Original subtitles

One day ladies will be walking their computers in the park and saying

'do you know, my iittie computer said a very funny thing to me this morning'.

In 1952, the greatest mathematician of his time

the man who gave birth to the computer age was in torment.

He was a recently convicted criminal.

In distress, he turned to a psychiatrist.

So what did you say to the police?

I told them I'd been having an affair with Arnold Murray

and that he'd given my address to a young man

who was known to burgle men he'd met for sex.

This man was Alan Turing.

Just a few years before, he'd helped to turn the course of World War Two

by cracking Germany's secret military codes.

Turing is one of the great original thinkers of the 20th century.

He had thoughts that nobody else was having.

Ten years earlier, he'd laid down the foundations for the computer.

There's often a seed that everything came from.

Alan Turing basically came up with everything that computers do today.

During his lifetime, Turing's achievements went unrecognised.

Instead he was disgraced.

But I can't get it outside myself to do it.

We all have decisions to make.

What are you saying?

I wish they'd leave me alone.

This film tells the story of Alan Turing

and how his ideas changed our world.

You may have something there, doctor.

The psychiatrist Alan Turing sought help from was Doctor Franz Greenbaum

a German Jew who had fled to Britain just before World War Two.

Presumably you'd like me to stop as well

but I can tell you now, there's little point in trying.

Like you to stop what?

Pursuing... male...

Male?

Companionship.

We're not here for me, you're here for you.

It doesn't matter to me what you do as long as you're not in conflict over it.

Our father Franz Greenbaum was treating Alan in the early 1950s.

He turned up in the most extraordinary clothes when he came.

He looked as though he'd been out of a rag bag.

I don't think our Dad was in any way prejudiced...

towards homosexuality. - Oh, I'm sure he wasn't. No.

At that time, in England, that was considered quite way out.

So, how do we do this?

We talk.

What do I have to say?

You don't have to say anything.

But you should feel free to say whatever you like.

There are some things I can't say, things you can't know, about the war...

Things you can't even think.

There are some things about which I'm under an obligation

a legal obligation, to remain discreet.

Well, there may be things that you feel you can't discuss

but direct conversation is not the only way that material gets conveyed.

How else does material get conveyed?

Through dreams, for instance.

Well then, I certainly won't be telling you my dreams.

I am his nephew. That means that my father, John, was Alan's older brother.

John and Alan were sons of the Empire.

Their father, my grandfather, was in the Indian civil service.

When my father was four years old and my grandmother is pregnant with Alan

they're sent back to England and are left with a foster family

and they don't see their parents again

until my grandfather has his next bout of long leave

which is going to be in several years' time.

I mean, I suspect that some of the eccentricities or perhaps being withdrawn

or being able to disappear into his own world could be attributed to some of that.

We're in the archive of Sherborne School and this is a photograph from 1926.

Alan Turing, who was then 14, is on the far left on the bottom row

looking at the camera very intently with great concentration.

You almost wonder if he was thinking about the camera and how it operated.

These are reports on his mathematics.

'He has considerable powers of reasoning

and should do well if he can quicken up a little and improve his style.'

His teachers didn't recognise they had a tremendous mathematical genius in their midst.

This is the log book of the Sherborne School library.

We see that he checked out Alice In Wonder/and and Through the Looking-Glass

on 11th of April 1930.

Interestingly, there are three books he took out that day.

Alice In Wonderland, Through the Looking-Glass and The Game of Logic.

There's this wonderful picture that his mother drew

called Hockey or Watching the Daisies grow.

And there is Alan with his hockey stick

ignoring the game, bending over and studying the daisies.

I think he's a bit of a loner. I think there's evidence of that from early on.

Turing was not someone who thrived in social situations with lots of other people.

He was very athletic but his sport of choice was running

which is of course a very solitary sport.

He had one very great friend who was a boy named Christopher Morcom.

Morcom was, I think, more important to Turing than any other human being in his life.

Turing was probably, in an adolescent way, quite in love with him.

I think, in a way, it was a kind of hero worship.

I think he did idolise him. I think he worshipped him.

There was someone I knew at school

someone who didn't at all approve of dirty talk.

Once or twice I tried to shock him but it didn't work out.

What do you mean, it didn't work out?

He didn't take the bait.

He was just... above it.

He made me want to be good.

He was in a different house.

And boys in different houses weren't meant to fraternise.

So I could only see him on Wednesdays when we both happened to be in the library.

He would make fun of me for my sloppy handwriting

for mistakes I made... the careless errors.

He made me want to improve my standards.

He was an example.

He was a friend.

I didn't care about his example.

What did you care about?

I cared about what I was in his eyes.

More so, in a sense, than what I was in my own.

Morcom's influence on Turing was absolutely enormous.

His importance was very, very profound and very deep

both intellectually and emotionally.

Christopher was a great scientist with tremendous gifts and tremendous curiosity

curiosity to match Turing's.

So they would often stargaze together.

They were both very interested in astronomy.

