early 1980s, he did something truly remarkable. 20 00:02:15,040 --> 00:02:18,040 He wrote a book and this is it. 21 00:02:18,050 --> 00:02:21,340 This is my copy of it. I've treasured this book for 30 years, 22 00:02:21,340 --> 00:02:28,090 and I've just Andrew's I've just shown it to Andrew and he's told me this was a particularly poor edition of the book and very bad value for money. 23 00:02:29,350 --> 00:02:32,379 But nevertheless, I did Treasury. I actually wrote rather quaintly. 24 00:02:32,380 --> 00:02:36,100 I wrote the date inside May 1985. I bought this copy of the book. 25 00:02:36,460 --> 00:02:42,910 The binding is not lasted as well as the words inside it, and the book is the story of Alan Turing. 26 00:02:43,420 --> 00:02:50,440 And what's important to remember is that before this book appeared, Turing's name was completely unknown outside computer science. 27 00:02:50,830 --> 00:02:58,780 And the remarkable things that he did in his life were completely unknown outside the field of computer science and and mathematics. 28 00:02:59,440 --> 00:03:03,370 I read a review of this book and was moved to order it from my bookshop. 29 00:03:03,370 --> 00:03:07,629 The town of Hereford, where I grew up, didn't stop this kind of book in the mid 1980s, 30 00:03:07,630 --> 00:03:11,500 so I had to order it and it made a tremendous and lasting impression on me. 31 00:03:11,500 --> 00:03:14,740 And indeed it's one of those books, as I say, that I've treasured throughout my life. 32 00:03:15,220 --> 00:03:20,800 So why did it make such a lasting impression on me? Well, firstly, it is a fantastic book. 33 00:03:21,460 --> 00:03:25,510 It is ranked as one of the greatest scientific biographies of all time. 34 00:03:25,900 --> 00:03:30,970 I'm assuming you're all you've all Reddit's. If you haven't read it, you should do so. 35 00:03:30,980 --> 00:03:35,320 It is your duty to do so. You will have the opportunity, in fact, to get copies of it. 36 00:03:35,320 --> 00:03:38,800 And Andrew has indicated he'd be happy to sign copies afterwards. 37 00:03:39,250 --> 00:03:44,409 But it is a great scientific biography and rarely do scientific biographies get 38 00:03:44,410 --> 00:03:48,880 under the skin of the science and the thinking that led to scientific innovation. 39 00:03:48,920 --> 00:03:52,390 So that's the first reason that it's remarkable. 40 00:03:54,020 --> 00:04:01,280 The second reason it's remarkable is, as I say, that it gave the world the Turing story for the first time before this book. 41 00:04:01,280 --> 00:04:07,879 There was no Turing story. And when I read the story, I'd never heard of Turing's life. 42 00:04:07,880 --> 00:04:13,730 And I was shocked and appalled at what happened to Turing in the later stage of his life. 43 00:04:14,300 --> 00:04:21,200 And I was always brought up to think that this country was on the right side of history, that basically we were decent people who did the right thing. 44 00:04:21,380 --> 00:04:26,660 And I was astonished to discover the kinds of things that happened in the 1950s in this country. 45 00:04:26,660 --> 00:04:27,920 And it opened my eyes. 46 00:04:28,160 --> 00:04:35,420 It gave me a burning sense of injustice and unfairness and a sense of injustice and unfairness that stayed stayed with me ever since. 47 00:04:36,590 --> 00:04:41,840 So the arc of human history tends towards justice, we are told. 48 00:04:42,140 --> 00:04:49,970 Well, if it does so, then from time to time, it needs some very big signposts along the way to point it in the right direction. 49 00:04:50,390 --> 00:04:54,950 The Turing story, I think, is exactly such a signpost. 50 00:04:55,250 --> 00:05:00,110 We read just the other week of in the press of the Alan Turing Law, 51 00:05:00,110 --> 00:05:08,689 thousands of gay men to be pardoned if they were prosecuted for crimes that are now no longer regarded as crimes, 52 00:05:08,690 --> 00:05:11,420 whatever one might think of that, whether it's a token gesture and so on, 53 00:05:11,630 --> 00:05:16,760 at least it suggests that our thinking as society is heading in the right direction. 54 00:05:17,600 --> 00:05:26,480 I don't believe I believe sorry that the Turing story is actually an important part of that of that trajectory. 55 00:05:26,750 --> 00:05:31,460 It was Andrew that gave us that story. We wouldn't have it in the form that we have it today. 56 00:05:31,490 --> 00:05:34,590 And Andrew, it's really all due to the work that you did in that book. 57 00:05:34,610 --> 00:05:38,180 So I'm very, very pleased to welcome you to give this evening straight to your lecture. 58 00:05:38,240 --> 00:05:52,650 Thank you. Well, thank you very much for that. 59 00:05:52,660 --> 00:05:56,559 I'm not sure I can follow that very easily. And I think you've done a spoiler. 60 00:05:56,560 --> 00:06:02,320 I think you've given away the ending of I will be talking a little bit at the end of that, 61 00:06:02,320 --> 00:06:05,770 more than I usually do about the events at the end of Alan Turing's life, 62 00:06:05,770 --> 00:06:12,100 because I think there is a a need for that, especially when it's been in the news so much in the recent period. 63 00:06:12,310 --> 00:06:19,080 But I'm going to try and give an overview of his whole scientific life before I get to that. 64 00:06:19,510 --> 00:06:26,559 And also, I should remember, while welcoming you that I'm being watched by people who see this as a podcast. 65 00:06:26,560 --> 00:06:30,879 And the podcast people may not know that we're in the wonderful setting of the Sheldon 66 00:06:30,880 --> 00:06:35,560 Ian Theatre and that this goes back to the scientific revolution of the 1660s. 67 00:06:35,890 --> 00:06:40,570 And I would like you to see Alan Turing, who lived from 1912 to 1954, 68 00:06:40,930 --> 00:06:49,810 as as as in that great stream of life, drawing on the past and reaching into our own present and future. 69 00:06:50,440 --> 00:06:56,640 Turing didn't have a strong personal connection with us here in Oxford, but he did have a link with Christopher Straight G, 70 00:06:56,890 --> 00:07:02,680 who became the founding figure of computer science here and whose name is remembered, of course, in this lecture series. 71 00:07:03,010 --> 00:07:09,010 Some people here may also have known Robin Ghandi, Major Oxford figure in mathematical logic. 72 00:07:09,310 --> 00:07:17,350 He was Turing's close friend and first student. And there are many more threads in this great intellectual web linking past and present. 73 00:07:17,800 --> 00:07:23,050 Some of these are brought out in a recent book, not my book, but another book called The Once and Future. 74 00:07:23,050 --> 00:07:28,660 Turing with contributions from leading people in a whole number of fields that Turing touch. 75 00:07:28,960 --> 00:07:32,800 One of these, Professor Scott Aaronson, was a Christopher Straight G. 76 00:07:32,800 --> 00:07:36,910 Lecturer last year, and I'm very honoured that this talk is the successor to his. 77 00:07:37,300 --> 00:07:41,980 It's my pleasure that other contributors Sir Roger Penrose and Dr. Tom Willey, 78 00:07:41,980 --> 00:07:49,720 representing the mathematical biology group Paradox, are also here, along with such fantastically distinguished guests as Michael, 79 00:07:49,990 --> 00:07:53,920 as has mentioned now of all these many threads, of course, 80 00:07:53,920 --> 00:08:00,880 the central one is the emergence of digital technology and the dominating role of the electronic computer. 81 00:08:01,240 --> 00:08:08,890 And of course, even just the podcasting of this talk, all the projection onto this screen, something we now take for granted depends on it. 82 00:08:09,220 --> 00:08:14,379 And all this leads me to choose the starting point for the story, which is not the obvious one, 83 00:08:14,380 --> 00:08:19,000 not the beginning, the usually begin and not the end, although it's extremely interesting. 84 00:08:19,570 --> 00:08:29,010 But it points in the middle 1951 because that's when Christopher Straight, she met Turing at the early Manchester computer laboratory. 85 00:08:29,680 --> 00:08:33,309 1951 was the end of the post-war period. 86 00:08:33,310 --> 00:08:39,820 It was the Festival of Britain. It was the start up for modernism and the flashing lights of those first computers 87 00:08:40,420 --> 00:08:46,030 and a very old fashioned class bound Britain was was an inspiring aspect of it, 88 00:08:46,270 --> 00:08:51,160 I think. Christopher Street, you saw this very clearly and while a maths master at Harrow School, 89 00:08:51,400 --> 00:08:56,710 he wrote this hearing about many ideas, including developing high A-level languages. 90 00:08:57,040 --> 00:09:03,160 And you won't be able to read his typescript, but there are two words in there programme and utopian, 91 00:09:03,430 --> 00:09:07,600 and his idea was a programme to write programmes at a lower level. 92 00:09:08,260 --> 00:09:15,190 Then a utopian idea, but something which advanced people like him was seeing was possible and indeed of course came about. 93 00:09:15,760 --> 00:09:21,400 After further contact straight, she arrived in Manchester with an advanced programme to try out on their computer. 94 00:09:21,610 --> 00:09:29,650 To everyone's amazement, it worked perfectly at the first attempt, never been seen before, and then gave a rendition of God Save the King. 95 00:09:30,520 --> 00:09:37,150 That was the first that was the start of serious operating systems, but also of computer based media. 96 00:09:37,810 --> 00:09:43,570 The Manchester computer played Jingle Bells to the Nation on the radio at Christmas 1951. 97 00:09:43,570 --> 00:09:49,960 And you may have seen recently that an audio recording of the Manchester Computer's tune playing has been recovered. 