In 1898 H. G. Wells wrote his most famous novel,The Time Machine. In this novel, a young Victorian invented a device that allowed him to travel into the future or the past. He travels 800,000 years into the future and finds a society very different from the one he was accustomed to, inhabited by the Eloi and the Morlocks. The Eloi appear to live an idyllic life, but the time traveler discovers that there is a horrible price they must pay.

In Back to the Future (1985), Marty McFly inadvertently finds himself in the 1950s, his "modern" car an oddity in a rural field.

Writers such as Wells used fiction to comment on their own society. However, serious paradoxes raised by time travel have led many to contend that it is impossible. For example, what if a time traveler accidentally killed his own father, long before he was...