Machine learning pioneers win Nobel prize in physics | Nobel prizes

Two researchers who helped lay the foundations for modern artificial intelligence – although one later warned of its potential harms – have been awarded the 2024 Nobel prize in physics.

Inspired by the workings of the brain, John Hopfield, a US professor emeritus at Princeton University, and Geoffrey Hinton, a British-Canadian professor emeritus at the University of Toronto, built artificial neural networks that store and retrieve memories like the human brain, and learn from information fed into them.

Hinton, 76, who is often called “the godfather of AI”, made headlines last year when he quit Google and warned about the dangers of machines outsmarting humans.

The scientists’ pioneering work began in the 1980s and demonstrated how computer programs that draw on neural networks and statistics could form the basis for an entire field, which paved the way for swift and accurate language translation, facial recognition systems, and the generative AI that underpins chatbots such as ChatGPT, Gemini and Claude.

Hopfield, 91, was honoured for building “an associative memory that can store and reconstruct images and other types of patterns in data”, while Hinton invented a method that can “independently discover properties in data”, an important feature of the large artificial neural networks in use today.

In 1982, Hopfield built a neural network that stored images and other information as patterns, mimicking the way memories are stored in the brain. The network was able to recall images when prompted with similar patterns, akin to identifying a song heard only briefly in a noisy bar.

Hinton built on Hopfield’s research by incorporating probabilities into a multilayered version of the neural network, leading to a program that could recognise, classify and even generate images after being fed a training set of pictures.

Announced by the Royal Swedish Academy of Sciences in Stockholm, the winners share the 11m Swedish kronor (about £810,000) prize for “foundational discoveries and inventions that enable machine learning with artificial neural networks”.

Ellen Moons, the chair of the Nobel committee for physics, said: “These artificial neural networks have been used to advance research across physics topics as diverse as particle physics, material science and astrophysics. They have also become part of our daily lives, for instance in facial recognition and language translation.”

Speaking at a press briefing immediately after the announcement, Hinton said he had received the call from Stockholm while staying in cheap hotel in California that lacked an internet connection. “I’m flabbergasted, he said. “I had no idea this would happen, I’m very surprised.”

Hinton quit Google in order to speak freely about his concerns over the possible harms AI could inflict, from spreading misinformation and upending the jobs market to threatening human existence.

Asked how AI might affect the world, Hinton told reporters: “I think it will have a huge influence. It will be comparable with the Industrial Revolution. But instead of exceeding people in physical strength, it’s going to exceed people in the intellectual ability.”

Having technology that was smarter than humans would be “wonderful in many respects”, Hinton said, leading to substantial improvements in healthcare, better digital assistants, and huge improvements in productivity. “But we also have to worry about a number of possible bad consequences, particularly the threat of these things getting out of control,” he added. “I am worried that the overall consequence of this might be systems more intelligent than us that eventually take control.”

Prof Michael Wooldridge, a computer scientist at the University of Oxford, said the award reflected the profound impact that AI was having. “The award is an indicator of just how much AI is transforming science,” he said. “The success of neural nets this century has made it possible to analyse data in ways that were unimaginable at the turn of the century. No part of the scientific world is left unchanged by AI: we find ourselves in a remarkable moment in scientific history, and it is wonderful to see the academy recognise this.”

But Prof Dame Wendy Hall, a computer scientist at the University of Southampton and an adviser to the UN on AI, said she was surprised at the award. “There is no Nobel prize for computer science so this is an interesting way of creating one, but it does seem a bit of a stretch,” she said. “Clearly artificial neural networks are having a profound effect on physics research, but is it fair to say that in themselves they are the result of physics research?”