98 00:09:50,590 --> 00:09:57,190 Street is a love letter programs which had generated syntactically correct random sentences, 99 00:09:57,340 --> 00:10:03,040 also got into the media and served to give a quite new public picture of what computers could be all about. 100 00:10:04,810 --> 00:10:09,639 Right. As Michael mentioned, there would be a day markings, Christopher Street centenary next month. 101 00:10:09,640 --> 00:10:16,420 So I don't need to say more about him, but I will just say that his draughts playing programs complemented the chess playing that Turing 102 00:10:16,420 --> 00:10:22,389 had already started and gave a first stab at machine intelligence all of these exercises. 103 00:10:22,390 --> 00:10:28,780 So this is what I want to emphasise illustrated Turing's concept of the computer as a universal machine. 104 00:10:29,110 --> 00:10:37,270 That was something that was by no means familiar in 1951, and it pushed out the boundaries of what could be expected of computers. 105 00:10:37,810 --> 00:10:40,900 Now, Turing situation at Manchester. I mean, why was he there? 106 00:10:40,900 --> 00:10:48,100 What was he doing? Well, it came about because of having had that idea of a universal machine back in 1936. 107 00:10:48,490 --> 00:10:56,500 In fact, the Manchester. A computer as working in 1948 had been the world's first practical embodiment of his idea. 108 00:10:56,920 --> 00:11:04,450 So what we're doing now is we're going back to the pre-war pre-computer world and see how the computer came into being. 109 00:11:04,810 --> 00:11:16,480 Taking Alan Turing story along with it. So back to 1936, Alan Turing at Cambridge and specifically a fellow of King's College, Cambridge. 110 00:11:16,840 --> 00:11:20,020 He was not a university lecturer and he was just 24. 111 00:11:20,560 --> 00:11:24,610 Now, he would have been seen as a pure mathematician in Cambridge in the thirties, 112 00:11:24,940 --> 00:11:30,790 but in fact he was in no way restricted by such Cambridge compartments as a student. 113 00:11:30,790 --> 00:11:37,390 In 1932, for instance, he was reading John von Neumann's New Mathematical Foundations of Quantum Mechanics. 114 00:11:38,350 --> 00:11:40,820 More precisely, of course, he was reading the original German. 115 00:11:41,350 --> 00:11:47,410 And you should remember that until Hitler took over and wrecked everything, Germany was still the scientific world centre. 116 00:11:47,740 --> 00:11:54,710 Turing's early work largely derived from that German speaking mathematical world, and he was hiking in Germany several times as well. 117 00:11:55,000 --> 00:12:03,910 And the greatest thing was his following up of Kurt Gödel in the revolutionary work of 1931, which showed up the incompleteness of axiomatic systems. 118 00:12:04,180 --> 00:12:11,110 He did this after attending the 1935 Cambridge Lectures on Mathematical Logic by Max Newman. 119 00:12:11,620 --> 00:12:22,210 Turing's now very famous work Defining Computer Ability was essentially complete in 1936, and this is the title page of it here, 120 00:12:22,870 --> 00:12:27,490 a title which would have been completely incomprehensible to almost everyone in the world, 121 00:12:27,700 --> 00:12:36,490 not helped by having a very long German word in the middle of it. This is not how to make a career, really, but this is what he did. 122 00:12:36,730 --> 00:12:47,080 And doing this problem, the decision problem of Hilbert is the German word and its curiosity that the very word application comes in the title. 123 00:12:47,470 --> 00:12:51,400 I mean, is that curiosity? Because an application now means a computer program. 124 00:12:51,400 --> 00:12:56,740 It's the word people use. And this paper actually effectively defined such programs. 125 00:12:56,920 --> 00:12:59,260 They are what came to be called Turing Machines. 126 00:12:59,630 --> 00:13:06,820 A universal machine can play any program, and so corresponds to a modern computer of the kind which then didn't exist. 127 00:13:07,390 --> 00:13:17,950 So I'll just point to some words in that like application on another page, the word the universal computing machine comes into the picture. 128 00:13:17,950 --> 00:13:26,530 And these interesting words, it is possible to invent a single machine which can be used, I mean, to do to do any application. 129 00:13:27,130 --> 00:13:33,190 And universal machines are now carried in your hand and passed at a click from one application to another. 130 00:13:33,850 --> 00:13:40,450 But we should note that actually the app, the application theory was talking about in this work was not an app. 131 00:13:40,840 --> 00:13:46,090 If the whole point was, it's not a program. His proof showed that there could not be no program. 132 00:13:46,090 --> 00:13:53,530 That was so the decision problem that Hilbert had defined a problem which in effect requires the understanding of all of mathematics. 133 00:13:53,800 --> 00:13:58,150 And this is one reason why this deep paper is not just about techniques of computing, 134 00:13:58,390 --> 00:14:02,860 but has a much greater significance, the absolute limitations of the computable. 135 00:14:03,550 --> 00:14:12,459 On another page, a mathematical joke, very typical of Turing is talking about, well, you might imagine doing mathematics. 136 00:14:12,460 --> 00:14:18,850 And at a certain point you arrive at theorem number 157767733, four, four, three, four, seven, seven. 137 00:14:19,900 --> 00:14:28,660 That is a mathematical joke, if you like. But actually, of course, thinking in those terms gets him into the mental framework of a programmer. 138 00:14:28,780 --> 00:14:36,969 You programmer of the computer has to allow for that that such things have to be you have to think of the computer, 139 00:14:36,970 --> 00:14:41,200 how the computer will read the data and and this and do so systematic way. 140 00:14:41,530 --> 00:14:46,750 So he invented in this paper the whole mentality of computer programming. 141 00:14:47,050 --> 00:14:52,450 And of course, it's not didn't come out of nowhere. It came out of the rigour of mathematical foundations. 142 00:14:52,990 --> 00:15:01,180 On another page, you see it was not just the mind of the programmer he was thinking, but we see these words state of mind to come out. 143 00:15:01,240 --> 00:15:08,320 There's an analysis here of the action of the human mind and what it is that a person is doing when they're computing. 144 00:15:08,710 --> 00:15:16,190 This meant going outside mathematics. I mean, he's way outside the box is not what maths people were really supposed to be doing. 145 00:15:16,780 --> 00:15:20,710 And there's a question here, where did it come from? What were the origins of this? 146 00:15:21,070 --> 00:15:26,230 Well, here it's we're in the dark ages. I mean, it's like the once and future King Arthur. 147 00:15:26,500 --> 00:15:32,260 There's very, very little written evidence. There are no precursor papers and no notes. 148 00:15:32,710 --> 00:15:37,420 We do just know of his earlier fascination with a question of mind and matter, 149 00:15:37,750 --> 00:15:45,730 which had taken him first to John von Neumann quantum mechanics in 1932, and then into the foundations of mathematics. 150 00:15:46,300 --> 00:15:49,390 A few more things about that that that history. That's a. 151 00:15:49,440 --> 00:15:53,970 Biologist Max Newman's lectures of 1935, one of the key stimulus. 152 00:15:54,270 --> 00:15:58,440 But there's been new work on the remarkable background to Max Newman's own interests, 153 00:15:58,440 --> 00:16:02,700 showing how exceptional it was not at all the Cambridge mainstream. 154 00:16:03,240 --> 00:16:12,390 There's also new work which gives it shows Turing serious interest in a different but related problem that of characterising random real numbers. 155 00:16:13,020 --> 00:16:20,610 He had a friend, David Champion, who was in the same matter at King's, who published one an undergraduate in 1933. 156 00:16:20,880 --> 00:16:27,600 The observation that a certain rather curious real number has some provably random characteristics in base ten. 157 00:16:28,230 --> 00:16:32,340 Turing took this up and is now seen to have gone a long way with generalising it, 158 00:16:32,400 --> 00:16:36,900 although he never published anything, it was in that same 1936 period. 159 00:16:37,140 --> 00:16:44,910 So there's another ingredient which might explain Turing's very individual formulation of Hilbert's problem in terms of computing numbers. 160 00:16:45,210 --> 00:16:47,010 Well, I'm not really explaining that. 161 00:16:47,220 --> 00:16:56,070 What I want to say is that there was a very wide range of inputs, the Turing story wide in mathematics and in sciences and in philosophy. 162 00:16:56,340 --> 00:17:03,450 But he was not to do with the actual calculation of numerical problems in this very abstract context. 163 00:17:03,480 --> 00:17:07,440 The universal machine arises like a by-product is on the side. 164 00:17:07,830 --> 00:17:15,510 And yet he certainly appreciated and discussed with his friend David Champion on this very striking property of his invention, 165 00:17:15,810 --> 00:17:18,180 a single machine that could do anything. 166 00:17:18,540 --> 00:17:28,019 He was very right to look very please in this in the in the passport photo, which unfortunately I've got missed out but said never mind. 167 00:17:28,020 --> 00:17:34,080 Well, we'll come to a nicer one with him here for showing him at Princeton, which was what the passport was for. 168 00:17:34,380 --> 00:17:43,710 He went off to Princeton, which since 1933 was the New World Scientific Centre, in effect, and arrived there and in 1936. 