Science fiction

Science fiction (often shortened to sci-fi or abbreviated SF) is the genre of speculative fiction that imagines advanced and futuristic scientific progress and typically includes elements like information technology and robotics, biological manipulations, space exploration, time travel, parallel universes, and extraterrestrial life. The genre often specifically explores human responses to the consequences of these types of projected or imagined scientific advances.

Science fiction's precise definition has long been disputed among authors, critics, scholars, and readers. It contains many subgenres include hard science fiction, which emphasizes scientific accuracy, and soft science fiction, which focuses on social sciences. Other notable subgenres are cyberpunk, which explores the interface between technology and society, climate fiction, which addresses environmental issues, and space opera, which emphasizes pure adventure in a universe in which space travel is common.

Precedents for science fiction are claimed to exist as far back as antiquity. Some books written in the Scientific Revolution and the Enlightenment Age were considered early science-fantasy stories. The modern genre arose primarily in the 19th and early 20th centuries, when popular writers began looking to technological progress for inspiration and speculation. Mary Shelley's Frankenstein, written in 1818, is often credited as the first true science fiction novel. Jules Verne and H. G. Wells are pivotal figures in the genre's development. In the 20th century, the genre grew during the Golden Age of Science Fiction; it expanded with the introduction of space operas, dystopian literature, and pulp magazines.

Science fiction has come to influence not only literature, but also film, television, and culture at large. Science fiction can criticize present-day society and explore alternatives, as well as provide entertainment and inspire a sense of wonder.

According to American writer and professor of biochemistry Isaac Asimov, "Science fiction can be defined as that branch of literature which deals with the reaction of human beings to changes in science and technology."

Science fiction writer Robert A. Heinlein stated that "A handy short definition of almost all science fiction might read: realistic speculation about possible future events, based solidly on adequate knowledge of the real world, past and present, and on a thorough understanding of the nature and significance of the scientific method."

American science fiction author and editor Lester del Rey wrote, "Even the devoted aficionado or fan—has a hard time trying to explain what science fiction is," and no "full satisfactory definition" exists because "there are no easily delineated limits to science fiction."

Another definition is provided in The Literature Book by the publisher DK: "scenarios that are at the time of writing technologically impossible, extrapolating from present-day science...[,]...or that deal with some form of speculative science-based conceit, such as a society (on Earth or another planet) that has developed in wholly different ways from our own."