Science fiction

Science fiction is a genre of speculative fiction that imagines plausible events set in an imagined framework, whose credibility rests on the physical, natural and social sciences. It usually starts from scientific or technological advances, real or imagined, and examines their consequences for individuals and society.

The term was consolidated in 1926, when Hugo Gernsback placed it on the cover of Amazing Stories. Before then, works now considered part of the genre were known by names such as "fantastic voyages", "utopias" or "scientific romances". Some scholars trace its roots to antiquity, such as the satirical tale in which Lucian of Samosata travels to the Moon, and to works of the Scientific Revolution such as Johannes Kepler's Somnium. For many critics the modern starting point is Mary Shelley's Frankenstein (1818), and in the nineteenth century Jules Verne and H. G. Wells established many of its themes, from space and time travel to alien invasion.

The genre is hard to delimit. Isaac Asimov defined it as the branch of literature concerned with human reactions to changes in science and technology, while Robert A. Heinlein stressed realistic speculation grounded in the scientific method. Within it coexist subgenres such as hard science fiction, which seeks scientific rigour, soft science fiction, focused on the social sciences, space opera, cyberpunk and climate fiction. Its preoccupations have shifted over time, from space exploration to information technology, transhumanism and environmental crises.

Current debate concerns whether science fiction should be judged by the accuracy of its scientific basis or by its capacity to reflect on society, and how clear its boundaries with fantasy or utopian writing really are. Its influence now extends well beyond literature into film, television and culture at large, and it often serves to criticise the present or imagine alternatives.