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Narrator/Host Introduction
Alan Turing is one of the most celebrated of all British scientists. His work in cracking Nazi codes at Bletchley park and his role in the evolution of the computer has earned him worldwide acclaim. Yet he died at the age of just 41, two years after being prosecuted for homosexual acts. In this episode of the History Extra Podcast, David Kenyon, research historian at Bletchley Park 10, tells Spencer Mizzen about a brilliant life marred by tragedy.
Spencer Mizzen
David, it's a real pleasure to welcome you to the History Extra Podcast today to talk about the life and legacy of Alan Turing. As a research historian at Bletchley park, you're clearly very familiar with Turing's life and work. You've done plenty of research into him and written about him. With this in mind, I wonder if you could give our listeners a quick introduction to Turing. How significant, in your opinion, was his contribution to modern British history?
David Kenyon
Well, Alan Turing's contribution to British history to where we are today is very, very important on a number of levels. The obvious one from Bletchley Park's point of view is that he was instrumental in breaking a number of German cipher systems during World War II, and obviously that gave the Allied powers a tremendous advant during the war, and Eisenhower wrote a letter saying it had contributed significantly to Allied victory. So his role in World War II is the most obvious one. But he was also a mathematician and logician of great powers and significance. And this begins before the war, when he was at Cambridge in the 1930s, he wrote a published paper about a rather obscure mathematical problem, but in it he hypothesized a machine, which I believe we'll talk about later, which was kind of the thought parent of all computers that have existed since. So in that sense, he is one of the theoretical fathers of modern computing. And that legacy, of course, is, as I'm speaking to you now, we wouldn't be doing this had that not happened. So really, really important.
Spencer Mizzen
So he achieved some truly extraordinary things in his life. I wonder if we could now rewind to the beginning of that life. Can you tell us about Turing's early years and maybe give us an insight into how those formative years shaped the man and the scientist that Turing would go on to become?
David Kenyon
Turing is a child of empire in the sense that his father worked for the Indian Civil Service out in India, and his elder brother was actually born in India. He was born in the UK because his mother, Sarah, came back to the UK before he was born. But then, at an extremely early age, he was fostered to a family in Kentucky who brought him up as a foster child, and his parents went back to India. So he had a childhood with his brother, but away from his parents in his very early years. And then he went to a prep school, a junior boarding school at the age of about 8, and then subsequently onto Sherborne School. So his upbringing, he was forced to be quite independent from a very early age. He didn't live sort of in the bosom of his family to that extent. I mean, his foster parents were amazing and they brought him up very well, but he was separated from his parents. And I wouldn't say it was typical for children in the 19th century, but for children within his sort of class, within people who worked in government and military in India. It was not unusual for this situation to prevail, that people would have their children raised in the UK while they were serving overseas.
Spencer Mizzen
And so he went to Sherborne. Did he enjoy that? Would you say he was happy at school?
David Kenyon
I think he was. Broadly. Some of the stories of Turing tend to set him up in sort of. Nowadays, as we call it, he was on the sort of nerd side, not the jock side, if you like. And there is a suggestion that he was somehow isolated or miserable. He was a man of solitary pursuits, or a child of solitary pursuits. He was a great reader and a great experimenter. His housemaster complained that he would set up little experiments on the windowsill of his study and there would be noxious smells wafting down the corridor. But the research I've done shows that he was also a sportsman. He played rugby for his house at Sherborne, and later in life he was a runner of course. So it's possible to be a scholar and an athlete, and I think he was both in a way that he doesn't necessarily get credit for, because people tend to shoebox him as the scholar nerd in the corner, which I don't think he was.
Spencer Mizzen
Can you tell us a little bit about his friendship with somebody called Christopher Morrikhan? Because that friendship and the way the friendship ended would have a profound impact on the young Turing, wouldn't it?
