After reading Jill Lepore’s The Rise and Fall of the Artificial State, I have a new destination for a time machine, should I ever finally get my hands on one. I’d set the dial to some night in the late 1970s or ’80s and visit the boyhood rooms of the Silicon Valley titans Elon Musk, Peter Thiel, and Sam Altman. Then I’d confiscate all of their science fiction. Isaac Asimov, Arthur C. Clarke, Robert Heinlein—all of it.As young people, the future billionaires were spending hours (under their covers with flashlights, I imagine) consuming stories about killer robots or Mars colonies....