169 00:17:44,520 --> 00:17:54,900 So that's we have a snapshot of Alan Turing course in a seminar at Princeton is not a selfie, but it looks a bit like that. 170 00:17:55,230 --> 00:18:01,920 And notably, he's a little bit at the edge of the picture, which is I think is about the correct place. 171 00:18:01,920 --> 00:18:06,350 He was not he didn't put it in self forward as a central person. 172 00:18:06,360 --> 00:18:09,750 He was someone who was always a little bit on the edge of the group. 173 00:18:10,050 --> 00:18:17,190 He's also looking remarkably smart, actually. I mean, the graduate students don't wear ties nowadays and nor that he usually so I'm 174 00:18:17,190 --> 00:18:22,259 not quite sure why he was looking quite as as brushed up what he was doing. 175 00:18:22,260 --> 00:18:29,130 There was a Ph.D. on Ordinal Logics, supervised by the American logician Alonzo Church. 176 00:18:29,430 --> 00:18:35,160 And that's I mean, a source of a huge amount of post-war thinking about the nature of the computable. 177 00:18:35,610 --> 00:18:44,200 It's nothing to do with practical computing, but on the side, he certainly was interested in implementing computing. 178 00:18:44,220 --> 00:18:54,390 You couldn't have built a universal Turing machine with 1936 technology, but you he applied his interest in implementation to smaller projects. 179 00:18:54,810 --> 00:19:00,300 Very unusual, again, for someone who's supposed to be a pure mathematician, got his hands dirty with it. 180 00:19:00,780 --> 00:19:09,930 And this in particular, he had a machine for computing the Riemann Zeta function on the critical line using various areas, 181 00:19:10,380 --> 00:19:13,290 and that was pursued further in 1939. 182 00:19:13,590 --> 00:19:21,870 And the point of this document here is it shows the interesting figure of £40, which you got from the Royal Society for this. 183 00:19:21,870 --> 00:19:25,380 I think that's the only really successful grant application he made. 184 00:19:25,680 --> 00:19:33,780 I don't think he was a model for research proposals, but not a role model for modern students or postdocs. 185 00:19:34,140 --> 00:19:41,280 But anyway, he managed and another machine he got no support for at all was absolutely his own thing. 186 00:19:41,580 --> 00:19:44,639 And this was the cipher machine. The cipher machine. 187 00:19:44,640 --> 00:19:49,800 We don't know quite what it was, but it was electromechanical. And that raises another very interesting question. 188 00:19:50,100 --> 00:19:53,850 How did he get into the world of codes and ciphers? 189 00:19:54,300 --> 00:20:02,280 Well, his idea in 1937 there at Princeton was an idea which would have to do with beating Germany if war came. 190 00:20:02,580 --> 00:20:09,420 So he said also, he said it arose as a by-product of thinking about abstract compatibility. 191 00:20:09,750 --> 00:20:18,440 In fact, he said that even back in 1936, right away now this scheme was put to the British governments in the summer of 1938. 192 00:20:18,450 --> 00:20:25,050 So this was the beginning of a very big story. He was pushing as an open door for two reasons. 193 00:20:25,620 --> 00:20:30,599 The first is that JCS, as it then was, and I'll call it HQ, 194 00:20:30,600 --> 00:20:35,790 because that's the same thing now, was actively recruiting mathematicians for the first time. 195 00:20:36,330 --> 00:20:46,080 And secondly, what you might call the liberal elite was at work for him a seamless interface between King's College and government. 196 00:20:46,710 --> 00:20:55,980 John Maynard Keynes. The Economist. You can't get. Liberal elite than that was in charge at a very powerful figure at King's College. 197 00:20:55,980 --> 00:21:03,560 And he was very familiar with hearing and with a department that had broken the codes in the First World War when actually Christopher Street, 198 00:21:03,570 --> 00:21:07,500 his father, Oliver, was one of the World War One codebreakers. 199 00:21:08,700 --> 00:21:14,129 In 1938, a contemporary of Oliver Straight is still when Knox was. 200 00:21:14,130 --> 00:21:21,000 This was one of the senior people in the department. He was a personal friend and indeed ex-lover of Kansas. 201 00:21:21,270 --> 00:21:27,299 Other King's fellows were joined there as well. So it was an easy transition for Turing to take. 202 00:21:27,300 --> 00:21:32,880 No mystery at all. But their main problem was the famous Enigma machine. 203 00:21:34,020 --> 00:21:37,530 And say a little bit about this, but not how it works. 204 00:21:37,530 --> 00:21:45,299 I'm not going to go on about how the rotors were and everything. But one thing I will say is often called this Nazi enigma machine. 205 00:21:45,300 --> 00:21:54,360 Actually, it wasn't Nazi at all. Ironically, it was one of the few things the Nazis retained and trusted from the Weimar Republic. 206 00:21:55,050 --> 00:21:59,370 It didn't change it from the adaptation that was made in 1931. 207 00:22:00,180 --> 00:22:02,470 European sons, whole level of it. 208 00:22:02,710 --> 00:22:13,560 It was much better represented by the Polish mathematicians who did work on breaking this machine and arrived at mechanical methods for for doing so. 209 00:22:13,920 --> 00:22:23,010 In July 1939, they gave vital revelations to the British and French who were behind on this, and the ball started rolling very quickly. 210 00:22:23,520 --> 00:22:33,300 War was declared on 33rd of September 1939, and Turing started at Bletchley Park, the new wartime headquarters, the next day. 211 00:22:34,200 --> 00:22:41,700 It actually wasn't new. It wasn't new place to him. He'd visited it a year earlier when the organisation surveyed it for suitability. 212 00:22:41,700 --> 00:22:49,830 I mean he was already one of the team. But other mathematicians, particularly Gordon Welchman and algebraic Germans, joined up at this point as well. 213 00:22:50,250 --> 00:22:58,680 It was very senior common room sort of atmosphere and Alan Turing wrote a letter back to King's about dealing with Knox, being his boss, 214 00:22:58,920 --> 00:23:09,720 a sort of joke that really and it wasn't the boss and type of relationship, but that was that's where they were at Bletchley. 215 00:23:09,990 --> 00:23:16,709 In fact, you can see the buildings where they worked and the left hand one, the cottage in the stable yard is still there. 216 00:23:16,710 --> 00:23:26,280 Now, in fact, this is an opportunity to say how much there is to see both preserved and displayed at the Bletchley Park Museum. 217 00:23:28,080 --> 00:23:32,570 And the other building is a pub where he lived. No. 218 00:23:32,620 --> 00:23:43,180 I wanted to draw attention to the text here, which has an extremely important date of 1st of November 1939, Turing and Welchman. 219 00:23:43,720 --> 00:23:49,720 So early, I mean, it's just a few weeks into the war and hearing in a Welshman had immediately had their way 220 00:23:49,720 --> 00:23:55,000 as mathematicians and an extraordinary new building machine was already under construction. 221 00:23:55,480 --> 00:24:06,280 Here in this text, it's actually described as a a super bomb machine, which is a great name for it. 222 00:24:06,290 --> 00:24:12,220 They didn't keep it, but it was a good name for it because it was a far larger than the bomb of the Poles. 223 00:24:13,540 --> 00:24:22,600 And that was essentially Turing's idea of the Welshman had extremely important parts in it later on for improving it. 224 00:24:24,670 --> 00:24:26,469 Some people may know something about this. 225 00:24:26,470 --> 00:24:33,760 I won't try and explain how it worked, but from a computer point of view, it's important to say that it was absolutely not a computer. 226 00:24:33,760 --> 00:24:38,830 It was an algorithm. It embodied an algorithm. It's nothing to do with universality at all. 227 00:24:39,280 --> 00:24:51,210 Now it would be an app and it did something which is comparable with solving tens of thousands of Sudoku puzzles in real time, 228 00:24:51,220 --> 00:24:58,780 very, very quickly, many times a second, which was pretty amazing thing to be able to do in 1939 technology. 229 00:24:59,170 --> 00:25:05,649 And that was the brilliance of Turing's both his logic and his experience with the machine building, 230 00:25:05,650 --> 00:25:14,560 to say that this could be done but done so quickly. The first one was built at Letchworth over the winter of 1930 940, 231 00:25:14,950 --> 00:25:21,760 and it was working in March 1940 before Churchill became prime minister, which a lot of people don't appreciate. 232 00:25:22,480 --> 00:25:28,570 This was all a triumph of the Neville Chamberlain regime. It was called victory. 233 00:25:28,780 --> 00:25:33,910 But victory would have seemed very far off at that point. Here's a picture of it. 234 00:25:34,390 --> 00:25:39,549 And underneath the picture of it is a little sketch of that during his own 235 00:25:39,550 --> 00:25:45,040 writing for explaining the sequence of logical deductions that makes it work. 236 00:25:45,520 --> 00:25:55,000 Now, that wasn't enough. It had to be surrounded by a host of other methods and a special algorithms. 237 00:25:55,960 --> 00:26:01,900 And the Naval Enigma messages were much the hardest to deal with, also the most vital. 238 00:26:02,650 --> 00:26:07,450 Turing took that on, really against the odds, and that was his most individual contribution. 239 00:26:07,870 --> 00:26:14,700 He wrote up the Bayesian probability theory, which he developed for this, and that's a little segment of it. 240 00:26:14,740 --> 00:26:19,180 This paper, incidentally, was only released by GHQ in 2012. 241 00:26:21,250 --> 00:26:25,810 I don't know why, but it was kept back for a very long time. 242 00:26:26,770 --> 00:26:34,450 Well, you can see things about, yeah, long odds he liked and you can see lots of 20 sixes, which have to do with alphabets. 