Science fiction, sci-fi or sf is a genre of fiction dealing with imaginative content such as futuristic settings, futuristic science and technology, space travel, time travel, faster than light travel, parallel universes and extraterrestrial life. It often explores the potential consequences of scientific and other innovations, and has been called a "literature of ideas".
H. G. Wells is called a father of science fiction and called himself a socialist.
Major 20th century sf writers were Isaac Asimov, Arthur C. Clarke and Robert Heinlein.
Major modern socialist sf writers are Kim Stanley Robinson, Ken MacLeod and Ursula K. Le Guin.