Good evening. Welcome, everybody, to the showdown in theatre on a beautiful autumn evening in Oxford.
My name's Mike Wooldridge.
I'm the head of Department of Computer Science and it's my pleasure this evening to host our Michaelmas term Straight to Lecture,
which is our distinguished lecture series. Before I do that, though, I should point out the Straight G lectures are a celebration.
They're a celebration of science, sometimes obscure science, sometimes somewhat more accessible science.
But we have another reason for celebration today.
Some of you may have seen in the press last week that we were delighted to be able to welcome back to
Oxford as a member of the Department of Computer Science and as a fellow at Christchurch College,
Sir Tim Berners-Lee, and as you will all know, is the inventor of the World Wide Web.
Tim is actually with us in the audience tonight with his with his wife, Rosemary and Tim.
Rosemary. You are most welcome back to Oxford. So on to this evening's business lecture this evening is Andrew Hotchkiss.
And I asked Andrew to give me some short biographical details, and this is what he actually told me to tell you.
He's a senior research fellow in the Mathematical Institute. He's been a long time fellow and tutor in mathematics at Wadham College.
His research was in mathematical physics, I think twist a theory under the supervision of Roger Penrose,
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,
and he also tells me he appeared on stage with the Pet Shop Boys in the Albert Hall in July 2014.
In all other respects, a distinguished but in some sense unremarkable career for an Oxford Don,
the kind of career that you would expect an Oxford Don to have.
But the reason that Andrew's here tonight is that in the late 1970s and early 1980s, he did something truly remarkable.
He wrote a book and this is it.
This is my copy of it. I've treasured this book for 30 years,
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.
But nevertheless, I did Treasury. I actually wrote rather quaintly.
I wrote the date inside May 1985. I bought this copy of the book.
The binding is not lasted as well as the words inside it, and the book is the story of Alan Turing.
And what's important to remember is that before this book appeared, Turing's name was completely unknown outside computer science.
And the remarkable things that he did in his life were completely unknown outside the field of computer science and and mathematics.
I read a review of this book and was moved to order it from my bookshop.
The town of Hereford, where I grew up, didn't stop this kind of book in the mid 1980s,
so I had to order it and it made a tremendous and lasting impression on me.
And indeed it's one of those books, as I say, that I've treasured throughout my life.
So why did it make such a lasting impression on me? Well, firstly, it is a fantastic book.
It is ranked as one of the greatest scientific biographies of all time.
I'm assuming you're all you've all Reddit's. If you haven't read it, you should do so.
It is your duty to do so. You will have the opportunity, in fact, to get copies of it.
And Andrew has indicated he'd be happy to sign copies afterwards.
But it is a great scientific biography and rarely do scientific biographies get
under the skin of the science and the thinking that led to scientific innovation.
So that's the first reason that it's remarkable.
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.
There was no Turing story. And when I read the story, I'd never heard of Turing's life.
And I was shocked and appalled at what happened to Turing in the later stage of his life.
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.
And I was astonished to discover the kinds of things that happened in the 1950s in this country.
And it opened my eyes.
It gave me a burning sense of injustice and unfairness and a sense of injustice and unfairness that stayed stayed with me ever since.
So the arc of human history tends towards justice, we are told.
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.
The Turing story, I think, is exactly such a signpost.
We read just the other week of in the press of the Alan Turing Law,
thousands of gay men to be pardoned if they were prosecuted for crimes that are now no longer regarded as crimes,
whatever one might think of that, whether it's a token gesture and so on,
at least it suggests that our thinking as society is heading in the right direction.
I don't believe I believe sorry that the Turing story is actually an important part of that of that trajectory.
It was Andrew that gave us that story. We wouldn't have it in the form that we have it today.
And Andrew, it's really all due to the work that you did in that book.
So I'm very, very pleased to welcome you to give this evening straight to your lecture.
Thank you. Well, thank you very much for that.
I'm not sure I can follow that very easily. And I think you've done a spoiler.
I think you've given away the ending of I will be talking a little bit at the end of that,
more than I usually do about the events at the end of Alan Turing's life,
because I think there is a a need for that, especially when it's been in the news so much in the recent period.
But I'm going to try and give an overview of his whole scientific life before I get to that.
And also, I should remember, while welcoming you that I'm being watched by people who see this as a podcast.
And the podcast people may not know that we're in the wonderful setting of the Sheldon
Ian Theatre and that this goes back to the scientific revolution of the 1660s.
And I would like you to see Alan Turing, who lived from 1912 to 1954,
as as as in that great stream of life, drawing on the past and reaching into our own present and future.
Turing didn't have a strong personal connection with us here in Oxford, but he did have a link with Christopher Straight G,
who became the founding figure of computer science here and whose name is remembered, of course, in this lecture series.
Some people here may also have known Robin Ghandi, Major Oxford figure in mathematical logic.