243 00:26:35,770 --> 00:26:39,000 This theory was probably the deepest contribution. 244 00:26:39,040 --> 00:26:43,480 It wasn't just to do with Enigma. It was used for all sorts of different other cipher purposes. 245 00:26:43,840 --> 00:26:49,030 And so it went into the purposes for which the famous electronic colossus was used later in the war, 246 00:26:49,390 --> 00:26:54,910 and its concept of weight of evidence was essentially equivalent to Shannon's measure of information. 247 00:26:56,500 --> 00:27:02,590 The story after 1941 was very much dominated by the industrial scale of the war. 248 00:27:03,010 --> 00:27:10,420 So over 200 of these machines were built eventually, and this went well beyond the power of British industry to cope. 249 00:27:10,810 --> 00:27:16,810 And the Churchillian part of it, really not the starting off part, but the continuing sustained part of it, 250 00:27:17,230 --> 00:27:22,540 of course, meant giving way to the United States, but trying to retain some British influence. 251 00:27:22,960 --> 00:27:34,600 That was part of Turing's role, very important. From November 1942 to March 1943, he went on a solo top level technical liaison in the United States, 252 00:27:34,930 --> 00:27:39,610 setting up the basis for what is now really the NSA GHQ relationship, 253 00:27:39,850 --> 00:27:46,870 a very tricky diplomatic mission you will see on these and many went various places, 254 00:27:46,900 --> 00:27:52,809 Washington and Dayton, Ohio, where the new machines were being built by the Americans. 255 00:27:52,810 --> 00:28:02,560 And New York, where the Roosevelt Churchill radio link was being built at Bell Laboratories speech incitement was especially secret, 256 00:28:02,800 --> 00:28:07,390 and the United States demanded that he keep things secret from the other Brits when he got back. 257 00:28:07,810 --> 00:28:11,620 Yeah, but he ran into a lot of problems here. You can see the stories here. 258 00:28:11,620 --> 00:28:15,130 He was kept on Ellis Island because he didn't have the right papers. 259 00:28:15,490 --> 00:28:19,300 He was told that he was going to have access and then it was withdrawn and so forth. 260 00:28:19,510 --> 00:28:25,209 He took a very dim view of this being messed up by security rules, and this was not his thing at all. 261 00:28:25,210 --> 00:28:32,110 I mean, he liked working with the people on the actual stuff, but this was it was a very annoying nevertheless. 262 00:28:32,110 --> 00:28:35,560 It introduced him and this is the important thing for the future story. 263 00:28:35,800 --> 00:28:38,950 This is what introduced him to Hands on electronics. 264 00:28:38,950 --> 00:28:42,519 It was the speech incitement question. This was the key to the future. 265 00:28:42,520 --> 00:28:46,390 This is how logic and electronics first came together. 266 00:28:47,590 --> 00:28:55,390 Well, he was able to work on that when he got back to Bletchley because Hugh Alexander, his deputy, had taken over the Naval Enigma section, 267 00:28:55,870 --> 00:29:04,030 and Turing went off to a smaller base, Hounslow Park in North Buckinghamshire, where he had a little laboratory. 268 00:29:04,480 --> 00:29:17,350 And there with one assistant, Donald Bailey, he built a what's called the Delilah machine, which is this small scale speech decipherment thing, 269 00:29:18,010 --> 00:29:23,860 I mean, not done for transatlantic communications, but the more modest but with very good security. 270 00:29:24,610 --> 00:29:28,330 And this gave the exposure to some serious electronics with his own hands. 271 00:29:29,350 --> 00:29:35,800 And it was also effectively practice for what at some point he must have decided it was the thing to do, 272 00:29:36,160 --> 00:29:45,819 which was to realise the universal Turing machine idea in electronics with the speed and reliability of the cutting edge digital electronics, 273 00:29:45,820 --> 00:29:49,690 which very few people but he knew about at that point. 274 00:29:50,170 --> 00:29:56,950 Again, we don't know. We didn't mean the Dark Ages. Again, there must have been a point where he saw he could do this and we don't know when it was. 275 00:29:57,130 --> 00:30:02,560 But this is at Denslow Park is where all this emerged. 276 00:30:03,910 --> 00:30:10,510 Von Neumann got in first in June 1945 with a plan for electronic computers, the Ed VAC report, 277 00:30:10,660 --> 00:30:15,250 and that's generally regarded as the foundation origin of modern computing. 278 00:30:15,730 --> 00:30:18,250 And so Turing, you know, missed that. 279 00:30:19,090 --> 00:30:27,340 But on the other hand, the American emphasis gave the Brits very good reason to compete with the U.S. and that everything went right. 280 00:30:27,340 --> 00:30:34,720 At first they looked at Turing and appointed him to the National Physical Laboratory at Teddington in south west London, 281 00:30:34,990 --> 00:30:38,770 and that's where he produced the first detailed computer prospectus, 282 00:30:39,100 --> 00:30:43,239 of which this is one page here, not an illuminating page to I mean, 283 00:30:43,240 --> 00:30:54,220 it's just to illustrate that it was done in detail and all aspects of the computer from its use and its rationale to detailed construction, 284 00:30:54,550 --> 00:31:01,360 had a striking list of examples of diverse applications, including a suggestion for artificial intelligence, 285 00:31:01,720 --> 00:31:05,620 something he'd become very keen on actually in the course of the war, 286 00:31:05,860 --> 00:31:13,360 and probably stimulated by the fact that algorithmic methods, as they'd used in the codebreaking, had been so incredibly successful. 287 00:31:14,710 --> 00:31:23,290 He was actually it was mentioned in the press as being the bright young fellow who was doing this thing for the new British triumph. 288 00:31:24,370 --> 00:31:30,280 He was probably more in the press for his amateur athletics because he was very keen on long distance running at the same time. 289 00:31:30,700 --> 00:31:36,219 These two things actually came together in in Boxing Day 1946, 290 00:31:36,220 --> 00:31:42,190 the sports reporter of the Evening News asked him about the electronic brain was his idea, 291 00:31:42,820 --> 00:31:50,530 and Turing said, well, the Americans had done the donkey work on it, a somewhat ambivalent tribute. 292 00:31:50,530 --> 00:31:54,850 And I think the only time he ever really commented on the big question of. 293 00:31:54,910 --> 00:32:00,430 Priority, which was still engaged, is a lot of people now on the whole, he didn't care very much about that. 294 00:32:00,730 --> 00:32:10,180 He always mentioned the 1936 origin of the ideas, but he never pressed the sense in which there'd been a line of development into computer, 295 00:32:11,110 --> 00:32:14,080 electronic computer, or certainly not his leading part of it. 296 00:32:14,980 --> 00:32:22,180 Well, a cut down version of the automatic computing engine, as it was called, was, in fact, completed in 1950. 297 00:32:22,660 --> 00:32:26,500 And Christopher Strictures first programming in 1951 was for it. 298 00:32:26,650 --> 00:32:31,900 But by that time, impatience with the NPL Turing had moved to Manchester. 299 00:32:31,930 --> 00:32:42,760 He started there in October 1948, after that June 1948, working off a tiny prototype, demonstrating his principle of the stored program. 300 00:32:43,060 --> 00:32:53,230 And that is the there's the early first working a manchester computer, which, again, is a very important moment. 301 00:32:53,650 --> 00:32:59,370 It wasn't Turing's moment. I mean, Turing on the whole, doesn't get as much credit as he should, I think, although, 302 00:32:59,620 --> 00:33:04,030 see, he doesn't get as much attention as it should as being one of the first computers. 303 00:33:04,870 --> 00:33:08,319 But during his connection with the Manchester computer tends to be overstated. 304 00:33:08,320 --> 00:33:13,300 I mean, you might even the read as he built it or something like that. He didn't he didn't even design it. 305 00:33:13,450 --> 00:33:19,959 What is important is that he and Newman told the electrical engineers what a computer was. 306 00:33:19,960 --> 00:33:25,420 It was the whole idea of a stored program embodying the universal machine idea. 307 00:33:26,680 --> 00:33:31,540 The media had caught on very quickly to the prospect of computers. 308 00:33:31,540 --> 00:33:39,580 There were a lot of talk about electronic brains rivalling human capacities right back in the 1946, 47, 48 period. 309 00:33:40,030 --> 00:33:42,159 And Turing rose to this. 310 00:33:42,160 --> 00:33:51,700 And in, for instance, in 1949, interviewed by The Times, he read it, he just said, oh, we're finding out if the machine could think for itself. 311 00:33:52,210 --> 00:33:57,460 This was not at all the line that was approved of by by Manchester University. 312 00:33:58,390 --> 00:34:02,020 I think nowadays they'd be very glad of that sort of a press release coverage. 313 00:34:02,020 --> 00:34:12,820 But in those days that was thought, not the thing, but it led to much stimulating interdisciplinary and philosophical discussions at Manchester. 314 00:34:13,090 --> 00:34:18,250 And it was after that that his most celebrated paper on artificial intelligence, 315 00:34:18,580 --> 00:34:28,630 the paper in the Philosophical Journal in mind of October 1950 called Computing Machinery and Intelligence that came out of these discussions. 316 00:34:29,050 --> 00:34:33,670 And of course, if you've seen it, you'll know that it's written to attract a wide number of people. 