David Kenyon
It would, yes. I mean, he became friends with Christopher Morcom, who was in another house at Sherborne, a different boarding house. And the way the school was set up, you weren't encouraged really, to hang around with people from other houses. There was a lot of competition between them, but he and Morcom were in some of the same classes and spent time in the library, and they really bonded over their interest in mathematics and science, and they would spend long periods discussing abstruse mathematical questions and speculating about science. And Morecambe was interested in astronomy in particular, and he influenced Turing's influence in astronomy significantly. I think Morecambe had a telescope and they would look at the stars and talk about astronomy. Sadly, Morecambe contracted bovine TB in his sixth form years at school and died when Turing would have been about 18. The two of them had actually gone up to Cambridge to be interviewed for positions at Cambridge University. Morecambe wanted to go to Trinity College and Turing wanted to go to Trinity College as well, so he could be there with Morecambe. Unfortunately, shortly after they returned from their visit in their sixth form year, Morecambe died, and Turing was hit very badly by Morecambe's death. But, interestingly, he got in touch with Christopher's mother and he seems to have established a very good relationship with her and with the Morcombe family more widely, and he holidayed with them that summer. And he kept in touch with Christopher's mother for many years. I think she provided an alternative to Sarah Turing, to Turing's own mother. She was a poetess and she kept goats and she was quite, for the 1930s, quite a sort of flamboyant bohemian character. And I think Alan Turing enjoyed that. And so a number of letters survive in his correspondence between Mrs. Morcom and him, and he would go and stay with them and all the rest of it, so that he's a sort of powerful influence on his late teen years. He persisted in trying to go to Cambridge, but Trinity College wouldn't have him. So he actually ended up, as we
Spencer Mizzen
know, at King's College Why wouldn't Trinity College have him?
David Kenyon
I don't know. Especially in mathematics, they are a very exclusive college. You know, you have to be the best of the best mathematically to go to Trinity. But more importantly, he was looking for a funded place for a scholarship, essentially, and he didn't get one, but he got one at King's. So he was clearly up there with the brightest people. But the other thing about Morecambe is he does write to Mrs. Morcom that he felt that Christopher had work that he would have done in maths and science, and that Alan felt an inspiration to sort of pick up the torch and do the things that Christopher would have done. So it certainly spurred him in his academic endeavors in that regard.
Spencer Mizzen
Okay, so he goes to King's College. At what point did Turin's genius first become apparent? Did people around him start to kind of look at him and say, wow, this guy's something special?
David Kenyon
Well, not straight away. It's apparent in his letters to his mother and in Cambridge records that in his first year he didn't get top marks, and he was slightly embarrassed that he hadn't performed as well as he'd hoped. But when he finished his undergraduate degree, he wrote a short dissertation, which was basically an application to become a Fellow. And it was good enough that they made him a Fellow of the College, which meant he had some teaching responsibility, but also he had a place to live, three square meals a day, and funding to do his own research. And it's at that point, as a Fellow of the College, that he really starts to move into territory that is really new in terms of his work.
Spencer Mizzen
Now, Turin's sexuality, he was a gay man, is an important part of his story with, as we'll discuss later, tragic consequences in his later life. But how open was he about his sexuality, especially when he got to King's, and what impact did that have on his time at King's College and on the early stages of his career?
David Kenyon
I think it's a very nuanced sort of situation in the 1930s, because homosexual activity remained illegal until the 1960s. And so you couldn't be openly homosexual or certainly not openly practicing. But Cambridge University and King's College in particular, had a very liberal sort of tradition. And you get the impression that it was quite easy to live not openly, but sort of tacitly as a gay man at King's College. And we know that there are a number of individuals who we know to have been other gay men who were also at King's College at the time. And it was kind of an open secret in the college that he had several relationships with other men. So it's one of those don't ask, don't tell kind of situations. And I think that made life quite comfortable for him. There were intellectual societies which were particularly friendly to other gay men in Kings, but he wasn't one of the popular social set to hang around necessarily in those groups. So some of the more famous Cambridge gay men of the time were sort of more visible, if you like. But one of my conclusions about him in later life was that the only place he really felt at home was at Cambridge University and at King's College in particular. And throughout his life, whether his fellowship continued or not, he tended to go back there. I think it was his happy place.
Spencer Mizzen
So did he feel that he could express himself more openly there without fear of judgment?
