TIME 100/AI: THINKERS

THE 100 MOST INFLUENTIAL PEOPLE IN ARTIFICIAL INTELLIGENCE

Geoffrey Hinton

EMERITUS PROFESSOR | UNIVERSITY OF TORONTO

EVER THE COURSE OF February, Geoffrey Hinton, one of the most influential AI researchers of the past 50 years, had a "slow eureka moment."

Hinton, 76, has spent his career trying to build AI systems that model the human brain, mostly in academia before joining Google in 2013. He had always believed that the brain was better than the machines that he and others were building, and that by making them more like the brain, they would improve. But in February, he realized "the digital intelligence we've got now may be better than the brain already. It's just not scaled up quite as big."

Developers around the world are currently racing to build the biggest AI systems that they can. At the current rate these models are growing, it could be less than five years until AI systems have 100 trillion connections-roughly as many as there are between neurons in the human brain.

Alarmed, Hinton left his post as VP and engineering fellow in May and gave a flurry of interviews in which he explained that he had left so he could speak freely on the dangers of AI-and on his regrets over helping bring that technology into existence. He worries about what could happen once AI systems are scaled up to the size of human brains and the prospect of humanity being wiped out by the technology. "This stuff will get smarter than us and take over," says Hinton. "And if you want to know what that feels like, ask a chicken."

THE HUMAN BRAIN always fascinated Hinton, who was born and raised in England. As a Cambridge University undergraduate, he tried a range of subjects-physiology, physics, philosophy-before graduating with a degree in experimental psychology in 1970. Two years later he started a Ph.D. in AI at the University of Edinburgh.