This week’s cover

The stunning success of ChatGPT, a chatbot that can write essays, pass law exams and even make bad jokes, has divided the world. Optimists think artificial intelligence (AI) will help us design new drugs or generate power by nuclear fusion. Pessimists fear that superintelligent machines will go rogue and wipe out humanity. Our cover package this week weighs the evidence. We needed an image that suggested both peril and promise.