What is Hard SF?

The subgenre exists because the readers have identified something which makes them seek out stories of a certain mood and atmosphere. The difficulty we have is defining to anyone’s satisfaction what that atmosphere is. It is like defining a family resemblance: you can see everyone in the Smith family has a certain cast of features, but it is hard to put into words.

My own definition (for what SF author does not dabble with his own definitions?) is that SF is “Hard” when the illusion of reality of the invented science in the work is bolstered by real science, or something in the spirit and approach of real science: and the science plays so crucial a role in the tale that the tale cannot be told without it.

Jules Verne makes a cannon shot to the moon seem realistic, even though we know such a thing is fantastic, by adding what we really do know about ballistics and astronomy to the mix. He places his moon-cannon in Florida for the same reasons in real life NASA launched from Florida: there the science is so realistic it is actually real.

I call it an illusion because story-telling, ultimately, is like casting a magic spell. If the spell does not work, the illusion is shattered, and the reader can no longer suspend his disbelief. In the case of Hard SF the illusion depends on the reader’s interest in, or familiarity with, real science.

Soft SF can rely on less plausible science, because science is not the emphasis, the humanities or some other discipline, like anthropology is. Character development means more than problem-solving in these stories.

Ray Bradbury’s FAHRENHEIT 451 is a fine example of a ‘soft’ SF book. The robot dogs or giant wall TV’s are not needed to tell the story. (The movie adaptation told the story with no mention of the robot dogs.) The science is peripheral. The solution to the problem of book-burning, that a devoted cadre memorize the texts, is not a hard science solution. The book is really about Montag’s rebellion against conformity of a intellectually deadened society.

Contrariwise, Larry Nivens’ NEUTRON STAR is ‘hard’ SF. The story cannot be told without telling real astronomy, what causes tides. The props like hyperdrive and invulnerable spaceship hulls are not scientifically realistic, but they are scientific in atmosphere, and so their use does not break the illusion of realism, as, say, a Harry Potter on the broomstick would do.

Let me mention in passing the THE COLD EQUATIONS is famous because it took the Campbellian premise of real science seriously, but did not add the Campbellian premise of can-do Yankee optimism. The problem is not solved and the girl dies. All other Hard SF stories are like chess problems; THE COLD EQUATIONS are a checkmate. The enjoyment of a chess problems story or checkmate story cannot be had except by someone who admires the rules of chess.

If I may press this analogy one step further, even if Hard SF invents a new chessman, a knight that captures like a pawn, let us say, the enjoyment of the story depends on using that chessman according to the rules, displaying an appreciation, shared by the reader, for the cool intellectual pleasure of the game.