He was Turing's close friend and first student. And there are many more threads in this great intellectual web linking past and present.
Some of these are brought out in a recent book, not my book, but another book called The Once and Future.
Turing with contributions from leading people in a whole number of fields that Turing touch.
One of these, Professor Scott Aaronson, was a Christopher Straight G.
Lecturer last year, and I'm very honoured that this talk is the successor to his.
It's my pleasure that other contributors Sir Roger Penrose and Dr. Tom Willey,
representing the mathematical biology group Paradox, are also here, along with such fantastically distinguished guests as Michael,
as has mentioned now of all these many threads, of course,
the central one is the emergence of digital technology and the dominating role of the electronic computer.
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.
And all this leads me to choose the starting point for the story, which is not the obvious one,
not the beginning, the usually begin and not the end, although it's extremely interesting.
But it points in the middle 1951 because that's when Christopher Straight, she met Turing at the early Manchester computer laboratory.
1951 was the end of the post-war period.
It was the Festival of Britain. It was the start up for modernism and the flashing lights of those first computers
and a very old fashioned class bound Britain was was an inspiring aspect of it,
I think. Christopher Street, you saw this very clearly and while a maths master at Harrow School,
he wrote this hearing about many ideas, including developing high A-level languages.
And you won't be able to read his typescript, but there are two words in there programme and utopian,
and his idea was a programme to write programmes at a lower level.
Then a utopian idea, but something which advanced people like him was seeing was possible and indeed of course came about.
After further contact straight, she arrived in Manchester with an advanced programme to try out on their computer.
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.
That was the first that was the start of serious operating systems, but also of computer based media.
The Manchester computer played Jingle Bells to the Nation on the radio at Christmas 1951.
And you may have seen recently that an audio recording of the Manchester Computer's tune playing has been recovered.
Street is a love letter programs which had generated syntactically correct random sentences,
also got into the media and served to give a quite new public picture of what computers could be all about.
Right. As Michael mentioned, there would be a day markings, Christopher Street centenary next month.
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
had already started and gave a first stab at machine intelligence all of these exercises.
So this is what I want to emphasise illustrated Turing's concept of the computer as a universal machine.
That was something that was by no means familiar in 1951, and it pushed out the boundaries of what could be expected of computers.
Now, Turing situation at Manchester. I mean, why was he there?
What was he doing? Well, it came about because of having had that idea of a universal machine back in 1936.
In fact, the Manchester. A computer as working in 1948 had been the world's first practical embodiment of his idea.
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.
Taking Alan Turing story along with it. So back to 1936, Alan Turing at Cambridge and specifically a fellow of King's College, Cambridge.
He was not a university lecturer and he was just 24.
Now, he would have been seen as a pure mathematician in Cambridge in the thirties,
but in fact he was in no way restricted by such Cambridge compartments as a student.
In 1932, for instance, he was reading John von Neumann's New Mathematical Foundations of Quantum Mechanics.
More precisely, of course, he was reading the original German.
And you should remember that until Hitler took over and wrecked everything, Germany was still the scientific world centre.
Turing's early work largely derived from that German speaking mathematical world, and he was hiking in Germany several times as well.
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.
He did this after attending the 1935 Cambridge Lectures on Mathematical Logic by Max Newman.
Turing's now very famous work Defining Computer Ability was essentially complete in 1936, and this is the title page of it here,
a title which would have been completely incomprehensible to almost everyone in the world,
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.
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.
I mean, is that curiosity? Because an application now means a computer program.
It's the word people use. And this paper actually effectively defined such programs.
They are what came to be called Turing Machines.
A universal machine can play any program, and so corresponds to a modern computer of the kind which then didn't exist.
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.
And these interesting words, it is possible to invent a single machine which can be used, I mean, to do to do any application.
And universal machines are now carried in your hand and passed at a click from one application to another.
But we should note that actually the app, the application theory was talking about in this work was not an app.
If the whole point was, it's not a program. His proof showed that there could not be no program.
That was so the decision problem that Hilbert had defined a problem which in effect requires the understanding of all of mathematics.
And this is one reason why this deep paper is not just about techniques of computing,
but has a much greater significance, the absolute limitations of the computable.
On another page, a mathematical joke, very typical of Turing is talking about, well, you might imagine doing mathematics.
And at a certain point you arrive at theorem number 157767733, four, four, three, four, seven, seven.
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.
You programmer of the computer has to allow for that that such things have to be you have to think of the computer,
how the computer will read the data and and this and do so systematic way.
So he invented in this paper the whole mentality of computer programming.
And of course, it's not didn't come out of nowhere. It came out of the rigour of mathematical foundations.
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.
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.
This meant going outside mathematics. I mean, he's way outside the box is not what maths people were really supposed to be doing.
And there's a question here, where did it come from? What were the origins of this?
Well, here it's we're in the dark ages. I mean, it's like the once and future King Arthur.