They were more than just pals.

There was a great intimacy between them

but a very innocent... it was entirely innocent of sexuality.

I think if you find a person like that

and I don't think everybody does find one

in fact I think it's terribly rare

then all you thought before

all your plans for yourself, you realise they were just filling a gap.

It was just something for you to do while you were waiting for this person

and everything you want to be is something for him, not yourself.

There is a drawback, however.

Finding such a person makes everybody else appear so ordinary

and if anything happens to him

you've got nothing left but to return to the ordinary world

and a kind of isolation that never existed before.

At the beginning of December 1929

Chris and Alan went together up to Cambridge for the scholarship examinations.

And at that time, they were both hoping that they would succeed and obtain scholarships

and go on to study together at Cambridge.

It wasn't known, of course, it couldn't be known

to Alan or to Chris

that shortly afterwards, Alan was to lose his best friend.

Chris died on the 13th of February 1930.

One friend put it quite accurately

when they said, 'poor old Turing was absolutely bowled over'.

Chris had contracted tuberculosis as a child.

He suffered from poor health all his life but he never complained.

He was very private that way.

When I heard he was dead

the world threatened suddenly to be so different.

I found ways of dragging him around with me to ease the transition.

I wrote to his mother a number of times.

I made no secret of the power of my feelings.

I told her I absolutely worshipped the ground on which he walked

and she, being his mother, found no reason to quibble with this.

We shared in the loss of him.

I asked her for a snapshot and she gave me one.

I have it here.

See?

This is a letter from Alan to my grandmother, Chris's mother

dated the 20th of February 1930.

He said, 'During the last year I worked with him continually

and I'm sure that I could not have found anywhere another companion so brilliant

and yet so charming and unconceited.

[Turing's voice] '/ regarded my interest in my Work as something to be shared With him

and I think he felt a little the same about me.

I know that I must put as much energy into my Work as if he were alive

because that is what he would like me to do.

Yours sincerely, Alan Turing.'

My mother was very worried at the time

because I insisted that Morcom was still with me

working with me, helping me.

He was my companion

and in some ways he was an even steadier companion after his death.

I didn't want to frighten anyone, but I knew he was still there.

After Chris's death, Alan was determined to go to Cambridge

and in fact Alan did end up with a scholarship to King's College.

Turing felt that there was unfinished work

which Chris had started and which he wanted to continue.

It was while he was at Cambridge that he wrote what would prove to be

I think, one of the...

seminal papers in mathematics of the 20th century.

I don't think anyone, Turing included

was remotely aware of the significance that this paper was going to have.

It introduces the idea of the computer.

Well, in my mind, the reason Alan Turing is

well, one of the greatest scientists of the 20th century

is this paper.

All our modern computers, from laptops to video games

are exactly what he laid out in this paper.

When Turing did his early work on computers

the word 'computer' didn't mean a machine, as it does now.

It meant a person.

It meant a person who calculates, who computes.

Hundreds and hundreds of young women with mechanical calculating machines in a room.

And they would do little bits of calculation and write the answers down on cards

and pass them along to the next person in line.

And so Turing is clearly starting to think 'can we automate the whole thing?'

And the answer he comes up with is 'yes!'

He was working on a mathematics problem.

Almost incidentally to a solution of that problem

he did a construction that he called the universal machine.

And what that construction did

was just change the way people thought about computation

in a very fundamental way.

Turing's Universal Machine was purely hypothetical

but it laid out the fundamental principle underpinning all computers -

that any conceivable mathematical calculation can be done by a single device

shuffling ones and zeros back and forth.

This is a model of his theoretical machine from this maths problem.

And the way this works is, he said, you'll have some kind of processing head

which is basically what the machine actually is.

It would be looking at a tape.

And so we've got here a tape with symbols on it.

And the machine would have instructions.

So as it reads different symbols, it can move the tape forward

it can wind it back.

And it could generally process the information on the tape

And part of Alan Turing's genius was to realise

that a machine like this can compute absolutely anything

because anything can be written as ones and zeros.

And this is the basis of all computers.

And the introduction of the universal machine

made up of apparently absurdly simple components

a strip of paper, a pencil

a wheel to move the paper left and right

a set of very simple instructions.

These apparently trivial devices turn out to have the most profound implications.

I've got here a generic smart phone.

And if you crack this open, inside it in the centre here is the processor.

So this chip here does exactly what Alan Turing described this machine doing.

And on the back of this I have the memory, which is the tape.

And again it's exactly what Alan Turing described.

A single machine that can be programmed to do virtually anything.

In the coming years, it would be seen as a moment of discovery, like Newton's apple.

The digital age had begun.

People credit Turing with the invention of the computer

because he invented the concept on which everything else was built.

[Archive footage narrator] 'In the electronics age

the development of giant computers, electronic brains, has been a key development...'

He writes something that is so original

that you can't categorise it into any of the normal mathematical categories that are around.

He started something genuinely new.