317 00:34:33,670 --> 00:34:42,490 It's not it's not just for experts. It's full of cultural references, mildly risque jokes, including the Imitation Game of Turing Test, 318 00:34:43,180 --> 00:34:47,230 introduced as a parlour game with ludicrous text message conversations. 319 00:34:47,530 --> 00:34:52,450 But behind it is a serious question of how to give an objective characterisation of intelligence. 320 00:34:53,410 --> 00:34:57,940 And there's much more in it, too. Although it's most famous for that test idea, 321 00:34:57,940 --> 00:35:05,350 it has this great content of exhibiting the new model of computer ability, the idea of a universal machine, 322 00:35:05,710 --> 00:35:13,150 and even the bit about the relationship of computer ability to physical law, which is a question which he just started to get going on. 323 00:35:13,390 --> 00:35:19,840 Also constructive ideas for artificial intelligence, both neural networks and top down programming. 324 00:35:20,110 --> 00:35:31,300 He said both should be tried and famously gave a cautious 50 year prophecy, but also has this subtext about Alan Turing, which is saying, I am human. 325 00:35:31,690 --> 00:35:40,240 I know what real intelligence and real life involves that made him an attractive character and speaker. 326 00:35:40,570 --> 00:35:43,990 And that brings us back to 1951 where we started. 327 00:35:43,990 --> 00:35:50,110 He was asked to give a third programme radio talk despite not being a very fluent speaker. 328 00:35:51,520 --> 00:35:55,959 And in fact, you'll see the BBC producers report did credit. 329 00:35:55,960 --> 00:36:01,570 They had a lively mind, the BBC thought. But he did have this hesitation in his speech. 330 00:36:02,310 --> 00:36:07,990 I didn't make him a media guru immediately, but nevertheless he was on the radio. 331 00:36:07,990 --> 00:36:12,940 And it was that radio talk in May 1951 that Christopher Straight she heard, 332 00:36:13,240 --> 00:36:21,820 and that's what got his career going by writing after Turing at Manchester and with a draughts, playing and love letters, all of that. 333 00:36:22,210 --> 00:36:28,330 So that's how in 1951, Turing was established in Manchester, a very minor public figure. 334 00:36:28,690 --> 00:36:34,930 He was also elected fellow for our society in 1951, and it was for that 1936 work. 335 00:36:35,590 --> 00:36:37,900 Two characteristic stories, he said. 336 00:36:38,470 --> 00:36:46,420 I suppose they couldn't have made me an IFRS when I was 24, which is rather bragging, but on the other hand he wasn't really like that. 337 00:36:47,230 --> 00:36:52,240 A young research student, rather tactless. They said to him, Oh, I didn't think of using the phrase. 338 00:36:52,840 --> 00:36:57,090 And he is laughed at that he didn't mind. He is. 339 00:36:58,030 --> 00:37:06,770 He had this lower upper middle class accent, of course, and Cambridge done background, but he still rather had this air of graduate students. 340 00:37:06,780 --> 00:37:13,140 And he didn't have a side, as people said. He was very accessible to people on the right wavelength. 341 00:37:14,610 --> 00:37:22,230 That's a fully engineered mass. Just the computer was inaugurated in that same year, July 1951, and it was summer, 342 00:37:22,680 --> 00:37:26,880 and the organisation was nothing like what had been envisaged originally by Newman. 343 00:37:27,150 --> 00:37:34,590 It was dominated by the fact that government had supplied money for the atomic bomb calculation to be run on it, and that's what it was for. 344 00:37:35,850 --> 00:37:42,929 And Turing's role wasn't really terribly clear. But on the other hand, he had a lot of freedom in using it, especially at night. 345 00:37:42,930 --> 00:37:48,420 So it almost got a private or personal computer, whether only three or four in the world. 346 00:37:49,290 --> 00:37:54,360 Now, one can see and there he is at the at the console of the machine on the right there. 347 00:37:55,480 --> 00:38:01,110 Now, you can see all the things that he might have done that I didn't do, could have promoted Turing machines, 348 00:38:01,290 --> 00:38:08,610 theory of computation, started complexity theory, higher programming conferences, books, all sorts of things. 349 00:38:08,680 --> 00:38:17,070 Well, none of that happened. He didn't do that. The future, of course, really lies in software architecture rather than this hardware building. 350 00:38:17,400 --> 00:38:21,090 But it was Christopher Street who followed that line of thought into the future. 351 00:38:21,120 --> 00:38:30,600 Turing himself left it to others. So that brings the question now, having gone to this other state, what does he do with it? 352 00:38:30,810 --> 00:38:34,080 What do you do next? Well, I tell you one thing he did next. 353 00:38:34,320 --> 00:38:40,710 He went on running and he had a new running partner and around Cheshire Villages where he lived. 354 00:38:41,010 --> 00:38:48,360 This was the 17 year old Alan Garner, later famous as the author of the Owl Service and other iconic fiction. 355 00:38:48,690 --> 00:38:59,910 But at that stage in the Manchester Grammar School, sixth form schoolboy and that is a very curious fact which of our time we'll we will come back to. 356 00:39:00,390 --> 00:39:06,510 But he was also doing completely new work. And we have very little idea of what the precursor to this was. 357 00:39:06,930 --> 00:39:16,140 And it came out of the blue and it was this mathematical theory of biological growth and form based on reaction and diffusion and physical chemistry. 358 00:39:17,970 --> 00:39:29,040 It was certainly going strong and in February 1951, and it had some possible connection with his interest in the question of brain growth itself, 359 00:39:29,040 --> 00:39:32,670 an outcome of his interest in intelligence and learning processes. 360 00:39:32,940 --> 00:39:39,420 But I think it was much deeper than that. He went back to physical chemistry he he'd done at school or even even earlier. 361 00:39:39,900 --> 00:39:42,270 Anyway, it's classical applied maths. 362 00:39:42,630 --> 00:39:52,260 It's not a business of the discrete as like in networks, it's actually classical analogue and continuous mathematics. 363 00:39:52,620 --> 00:39:58,110 But the computer comes in crucially because the equations that he wrote down cannot be solved analytically, 364 00:39:58,530 --> 00:40:04,140 and the computer gave the prospect of pure scientific research that would never have been possible before. 365 00:40:04,650 --> 00:40:12,540 So his first paper, on the Chemical Basis of Morphogenesis, was submitted in November of that important year, 1951, 366 00:40:12,540 --> 00:40:19,800 and it has become one of the most cited in mathematical literature and a founding work in mathematical biology. 367 00:40:20,400 --> 00:40:22,740 But I'm going to skip a description of his theory, 368 00:40:22,740 --> 00:40:30,960 even though he had a delightful model for the processes of reaction and diffusion in an island of missionaries and cannibals. 369 00:40:31,800 --> 00:40:34,950 Very typical way to illustrate ideas. 370 00:40:35,220 --> 00:40:42,570 I'm going to go straight and quote something very important about the unpublished work that's here and did after finishing this paper. 371 00:40:42,960 --> 00:40:45,300 And this is by Professor Jonathan Dawes. 372 00:40:45,840 --> 00:40:54,390 Building on earlier work, especially that of Jonathan Swensen, who looks at the very difficult pile of manuscripts that Turing left. 373 00:40:54,810 --> 00:40:58,590 He's gone much further in piecing together some of the disordered pages. 374 00:40:58,950 --> 00:41:03,940 And one of his conclusions is that, well, I've posted here and it's essential. 375 00:41:03,950 --> 00:41:10,170 The point is that the work that Turing was doing throughout the two years, from 1952 to 54, 376 00:41:10,590 --> 00:41:16,050 where new ideas and applied mathematics that would have had substantial influence across the whole subject, 377 00:41:16,500 --> 00:41:22,230 they would have spurred the development of parts of the subject that otherwise took several decades to be realised. 378 00:41:22,740 --> 00:41:29,010 In particular, Turing arrives as an equation for a model that otherwise was only arrived at in 1977. 379 00:41:29,910 --> 00:41:33,660 His ideas are relevant not only to biology, but to nonlinear dynamics. 380 00:41:33,660 --> 00:41:36,420 For instance, in the novella Stokes Equations for Fluids. 381 00:41:37,440 --> 00:41:45,150 This was miles ahead, and the Manchester computer, of course, had none of the fast, visible graphic displays that we now enjoy. 382 00:41:45,540 --> 00:41:54,570 So this was the kind of graphic display he had. It was a printout in which he'd do his own coloured drawings based on the on the print. 383 00:41:54,650 --> 00:42:03,260 Doubt. I mean, you can just see from the picture that he he he should have been living at least 1984 or not 54. 384 00:42:03,290 --> 00:42:09,380 I mean, he was miles, miles ahead and other things in the 5354 period. 385 00:42:10,700 --> 00:42:16,549 There was work in a number theory and he showed himself really up with ideas in quantum mechanics and 386 00:42:16,550 --> 00:42:23,330 relativity and everything was going really well in that his university position was on a more solid footing. 387 00:42:23,570 --> 00:42:25,370 He had a small research group going. 388 00:42:25,670 --> 00:42:31,730 And so you could imagine him as being an absolute leading figure of the 1960s with the new universities, if he'd wanted to. 389 00:42:31,760 --> 00:42:39,440 I mean, that's the kind of position he was in. But on the morning of June the eighth, 1954, he was found dead in his bed. 390 00:42:40,040 --> 00:42:48,109 It was cyanide poisoning. The setting was a strange one of electroplating experiments in the next room and bedside slices. 