There's very, very little written evidence. There are no precursor papers and no notes.
We do just know of his earlier fascination with a question of mind and matter,
which had taken him first to John von Neumann quantum mechanics in 1932, and then into the foundations of mathematics.
A few more things about that that that history. That's a.
Biologist Max Newman's lectures of 1935, one of the key stimulus.
But there's been new work on the remarkable background to Max Newman's own interests,
showing how exceptional it was not at all the Cambridge mainstream.
There's also new work which gives it shows Turing serious interest in a different but related problem that of characterising random real numbers.
He had a friend, David Champion, who was in the same matter at King's, who published one an undergraduate in 1933.
The observation that a certain rather curious real number has some provably random characteristics in base ten.
Turing took this up and is now seen to have gone a long way with generalising it,
although he never published anything, it was in that same 1936 period.
So there's another ingredient which might explain Turing's very individual formulation of Hilbert's problem in terms of computing numbers.
Well, I'm not really explaining that.
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.
But he was not to do with the actual calculation of numerical problems in this very abstract context.
The universal machine arises like a by-product is on the side.
And yet he certainly appreciated and discussed with his friend David Champion on this very striking property of his invention,
a single machine that could do anything.
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.
Well, we'll come to a nicer one with him here for showing him at Princeton, which was what the passport was for.
He went off to Princeton, which since 1933 was the New World Scientific Centre, in effect, and arrived there and in 1936.
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.
And notably, he's a little bit at the edge of the picture, which is I think is about the correct place.
He was not he didn't put it in self forward as a central person.
He was someone who was always a little bit on the edge of the group.
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
not quite sure why he was looking quite as as brushed up what he was doing.
There was a Ph.D. on Ordinal Logics, supervised by the American logician Alonzo Church.
And that's I mean, a source of a huge amount of post-war thinking about the nature of the computable.
It's nothing to do with practical computing, but on the side, he certainly was interested in implementing computing.
You couldn't have built a universal Turing machine with 1936 technology, but you he applied his interest in implementation to smaller projects.
Very unusual, again, for someone who's supposed to be a pure mathematician, got his hands dirty with it.
And this in particular, he had a machine for computing the Riemann Zeta function on the critical line using various areas,
and that was pursued further in 1939.
And the point of this document here is it shows the interesting figure of £40, which you got from the Royal Society for this.
I think that's the only really successful grant application he made.
I don't think he was a model for research proposals, but not a role model for modern students or postdocs.
But anyway, he managed and another machine he got no support for at all was absolutely his own thing.
And this was the cipher machine. The cipher machine.
We don't know quite what it was, but it was electromechanical. And that raises another very interesting question.
How did he get into the world of codes and ciphers?
Well, his idea in 1937 there at Princeton was an idea which would have to do with beating Germany if war came.
So he said also, he said it arose as a by-product of thinking about abstract compatibility.
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.
So this was the beginning of a very big story. He was pushing as an open door for two reasons.
The first is that JCS, as it then was, and I'll call it HQ,
because that's the same thing now, was actively recruiting mathematicians for the first time.
And secondly, what you might call the liberal elite was at work for him a seamless interface between King's College and government.
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.
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,
his father, Oliver, was one of the World War One codebreakers.
In 1938, a contemporary of Oliver Straight is still when Knox was.
This was one of the senior people in the department. He was a personal friend and indeed ex-lover of Kansas.
Other King's fellows were joined there as well. So it was an easy transition for Turing to take.
No mystery at all. But their main problem was the famous Enigma machine.
And say a little bit about this, but not how it works.
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.
Actually, it wasn't Nazi at all. Ironically, it was one of the few things the Nazis retained and trusted from the Weimar Republic.
It didn't change it from the adaptation that was made in 1931.
European sons, whole level of it.
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.
In July 1939, they gave vital revelations to the British and French who were behind on this, and the ball started rolling very quickly.
War was declared on 33rd of September 1939, and Turing started at Bletchley Park, the new wartime headquarters, the next day.
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.
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.
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,
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.
In fact, you can see the buildings where they worked and the left hand one, the cottage in the stable yard is still there.
Now, in fact, this is an opportunity to say how much there is to see both preserved and displayed at the Bletchley Park Museum.
And the other building is a pub where he lived. No.
I wanted to draw attention to the text here, which has an extremely important date of 1st of November 1939, Turing and Welchman.
So early, I mean, it's just a few weeks into the war and hearing in a Welshman had immediately had their way
as mathematicians and an extraordinary new building machine was already under construction.
Here in this text, it's actually described as a a super bomb machine, which is a great name for it.
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.
And that was essentially Turing's idea of the Welshman had extremely important parts in it later on for improving it.
Some people may know something about this.
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.
It was an algorithm. It embodied an algorithm. It's nothing to do with universality at all.