David Kenyon
I think so. We know of other gay individuals at Bletchley park who were much more flamboyantly and openly camp, if you like. He was never that, but he was comfortable in able to, you know, he could speak freely to people. One of the subjects that we may get onto when we talk about his personality is that people often suggest that he was quite awkward in social situations, things like that. And that has been attributed to neurodiversity or something like that. But my view is that if you are having to be cautious about your sexuality in a time when it is illegal, inevitably if you go into a big room full of strangers, you are going to be kind of on your guard in a way that a straight person wouldn't be. But I feel that King's certainly was a place where he could relax completely. He didn't have to guard his words, if you know what I mean.
Spencer Mizzen
Okay, so let's look at that in a little bit more detail then. What did people who came into contact with Turing write about him, say about him? What was he like as a person? What was it like to be in a room with Alan Turing? And on top of that, you mentioned earlier that he enjoyed running. I mean, how did he relax from his scientific research? What hobbies did he.
David Kenyon
Cambridge, he took up rowing and he rode in a college eight reasonably successfully. We have some of his bumps trophies in our display case here at Bletchley Park. And he was popular in the rowing club. He spent a lot of time there in terms of if you met him, if you went into a room. No audio recordings of him survived, which is a shame. He did several talks on the BBC, but unfortunately none of them were recorded. So we don't know what he actually sounded like, but he had quite a high pitched voice. And when he was thinking, he would say something and then he would kind of go, ah, well, he was thinking of his next thought, so he would be quite awkward to talk to. But almost everybody who knew him personally describes his sense of humor. They said he was a funny guy when he wanted to be and obviously a very clever guy. And I think when he was at his happiest was when he was talking to people, firstly with whom he could relax, but secondly with whom he could have conversations that he considered interesting, which would mean quite high level, you know, scientific or literary or mathematical conversations. He wasn't a guy for small talk. It wasn't really his thing. But if there was somebody who he could engage with on his level, if you like, he would chat away and be very entertaining. The other thing that comes out is he was very comfortable around children and a number of people said how good he was with their kids and how he was very friendly. And Max Newman in particular, who was his mentor at Manchester but also worked at Bletchley Park. Max's son spent a lot of time with Turing as a child and they played board games together and did puzzles. And people felt that he was really good with kids in that way. He had an ability to sort of return to a kind of childish frame of mind. And I think this is significant in his academic work and his legacy more generally. That what drives not only his mathematical work, but also his biological work and morphogenesis and everything else is he has this sort of childlike sense of wonder. He's fascinated by things of all kinds. And the question he asks about all things is, well, how does that work? How does that come about? And this endless curiosity. He wouldn't be satisfied to be told, oh, it works like this, he'd have to understand it for himself. So his research can be viewed in some regards as a slightly scattergun because he sees things and he goes, oh, that's really interesting. And he picks it up and he prods it and pokes it and unpicks it and figures out. But once he thinks he's got to grips with it, he'll kind of drop it and pick up something else, you know. So that sense of enthusiastic inquiry, I think is a real strong feature of his character. And I think if you, if you caught him on a day when he was really fired up to be interested in something, he could be a fascinating and really engaging chapter.
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Spencer Mizzen
let's talk about the maths in a bit more detail then, David. I mean you're gonna have to bear with me a little bit here. I scraped a sea at maths GCSE 38 years ago, so I can't be described as an expert.
David Kenyon
I got an O level, but that was 44 years ago, so.
Spencer Mizzen
So both quite a long time ago then we can safely agree. But I wonder if you could talk us through perhaps two or three of the great breakthroughs that you achieved in the 1930s. You know, really Murrick him out is a great in the field of computer science. I'm thinking here, for example, of Turing's proof, the famous Turing machine and although this was a little bit later, the Turing pattern.