391 00:42:48,110 --> 00:42:51,650 Apple cyanide organs are full of the cyanide. 392 00:42:51,800 --> 00:42:59,570 And he died the evening before. And it was assumed, I think, perfectly correctly, that he had eaten a poisoned apple. 393 00:43:00,140 --> 00:43:04,880 Now, why? And that gives the attention to this question. 394 00:43:05,480 --> 00:43:12,920 Of course, it's all connected with his being homosexual when all male same sex relations were illegal. 395 00:43:13,340 --> 00:43:22,220 He was arrested on the day. Well, it was the day George six died and he underwent a criminal trial on 31st of March, 1952. 396 00:43:24,050 --> 00:43:27,790 Well, I want to get some picture of his identity as a gay man. 397 00:43:27,830 --> 00:43:32,340 You have to go back because he's not an axiomatic system. You have to think he was a real person now. 398 00:43:32,360 --> 00:43:37,190 I mean, he's Alan now, I think to me. And he himself. 399 00:43:37,640 --> 00:43:38,210 Certainly. 400 00:43:38,720 --> 00:43:47,690 I mean, I want to draw a parallel with his scientific life in that he starts off immersed in very old fashioned class and privileged questions, 401 00:43:48,110 --> 00:43:54,620 becomes very modernised in such a way that as Michael introduced him to us this evening, 402 00:43:54,620 --> 00:44:00,760 how our legislation, our culture is now involves his story in quite an essential way. 403 00:44:00,770 --> 00:44:04,490 So let's go back and see what what he was like. 404 00:44:04,790 --> 00:44:10,460 What I'm going to give you a nice picture of what he was like at school is in 1919. 405 00:44:10,490 --> 00:44:14,990 These are pictures of 1931. You can see he was in a cell. 406 00:44:14,990 --> 00:44:18,020 He anticipated the selfie. You can certainly see that. 407 00:44:18,620 --> 00:44:24,110 And you can see that he would have had no problem with surfing the Internet at all if it survived. 408 00:44:24,590 --> 00:44:28,670 But the thing is, these are here to see his physical look. 409 00:44:29,750 --> 00:44:32,989 I mean, swimming, running, cycling, hiking, boating. 410 00:44:32,990 --> 00:44:41,990 These were his things. And this scruffy look that everyone moaned about all the time in the in the forties and fifties, this was him, too. 411 00:44:42,650 --> 00:44:48,980 He was just too early for the jeans and t shirt of the 1960s in which he would have been perfectly happy and acceptable. 412 00:44:50,780 --> 00:44:57,480 That was what he was like. And he retained all that outdoor and and this sort of physical look. 413 00:44:57,500 --> 00:45:04,010 That's what he was like. There's a well-known story that move on. 414 00:45:04,190 --> 00:45:07,850 Yeah, that was a well-known story that he was at school. 415 00:45:08,450 --> 00:45:13,250 He worshipped from a far slightly older boy called Christopher Walken. 416 00:45:13,760 --> 00:45:14,149 In fact, 417 00:45:14,150 --> 00:45:23,540 the nearest you got to friendship really was going on a group to Cambridge for the scholarship exams when they went together in December 1929. 418 00:45:24,050 --> 00:45:28,400 Christopher then died very suddenly after this, and it had a great impact on Alan Turing. 419 00:45:28,610 --> 00:45:36,200 Something which I must say he was very open about. This was something he discussed his feelings and his is the thoughts that it evoked. 420 00:45:36,620 --> 00:45:46,340 And in particular, it was actually much closer to another boy called Victor Beutel and helped him get over the crisis in 1932. 421 00:45:46,970 --> 00:45:52,550 Another important aspect of this was going to King's College. He was lucky that he got into his second choice college, if you like, 422 00:45:52,880 --> 00:45:59,330 because that was the liberal gay enclave with the main Arkansan, a number of other people. 423 00:45:59,340 --> 00:46:01,160 It was the liberal establishment. 424 00:46:01,670 --> 00:46:07,409 And he formed new friends there, one of them being David Champion down, who I mentioned, who remained a lifelong friend, 425 00:46:07,410 --> 00:46:13,430 a very understanding person and indeed a sexual relationship with one of the other math students, James Atkins. 426 00:46:13,790 --> 00:46:20,540 He had a lot of support for Summit in the 1930s. He really had a lot, but he was not at ease with himself at all. 427 00:46:22,100 --> 00:46:25,250 Usual things. Unrequited passion, loneliness. 428 00:46:25,550 --> 00:46:33,020 Why me? Why is this happened? All those thoughts, I think, very much depressed him in that period. 429 00:46:35,420 --> 00:46:43,610 One of those friends was the king's classicist, Fred Clayton, who has been in Germany in 1937, 430 00:46:43,610 --> 00:46:51,190 and they'd sponsored two Jewish boys who came as refugees in early 1939, and they helped them out. 431 00:46:51,200 --> 00:46:57,589 And there's a striking picture here in the last week of peace, the last week of August 1939, 432 00:46:57,590 --> 00:47:03,200 where they took them boating along the front and Fred at the back and the two boys in between. 433 00:47:04,430 --> 00:47:14,389 And I'm yeah. So and went off to war immediately after that and it would seem to me that actually 434 00:47:14,390 --> 00:47:19,400 that the elder of those two boys was probably the person most on his mind emotionally. 435 00:47:19,400 --> 00:47:23,150 I mean, purely emotionally. I mean, there's no no physical contact. 436 00:47:23,810 --> 00:47:27,620 And I think it may well be that this was he didn't. 437 00:47:27,620 --> 00:47:30,890 So this is not a good direction to be going in. 438 00:47:31,250 --> 00:47:39,710 And this is one reason why in spring 1941, he made a marriage proposal to Joan Clarke, who was on their right there. 439 00:47:40,400 --> 00:47:48,200 She was Gordon Welshman's fourth year and students at Newnham College and sister of the King's College Fellows at one of the of the group. 440 00:47:48,380 --> 00:47:53,000 She and she joined Alan Turing section on Naval Enigma. 441 00:47:53,000 --> 00:48:01,550 And in June 1940, I mean, she was a real kindred spirit and someone that Alan said he could talk to as a man, but she wasn't. 442 00:48:02,120 --> 00:48:10,099 And it was essentially doomed, especially as he started immediately on the engagement with a talk about his homosexual tendencies. 443 00:48:10,100 --> 00:48:13,280 Joan knew this was not really going to go somewhere. 444 00:48:13,640 --> 00:48:22,070 It ended in August 1941 in Wales when they had a week off and perhaps there was more opportunity for physical contact anyway. 445 00:48:22,070 --> 00:48:27,680 It was impossible to go on and Alan used a literary reference. 446 00:48:27,680 --> 00:48:33,660 When he called it off, he quoted Oscar Wilde for Each Man Kills the Thing He Loves and so on. 447 00:48:33,680 --> 00:48:38,089 It's from The Ballad of Reading Gaol. So yes, the service, his life. 448 00:48:38,090 --> 00:48:42,770 This is very a very difficult period. It was not something that we found very fulfilling. 449 00:48:43,100 --> 00:48:47,900 He became much more confidence in the later part of the war and in after the war. 450 00:48:48,590 --> 00:48:55,969 One reason seems to be he discovered, I think while in the United States on that liaison trip and then possibly in Paris 451 00:48:55,970 --> 00:49:02,480 when going to on the way to Germany to to to see the German communications equipment, 452 00:49:03,350 --> 00:49:11,180 the possibility of consular pickups. Anyway, back in King's College, Cambridge in 1948, he was much more confident. 453 00:49:11,570 --> 00:49:15,710 That was when he came out and made friends on a new level with Robin Gandhi, 454 00:49:16,640 --> 00:49:22,219 but also made new friends, one of whom became a longer term lover, Neville Johnson. 455 00:49:22,220 --> 00:49:30,020 His name was a boy from Newcastle. He was 24. Then after coming out of service they went cycling in France in 1948, 456 00:49:30,020 --> 00:49:35,450 just the kind of thing that had the best chance of setting, settling into a continuing relationship. 457 00:49:35,900 --> 00:49:40,670 But that was really bedevilled by their long distance problem, which affects so many people. 458 00:49:40,840 --> 00:49:45,890 Alan Turing move to Manchester and never had his job in reading and it was difficult to keep going. 459 00:49:46,400 --> 00:49:56,900 Meanwhile, in Manchester, temptation lurked because by the university there was this unique area, unique in the north of England anyway, 460 00:49:56,900 --> 00:50:03,470 of this sort of gay identified cruising block and Alan Turing could be seen there after 1950 or so. 461 00:50:04,010 --> 00:50:07,040 So that brings us to that fateful year in 1951. 462 00:50:07,730 --> 00:50:17,600 That was when he decided, after submitting his paper, that he had earned what he described as another gay man. 463 00:50:17,960 --> 00:50:22,070 It's interesting he used the word gay, which was then American usage. 464 00:50:22,070 --> 00:50:25,880 It wasn't really the British usage, but there it is in his writing. 465 00:50:26,360 --> 00:50:31,579 And he did. He met this young photo printer called Arnold Murray and took a shine to him. 466 00:50:31,580 --> 00:50:38,240 His chest up line was that he worked on the electronic brain and the electronic brain got everywhere. 467 00:50:38,780 --> 00:50:45,740 And unfortunately Alan Arnold was not a very suitable boy. 468 00:50:46,280 --> 00:50:55,940 And after some petty theft, Turing had to go to the police on the grounds that he was subject to an implicit kind of blackmail. 