Innovator Under 35: Sergey Levine

While serving a nine-month stint at Google, Sergey Levine watched as the company's AlphaGo program defeated the world's best human player of the ancient Chinese game Go in March. Levine, a robotics specialist at the University of California, Berkeley, admired the sophisticated feat of machine learning but couldn't help focusing on a notable shortcoming of the powerful Go-playing algorithms. "They never picked up any of the pieces themselves," he jokes. One way that the creators of AlphaGo trained the program was by feeding 160,000 previous games of Go to a powerful algorithm called a neural network, much the way similar algorithms have been shown countless labeled pictures of cats and dogs until they learn to recognize the animals in unlabeled photos. So roboticists have instead turned to a different technique: the scientist gives a robot a goal, such as screwing a cap onto a bottle, but relies on the machine to figure out the specifics itself.