Time travel is a common theme in science fiction and fantasy, and it has been depicted in a variety of media from prose fiction to television and other advertisements. It can be the central theme of the plot, or merely a plot device to set the story in motion. Whereas hard science fiction may examine the causes and effects of time travel paradoxes, soft science fiction and science fantasy may ignore negative aspects and focus on fantastic wonders and adventures. Time travel themes can include: Changing the past; Alternate future, history, timelines, and dimensions; Butterfly effect; Communication from the future; Precognition; Time loop; Time paradox; Time slip; and Time war. |