When you look back at something like computers

there's often a seed that everything came from.

Alan Turing was sort of at the top of everything that ever developed

all the future research that was done by people building real equipment

that can clink, clink, clink - compute!

One day ladies will be walking their computers in the park and saying

'do you know, my little computer said a very funny thing to me this morning'.

We have universal Turing machines in hardware in our homes

and we use them for dozens and dozens of different tasks.

Very few parts of our modern life aren't impacted by Turing's ideas.

The things that he contributed to computer science

weren't the things that just happened to be true in one particular year

or in one particular decade.

They're the things that are fundamentally true.

So they're always goings to be with us

in the same way that the things Galileo and Newton contributed to physics

are always going to be with us.

All our modern computing grew from this one idea of Alan Turing's.

Incredible.

But that would be the future.

Back in 1939, Turing's brilliant visions were interrupted by the shock of war.

In 1939, with the advent of the Second World War

Turing was recruited to be part of a team

who were involved in the effort to break German codes.

The centre of operations for this code-breaking effort was Bletchley Park

which was a country estate, equidistant from Cambridge and Oxford.

And also very easily accessible from London.

It was a completely secret effort.

There's never been a place where secrets were better kept

than they were kept at Bletchley.

We were on our honour not to talk about this and we didn't.

My parents never knew what I did until the day they died.

It was an extremely eccentric bunch of people who were recruited.

There were mathematicians. There was a British chess champion.

There were people who had won contests to do crossword puzzles in a very, very fast time.

Turing was, in some ways, the main architect of the code-breaking effort.

You needed exceptional talent

you needed genius at Bletchley, and Turing was the genius.

I regarded him with a certain amount of awe because he was 'The Prof'.

He was just regarded as very clever.

The Germans were coding their messages using what was called an Enigma machine.

What you have here is a German Enigma machine

developed in World War II

to encipher messages between parts of the German forces.

The whole point about the Enigma machine

is it could be configured in a large number of ways -

15 million, million ways.

The German operator set the machine up

keyed the message in which scrambled it

transmitted the scrambled text.

The other intended recipient had a machine set to exactly the same settings

and that descrambled the message and revealed the plain text.

The Germans believed that this machine was completely unbreakable.

Turing sat down with an Enigma machine, and he looked at it

and he thought I can break that.

I had a dream.

Oh, good.

I didn't write it down though.

You should write them down.

What did you dream about?

I dreamt about Joan Clarke.

We worked together. I can't say.

Of course.

But, we were...

It was...

There was a war on.

I 'loved' her.

Or rather - I didn't not love her.

Joan Clarke was a rarity at Bletchley.

She was a woman who did the same work and had the same status as male codebreakers

but she was probably paid less.

She was a mathematician.

It was known that she and Turing had been close.

Joan and I, we...

we went to the pictures.

One didn't have to speak differently to her.

One could be amusing, have a laugh.

One didn't have to pretend.

Anyway, I thought that if she was so sporting

one might just as easily imagine her as a wife.

So I proposed marriage and she immediately said 'yes'.

And just to be as sporting with her as she was with me

I told her straight away that I fancied men.

And... this didn't bother her a jot.

At least she gave no outward sign.

It was a surprise to me when he said, I think his words probably were

'Would you consider marrying me?'

He told me that he had this homosexual tendency

and naturally that worried me a bit

because I did know that was something that was almost certainly permanent

but...

we carried on.

Turing was doing something that was fairly common at that time

which was, he was going to make an effort.

He was going to make a sort of stab at heterosexuality.

What was interesting was that he never even reached the phase of marrying her.

He realised very quickly that it was not going to work.

Did you never tell her that you acted on your desires?

No.

Joan and I, we were interested in how mathematics expresses itself in nature.

I thought our wonderful conversations would be enough for both of us.

But a moment came

when you realised you would never be able to be as honest with her

as she was with you?

Yes.

So I called it off.

I knew it would hurt her.

But it would hurt her less than years of deceit?

Yes.

Turing was such, in some ways, such an honest person.

Most would've married and either led a sort of secret life with other men

or eventually divorced their wives.

And what this suggests to me was a much higher degree of self-awareness

than a lot of other men of his generation had.

I learnt nothing about his homosexuality at Bletchley.

Turing was a very eccentric person.

He would wear a gas mask as he went into work on his bicycle

because he suffered from hay fever.

He often went into work with his pyjamas under his jacket.

This is the most eccentric thing of all: he couldn't trust the banks.

He therefore decided he would buy silver ingots.

And he would plant them in the park.

But he forgot where he had planted them.

And they have never been found since.

For Turing, wartime Bletchley was a paradise.

It didn't matter if you were different.

All that counted was outwitting the Germans.

The greatest threat to Britain's survival was the war in the Atlantic.

Convoys were being attacked by German naval U-boats.

It mattered because we depended on sea transport

to get an enormous amount of supplies into the United Kingdom for the war.

Defeating of the U-boats was the most important task we had to perform

and without it we wouldn't have been able to win the war at all.