David Kenyon
Well, the really important moment is in 1935 when as a fellow he writes with Max Newman, who was at Cambridge at the time and was sort of his mentor in mathematics. He started working on the Entscheidungproblem in German, which translates as the decidability problem. And this is a concept in mathematics where the question is whether it is possible that all things in maths can be resolved, that you can write an algorithm that would give you the answer to any problem. And some mathematicians had argued that that actually maths is Fundamentally unprovable on some levels. There are some aspects of mathematics that, while they appear to be true, you could never rigorously demonstrate them using logic. And Turing addressed this problem in a paper called On Computable Numbers, which is published in 1936. He basically proved that the decidability problem in Scheidung's Problem existed, that maths was not fundamentally provable, that this uncertainty principle Godel applied. Actually, that discovery was not massively groundbreaking because another mathematician called Alonso Church, who was working at Princeton at the time, had actually proved the same thing. But Newman went to the London Mathematical Society who were publishing the paper and said, look, even though Church has reached the same conclusion, Turing has reached that conclusion by such a different working methodology that his proof is also really important because he kind of attacked the problem from a different direction. But what makes that paper significant beyond the world of mathematical logic is that in it, as part of his proof of the decidability problem, Turing did a thought experiment. He hypothesized an imaginary machine, which becomes referred to as the Turing machine. And what it did was it did very well, simple logical procedures on an imaginary paper tape. Basically, the machine could print characters on the tape and delete characters on the tape and print different ones and move up and down. And Turing demonstrated that by giving this machine, step by step, instructions, by programming it, as we call it nowadays, although we didn't use that term, that this machine could do almost all mathematical calculations. But the reason it was important in the paper was he demonstrated that there were some mathematical calculations that the machine would never be able to do, or it would get stuck in an infinite loop and never resolve itself. So that thought experiment, I don't think Turing laid it out envisioning that this would be embodied in digital machines in the future. He was just using it as an argument within a paper about mathematics. But as soon as people read the paper, they realized that this theoretical device was actually really important from the point of view of the theory of computing and how machines could do maths, basically. And so one of the slight misunderstandings about it is people talk about a Turing machine as if you could build one, or that if it existed as a physical device, it didn't, it. It would be impossible to build one, because what it actually does is, while very simple, actually very, very complicated. And so it only really exists as a theoretical concept. But it's a theoretical concept that has inspired and underpinned computer development ever since. And it's striking that Turing didn't propose it by accident, but he didn't propose it in order to invent computing. He proposed it in order to solve a specific problem. But one of the consequences of that was he was then able to take up a post at Princeton in the United States. And Princeton is really important in this story because the Institute for Advanced Study had recently been established at Princeton. And this was a sort of think tank of the brightest brains in the world. And so when Turing went to Princeton in 1936, 1937, he was in a world that included not only Alonzo Church, but Einstein was there, for example, Claude Shannon was there, who is one of the other founding figures in computing. The great mathematical brains from the whole world were there. And in particular at that point in the 1930s, there had been an exodus of European mathematicians from Hungary and from Germany, John von Neumann and people like that who would move to the States because of Nazism. So you get this little moment of a kind of hotbed of talent thinking about mathematics and computing. And what's interesting is that the Second World War follows on and some of those people end up at Bletchley park, some of those people end up in Los Alamos on the Manhattan Project working on the atom bomb. And then they all reconvene at conferences and at Princeton and things in the late 1940s. And you can argue that there's a pool of probably a dozen people, including Alan Turing, who are subsequently responsible both for the digital age and for nuclear weapons, which are the kind of the two things that define the late 20th and 21st century, I think. So it's really striking that he's in that group at that time, in the 1930s.
Spencer Mizzen
You've just mentioned Bletchley park there. David, as I said at the start, you're the research historian at Bletchley Park. You're sat there doing this interview. Now, as most people know, Bletchley is sort of the iconic code breaking site, famous for an incredible work that was done there in the Second World War. And your is well qualified, I imagine, as anyone, to talk about this next stage in Turing's life. And when was the idea of Turing going to Bletchley and sort of lending his, you know, his incredible brain power to the fight against Germany. When was that first mooted?
