The idea of machines outsmarting humans has long been the subject of science fiction. Rapid improvements in artificial-intelligence (ai) programs over the past decade have led some experts to conclude that science fiction could soon become fact. On March 19th Jensen Huang, the chief executive of Nvidia, the world’s biggest manufacturer of computer chips and its third most valuable publicly traded company, said he believed today’s models could advance to the point of so-called artificial general intelligence (agi) within five years. What exactly is agi—and how can we judge when it has arrived?…utm_id=1870466