We knew how important it was

and we knew also that when we were not breaking

what the consequences were.

We had somehow or other to break the U-boat codes.

Turing considered that the major way of attacking Enigma cyphers was with cribs.

That is known plain text, in modern speak.

And this is where you could guess the German text

which the operator had keyed into the machine

in order to get the cypher text, which you have actually intercepted.

A crib might be something so simple as a word that would often occur

such as the word 'weather'.

The Germans always reported to each other on the weather.

So the word 'wetter' - W-E-T-T-E-R, became a very useful crib.

Time was of the essence.

And the conceptual breakthrough that Turing came up with

was: well, if a machine is being used to code these messages

we need to build a machine to break the code.

The machine, designed by Turing and a colleague, Gordon Welchman

was called The Bombe.

There were over 200 of these machines

working 24 hours a day, 7 days a week

looking for the settings on the rotors of the Enigma machine.

What the Bombe did was to explore the relationships

between the cipher text and the crib

looking for the Enigma configuration.

It would've taken people with pencil and paper weeks to do that by hand.

And the Bombe could do it in a few minutes.

Within a couple of years they were able to read virtually all the Enigma traffic

except for the traffic that was pertaining to the Navy.

The reason it was so difficult to crack

was because the Enigma machine used by the German Navy

had even more permutations that it put the letters through.

Nobody had actually managed to break the naval Enigma system

and understand this extra level of complexity.

And that was what Turing did.

He realised that you could actually use mathematics.

That if you applied maths to the codes and the ciphers

then you could reduce the space that had to be searched.

You could then use the Bombe to search those reduced spaces.

He just took a large number of messages which were intercepted

and he sat down and played around with these, pencil and paper

and he worked it out.

Suddenly, we could begin to break the messages

from the German high command to U-boats in the North Atlantic

and that was absolutely vital.

We certainly couldn't have gone ahead with D-Day when we did

if we hadn't cracked naval Enigma.

This ability to crack the code and thereby read the German military traffic

helped the allies strategically so much.

Alan Turing's contribution cannot be overstated.

I think that Turing's own personal contribution towards winning the war was crucial.

At the end of the war

we all left Bletchley without being allowed, as it were

to say anything about what we'd been doing

which I think was a very great mistake.

I think we could've said more.

Turing's contribution was virtually unknown during his lifetime.

And in fact, it took quite a few years after his death before it eventually emerged.

Somehow the step of recognising and acknowledging and thanking him was skipped.

He was treated abysmally by his own government.

By the time the war had ended, a new age had already begun.

The computer age.

And Alan Turing was at the heart of it.

In 1945, he designed one of the world 's first computers.

The theoretical ideas he'd laid out in his 1936 paper had become reality.

[Archive footage narrator] 'Manchester University

where anyone who urgently wishes to know

Whether 2 to power of 127 minus 1 is a prime number or not

can be given the answer by an electronic brain in 25 minutes

instead of by a human brain in 6 months...'

in 1948, Turing joined the mathematics department at Manchester University

to work in a new computer lab.

Computers had only just been invented.

The prototype computer was built here in Manchester

and it ran its first program in June 1948.

It was early years in the era of using computers.

[Archive footage narrator] 'The brain at present is only in the experimental stage.

The answer being read from a cathode ray tube.'

Though by our standards these computers are primitive

they sparked an extraordinary idea in Turing's mind.

After a while, he started to wonder, could a computer ever be truly intelligent?

Can machines really think? Even the scientists argue that one.

He's obviously realised the potential power of these machines.

He can see where they're going and he's tackling a basic philosophical question.

Can a machine think?

Why can't something of a person remain alive?

I'm not mad.

I don't believe an individual consciousness could be transplanted into a machine now

though given a few years, who knows?

But for now I only ask

can we not house something like a human consciousness inside an inorganic vessel

something permanent, so it will remain and learn

and achieve something like wisdom, a wisdom to which you and I can refer?

Would it ease your grief over Christopher Morcom?

The creation of this machine of yours.

No, no, yes, but not in the way you think.

Not because I myself could vindicate Chris's mortality by creating another intelligence.

It wouldn't be Chris after all, so how could it possibly provide any relief?

No.

But because it would show Chris his living hadn't been in vain.

That he would have inspired me to create something

an intelligence, not his, but in his name.

Something that would never die.

There's no question but that Alan Turing

was the real father of AI

of Artificial Intelligence.

He was already making the argument that there could be such a thing as a thinking machine

an intelligent machine.

Towards the end of 1950, Alan Turing published a remarkable essay.

And in this essay, Alan Turing argued that it was possible

to work out whether machines possess intelligence.

Turing's basic idea is that if you're trying to decide whether something is intelligent

it doesn't matter what's going on inside, all that matters is the output.

His idea was that computers, if they can pretend to be intelligent

then we may as well consider them intelligent.

He realises there's a whole world of philosophical debates and arguments

about what is and isn't consciousness.

