Since I’ve been discussing the definition of hard SF, it’s interesting to look at what other writers think it is. Ben Bova, for example, seems to have a very free-wheeling definition. He’s written a very upbeat essay here where he says this: “The rule of thumb for a writer of “hard” science fiction is that the writer is free to use anything his or her imagination can invent and depict — so long as no one can show that it contradicts the tenets of known science.”

This is a sort of backward way to come at the definition. What I’ve discussed heretofore is more about hard SF having to have real, demonstrable science in it. Bova seems to be saying you’re free to make up science as long as nobody can contradict it. Of course this doesn’t completely open the floodgates to let in science that completely contradicts Newton’s Laws, for example. According to Bova’s definition, you have to have your ducks in a row well enough to argue with people who want to say what you’ve written isn’t science. Still, I’m wondering if this doesn’t let in a lot of fantasy science. His definition means that Bova falls somewhere in the low to mid-range of TVTropes’ scale, maybe 2.0-4.0.

For anyone who vague, Bova is a long-time, successful writer of both “traditional” science fiction and non-fiction who got started in the 1950s as a technical writer. He is also a one-time editor of Analog. During his career, he’s been especially interested in space colonization.