In 1980, Robert A. Heinlein wrote, “The most difficult speculation for a science fiction writer to undertake is to imagine correctly the *secondary* implications of a new factor. Many people correctly anticipated the coming of the horseless carriage... but I know of no writer, fiction or non-fiction, who saw ahead of time the vast change in the courting and mating habits of Americans which would result." (Expanded Universe, p. 326).

Heinlein and many others, from the SF Golden Age to now, have built brilliant stories out of trying to work out these secondary implications, but, like any science, the science of working out social implications goes faster and farther with specialist tools, not just those of STEM, but also of social science. After all, America’s courting habits did change with the advent of the automobile, and changed again with e-mail, and cell phones, but beyond secondary implications come tertiary implications, four steps, five, in chains of change in which, over centuries, there may or not be such a thing as courting, or Americans, or nationality as we know it at all.

Recently I had the pleasure of hearing a debate between two friends who had just heard that the first book of my Terra Ignota series (Too Like the Lightning) had surfaced briefly—like a breath-snatching dolphin—at the top of Amazon’s list of “hard science fiction.” “But it isn’t hard SF” was the thrust of the debate, since, while we hear about flying cars, the Moon base, and the 500-year Martian terraforming project, we don’t hear what fuel system keeps the cars flying at 10,000 km/hr, what the lunar domes are made of, or the chemical and geological details of Mars’s transformation.

The debate reminded me of a scene in Kerry Callen’s short but acclaimed comic Halo and Sprocket, when friends take Earth’s first sentient robot to see a local art show, and the robot expresses confusion at the descriptions of two paintings, one a nightscape, the other a collection of wiggly shapes. The first is labeled realistic, the second abstract, but—the robot argues—both are abstract since the stars in the painted sky aren’t in their real positions, but distributed chaotically as if depicting an incomprehensible universe with no physical laws to govern the magnitude and movements of celestial bodies.