469 00:50:56,600 --> 00:51:01,850 He didn't handle it very well, and the police soon came to arrest him. 470 00:51:01,880 --> 00:51:04,880 In fact, both of them are charged in exactly the same way. 471 00:51:05,240 --> 00:51:14,090 Under the 1885, at the same one as Oscar Wilde had been prosecuted under the new conservative government, 472 00:51:14,090 --> 00:51:20,330 was leading quite a crack down at this point. And this was part of what was a very large scale thing that was happening. 473 00:51:21,430 --> 00:51:25,940 Public opinion was entirely in favour of the law as it was. There was virtually no opposition to it. 474 00:51:26,330 --> 00:51:33,380 So Turing's response to being charge when he said, I thought there was a royal commission sitting to legalise it, well, it certainly wasn't. 475 00:51:33,730 --> 00:51:41,530 But the thing is that hearing said what the liberal elite may have thought but kept to themselves, and that was his characteristic. 476 00:51:41,530 --> 00:51:46,720 It was very modern and in 1952 quite shocking, and it did him no good at all. 477 00:51:47,950 --> 00:51:54,910 It's well known now that what happened when he was convicted was that he was on probation, 478 00:51:55,180 --> 00:51:59,410 having to take these hormone injections actually for a year. 479 00:52:00,730 --> 00:52:07,240 And that's I suppose people think of that as being some very cruel thing that was devised at the time that would have been seen as the soft option. 480 00:52:07,450 --> 00:52:12,130 I mean, the fact was it was the modern, it was the scientific option. 481 00:52:12,670 --> 00:52:15,340 The irony of this, I'm sure everyone appreciates. 482 00:52:15,640 --> 00:52:20,770 But it did mean that he didn't lose his job as he would have done if he'd refused and gone to prison. 483 00:52:21,640 --> 00:52:28,080 And again, it's often thought that he declined thereafter and fell away and his mind was 484 00:52:28,090 --> 00:52:34,840 wrecked and originality left him by this dreadful assault of the biochemistry. 485 00:52:35,230 --> 00:52:36,940 But there's really no evidence at all. 486 00:52:36,940 --> 00:52:44,979 And that's why I emphasised in this earlier section that he was doing work of the greatest originality stuff that was decades ahead, 487 00:52:44,980 --> 00:52:49,950 and that continued right up to the end. In fact, it was the other way round. 488 00:52:49,960 --> 00:52:57,130 I mean, he really stood up to this and insisted on continuing work of the highest quality, and he stayed. 489 00:52:57,130 --> 00:53:04,690 His whole response to the crisis was very sophisticated. It had that same mixture of dead seriousness and humour, as in the scientific writing. 490 00:53:05,170 --> 00:53:11,020 I had a very agreeable feeling of irresponsibility, he said of the trial, rather like being back at school. 491 00:53:11,530 --> 00:53:19,329 And it's a very upper middle class thing to say for that, but slightly more modern existentialist way, he said. 492 00:53:19,330 --> 00:53:24,250 No doubt I shall emerge from as a different man, but quite who I have not found out. 493 00:53:25,360 --> 00:53:33,189 He made a quite decisive step in this existential question by consulting a union psychotherapist, 494 00:53:33,190 --> 00:53:38,350 Franz Greenbaum, who was another refugee, Jewish refugee from Nazi Germany. 495 00:53:38,890 --> 00:53:46,100 And he was reading in modern literature. And he did. He was writing, too, because he wrote a short story about his experience. 496 00:53:46,120 --> 00:53:53,950 Interestingly, quite avant garde in that he looked at how he himself would be seen by a working class young man. 497 00:53:54,310 --> 00:53:59,050 But the most positive thing of all was escape to Norway of all places. 498 00:53:59,890 --> 00:54:02,650 And that's sorry, that's the photograph at the bottom, 499 00:54:03,040 --> 00:54:11,259 which is from the Scandinavian very early Scandinavian gay rights movement of 1952 and was their magazine. 500 00:54:11,260 --> 00:54:15,440 And that was exactly what he wanted. I mean, that was the idea was was marvellous. 501 00:54:15,910 --> 00:54:25,730 And he switched over to Norway in the summer of 1952, despite being on this treatment and the rest of it and fact it, 502 00:54:25,750 --> 00:54:29,560 he was learning Danish and Norwegian with great enthusiasm. 503 00:54:29,680 --> 00:54:38,049 In Bergen, he met a young man called Kjell and you'll see Kjell theory and kill programs all over the morphogenesis work. 504 00:54:38,050 --> 00:54:44,560 And that's where it where it comes from. He didn't divide his life into into compartments very well. 505 00:54:44,560 --> 00:54:49,330 And indeed, he talks about all these events a great deal with people in the computing laboratory. 506 00:54:51,700 --> 00:55:00,730 Well, no, he lost Neville. Neville Johnson, the boyfriend from 48 to 1950 or so because Neville's mother forced him never to see Alan again. 507 00:55:01,030 --> 00:55:05,889 I mean, she was she had a point. I mean, he was dangerous to know about one person. 508 00:55:05,890 --> 00:55:12,670 He did become a lot closer. Was Nick Fairbank from King's College, Penn Fairbank you could have seen his name. 509 00:55:13,000 --> 00:55:19,719 He is the biographer of E.M. Forster and in fact, a critic with many articles in the Times, literary supplements and things like that. 510 00:55:19,720 --> 00:55:24,480 Until his recent death, actually the release of some papers. 511 00:55:24,490 --> 00:55:29,290 And Nick Fairbank gives a little bit more explanation for Turing's frame of mind, which I'd like to share with you. 512 00:55:30,520 --> 00:55:40,030 It's clear now that for a time in late 52 and in 53, Alan Turing seriously entertained the thought that he would become bisexual, 513 00:55:40,600 --> 00:55:48,220 like many people he knew were all least claim to be. I mean, anyway, Maynard Keynes comes to mind certainly was his thing. 514 00:55:48,340 --> 00:55:53,710 His view of the psychotherapy was that a heterosexual side of him could emerge 515 00:55:54,250 --> 00:56:00,340 from the subconscious is unblocked by young young in analysis of his dreams. 516 00:56:00,580 --> 00:56:04,870 Indeed, he told Nick about a dream, which he said proved that this was happening. 517 00:56:06,070 --> 00:56:11,229 It was unusual, I think, as a gay man, as he was never denying his gay side at all. 518 00:56:11,230 --> 00:56:17,350 He was always very positive and open about who he was attracted by and the excitement of encounters. 519 00:56:17,830 --> 00:56:23,890 But it seemed that he hoped that he could feel heterosexual attraction as well, not as some kind of cover story, 520 00:56:24,130 --> 00:56:30,100 but as really authentic and then settled down in marriage, I think very similar to what he'd hoped in 1941. 521 00:56:30,490 --> 00:56:40,910 And that's, I think, is to explain something that always. It's not hard to understand why on earth he chose Corfu for his summer 1953 holiday. 522 00:56:41,420 --> 00:56:49,640 He went to the club Mediterranee just started and is really the vanguard of the new leisure 1950s, sunny sort of Europe. 523 00:56:50,150 --> 00:56:59,270 I think he went there to see if in this liberated environment he could detect any new physical interest in him in the other sex in himself. 524 00:57:00,230 --> 00:57:08,570 In fact, he wrote to Nick before he went that he would be making love, the nationality and sex of the partner to be decided. 525 00:57:08,810 --> 00:57:14,390 Perhaps, perhaps not at all, though, as it was something permanent that he wanted and why he was there. 526 00:57:14,750 --> 00:57:22,700 This is a little vignette of Alan Turing in this so absolutely critical period as the postcard that he sent to the psychiatrist. 527 00:57:23,060 --> 00:57:29,090 And it says, I'm here at Corfu. It is tremendously hot and one wears bathing things all day. 528 00:57:29,870 --> 00:57:33,620 This is not the picture of the shattered person. 529 00:57:34,130 --> 00:57:38,900 There's someone who is actually living life as much as they can. 530 00:57:39,230 --> 00:57:44,600 However, I doubt very much that this came this idea of bisexuality came to anything. 531 00:57:45,020 --> 00:57:49,370 He returned with a long list of Greek and French names and addresses. 532 00:57:49,640 --> 00:57:54,380 It seems that he did find some partners and be astonishing if they were other than young men. 533 00:57:54,740 --> 00:57:58,160 Leopards don't change their spots very easily. 534 00:57:58,460 --> 00:58:07,010 And this was just, I think, a dream of a genuine, stable, married state that could emerge for him just as it had been in 1941. 535 00:58:08,210 --> 00:58:11,360 So I think that's an important element of his story. 536 00:58:11,360 --> 00:58:18,290 And we think about the relationship between the arrest and and the trial and his death two years later. 537 00:58:18,320 --> 00:58:25,150 There's a whole journey here. To treat him as a whole person means taking these things into account and not just having a 538 00:58:25,160 --> 00:58:32,120 very one dimensional picture of of a wound and damage and collapse that was fighting back. 539 00:58:32,420 --> 00:58:35,420 There was very considerable uncertainty about what to do. 540 00:58:35,780 --> 00:58:40,580 But then there was something else that had to be has to be taken into consideration as well. 541 00:58:41,090 --> 00:58:46,820 And that is his special status. When the police had arrested him, it was just a very ordinary arrest. 542 00:58:46,830 --> 00:58:54,110 They had no idea who he was, but he was someone special. He was the Anglo-American world's top crypto consultant. 543 00:58:54,860 --> 00:59:01,520 And he, of course, his friends had no idea of this whatsoever, and they had no idea what he'd done in the war. 544 00:59:01,790 --> 00:59:04,820 No one breathed a word about this until the 1970s. 545 00:59:05,210 --> 00:59:13,400 Additionally, since 1948, he'd done further work for GC HQ, which is of course abruptly stopped when he was arrested. 