David Kenyon
Well, it was first mooted in 1937 and 1938 because a man called Alistair Denniston was the head of an organization called the Government Code and Cipher School. And this was Britain's code breaking agency. And it had been established back in 1919 at the end of World War I, based in London as part of the Secret Intelligence Service. But Denniston knew that a war was potentially imminent and he applied to the Foreign Office, who were his bosses to say, I need to build my organization, I need to recruit a lot more people, because he only had a team of between 50 and 100 people at that point. And so he compiled what he called a list of men of a professor type. And what he did was he went out to his old boy network and it was mostly boys to find people who he could augment his code breaking team with in event of war. And as I joke to our visitors, he spread his net incredibly widely. He went to both Oxford and Cambridge. In the end, There are about 100 people, mostly men, some women as well, were identified by his friends and connections. And these people were sort of discreetly tapped on the shoulder and told, there's a thing the government's very interested you in doing. Would you be available? And if they said yes? Turing, for example, went on training courses in London at GCS headquarters in March of 1939. Basically, they went for two weeks and they were given an introduction to cryptanalysis and the sorts of things they might be doing, and then they went back mostly to their academic jobs.
Spencer Mizzen
Do you get the sense that Turing was energized by the prospect of lending his knowledge to the war effort?
David Kenyon
It's notable that some of the other people who were on the emergency list did their training and then went away and then got a telegram on the first of September saying, Come back. Turing remained in touch with GCNCs, and throughout the summer of 1939, he worked with Dilwyn Knox, who was head of research on the German Enigma code system. Turing worked with Knox through that summer and indeed stayed with Knox in his house. So I think that he was bitten by the bug of the Enigma problem once he was introduced to it. And as I say, this goes back to his fundamental curiosity about things. It was like, here was a problem that was clearly very, very challenging that nobody else was able to figure out. And that was meat and drink tattooing. That's exactly the kind of thing he liked to do. And so he spends the whole summer of 1939, and when he comes to Bletchley on 4th of September, he carries on in a small team of about half a dozen people banging their heads against German Enigma. And by Christmas of that year, they figured out a solution. So, incredibly significant work, but I think he relished it to a certain extent.
Spencer Mizzen
Okay, there are obviously a lot of brilliant minds at BLETCHLEY during the war, what in particular did Alan Turing bring to the party? Why is his name in particular so synonymous with Bletchley?
David Kenyon
It's interesting that it is synonymous because there are other people who did equivalent work, broke other code systems, were geniuses in different ways. But his story seems to have captured the public imagination. There's no doubt that the work he did, the ideas he had around how you could break German Enigma and Naval Enigma especially, were absolutely game changing from the point of view of Bletchley Park's ability to read German message traffic. So the fact that he was able to contribute to that and come up with some of the fundamental ideas involved in solving that problem is massive. You know, the organization is as big as it was. It was nearly 10,000 people by the end of the war. The reason you need 10,000 people is because you can break Enigma and you can break Enigma because Alan Turing came up with a way of doing it.
Spencer Mizzen
So how important was this work? I mean, how did the work that was going on in Bletchley park impact the course of the Second World War?
David Kenyon
Well, the example I often give, we have an exhibition about it and I wrote a book about it, is D Day. I mean, we've all heard of the Normandy invasion. People tend to think of Bletchley park as a bit like a news agency, that the Germans would send a message and the British would read it and they say, oh, yesterday the Germans did this or tomorrow the Germans are going to do that. Actually, the process is a lot more complex than that. And it's more about collecting thousands and thousands of messages and integrating them all together and indexing all of that information and creating a very large picture of who your enemy is, where they are, what they're going to do. And for D Day in particular, a team at Bletchley park worked specifically on that challenge. From October 1942, for nearly two years, they're collecting nugget by nugget information about the Germans. And what that means is when the generals come to plan the Normandy invasion, they know how many Germans there are, where they are, all 58 divisions. They know their order of battle, they know how many tanks they've got, they know how their communications work, they know the general's birthdays, they have a really complete picture of their enemy. And that means that you can fight a battle with a tremendous advantage. The historian at GCHQ described it as information dominance. This idea that knowledge is power. And by working in such volume, by breaking thousands and thousands of messages, and integrating all of that information, it gives you this huge information advantage. And the Normandy campaign is successful. And this can be applied in other theaters of war, be it the Battle of the Atlantic or Italy or wherever. The information that is able to be gleaned from not just breaking one or two coded messages, but literally breaking thousands of messages on an industrial scale, means that the information advantage that the Allied powers have is absolutely tremendous.
