
About Science Fiction
Definition
Science fiction is difficult to define, as it includes a wide range ofsubgenres and themes. Author and editor Damon Knight summed up the difficulty, saying "science fiction is what we point to when we say it", a definition echoed by author Mark C. Glassy, who argues that the definition of science fiction is like the definition of pornography: you do not know what it is, but you know it when you see it. Vladimir Nabokov argued that if we were rigorous with our definitions,Shakespeare's play The Tempest would have to be termed science fiction.
Innovation
Science fiction has criticized developing and future technologies, but also initiates innovation and new technology. This topic has been more often discussed in literary and sociological than in scientific forums. Cinema and media theorist Vivian Sobchack examines the dialogue between science fiction films and the technological imagination. Technology impacts artists and how they portray their fictionalized subjects, but the fictional world gives back to science by broadening imagination. How William Shatner Changed the World is a documentary that gave a number of real-world examples of actualized technological imaginations. While more prevalent in the early years of science fiction with writers like Arthur C. Clarke, new authors still find ways to make currently impossible technologies seem closer to being realized.
Doctor Who is currently the longest running science fiction television series, running from 1963 to now.
Time travel
Time travel stories have antecedents in the 18th and 19th centuries. The first major time travel novel was Mark Twain's A Connecticut Yankee in King Arthur's Court. The most famous is H. G. Wells' 1895 novel The Time Machine, which uses a vehicle that allows an operator to travel purposefully and selectively, while Twain's time traveler is struck in the head. The term "time machine", coined by Wells, is now universally used to refer to such a vehicle. Back to the Future is one of the most popular franchises of this category. Stories of this type are complicated by logical problems such as the grandfather paradox. Time travel continues to be a popular subject in modern science fiction, in print, movies, and television episodes of Stargate SG1 and the BBC television series Doctor Who.
Superhuman
Superhuman stories deal with the emergence of humans who have abilities beyond the norm. This can stem either from natural causes such as in Olaf Stapledon's novel Odd John, Theodore Sturgeon's More Than Human, and Philip Wylie'sGladiator, or be the result of scientific advances, such as the intentional augmentation in A. E. van Vogt's novel Slan. These stories usually focus on the alienation that these beings feel as well as society's reaction to them. These stories have played a role in the real life discussion of human enhancement. Frederik Pohl's Man Plus also belongs to this category.

