Consider how carefully Isaac Asimov must have read Gibbon’s Decline and Fall of the Roman Empire to fabricate the galactic civilization in his Foundationseries, or how much history and sociology (along with math) went into his made-up discipline,“psychohistory,” which predicted the future by statistically analyzing the behavior of large populations. (Psychologist Martin Seligman has said that Asimov’s psychohistory inspired him to come up with a new method of forecasting elections.) Constructing a viable fictional world, human or alien, takes more tools than they give you in games like Settlers of Catan. It requires a working knowledge of—to give the short list—cartography, geography, cultural anthropology, linguistics, law, history, religion, and, of course, mythology. Political and moral philosophy come into play, too, because many of the great works of science fiction explore and amplify the social and moral consequences of technological innovation.