Frankly, he said

if computer can convince you it's acting intelligently, who's to say it's not?

Turing proposed something he called the Imitation Game.

He imagines a machine and a human and a judge.

If a machine can convince the judge that it's a human

the machine should be judged to be intelligent.

That's the Turing Test.

Turing is one of the great original thinkers of the 20th century.

He seemed to be able to see further.

You get a feeling when you read his work that his mind is way out in front.

Until now Turing's work had been secret, or comprehensible only to mathematicians.

But his ideas on artificial intelligence caught the public imagination.

He was now being quoted in the national press.

[Turing's voice] ' This is only a fore taste of what is to come

and only the shadow of what is to be

but I do not see why it should not enter any one of the fields

normally covered by the human intellect

and eventually compete on equal terms.

I do not think you can even draw the line at sonnets

though the comparison is perhaps a little bit unfair

because a sonnet written by a machine would be better appreciated by another machine.

Turing was attempting to demystify the idea

that human beings have a sort of exclusive ability to experience emotion

to experience pleasure, to experience pain.

Very, very controversial thing to say

because it was in effect taking mankind off the pedestal that mankind had put itself on.

The idea that robots and computers challenge us with

is their ability to imitate what we do

and therefore it becomes more and more difficult to tell the difference.

What Turing's argument did was to give computer designers ambition

and everyone else a sense of the scope and scale of what might well happen.

Because, what he understood from his wartime work and his work in the later 1940s

was that it would be possible to make systems of machines of unimaginable scale.

They would develop, they would have experience

they would have careers and in a very interesting way they would have lives.

And that mixture of ambition and clarity, I think, is one of Turing's greatest legacies to modernity.

Turing's ideas on artificial intelligence established him as a visionary scientist

but there was more to his life.

By the 1950s, Alan was in one sense an ivory tower intellectual

but in another sense he, you know, he lived, occasionally at least, on the streets.

In many parts of Manchester, there were cruising areas for gay men

where people could meet other men from all classes and situations.

For someone like Alan, entering the gay scene, the queer world

must have been intensely thrilling.

Surrounding all this of course was the threat of the law

because male homosexuality was totally illegal

whether in public or in private.

Turing, at a certain point in Manchester, met a young man named Arnold Murray.

Meeting Murray started this chain of misfortunes that eventually led to his arrest.

So what happened?

I met a young man - Arnold Murray - in Manchester. On the Oxford Road.

He looked hungry, so I bought him a meal.

I gave him my address and later he came to my home to see me.

He spent the night.

He was 19.

He didn't have a privileged upbringing but he has aspirations.

I know in a sense he brought me down

but I feel sorry because I brought him down as well.

I think Turing, like many other men of his generation

would've felt they were living on the edge.

Not all the time

but were aware that one step into the wrong direction could push them over the edge.

He would've been aware of the risk.

Perhaps he wasn't entirely surprised when disaster struck.

I think he stole from me.

A few pounds, but I couldn't be certain.

I accused him. He became angry. I weakened.

He spent the night again.

This theme repeated itself throughout our acquaintance.

And then one day I came home and found I'd been burgled.

Alan invites this young man into his home.

And the result of this encounter or series of encounters

is that my grandfather's pocket watch

which was given to Alan as a very special gift, was stolen.

So I confronted Arnold.

I believed him when he said he'd had nothing to do with it himself.

He'd been chatting to a friend of his

Harry, who was a proper renter

not like Arnold, who appreciated favours

but would absolutely accept no cash unless it was dressed up as a loan.

Anyway, this Harry, he'd seen a letter Arnold was posting to me.

He'd seen my address.

Arnold talked to him about me,

told him that I worked on the electronic brain.

And this must have suggested privilege.

So Harry concocted this burglary in Arnold's company

but Arnold did nothing to warn me about it.

In his defence, when I confronted him, he spilled everything.

Turing was such an honest person

and he was so much the opposite of calculating

he was not Machiavellian in the least.

He'd been robbed.

When you're robbed you go to the police.

He was naive, in a lot of ways.

He had faith that the system would protect him

and that turned out to be a disastrous misstep on his part.

And of course the police then discover that they'd hit the jackpot.

They'd discovered that he had a young man in his house

and there couldn't be any sensible reason for him being there

other than something which was criminal, disgusting

and, you know, possibly a security risk.

The police didn't care about the robbery.

The police were much more interested in arresting a professor

on charges of gross indecency.

So what did you say to the police?

I told them everything.

I told them I'd been having an affair with Arnold Murray

and that he'd given my address to a young man

who was known to burgle men he'd met for sex.

And you told the police that you had sex with Murray?

They asked me what we got up to.

I told them we engaged in mutual masturbation, soixante-neuf, and inter-genital friction.

Soixante-neuf?

Sixty nine.

Yes I know what it means.

I was just wondering, why you would say that to the police?

I told you. I revealed everything.

I was wondering

if you cloaked it in elitist language to keep the police in their place.