546 00:59:13,820 --> 00:59:17,270 He also had, if you remember, special United States clearance. 547 00:59:17,270 --> 00:59:23,960 So what in 1954 would have been extremely sensitive topic, speech, incitement at once. 548 00:59:24,410 --> 00:59:32,000 What happened was the boy from Norway, Kalle, came over and landed at Newcastle intending to visit him. 549 00:59:32,600 --> 00:59:39,770 But as Turing reported, half the police in the north of England seemed to be out looking for him and intercepted him and sent him back to Norway. 550 00:59:40,250 --> 00:59:45,740 The poor sweeties, he said, did not know there was nothing but a kiss with this young man in Norway. 551 00:59:46,010 --> 00:59:49,190 Well, the poor sweeties were not the local police. 552 00:59:49,430 --> 00:59:52,550 This is a national operation. And the reason is obvious. 553 00:59:53,030 --> 00:59:59,330 His activities with their potential for entrapment were real anxiety for national security. 554 00:59:59,810 --> 01:00:03,650 In 1954, it was clear policy to exclude homosexuals. 555 01:00:03,650 --> 01:00:04,370 Absolutely. 556 01:00:04,370 --> 01:00:14,130 From GHQ work and the current director of GHQ, Robert Hannigan, as recently confirmed that this was the case and remained the case until the 1990s. 557 01:00:14,150 --> 01:00:21,560 It's changed completely now. That was the point of his remark. This is in 1948 on their American influence, 558 01:00:21,650 --> 01:00:25,700 and it meant that during situation was nothing like what it had been in the Second World 559 01:00:25,700 --> 01:00:30,770 War when being a good chap from the right school and the right college was all you needed. 560 01:00:31,640 --> 01:00:38,090 GHQ could hardly have ignored their own security policy when a top scientific consultant very real, 561 01:00:38,090 --> 01:00:42,290 revealed as the very thing they wanted to exclude at all costs. 562 01:00:42,830 --> 01:00:45,979 And not just that. It wasn't just that he was gay. He was involved. 563 01:00:45,980 --> 01:00:52,460 The lowlife is stroppy, utterly unrepentant and set on foreign travel to escape British law. 564 01:00:52,910 --> 01:00:59,330 It's really surprising that he was allowed to go abroad in the summer of 1953 and probably had to fight for permission. 565 01:00:59,720 --> 01:01:07,340 In fact, there's a big page of hints that he wrote to Robin Gandy in joke, hints about being stopped from from leaving the country. 566 01:01:07,340 --> 01:01:11,720 But Robin didn't guess it. I think Turing's humour was sometimes too subtle. 567 01:01:12,080 --> 01:01:22,940 Anyway, it may be that it was after this period that I think he seriously considered the only existentialist way out of this, which is suicide. 568 01:01:24,020 --> 01:01:32,419 He in March 1953, he announced that he'd put together a chemistry laboratory in his house, mentioned that very offhand. 569 01:01:32,420 --> 01:01:37,010 But that had a real. Meaning it was the means of his death if he chose to take it. 570 01:01:37,790 --> 01:01:40,669 It always had this melodramatic thing about chemistry. 571 01:01:40,670 --> 01:01:46,490 It goes right back to his school days, even joking with Christopher Malcolm about absolutely deadly substances. 572 01:01:46,520 --> 01:01:52,110 He had a slightly melodramatic and slightly morbid interest in this in this whole thing. 573 01:01:53,600 --> 01:02:02,630 In fact, we can see even in 1936 when he was so successful and everything was going so well, his mother knew there was something really wrong. 574 01:02:02,990 --> 01:02:09,320 And it turns out that she wrote behind his back to the dean of the Graduate College in Princeton saying To wash out, 575 01:02:09,710 --> 01:02:16,100 there might be some unforeseen emergency and they should know how to contact the Turing family if such a thing happened. 576 01:02:16,940 --> 01:02:21,830 Clearly, she knew something, and this was classic interference, but she had a real point. 577 01:02:22,340 --> 01:02:29,570 In 1937, Alan Turing wrote to his King's College boyfriend, James Atkins, about having a suicide plan. 578 01:02:30,260 --> 01:02:35,300 Indeed, there was an event in 1937 could very well have triggered such thoughts. 579 01:02:35,780 --> 01:02:40,460 And the plan, as James recalled to me, involved an apple and electrical wiring. 580 01:02:40,640 --> 01:02:46,910 And the point of the plan is to have a plan at all was that it was to disguise suicide as an accident, 581 01:02:46,910 --> 01:02:50,120 as a chemical accident and accident doing a chemistry experiment. 582 01:02:50,360 --> 01:02:57,650 And it was for the sake of his mother. I mean. So other people can confirm some of this. 583 01:02:58,220 --> 01:03:02,299 And so he knew his mother well, and she did indeed fall for this. 584 01:03:02,300 --> 01:03:10,670 Exactly. And believed that he had transferred the cyanide by accident from the experiment to his apple and ate it by mistake. 585 01:03:11,150 --> 01:03:15,380 Getting the sun was easy. He got it from the Manchester Chemistry Department. 586 01:03:16,130 --> 01:03:23,480 Very telling is that after March 1953, the same point, he was pressing Nick Fairbank to be the executor of his will. 587 01:03:23,960 --> 01:03:32,990 This is a very special will and it is clear from his letters to Nick, which were written in French, it's a cushion, I think is a very sensitive thing, 588 01:03:32,990 --> 01:03:35,810 is using Nick's own interest in French literature, 589 01:03:36,320 --> 01:03:44,510 and it puts it as something that might be necessary since trouble might come again, and it puts it in that way. 590 01:03:44,510 --> 01:03:53,260 And Nick agreed that Will itself was was signed in February 1954, very careful, totally unconventional. 591 01:03:53,270 --> 01:04:00,350 He cut his lawyer brother completely and devises his estate between the five most supportive people in his life. 592 01:04:00,680 --> 01:04:05,660 Nick Robyn Neville, David Champion and his mother. 593 01:04:07,600 --> 01:04:15,130 Now we don't know what happens. Robert Hannigan's recent statement from GCA HQ says that they stood by him. 594 01:04:15,160 --> 01:04:25,330 And I'm sure that Hugh Alexander, his deputy in the war and then the scientific head of THQ after the war, did stick up for him very strongly. 595 01:04:25,900 --> 01:04:33,150 But from the point of view of security and Alan Turing would have seemed criminally irresponsible if not certifiably insane, 596 01:04:33,160 --> 01:04:40,480 it would be very hard, very hard for you, Alexander, to argue that he did not need to be protected from himself. 597 01:04:41,140 --> 01:04:47,740 The Cold War was at its height in 1954. Opposite number Robert Oppenheimer was effectively on trial. 598 01:04:48,280 --> 01:04:53,180 Turing's friends and contacts would give no cause for complacency. 599 01:04:53,200 --> 01:04:56,590 They included numerous communists, as well as atomic scientists. 600 01:04:57,040 --> 01:05:00,489 But the main thing was he knew what hardly anyone in the world knew. 601 01:05:00,490 --> 01:05:09,370 This very nature of Anglo-American communication, crypto and security as the biggest secret of the lot in the circumstances. 602 01:05:09,520 --> 01:05:12,850 The amazing thing is not that he went, but that he lasted so long. 603 01:05:13,360 --> 01:05:19,060 He was a man who tried to be honest and truthful, which is what Newman said for him at the trial. 604 01:05:19,540 --> 01:05:24,320 But he was cursed with two things which went in the opposite direction and made everything a lie. 605 01:05:24,820 --> 01:05:28,600 The secrecy of the war work and the criminalisation of his sexuality, 606 01:05:28,600 --> 01:05:33,730 the combination of them both in the security issue, was clearly absolutely toxic. 607 01:05:33,930 --> 01:05:37,540 It's hardly surprising that he was crushed. Well, 608 01:05:37,540 --> 01:05:47,679 I think I'll have to leave this story at this point and invite you to see that and other ramifications and extraordinary episodes which feed into 609 01:05:47,680 --> 01:06:00,640 this and very interesting people and whole world of life and history which which is part of the human story and feed into this great web of science, 610 01:06:00,880 --> 01:06:09,070 which I referred to at the beginning, is a web in which he himself believed an individual only contributes a little bit. 611 01:06:09,070 --> 01:06:14,230 It is essentially a communal operation, and that's something where he ceased. 612 01:06:14,560 --> 01:06:30,880 But what he did lives on. Secondly, I should have done this at the beginning that I should thank Oxford Asset Management. 613 01:06:31,090 --> 01:06:34,820 Oxford Asset Management are our sponsors for these events. We couldn't. 614 01:06:34,840 --> 01:06:42,549 It isn't free to get a venue like this. They they do cost and we couldn't do an event on this scale and complexity without their support. 615 01:06:42,550 --> 01:06:47,110 So we're tremendously grateful to them. You can find out more about Oxford Asset Management over there. 616 01:06:47,320 --> 01:06:50,200 You can find out more about the department and what we do over here. 617 01:06:50,470 --> 01:06:56,740 And finally, just a reminder, if you'd like to pick up a copy of the book and Andrew indicated he'd be happy to sign copies, 618 01:06:56,890 --> 01:07:00,250 you're very, very welcome to over that. But one more time. 619 01:07:00,340 --> 01:07:03,790 Andrew, I've been waiting 31 years to hear you give this lecture. 620 01:07:03,970 --> 01:07:07,810 You didn't disappoint. That was a fantastic straight G lecture. Thank you so much.