Spencer Mizzen
And you mentioned ouda, but Chorin's name is synonymous with Bletchley. Why do you think that is? Why do you think when most people think of Bletchley, he's probably the first name that comes to mind?
David Kenyon
It's an unfortunate term to use about someone who died so young, but there is a sort of romance about his story and a. About how he did all this amazing work during the war and he made such an influence on the world we live in. But then he suffered as a consequence of his sexuality, and then he ultimately died before his time. And so that gives an edge to his story that if he perhaps had lived to a ripe old age and become a aged, learned professor at King's College, we would think about him in a different way. And one of the things that I sometimes speculate about is that mathematicians tend to do their best work very young. But there's no doubt that Turing would have had more things to say which would have been important. And some of our veterans here at Bletchley park, the fact that they were at Bletchley park is kind of incidental in their biographies, because they went on to be great authors or government ministers or whatever. And so I think in that regard, had Turing lived longer, Bletchley would perhaps fade in his biography in favor of other more important achievements.
Spencer Mizzen
So what did he do after Bletchley? Obviously, the war finished in 45. Where did he go next?
David Kenyon
Well, immediately in 45, he had been working with Max Newman, not full time. He went to Hansloke park and was devising a speech encryption system called Delilah. But after the war, he went to the National Physical Laboratory in Teddington in London, and they were working on one of the first British computers, a machine called Ace. And he stayed at Teddington for a couple of years. But in 1948, I think Max Newman, who was his mentor at Cambridge, and then he worked with Bletchley, Max Newman had gone to Manchester to set up the Royal Society Computing Centre at Manchester University, and Turing was getting a little bit fed up with progress on the computer at Teddington, and Newman managed to persuade him to go to Manchester. And so he went up to Manchester and I can't remember who it was, said this phrase to me. But it was very important that Turing didn't build a computer, but he worked on a computer because he did all the designs for the Ace machine at Teddington, but that didn't get built until after he left. And then he went to Manchester. And at that point Newman's team, which included a couple other people at Bletchley park, actually the Manchester Mark one, the Manchester baby and then the Manchester Mark one that they built up there, were more or less finished. But what Turing did was come in and he wrote the first programming manual for that computer. And he was very key to understanding what it could do and its potential. And so having been at Teddington for a couple of years, he then moved to Manchester. And he remained living in Manchester and employed by Manchester University until his death in 1954. We also know that he was an informal consultant for GCHQ and for the government. So he was still involved in code breaking work, but the nature of that work remains classified. So we don't actually know what he was doing.
Spencer Mizzen
Okay, here's a quick note for our listeners. If you'd like to delve further into this subject. Then why not check out the article about the secret and undervalued work of the female codebreakers of Bletchley park, which is on the History Extra website. I'll leave the link to that article in this podcast. Show Notes. So Turin's life story is one of clearly of brilliance, of genius, of triumph, but it's also one that ended in tragedy. Homosexual acts were illegal in Britain in the 1950s. And in 1952, Turing was convicted of gross indecency and he subsequently consented to chemical castration rather than face imprisonment. Can you describe the events that led to his conviction?
David Kenyon
I can. Turing was living in Wilmslow. He had a house there and he was still an active homosexual. And he would go into Manchester to meet other gay men. Cause there was an underground gay scene in Manchester in the 1950s, and he met a young man called Arnold Murray and they began a relationship. But unfortunately, a friend of Murray's heard about this posh bloke that Murray was going out with and decided to burgle his house. So Turing's house was burgled and he went to the police and the police said, what do you know about this? And he rather naively told the police, well, I think the burglary might have been done by this chap that I was in a relationship with. And the police kind of went, wait a minute, never mind the burglary. What are you and Arnold up to? And that was what he was prosecuted for. The burglar was subsequently prosecuted as well. And it's interesting that in his remarks to the police he was quite frank about it, but he said, oh, I didn't think those things were very important anymore. There was a climate for change at the time around the discriminatory laws against homosexuality, but the necessary legal changes hadn't actually happened yet. So he was duly charged and pled guilty in court. There is some of the sort of mythology around Al Turing will suggest that in some sense the government threw him to the wolves at this point, but that's actually the reverse is true. Max Newman, who was his boss at Manchester University, appeared as a character witness in court. And Hugh Alexander, who had worked at Bletchley park and was now working for gchq, also came and was a character witness for him in court. So to the extent that they could do anything, his professional and government connections were trying to stick up for him, but they weren't in a situation that they could just overrule the law of the land. And much of what he was doing had been secret, so they couldn't really defend him overtly in that sense. So he is sentenced to receive a estrogen derivative supplement for 12 months, which he does. It has a variety of quite unpleasant physical changes on him. But after 12 months, he writes in his surviving correspondence the sort of on the day that the 12 months expired, he'd had a capsule placed in his leg which slow released the chemicals and he went straight back to hospital and said, you can take that out now because I'm done sort of thing. And so it was extremely unpleasant. But after the 12 months, my understanding is that the symptoms receded and he was able to get on with his life. But it had had a number of impacts because with a criminal conviction, his government security clearances were rescinded so he could no longer do his consulting work for GCHQ and his ability to visit the United States was affected. So he was less able to go to America if he wanted. I don't think he was desperate to go to America, but it was one of the long term consequences of his sentence.