Now it would be an app and it did something which is comparable with solving tens of thousands of Sudoku puzzles in real time,
very, very quickly, many times a second, which was pretty amazing thing to be able to do in 1939 technology.
And that was the brilliance of Turing's both his logic and his experience with the machine building,
to say that this could be done but done so quickly. The first one was built at Letchworth over the winter of 1930 940,
and it was working in March 1940 before Churchill became prime minister, which a lot of people don't appreciate.
This was all a triumph of the Neville Chamberlain regime. It was called victory.
But victory would have seemed very far off at that point. Here's a picture of it.
And underneath the picture of it is a little sketch of that during his own
writing for explaining the sequence of logical deductions that makes it work.
Now, that wasn't enough. It had to be surrounded by a host of other methods and a special algorithms.
And the Naval Enigma messages were much the hardest to deal with, also the most vital.
Turing took that on, really against the odds, and that was his most individual contribution.
He wrote up the Bayesian probability theory, which he developed for this, and that's a little segment of it.
This paper, incidentally, was only released by GHQ in 2012.
I don't know why, but it was kept back for a very long time.
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.
This theory was probably the deepest contribution.
It wasn't just to do with Enigma. It was used for all sorts of different other cipher purposes.
And so it went into the purposes for which the famous electronic colossus was used later in the war,
and its concept of weight of evidence was essentially equivalent to Shannon's measure of information.
The story after 1941 was very much dominated by the industrial scale of the war.
So over 200 of these machines were built eventually, and this went well beyond the power of British industry to cope.
And the Churchillian part of it, really not the starting off part, but the continuing sustained part of it,
of course, meant giving way to the United States, but trying to retain some British influence.
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,
setting up the basis for what is now really the NSA GHQ relationship,
a very tricky diplomatic mission you will see on these and many went various places,
Washington and Dayton, Ohio, where the new machines were being built by the Americans.
And New York, where the Roosevelt Churchill radio link was being built at Bell Laboratories speech incitement was especially secret,
and the United States demanded that he keep things secret from the other Brits when he got back.
Yeah, but he ran into a lot of problems here. You can see the stories here.
He was kept on Ellis Island because he didn't have the right papers.
He was told that he was going to have access and then it was withdrawn and so forth.
He took a very dim view of this being messed up by security rules, and this was not his thing at all.
I mean, he liked working with the people on the actual stuff, but this was it was a very annoying nevertheless.
It introduced him and this is the important thing for the future story.
This is what introduced him to Hands on electronics.
It was the speech incitement question. This was the key to the future.
This is how logic and electronics first came together.
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,
and Turing went off to a smaller base, Hounslow Park in North Buckinghamshire, where he had a little laboratory.
And there with one assistant, Donald Bailey, he built a what's called the Delilah machine, which is this small scale speech decipherment thing,
I mean, not done for transatlantic communications, but the more modest but with very good security.
And this gave the exposure to some serious electronics with his own hands.
And it was also effectively practice for what at some point he must have decided it was the thing to do,
which was to realise the universal Turing machine idea in electronics with the speed and reliability of the cutting edge digital electronics,
which very few people but he knew about at that point.
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.
But this is at Denslow Park is where all this emerged.
Von Neumann got in first in June 1945 with a plan for electronic computers, the Ed VAC report,
and that's generally regarded as the foundation origin of modern computing.
And so Turing, you know, missed that.
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.
At first they looked at Turing and appointed him to the National Physical Laboratory at Teddington in south west London,
and that's where he produced the first detailed computer prospectus,
of which this is one page here, not an illuminating page to I mean,
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,
had a striking list of examples of diverse applications, including a suggestion for artificial intelligence,
something he'd become very keen on actually in the course of the war,
and probably stimulated by the fact that algorithmic methods, as they'd used in the codebreaking, had been so incredibly successful.
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.
He was probably more in the press for his amateur athletics because he was very keen on long distance running at the same time.
These two things actually came together in in Boxing Day 1946,
the sports reporter of the Evening News asked him about the electronic brain was his idea,
and Turing said, well, the Americans had done the donkey work on it, a somewhat ambivalent tribute.
And I think the only time he ever really commented on the big question of.
Priority, which was still engaged, is a lot of people now on the whole, he didn't care very much about that.
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,
electronic computer, or certainly not his leading part of it.
Well, a cut down version of the automatic computing engine, as it was called, was, in fact, completed in 1950.
And Christopher Strictures first programming in 1951 was for it.
But by that time, impatience with the NPL Turing had moved to Manchester.
He started there in October 1948, after that June 1948, working off a tiny prototype, demonstrating his principle of the stored program.
And that is the there's the early first working a manchester computer, which, again, is a very important moment.
It wasn't Turing's moment. I mean, Turing on the whole, doesn't get as much credit as he should, I think, although,
see, he doesn't get as much attention as it should as being one of the first computers.
But during his connection with the Manchester computer tends to be overstated.
