In a small room in San Diego last week, a man in a black leather jacket explained to me how to save the world from destruction by AI. Max Tegmark, a notable figure in the AI-safety movement, believes that “artificial general intelligence,” or AGI, could precipitate the end of human life. I was in town for NeurIPS, one of the largest AI-research conferences, and Tegmark had invited me, along with five other journalists, to a briefing on an AI-safety index that he would release the next day. No company scored better than a C+.