Spencer Mizzen
So the conviction would quite clearly have had a significant impact on both his professional and private life then.
David Kenyon
It did, yes. It's one of the controversial areas of his biography is that he's sentenced in January 1952 and he is found dead in June 1954. And some people make a direct connection between the two. And although his death may have been accidental, we don't know. The coroner's verdict at the time was that he committed suicide. And people have suggested that there is a link between his experiences after his prosecution and his death. Whether that's the case or not, we will never know. I've read most of the material that's available about Turing, including a lot of his letters, and it's difficult to prove a link between the two events in my mind. His correspondence after his treatment is over suggests that he's reasonably cheerful, he's getting on with his life. And so his death in 1954 comes as a surprise if you're reading the literature. But also to his friends at the time, people went, well, this is weird. Well, you know, why is he dead? You know, we saw him on Thursday, he seemed absolutely fine. The exact personal and psychological impact of his conviction is really hard to nail down.
Spencer Mizzen
Sure. Now, Turin was given a royal pardon for his conviction for GROSS Indecency in 2013, which was, to put it mildly, somewhat overdue. How important a moment was this? And why do you think it took so long?
David Kenyon
I think it's extremely important because although the legislation had been repealed by the. I think it's the Sexual Offences act of 1967, there were many people still alive, many men who had been convicted of these offences in the 40s and 50s, who still had criminal records, still had this stigma hanging over them. And Gordon Brown had issued his official apology to Turing as Prime Minister back in 2009, but that was just him. In all the other people who'd been convicted, they were still out there. And so there was a campaign that using. Because he was becoming a very, very recognisable figure around the world, his fame was growing. He was a great exemplar of the injustice of the law. And so there was a campaign started in the House of Commons to change the law, had already been changed, but to institute a system whereby the previous convictions could be set aside is the technical term, I think. And in the course of that process, he was given an individual pardon by the late Queen. The problem with pardons is if you are pardoned of an offence, it implies that you were rightly prosecuted for it, but they've let you off. And a great many people felt that a pardon was the wrong term because he hadn't committed an offence in the first place. And so the law that was changed in 2013, or I can't remember exactly when the law was changed or various stages in this process. The law is specifically framed so that people who had a conviction can apply to have that conviction effectively deleted as if it had never happened and their record cleared, which is really important. And it's slightly oddly framed, because if the person who was prosecuted is deceased, it happens automatically. But if you're still alive, you have to fill in a form, you have to apply. But, I mean, it's a diminishing number of people now who carry these convictions. But the fact that they are being symbolically set aside is really important within the LGBTQ community. It's recognition that what was done was wrong, which is really important. And Turing stands as a figure in the public sphere who suffered this injustice. And so he's a great representative of a much wider group of people and of historic prejudice in general. And so he's really important from that point of view. And we are aware here at Bletchley park that his status as a very significant figure within the LGBT community does bring people to the park. And we have a responsibility to acknowledge that aspect of his character and his importance in that world.