I mean, you might even the read as he built it or something like that. He didn't he didn't even design it.
What is important is that he and Newman told the electrical engineers what a computer was.
It was the whole idea of a stored program embodying the universal machine idea.
The media had caught on very quickly to the prospect of computers.
There were a lot of talk about electronic brains rivalling human capacities right back in the 1946, 47, 48 period.
And Turing rose to this.
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.
This was not at all the line that was approved of by by Manchester University.
I think nowadays they'd be very glad of that sort of a press release coverage.
But in those days that was thought, not the thing, but it led to much stimulating interdisciplinary and philosophical discussions at Manchester.
And it was after that that his most celebrated paper on artificial intelligence,
the paper in the Philosophical Journal in mind of October 1950 called Computing Machinery and Intelligence that came out of these discussions.
And of course, if you've seen it, you'll know that it's written to attract a wide number of people.
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,
introduced as a parlour game with ludicrous text message conversations.
But behind it is a serious question of how to give an objective characterisation of intelligence.
And there's much more in it, too. Although it's most famous for that test idea,
it has this great content of exhibiting the new model of computer ability, the idea of a universal machine,
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.
Also constructive ideas for artificial intelligence, both neural networks and top down programming.
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.
I know what real intelligence and real life involves that made him an attractive character and speaker.
And that brings us back to 1951 where we started.
He was asked to give a third programme radio talk despite not being a very fluent speaker.
And in fact, you'll see the BBC producers report did credit.
They had a lively mind, the BBC thought. But he did have this hesitation in his speech.
I didn't make him a media guru immediately, but nevertheless he was on the radio.
And it was that radio talk in May 1951 that Christopher Straight she heard,
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.
So that's how in 1951, Turing was established in Manchester, a very minor public figure.
He was also elected fellow for our society in 1951, and it was for that 1936 work.
Two characteristic stories, he said.
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.
A young research student, rather tactless. They said to him, Oh, I didn't think of using the phrase.
And he is laughed at that he didn't mind. He is.
He had this lower upper middle class accent, of course, and Cambridge done background, but he still rather had this air of graduate students.
And he didn't have a side, as people said. He was very accessible to people on the right wavelength.
That's a fully engineered mass. Just the computer was inaugurated in that same year, July 1951, and it was summer,
and the organisation was nothing like what had been envisaged originally by Newman.
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.
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.
So it almost got a private or personal computer, whether only three or four in the world.
Now, one can see and there he is at the at the console of the machine on the right there.
Now, you can see all the things that he might have done that I didn't do, could have promoted Turing machines,
theory of computation, started complexity theory, higher programming conferences, books, all sorts of things.
Well, none of that happened. He didn't do that. The future, of course, really lies in software architecture rather than this hardware building.
But it was Christopher Street who followed that line of thought into the future.
Turing himself left it to others. So that brings the question now, having gone to this other state, what does he do with it?
What do you do next? Well, I tell you one thing he did next.
He went on running and he had a new running partner and around Cheshire Villages where he lived.
This was the 17 year old Alan Garner, later famous as the author of the Owl Service and other iconic fiction.
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.
But he was also doing completely new work. And we have very little idea of what the precursor to this was.
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.
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,
an outcome of his interest in intelligence and learning processes.
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.
Anyway, it's classical applied maths.
It's not a business of the discrete as like in networks, it's actually classical analogue and continuous mathematics.
But the computer comes in crucially because the equations that he wrote down cannot be solved analytically,
and the computer gave the prospect of pure scientific research that would never have been possible before.
So his first paper, on the Chemical Basis of Morphogenesis, was submitted in November of that important year, 1951,
and it has become one of the most cited in mathematical literature and a founding work in mathematical biology.
But I'm going to skip a description of his theory,
even though he had a delightful model for the processes of reaction and diffusion in an island of missionaries and cannibals.
Very typical way to illustrate ideas.
I'm going to go straight and quote something very important about the unpublished work that's here and did after finishing this paper.
And this is by Professor Jonathan Dawes.
Building on earlier work, especially that of Jonathan Swensen, who looks at the very difficult pile of manuscripts that Turing left.
He's gone much further in piecing together some of the disordered pages.
And one of his conclusions is that, well, I've posted here and it's essential.
The point is that the work that Turing was doing throughout the two years, from 1952 to 54,
where new ideas and applied mathematics that would have had substantial influence across the whole subject,
they would have spurred the development of parts of the subject that otherwise took several decades to be realised.
In particular, Turing arrives as an equation for a model that otherwise was only arrived at in 1977.
His ideas are relevant not only to biology, but to nonlinear dynamics.
For instance, in the novella Stokes Equations for Fluids.
This was miles ahead, and the Manchester computer, of course, had none of the fast, visible graphic displays that we now enjoy.
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.
Doubt. I mean, you can just see from the picture that he he he should have been living at least 1984 or not 54.
