Science fiction, coming under the umbrella of speculative fiction, is a broad genre that is not easily defined. So many interlinked subgenres and themes make it difficult to define succinctly. Science fiction grand master Isaac Asimov defined it as “that branch of literature which deals with the reaction of human beings to changes in science and technology”. More broadly, science fiction:
- can be set in the future, the past, or the present, and sometimes employs time travel as a plot element.
- uses advanced technology in the plot, either as a possibility for the future or as a purely imaginative device.
- uses past technologies in anachronistic settings.
- uses scientific principles to explain elements of the story, or extending scientific principles into the realm of speculation (generally plausible, though sometimes not).
- is set in space; on a space craft; on other planets or other celestial bodies; in alternate or virtual realities.
- explores the possibility of extraterrestrial life and the development of artificial intelligence, also the ramifications and human interactions with these.
- examines political, social, cultural, environmental, and economic systems in a future setting, either pertaining to human or extraterrestrial civilisations.
- can use elements of the paranormal.
- comments on past or current social climates in a representative way, or as a forecast of what the future may hold as a result of the past or present.
In no way is the above list exhaustive, but it should give some indication as to the scope of the genre. For more scholarly discussions, the Science Fiction Research Association publishes the SFRA Review, available on their website. But a better way to learn about science fiction is to consume it. Books, comics, movies, TV shows, video games—the options are endless. To give you a head start, check out the post Science Fiction Subgenres and Themes.