Guess what? Just like fantasy, science fiction can be divided into types. Again, dividing lines can be age, plot elements, theme, or setting. SF can also be defined by the rigor with which science is addressed.
- Yup. Middle-grade and young adult, again. There’s some cross-over between the ages, but these are target ranges. My son really enjoys The 13th Reality series by James Dashner and the Leviathan Trilogy by Scott Westerfeld, if you want some recommendations.
- Steam-driven technology, often but not always Victorian era sensibilities: steampunk. (If you’ve somehow missed the whole steampunk phenomenon, go watch the original Wild Wild West series. Jules Verne doesn’t really belong in this subgenre because he was writing about contemporary society.)
- Spring-driven technology: clockpunk. (Example: Mainspring by Jay Lake)
- Dystopian near-future world (or at least future when it was written) with direct connections (jacking) between humans and computers: cyberpunk. (Think William Gibson and a lot of early ’80s work.)
- Near future, obvious extrapolation of current tech, some sort of ticking clock: SF thriller. (I’m currently working on a novella in this subgenre, Jekylls.)
- Good vs. evil, in space: space opera or epic science fiction. Examples include the Saga of the Seven Suns by Kevin J. Anderson and The Risen Empire series by Scott Westerfeld.
- Exploration of culture and values: sociological SF/anthropological SF. Arguably, this includes such works as Orson Scott Card’s Speaker for the Dead and Xenocide.
- Our world, different history: alternate history.
- Alien world, often (but not necessarily) with no humans involved: sociological SF/anthropological SF.
- Very conscious of all the laws of physics, with all tech extrapolated from known principles: hard SF. Some otherwise hard SF may use hyperspace, gates, special drives (including ramjets), or similar devices to avoid lightspeed limitations and permit galaxy-wide exploration. This category includes Kim Stanley Robinson, Larry Niven and Jerry Pournelle, and Iain Banks. I also include stories grounded firmly in biology, which is a hard science, although some people do not — thus, I include Lois McMaster Bujold’s Vorkosigan books here as well.
- Low rigor, including things like faster-than-light (FTL) travel or no discussion of science behind things in the story: soft SF.
When it comes down to it, I don’t use a lot of these labels on a regular basis. Hard SF is an important distinction, I think, because people tend to either love it or hate it — and many who enjoy it don’t care for other forms of SF at all. Alternate history’s pretty self-evident, and Harry Turtledove’s made a good career for himself out of it. Steampunk’s generally pretty obvious. For the rest, though, I’ll often just say “science fiction.” Even if it’s space opera, which I love.
Comments, questions, quibbles, differences of opinion? Let me know in the comments!