I mean, he was miles, miles ahead and other things in the 5354 period.
There was work in a number theory and he showed himself really up with ideas in quantum mechanics and
relativity and everything was going really well in that his university position was on a more solid footing.
He had a small research group going.
And so you could imagine him as being an absolute leading figure of the 1960s with the new universities, if he'd wanted to.
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.
It was cyanide poisoning. The setting was a strange one of electroplating experiments in the next room and bedside slices.
Apple cyanide organs are full of the cyanide.
And he died the evening before. And it was assumed, I think, perfectly correctly, that he had eaten a poisoned apple.
Now, why? And that gives the attention to this question.
Of course, it's all connected with his being homosexual when all male same sex relations were illegal.
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.
Well, I want to get some picture of his identity as a gay man.
You have to go back because he's not an axiomatic system. You have to think he was a real person now.
I mean, he's Alan now, I think to me. And he himself.
Certainly.
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,
becomes very modernised in such a way that as Michael introduced him to us this evening,
how our legislation, our culture is now involves his story in quite an essential way.
So let's go back and see what what he was like.
What I'm going to give you a nice picture of what he was like at school is in 1919.
These are pictures of 1931. You can see he was in a cell.
He anticipated the selfie. You can certainly see that.
And you can see that he would have had no problem with surfing the Internet at all if it survived.
But the thing is, these are here to see his physical look.
I mean, swimming, running, cycling, hiking, boating.
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.
He was just too early for the jeans and t shirt of the 1960s in which he would have been perfectly happy and acceptable.
That was what he was like. And he retained all that outdoor and and this sort of physical look.
That's what he was like. There's a well-known story that move on.
Yeah, that was a well-known story that he was at school.
He worshipped from a far slightly older boy called Christopher Walken.
In fact,
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.
Christopher then died very suddenly after this, and it had a great impact on Alan Turing.
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.
And in particular, it was actually much closer to another boy called Victor Beutel and helped him get over the crisis in 1932.
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,
because that was the liberal gay enclave with the main Arkansan, a number of other people.
It was the liberal establishment.
And he formed new friends there, one of them being David Champion down, who I mentioned, who remained a lifelong friend,
a very understanding person and indeed a sexual relationship with one of the other math students, James Atkins.
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.
Usual things. Unrequited passion, loneliness.
Why me? Why is this happened? All those thoughts, I think, very much depressed him in that period.
One of those friends was the king's classicist, Fred Clayton, who has been in Germany in 1937,
and they'd sponsored two Jewish boys who came as refugees in early 1939, and they helped them out.
And there's a striking picture here in the last week of peace, the last week of August 1939,
where they took them boating along the front and Fred at the back and the two boys in between.
And I'm yeah. So and went off to war immediately after that and it would seem to me that actually
that the elder of those two boys was probably the person most on his mind emotionally.
I mean, purely emotionally. I mean, there's no no physical contact.
And I think it may well be that this was he didn't.
So this is not a good direction to be going in.
And this is one reason why in spring 1941, he made a marriage proposal to Joan Clarke, who was on their right there.
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.
She and she joined Alan Turing section on Naval Enigma.
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.
And it was essentially doomed, especially as he started immediately on the engagement with a talk about his homosexual tendencies.
Joan knew this was not really going to go somewhere.
It ended in August 1941 in Wales when they had a week off and perhaps there was more opportunity for physical contact anyway.
It was impossible to go on and Alan used a literary reference.
When he called it off, he quoted Oscar Wilde for Each Man Kills the Thing He Loves and so on.
It's from The Ballad of Reading Gaol. So yes, the service, his life.
This is very a very difficult period. It was not something that we found very fulfilling.
He became much more confidence in the later part of the war and in after the war.
One reason seems to be he discovered, I think while in the United States on that liaison trip and then possibly in Paris
when going to on the way to Germany to to to see the German communications equipment,
the possibility of consular pickups. Anyway, back in King's College, Cambridge in 1948, he was much more confident.
That was when he came out and made friends on a new level with Robin Gandhi,
but also made new friends, one of whom became a longer term lover, Neville Johnson.
His name was a boy from Newcastle. He was 24. Then after coming out of service they went cycling in France in 1948,
just the kind of thing that had the best chance of setting, settling into a continuing relationship.
But that was really bedevilled by their long distance problem, which affects so many people.
Alan Turing move to Manchester and never had his job in reading and it was difficult to keep going.
Meanwhile, in Manchester, temptation lurked because by the university there was this unique area, unique in the north of England anyway,
of this sort of gay identified cruising block and Alan Turing could be seen there after 1950 or so.
So that brings us to that fateful year in 1951.
That was when he decided, after submitting his paper, that he had earned what he described as another gay man.
It's interesting he used the word gay, which was then American usage.
It wasn't really the British usage, but there it is in his writing.
And he did. He met this young photo printer called Arnold Murray and took a shine to him.
