Many years ago, I spent two days in Pompeii.  It was low season, and I had the city almost entirely to myself as I walked its streets, trying to imagine what a typical day in a first-century Roman city must have been like, based only on the naked structures around me—an amateur paleontologist reconstructing life from the bones that dotted the countryside.  That experience has stayed with me, and led me to think about what it would be like to walk around an empty, Pompeii-like New York City that had been excavated and restored by some future civilization.  What would it look like? What would it tell us about its long-gone inhabitants?