Noun
Counterfactual history, a form of scientific speculation used by historians.
(fiction) A genre of fiction based around or involving ahistorical events (often occurring after a fixed point of divergence from real history).
Source: en.wiktionary.orgAlternate history has long been a staple of Japanese speculative fiction with such authors as Futaro Yamada and Ryō Hanmura writing novels set in recognizable historical settings with supernatural or science fiction elements present. Source: Internet
ISBN 978-1468178807) Alternate history * The feature-length movie The Final Countdown (1980), in which the nuclear aircraft carrier USS travels through time to one day before the attack. Source: Internet