They're unlikely to speak French, aren't they, the police.

To say that they may be the foot soldiers that are out there to enforce the law

but you, who speak French, are amongst the lawmakers

the politicians, the inventors, the forgers of new paths.

I wanted my watch back, my father's watch.

I wanted them to do their job.

But as soon as they knew you were a sodomite

you gave up your right to command them.

You became their prey.

I didn't go down for sodomy.

I'm sorry, I thought you practised sodomy with Murray?

For God's sake, would you stop saying 'practised sodomy' as if it were the bloody piano.

And the charge was not buggery

it was 'Gross indecency contrary to Section 11 of the Criminal Law Amendment Act of 1885'.

It was the same law that convicted Oscar Wilde.

It's good to know things are moving forwards.

You're right, by the way.

As soon as they learned I was a homosexual the burglary more or less vanished.

One of them actually said to me

'if you consort with naughty people, naughty things are bound to happen'.

As if by having sex with another man

it was fit and proper that burglary should follow close on its heels.

[Turing's voice] Dear Norman

I've now got myself into the kind of trouble

that I have always considered to be quite a possibility for me

though I have usually rated it at about 10 to 1 against.

I shall shortly be pleading guilty to a charge of sexual offenses with a young man.

The story of how it all came to be found out is a long and fascinating one.

No doubt I shall emerge from it all a different man

but quite who I've not found out.

Yours in distress, Alan.'

In March 1952, Alan Turing was convicted of Gross indecency.

He'd become well enough known for it to be a public disgrace.

What the court ordered was effectively to have Turing chemically castrated.

That was to effectively remove his body of the male hormone testosterone.

He's given a choice. He could go to jail or he could agree to this treatment.

He chose the so-called organo therapy which amounted to chemical castration.

Turing was probably given a drug that we now know as stilboestrol.

That is a synthetic version of the female sex hormone, oestrogen.

He had to attend the Manchester Royal Infirmary

on a monthly basis for the first 9 months.

He had to take daily tablets

and then for the final 3 months an implant was put into his thigh.

'Chemical castration' they call it.

Very civilised.

I take it every day and once a month I get tested at the hospital

to make sure I don't have any of that naughty testosterone in my blood.

It's meant to cure me of my desires.

The kinds of the things that Alan Turing would have experienced

would have been an immediate change in his libido

his inability to get an erection. He would have become impotent.

His testicles would have shrunken in size.

He would've stopped shaving.

Over time, he would've grown breasts.

And that would have been the distinctive signature of somebody who was chemically castrated.

He was told the effects of the treatment were reversible

and no doubt that was part of the reason he agreed to it.

The arrest was, I think, a turning point in his life

because it was at that moment that for the first time

he understood how untrustworthy British society was

and the he was very, very expendable.

I think it was a demoralising experience and embittering experience for him.

And he was never the same afterwards.

I mean what's going on, partly, in the insupportable tragedy of Turing's fate

is what happens when deeply institutionalised English intellectuals

encounter what life's like outside the walls.

They forget and cannot imagine how evil and vicious life can be.

Spring, 1953.

Alan Turing had been visiting Dr Greenbaum for six months.

For some mad reason the number of petals on most flowers is a Fibonacci number.

Each number the sum of the previous two, yes?

1,1, 2, 3, 5, 8,13, 21, 34...

So...

Our father was very interested with everything that Turing was doing.

I think he recognised a genius.

And in talking and sharing ideas, it must have been fascinating for him.

Cells don't have a mind of their own.

But a clump of cells will split

and eventually some of the cells will become the backbone of a bird

and some of the others will become its wings.

But how do the individual cells know what part of the organism to become?

So I asked myself whether there might be some mathematical underpinning

to patterns that occur in nature...

like the spots on a cow or the petals on this daisy.

Turing had been working on a revolutionary idea

that mathematics can in principle describe a process called morphogenesis

the way shapes and patterns emerge in living organisms as they develop.

After the war, Turing got interested in biology.

He got interested in plants, and the patterns in plants.

He was also interested in markings on animals.

Why are tigers striped, leopards have spots?

And the idea that there could be a mathematical theory of stripes and spots

was something that biologists just hadn't really thought about.

And for that matter, neither had the mathematicians.

People did not put those two things together.

So Turing was right out on the forefront of mathematical biology

that's now become very important.

What he did, he came up with a mathematical equation

that described how the patterns formed.

If you look at tropical fish you'll see that there are spots, there are stripes...

How does that actually come about?

And Alan Turing, in the early 1950s, really began to attack this problem.

And the way in which he approached this was from a very pure mathematical point of view.

This equation shows that chemicals following incredibly simple mathematical rules

can, in principle, spontaneously create the markings on living creatures.

It's such an interesting equation because it looks very simple...

it doesn't sort of scream stripes or spots at you.

But as soon as you start thinking about it

certainly when Turing started thinking about it

he had had this big insight that patterns are going to form.

The rules are not just put black here, put white there

put black here, put white there

they are not paint zebra by numbers rules.

