People of Science with Brian Cox – Dame Wendy Hall on Alan Turing

Hello. I’m Professor Brian Cox.
Welcome to People of Science. Brian: Dame Wendy Hall thank you for joining us and could you just give us a brief
description of who you are and what you do? Wendy: Yes, it’s a pleasure to be here
and to talk about one of my heroes. I’m a mathematician originally and I’m most well-known these days for my work in multimedia and hypermedia and the web
and the internet. But in my early career I did all sorts of things in computing including teaching about Turing Machines. And when I was asked to do this, how could I choose anybody better than the person who really gave us the theory for everything we’re doing today with computers: Alan Turing. Brian: I suppose Alan Turing is most well known for his code breaking. We’ll talk about that later but his early career, working on the theory of computing. I would have thought most people would be surprised that you need it. Why do we need a theory of computing and what did he do? Wendy: Well because before Turing we didn’t have machines that you could program in the way we think of them today because in those days human beings were called computers. We’re talking here the 1930s when he went to Kings College and read Mathematics and he started thinking about how could a machine imitate what human beings could do in terms of doing the mathematics to perform much bigger and much more complicated problems much more quickly. And he’d develop the Universal Turing Machine and prove that that could compute anything. Brian: Can you describe it just very briefly? Wendy: Well it’s basically you run a tape through the machine and there are instructions. It’s naughts and ones and the algorithm he designed to do the computing basically shifts the tape backwards or forwards depending on what the instruction is and it’s just as simple as that. Brian: And then can we move on to his most famous work. Bletchley Park. The code breaking during the war. So what was he doing there? Wendy: He went there at the beginning of the war I guess the government were looking for all the bright young mathematicians and it was all about cracking the codes the Germans used and Turing led a team to build what became known as The Bombe with an ‘e’. And if you go to Bletchley Park now you can see a replica of The Bombe actually working. Brian: So is that essentially a prototype computer? Wendy: Yes it was an early form of a computer. Yeah. Interestingly I think that the war was a continuation of his academic work. It was just applied in a way that, you know, shortened the war and saved a lot of lives. Brian: So this is the Certificate of a Candidate for Election. Wendy: This tells us he wasn’t elected the first year he was put forward. Which is true for most people. Brian: Yeah. Wendy: There’s very few people that get it the first year but he went in in 51. Brian: Yeah but interestingly no mention of the war. Wendy: He has worked since 1945. But you see in 1950 they couldn’t talk about Bletchley Park. Brian: That’s interesting isn’t it. So he was elected perhaps without the knowledge of what he’d done. That really does speak to his eminence as a mathematician doesn’t it. When you went to Bletchley Park and you looked at his office which is still there. Did you get more of a sense of the man? Wendy: It’s a replica of his office but it is beautifully done and there’s all the sort of artefacts of that time the 1940s. He had two typewriters that they’ve set up in his office and both them said “do not use this machine leave as is.” So he was clearly very precious about his own stuff his own possessions. Brian: This is an interesting picture you paint of this man because I was surprised when I saw that he almost qualified for the 1948 Olympics. Wendy: He was a runner. And of course you know the end was very sad. He was homosexual which of course completely illegal in those days. And he outed himself to the police because his lover stole from him and he named him to the police. And that’s how it became known that he was homosexual. So they charged him and offered him a prison sentence or chemical castration. What a choice and he chose the chemical castration. And then of course he died in 1954. The inquest said it was suicide but we won’t ever really know the truth of what happened. But it’s tragic to lose someone so bright and who could have done so much. Brian: But his legacy now in terms of the theoretical work around computing does that still echo today? Wendy: Absolutely. His theories are still taught. I mean we’re moving into the world of quantum, I bet he’d have been there before all of us. But in terms of the computers we use today and the computers we have in our mobile phones everything we do today with computers is based on his original theory. It’s quite amazing.