His chest up line was that he worked on the electronic brain and the electronic brain got everywhere.
And unfortunately Alan Arnold was not a very suitable boy.
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.
He didn't handle it very well, and the police soon came to arrest him.
In fact, both of them are charged in exactly the same way.
Under the 1885, at the same one as Oscar Wilde had been prosecuted under the new conservative government,
was leading quite a crack down at this point. And this was part of what was a very large scale thing that was happening.
Public opinion was entirely in favour of the law as it was. There was virtually no opposition to it.
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.
But the thing is that hearing said what the liberal elite may have thought but kept to themselves, and that was his characteristic.
It was very modern and in 1952 quite shocking, and it did him no good at all.
It's well known now that what happened when he was convicted was that he was on probation,
having to take these hormone injections actually for a year.
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.
I mean, the fact was it was the modern, it was the scientific option.
The irony of this, I'm sure everyone appreciates.
But it did mean that he didn't lose his job as he would have done if he'd refused and gone to prison.
And again, it's often thought that he declined thereafter and fell away and his mind was
wrecked and originality left him by this dreadful assault of the biochemistry.
But there's really no evidence at all.
And that's why I emphasised in this earlier section that he was doing work of the greatest originality stuff that was decades ahead,
and that continued right up to the end. In fact, it was the other way round.
I mean, he really stood up to this and insisted on continuing work of the highest quality, and he stayed.
His whole response to the crisis was very sophisticated. It had that same mixture of dead seriousness and humour, as in the scientific writing.
I had a very agreeable feeling of irresponsibility, he said of the trial, rather like being back at school.
And it's a very upper middle class thing to say for that, but slightly more modern existentialist way, he said.
No doubt I shall emerge from as a different man, but quite who I have not found out.
He made a quite decisive step in this existential question by consulting a union psychotherapist,
Franz Greenbaum, who was another refugee, Jewish refugee from Nazi Germany.
And he was reading in modern literature. And he did. He was writing, too, because he wrote a short story about his experience.
Interestingly, quite avant garde in that he looked at how he himself would be seen by a working class young man.
But the most positive thing of all was escape to Norway of all places.
And that's sorry, that's the photograph at the bottom,
which is from the Scandinavian very early Scandinavian gay rights movement of 1952 and was their magazine.
And that was exactly what he wanted. I mean, that was the idea was was marvellous.
And he switched over to Norway in the summer of 1952, despite being on this treatment and the rest of it and fact it,
he was learning Danish and Norwegian with great enthusiasm.
In Bergen, he met a young man called Kjell and you'll see Kjell theory and kill programs all over the morphogenesis work.
And that's where it where it comes from. He didn't divide his life into into compartments very well.
And indeed, he talks about all these events a great deal with people in the computing laboratory.
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.
I mean, she was she had a point. I mean, he was dangerous to know about one person.
He did become a lot closer. Was Nick Fairbank from King's College, Penn Fairbank you could have seen his name.
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.
Until his recent death, actually the release of some papers.
And Nick Fairbank gives a little bit more explanation for Turing's frame of mind, which I'd like to share with you.
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,
like many people he knew were all least claim to be. I mean, anyway, Maynard Keynes comes to mind certainly was his thing.
His view of the psychotherapy was that a heterosexual side of him could emerge
from the subconscious is unblocked by young young in analysis of his dreams.
Indeed, he told Nick about a dream, which he said proved that this was happening.
It was unusual, I think, as a gay man, as he was never denying his gay side at all.
He was always very positive and open about who he was attracted by and the excitement of encounters.
But it seemed that he hoped that he could feel heterosexual attraction as well, not as some kind of cover story,
but as really authentic and then settled down in marriage, I think very similar to what he'd hoped in 1941.
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.
He went to the club Mediterranee just started and is really the vanguard of the new leisure 1950s, sunny sort of Europe.
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.
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.
Perhaps, perhaps not at all, though, as it was something permanent that he wanted and why he was there.
This is a little vignette of Alan Turing in this so absolutely critical period as the postcard that he sent to the psychiatrist.
And it says, I'm here at Corfu. It is tremendously hot and one wears bathing things all day.
This is not the picture of the shattered person.
There's someone who is actually living life as much as they can.
However, I doubt very much that this came this idea of bisexuality came to anything.
He returned with a long list of Greek and French names and addresses.
It seems that he did find some partners and be astonishing if they were other than young men.
Leopards don't change their spots very easily.
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.
So I think that's an important element of his story.
And we think about the relationship between the arrest and and the trial and his death two years later.
There's a whole journey here. To treat him as a whole person means taking these things into account and not just having a
very one dimensional picture of of a wound and damage and collapse that was fighting back.
There was very considerable uncertainty about what to do.
But then there was something else that had to be has to be taken into consideration as well.
And that is his special status. When the police had arrested him, it was just a very ordinary arrest.