Spencer Mizzen
Sure. And his face is now on the £50 note, of course. And the Turing Award recognises contributions of Larson and Maeve, technical importance of computer science. So it does finally feel that he's getting the recognition he deserves.
David Kenyon
His recognition worldwide is absolutely astonishing. We did a piece of research looking at his place in pop culture, if you like, and it's amazing. You can get his morphogenetic patterns that he developed in his later career. He drew colored diagrams of them and those have inspired artwork. You can get them on T shirts, you can get them on shoes. The most astonishing thing was we discovered that a Filipino rapper had written a rap in honor of Turing in Tagalog in the Philippines.
Spencer Mizzen
That's incredible.
David Kenyon
And that shows just how. We have a Spotify playlist of Turing inspired music from all over the world. And it's rather brilliant that so many people know of him, but also find him an inspiration. We need more people in STEM subjects, we need more people to do maths and science, and we need to encourage not just straight white men to do it. We need to get everybody involved. So he's a wonderful exemplar of that, even though he suffered an extreme injustice.
Spencer Mizzen
I was at Bletchley Park a few weeks ago. There's an exhibition on there at the moment about the evolution of AI. Is it possible to draw, do you think, a direct line between Turing's work and the advent of artificial intelligence. And what do you think Turin would make of the world of AI and 21st century computer science? If he was still alive today, I
David Kenyon
think he'd say, I told you so. What's interesting about his work post war in particular, is although he's working on the contemporary computing of the 1950s, he's programming the Manchester mark one and things, he's much more significant as a sort of futurologist, he writes a number of academic papers, in particular his paper in the journal mind in 1950, where he used the phrase can machines think? And he wasn't really so much interested in how do you build a 1950s computer in the relatively primitive way that they functioned at the time, he was saying, right, given the premise that we can build ever better computers, where does that lead us? Will there be a day when, for example, the famous Turing Test, will there be a day when an average person will encounter a computer and they can't tell the difference between a computer and a human being? And that's the so called Turing Test. And it's arguable that we all brush up against bots when our social media doesn't work or when our Amazon parcel hasn't arrived. So we are already living in that age. And his predictions about. Well, they weren't predictions, they were speculations. He was going to what is it about a human brain that makes it special? And will there be a time when a machine can effectively mimic that on whatever level? And we are living in those times now. People are thinking about and designing machines around those exact concepts. So I think you can make a very clear link between what he suggested might happen back in the 1950s and what is happening now, 70 years later. And if you ask anyone in the world of AI, Turing is a significant person to them because he made these predictions he thought about. He was one of the first people to really think about these questions and to not necessarily to come up with answers, but to pose other important questions. And he also popularized it. I mean, he went on the BBC talking about this and he gave talks saying, in the future, will this be the world we live in? What implications does that have for us? And that is profoundly important, I think, because now we still haven't got there. You know, Turing's questions are still open questions, in a way. Will there ever be a machine that can completely mimic a brain? I don't know, but he was one of the first people to ask.
Spencer Mizzen
David, that seems like a really great place to wrap this interview up. So thank you so much. That was absolutely fascinating. Thank you for your time.
David Kenyon
It's my pleasure.
Narrator/Host Introduction
That was David Kenyon speaking to Spencer Mizzen. David is the research historian at Bletchley Park. His books include Bletchley park and D Day. The Untold Story of How the Battle for Normandy Was Wonderful.
Release Date: June 1, 2026
Guests: David Kenyon (Research Historian, Bletchley Park)
Host: Spencer Mizzen
This episode of the HistoryExtra Podcast delves into the remarkable life, work, and complex legacy of Alan Turing—mathematician, codebreaker, and one of the foundational figures in computer science. In an engaging conversation, host Spencer Mizzen and Bletchley Park historian David Kenyon explore Turing's early life, his immense contributions to wartime intelligence, his role in the birth of modern computing, and the tragic circumstances surrounding his persecution and untimely death.
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David Kenyon offers listeners a comprehensive, empathetic, and highly engaging account of Alan Turing's life, the far-reaching impact of his work, the injustices he suffered, and the enduring inspiration he provides to people around the world. This episode is essential listening for anyone interested in the intersections of science, history, social progress, and the human stories behind technological transformation.