There are just a naturally running mathematical system

which by some beautiful feature of the mathematics

you crank the handle on the mathematics and out comes the stripes or the spots.

One of the first areas in which he applied this

was to explain the black and white dappling on cows

and he published a famous paper

his morphogenesis paper, explaining that.

You can even draw some sort of parallel between what Turing did for nature

and what he did in Bletchley Park.

Turing is decoding nature.

He had an almost physical feeling for how those equations moved and played together.

And probably the closest analogy for me is of a composer.

Turing is a little bit like Mozart.

He could hear the whole glorious structure of it somewhere inside his head.

Turing really set the scene for a lot of science that is now going on

50 or 60 years after he started this work.

I don't expect you to read my paper

as fascinated as you appear to be in the activities of my imagination.

To me, morphogenesis is a giant beautiful mathematical dream

but to you - I think it would just appear a series of scary mathematical functions.

In a funny way, he had returned to where he started intellectually.

When he was a boy at Sherborne, he was very interested in botany and biology.

There's of course that famous image of him

during the hockey game - watching the daisies grow.

Turing effectively came full circle and returned to that period in his youth.

As their sessions continued, Greenbaum saw Turing not just as a patient

but also as a friend.

I think the empathy that he developed with Alan Turing was very much that.

It was a friendship thing that developed out of the medical relationship.

He was part of the family.

He was very friendly towards me.

And Alan would come and sit by me and talk to me

and take an interest in what I was doing.

I just liked him as a person.

As a child, I would sit there on the floor playing the solitaire game.

And he would sit there chatting.

And then out of the blue this letter arrived in the post.

It says, 'Dear Maria. It is just to tell you how to do the solitaire puzzle.'

And there he's drawn a little diagram.

And then he goes on to close the letter

'I hope you all have a very nice holiday in Italian Switzerland.

I shall not be very far away

at Club Mediterranée, Ipsos, Corfu, Greece.

Yours, Alan Turing.'

During this period, Turing made a couple of trips to the continent.

British gay men often went abroad because they were able to live more freely abroad.

There was not this constant looming threat of arrest.

He sent us a card from Greece.

'I've met the most lovely young man on the beach', he says.

The continent offered joys, pleasures, especially after the war.

And Greece had this mythological status.

And by the 1950s, Paris, parts of Scandinavia, offered these golden opportunities.

During this period, he decided to make a trip to Bergen, Norway for a holiday.

He caught the ferry here in Newcastle

and it was a ferry ride right out there across the North Sea.

Norway represented for him

an alternative to the much more rigid, repressive atmosphere of England at the time.

I've been learning Norwegian.

I rather like Norway.

It may become a routine.

They have dances there for men only.

Men dancing with men. Imagine!

While he was in Bergen, he met a young Norwegian man named Kjell

with whom, as he described it, he shared a drunken kiss under a flag post.

This episode, which seemed very innocent

was unfortunately to have very, very serious repercussions for him.

There was a boy from Norway who apparently came to visit me

but something happened involving the police and I never got to see him.

His name was Kjell.

He wrote to me to say he was coming to visit.

And, as I understand it, he arrived

but before he could make contact

it appears he was chased by the police all over the north of bloody England

and finally he went home.

He was quiet.

Handsome.

A winning combination!

I know they've been watching my house.

Perhaps that's what spooked him.

I wish they'd leave me alone.

An important question is why the police were following Turing.

I suspect the reason was because he was perceived as a major security risk.

We have to remember that 1952 was the absolute height of Cold War paranoia

during which the idea of the homosexual traitor was taking hold in the popular imagination.

Homosexuals must not be handling top secret material.

The pervert is easy prey to the blackmailer.

Turing fit the part perfectly.

We know that he had a lot of classified, secret information

that he had gathered during his time at Bletchley Park.

I think there was probably an assumption that Turing might very well go rogue.

And so the police really began to close in on him.

And this, I think, is something very, very tragic.

I think he began to feel increasingly that he had no freedom anymore

that he couldn't have any kind of an ordinary life.

It's worth bearing in mind that at the same time he was undergoing the organo therapy

which was playing havoc with his hormones.

It wasn't just Turing's body that had been damaged.

His brain too had been affected.

We know from the medical evidence that if you castrate a man

then you change his ability to think and his ability to concentrate.

And if you take testosterone away, then the brain will become muddled.

[Turing's voice] I've got a shocking tendency at present to fritter my time away

in anything but what I ought to be doing.

I thought I'd found the reason for all this, but that hasn't made things much better.

In April 1953, his oestrogen treatment ends.

Turing was perhaps expecting things to change quickly

but his body was not responding in the way that he may have thought it would have done.

The theory is if you stop exposure of the male body to oestrogen

then slowly over time his testosterone levels will begin to rise.

That's fine, in theory.

It can take many, many months, six, seven, eight, nine months, to recover sexual function, if at all.