They had no idea who he was, but he was someone special. He was the Anglo-American world's top crypto consultant.
And he, of course, his friends had no idea of this whatsoever, and they had no idea what he'd done in the war.
No one breathed a word about this until the 1970s.
Additionally, since 1948, he'd done further work for GC HQ, which is of course abruptly stopped when he was arrested.
He also had, if you remember, special United States clearance.
So what in 1954 would have been extremely sensitive topic, speech, incitement at once.
What happened was the boy from Norway, Kalle, came over and landed at Newcastle intending to visit him.
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.
The poor sweeties, he said, did not know there was nothing but a kiss with this young man in Norway.
Well, the poor sweeties were not the local police.
This is a national operation. And the reason is obvious.
His activities with their potential for entrapment were real anxiety for national security.
In 1954, it was clear policy to exclude homosexuals.
Absolutely.
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.
It's changed completely now. That was the point of his remark. This is in 1948 on their American influence,
and it meant that during situation was nothing like what it had been in the Second World
War when being a good chap from the right school and the right college was all you needed.
GHQ could hardly have ignored their own security policy when a top scientific consultant very real,
revealed as the very thing they wanted to exclude at all costs.
And not just that. It wasn't just that he was gay. He was involved.
The lowlife is stroppy, utterly unrepentant and set on foreign travel to escape British law.
It's really surprising that he was allowed to go abroad in the summer of 1953 and probably had to fight for permission.
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.
But Robin didn't guess it. I think Turing's humour was sometimes too subtle.
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.
He in March 1953, he announced that he'd put together a chemistry laboratory in his house, mentioned that very offhand.
But that had a real. Meaning it was the means of his death if he chose to take it.
It always had this melodramatic thing about chemistry.
It goes right back to his school days, even joking with Christopher Malcolm about absolutely deadly substances.
He had a slightly melodramatic and slightly morbid interest in this in this whole thing.
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.
And it turns out that she wrote behind his back to the dean of the Graduate College in Princeton saying To wash out,
there might be some unforeseen emergency and they should know how to contact the Turing family if such a thing happened.
Clearly, she knew something, and this was classic interference, but she had a real point.
In 1937, Alan Turing wrote to his King's College boyfriend, James Atkins, about having a suicide plan.
Indeed, there was an event in 1937 could very well have triggered such thoughts.
And the plan, as James recalled to me, involved an apple and electrical wiring.
And the point of the plan is to have a plan at all was that it was to disguise suicide as an accident,
as a chemical accident and accident doing a chemistry experiment.
And it was for the sake of his mother. I mean. So other people can confirm some of this.
And so he knew his mother well, and she did indeed fall for this.
Exactly. And believed that he had transferred the cyanide by accident from the experiment to his apple and ate it by mistake.
Getting the sun was easy. He got it from the Manchester Chemistry Department.
Very telling is that after March 1953, the same point, he was pressing Nick Fairbank to be the executor of his will.
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,
is using Nick's own interest in French literature,
and it puts it as something that might be necessary since trouble might come again, and it puts it in that way.
And Nick agreed that Will itself was was signed in February 1954, very careful, totally unconventional.
He cut his lawyer brother completely and devises his estate between the five most supportive people in his life.
Nick Robyn Neville, David Champion and his mother.
Now we don't know what happens. Robert Hannigan's recent statement from GCA HQ says that they stood by him.
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.
But from the point of view of security and Alan Turing would have seemed criminally irresponsible if not certifiably insane,
it would be very hard, very hard for you, Alexander, to argue that he did not need to be protected from himself.
The Cold War was at its height in 1954. Opposite number Robert Oppenheimer was effectively on trial.
Turing's friends and contacts would give no cause for complacency.
They included numerous communists, as well as atomic scientists.
But the main thing was he knew what hardly anyone in the world knew.
This very nature of Anglo-American communication, crypto and security as the biggest secret of the lot in the circumstances.
The amazing thing is not that he went, but that he lasted so long.
He was a man who tried to be honest and truthful, which is what Newman said for him at the trial.
But he was cursed with two things which went in the opposite direction and made everything a lie.
The secrecy of the war work and the criminalisation of his sexuality,
the combination of them both in the security issue, was clearly absolutely toxic.
It's hardly surprising that he was crushed. Well,
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
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,
which I referred to at the beginning, is a web in which he himself believed an individual only contributes a little bit.
It is essentially a communal operation, and that's something where he ceased.
But what he did lives on. Secondly, I should have done this at the beginning that I should thank Oxford Asset Management.
Oxford Asset Management are our sponsors for these events. We couldn't.
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.
So we're tremendously grateful to them. You can find out more about Oxford Asset Management over there.
You can find out more about the department and what we do over here.
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,
you're very, very welcome to over that. But one more time.
Andrew, I've been waiting 31 years to hear you give this lecture.
You didn't disappoint. That was a fantastic straight G lecture. Thank you so much.