An innocent viewer of the new Apple TV+ series “Foundation”—a lavish production complete with clone emperors, a haunted starship, and a killer android who tears off her own face—might be surprised to learn that the novels it’s based on inspired Paul Krugman to become an economist. Isaac Asimov’s classic saga revolves around the dismal science of “psychohistory,” a hybrid of math and psychology that can predict the future. Its inventor, Hari Seldon, lives in a twelve-thousand-year-old galactic empire, which, his equations reveal, is about to collapse. “Interstellar wars will be endless,” he warns. “The storm-blast whistles through the branches of the Empire even now.”