Some men report that they never recover their sexual function

after they've taken oestrogen therapy for that long.

Organo therapy was court-ordered at my trial if I wanted to avoid prison.

They're hormones, female hormones.

They're meant to decrease my libido. And they do... have.

But being hormones, they also cause other physical reactions.

They say the effects are reversible.

Well, it ends there.

The thought ends there.

I don't know why I should have gone to such lengths to avoid prison.

Being locked up with a bunch of ruffians? I can imagine myself paying for that.

Should we go inside?

The condition of his life was becoming increasingly untenable, increasingly grim.

Somewhere along the line, something broke.

His ability to endure failed

and the suffering that he was undergoing became, I suspect, overwhelming.

In May 1954, Alan Turing joined Franz Greenbaum and his family on a day trip to Blackpool

a beach town in Northwest England.

Alan was wearing a stripy blazer with the sleeves up here

on the white shirt poking out from underneath.

So he really looked very strange.

There was a fortune teller's tent on the promenade

and Alan decided that he would like to go in and see the fortune teller.

And he went in there and he was gone for a little while

and he came out and we looked at him

and he was ashen-faced

absolutely horrified expression on his face.

Do you know what's here?

What?

Signals. Radio signals. Just here.

The air is full of radio signals flying past our heads

ready to be intercepted.

We all see different things.

Do you know honeybees see by ultraviolet light?

Their eyes perceive a range of wavelengths entirely different to what we can see as humans

and so, even though we're in the same world, we see another world entirely.

When I went to see that fortune teller in Blackpool

she told me one or two things I suppose I didn't want to know.

What did she say?

Our session was private, just like yours and mine.

But she saw things other people don't.

Rather like you.

He wouldn't divulge what had happened, what the woman had said to him.

He was desperately, desperately unhappy.

And he didn't say anything more after that.

I don't think I'm allowed to travel anymore.

It doesn't matter what I say now, does it.

They think our sort are weak-willed and so we're bound to talk

so fuck them, fuck them sideways. I'll say whatever I please.

Alan, what's happened?

Nothing.

Nothing's happened.

Nothing new anyway, nothing different.

There must have come a moment when he felt it just wasn't worth it.

That sense of despair.

Whatever the possibilities of his life, for him, those possibilities didn't seem realistic anymore.

I've seen Snow White and the Seven Dwarfs seven times.

That's 49 times I've seen a dwarf.

Do you ever wonder what poison she soaks the apple in?

They don't say in the film.

She'd have had her pick.

Poisons appear everywhere in nature.

Some of the most beautiful flowers contain the deadliest poisons.

Oleander, Rhododendron, Narcissus.

Do you know what their poison did to me?

It shrunk my testicles.

I grew breasts.

I, we all, worked to break Hitler because what did he do?

Amongst other things?

He sterilised Jews. Jews like you.

We fought that bastard. We defeated him.

And when we were finished, what did they do to me?

And I'm supposed to allow it.

It would be despicable to do that to anyone

but to do that to someone who ought to have been treated as a national hero

seems to me especially despicable.

What he suffered was too profound and too debilitating for him to recover from.

He suddenly saw what a nasty place the world was.

There are things I can do. We're all at war

all of us, all of the time, each in our own little fucking war.

What are you saying?

Don't worry. I'm not saying anything.

Although Snow White, coupled with my own perverse thinking

did yield an amusing idea as to how someone might kill himself

using an apple and electrical wiring.

That would be illegal.

Well, if a man were successful

the bastards would have to try to pull him back from the mouth of hell

and I have to say - though I'm not telling you this

it would almost be worth it just to see them try.

We all have decisions to make.

I don't know what it was that finally tipped him over the edge.

But I think you've got a mixture there that is just at boiling point

and it won't take a lot more to make it boil right over.

Mathematicians talk about the beauty of numbers

but I know - because I was one -

they're talking about the computable

the beauty of what can be resolved.

But what about the rest, the greater infinity?

What's not computable lies beyond the infinitesimal sliver of knowledge

we've managed to subdue inside our fragile, trembling human consciousness

a consciousness which is, in fact, decaying within us from the moment we're born.

I won't be able to come for dinner on Sunday.

I'm afraid I've made other plans.

Alan, come back! Sit down!

Alan Turing's body was found by his housekeeper on June the 8th, 1954.

He was 41 years old.

The death was recorded as suicide, caused by cyanide poisoning.

A half-eaten apple lay by his bedside.

He left no note.

My mum came in and she said, 'I've got something to tell you'.

And she said, 'Alan has died'.

And I was just so upset.

When we heard that he'd died, our father was very upset.

It was very disturbing. Terrible waste of a brilliant brain.

We lost one of our great computer scientists, one of our great mathematicians

one of our first mathematical biologists

and I think British science would have advanced faster

and would have been different in many ways

more creative, in some ways, if Turing had lived.

I think all we can say is that it is a terrible tragedy

that such a great and brilliant man should have had to suffer so much.

And that his life should have ended in such a tragic way.