On October 8, American physicist John Hopfield and British-Canadian computer scientist Geoffrey Hinton were awarded the 2024 Nobel Prize in Physics for their discoveries in machine learning, which laid the foundations for artificial intelligence.
Established in 1901, the Nobel Prize for Physics has celebrated major breakthroughs ranging from supermassive black holes to gravitational waves. This year, however, it has recognized significant research on the impact of artificial intelligence on various fields of physics. According to the Nobel Prize Committee, AI’s ability to process large amounts of data plays a crucial role in scientific advancement. In a tweet, the committee stated, “[Hopfield and Hinton] have shown a completely new way for us to use computers to aid and to guide us to tackle many of the challenges our society faces.”
Artificial intelligence refers to machine-based learning in artificial neural networks, a technology inspired by the structure of the human brain. Just as brains have neurons, artificial networks use nodes – artificial neurons – with different values that represent them. In 1982, Hopfield developed a model known as the Hopfield network, designed to preserve and recall patterns for information-based memory, which is used in fields other than physics, such as physiology and neuroscience. In this system, nodes can be visualized as pixels. The Hopfield network uses principles from physics that describe a material's atomic spin—a quality that makes each atom behave like a tiny magnet. When presented with a distorted or partial image, this network adjusts node values to reduce energy and gradually retrieves the stored image most similar to the input.
In 1985, Geoffrey Hinton introduced a new model based on the Hopfield network: the Boltzmann machine. This machine utilizes the Boltzmann equation instead of a spin and can classify images and generate new examples of its learned patterns.
While being a pioneer in the earliest stages of AI, Hinton has also cautioned the public about the technology's dangers. In May of 2023, he left his role at Google after stating that the technology’s intelligence was dangerous. In an interview with CNN last year, Hinton said, “I’m just a scientist who suddenly realized that these things are getting smarter than us. I want to sort of blow the whistle and say we should worry seriously about how we stop these things getting control over us.”