The use of AI in our daily lives is becoming more ubiquitous than ever before. Anything you read online could be written, or assisted, by AI. But is it possible to know whether you’re reading words typed by a human or generated by a machine? And can computers really be considered “intelligent”?

Alan Turing, a British mathematician and computer scientist who played a pivotal role in WWII codebreaking, was one of the first people to think about these questions seriously, back in the 1950s. In response to the early disbelief in the power of computing, he invented the Turing test, in which a person would type out a question on a computer, and either a human or machine would answer back. If a machine could fool the user into thinking there was a human on the other side of the screen, Turing wanted those users to accept that the machine was doing something intelligent. 

The test has since become a standard way to benchmark the progress of AI research. In this video, Oxford Professor Michael Wooldridge emphasizes Turing’s incredible contributions to computing and AI, and how his ideas continue to pave the way for our modern AI revolution.

Wooldridge: The limits to computing are not the limits of physical device. They're not the limits of concrete or steel or anything like that in the physical world, the limits to computing are the limits of your imagination. When the first computers began to appear in the late 1940s, early 1950s, people were fascinated by these incredibly complex machines that could do things like process huge numbers of mathematical equations incredibly quickly. And so there was a buzz at the time around these electronic brains. Lots of people thinking around could machines really be intelligent? 

So Alan Turing, I think, was one of the most remarkable people in the 20th century. What he did was he invented a beautiful test. He said, "Look, here is this test. If we ever get something that would passes it, then just stop asking that question because you can't tell the difference." He never really expected that anybody was seriously going to try it out, but actually people did try it out. But it's been wildly misinterpreted, I say since then. What Turing's most famous for is working at Bletchley Park, a code breaking center in the United Kingdom throughout the Second World War. And actually, if that was the only thing he'd done in his life, he would have a place in the history books. But almost as a side product of his PhD work, he invented computers, which are just any one of the most remarkable sort of, you know, quirks of history. And with incredible precociousness, he picked one of the biggest mathematical problems of the age, the Entscheidungsproblem, which means decision problem; whether mathematics can be reduced to following a recipe. 

So the question that Turing asked was, is it the case that for any mathematical problem that you might come up with, you can find a recipe which you can just follow in the same way that you would follow for arithmetic? Incredibly quickly, within about 18 months, Turing solved it. And the answer is no, mathematics doesn't reduce to following a recipe. But the interesting thing is what Turing did is to solve that problem, he had to invent a machine which could follow instructions, and nowadays we call them Turing machines, but actually it's basically a modern computer. And he was one of the first serious thinkers about AI. And so in 1950, he published what we think is the first real scientific work around artificial intelligence.

If we ever achieved the ultimate dream of AI, which I call the Hollywood dream of AI, the kind of thing that we see in Hollywood movies, then we will have created machines that are conscious potentially in the same way that human beings are. So Alan Turing, I think, was really frustrated by people saying, "Well, no, of course these machines can't be intelligent or creative or think or reason," and so on. So Turing's genius was he invented a beautiful test. We call it the Turing Test in his honor. Okay, so here's how the test goes. You've got somebody like me, who's sitting at a computer terminal with a keyboard and a screen, and I'm allowed to ask questions. I type out questions on the keyboard, but I don't know what's on the other end, right? I don't know whether it's a computer program or another human being. So Turing's genius was this. He said, "Well, look, imagine after a reasonable amount of time, you just can't tell whether it's a person or a machine on the other end. If a machine can fool you into not being able to tell that it's a machine, then stop arguing about whether it's really intelligent because it's doing something indistinguishable. You can't tell the difference. So you may as well accept that it's doing something which is intelligent."

And I think Turing never really expected that people would seriously try it out. And so there are annual Turing Test competitions across the world where people will enter computer programs, and there will be judges who will try and tell whether they're a computer program or a human being. Most of the entries in them are like these kind of crude internet chat bots. And what these chat bots do is they just look for keywords like sad or family or lonely or drunk or something like that. And they plug that keyword into a canned response. And so they're really just trying to fool the investigators. And I have to say, there's not really much AI in most of those programs because they're doing something which is really much more superficial. It's a boom period for AI now because a very narrow class of techniques have turned out to be very successful on a wide range of problems.

Modern AI is really focused on doing very specific tasks, and in those specific tasks like playing a game of chess or something, it might be better than any living human being, but it can't do anything else. Those programs are just tuned, very finely tuned, to do one tiny thing very well. But going back to Alan Turing's invention, he invented machines that for following lists of instructions, but the computer can adapt those instructions. It can learn to adapt those instructions over time. And that's basically what you're doing in machine learning. He's one of the founders of the field, not just of computing, but also of artificial intelligence. One of the most remarkable people of the 20th century.