Time travel

The concept of time travel—travelling backwards and forwards through time—has always been a popular staple of science fiction film and science fiction television series. Time travel usually involves the use of some type of advanced technology, such as H. G. Wells' classic The Time Machine, or the commercially successful 1980s-era Back to the Future trilogy. Other movies, such as the Planet of the Apes series, explained their depictions of time travel by drawing on physics concepts such as the Special relativity phenomenon of time dilation (which could occur if a spaceship was travelling near the speed of light). Some films show time travel not being attained from advanced technology, but rather from an inner source or personal power, such as the 2000s-era films Donnie Darko and The Butterfly Effect.

More conventional time travel movies use technology to bring the past to life in the present, or in a present that lies in our future. The movie Iceman (1984) told the story of the reanimation of a frozen Neanderthal (similar to the 1973 Christopher Lee film Horror Express), a concept later spoofed in the comedy Encino Man (1992). The movie Freejack (1992) shows time travel used to pull victims of horrible deaths forward in time a split-second before their demise, and then use their bodies for spare parts; a similar theme is used in Millennium (1989).

A common theme in time travel movies is the paradoxical nature of travelling through time. In the French New Wave film La Jetée (1962), director Chris Marker depicts the self-fulfilling aspect of a person being able to see their future by showing a child who witnesses the death of his future self. La Jetée was the inspiration for Twelve Monkeys, (1995) director Terry Gilliam's film about time travel, memory, and madness. In Slaughterhouse-Five (1969), the main character becomes unstuck in time, and jumps backwards and forwards across his life.

The Back to the Future series goes one step further and explores the result of altering the past, while in Star Trek: First Contact (1996) the crew must rescue the Earth from having its past altered by time-travelling cyborgs. The Terminator series uses self-aware robots which travel to the past in order to alter the future outcome of a future human-robot war by killing the future leaders of the human resistance.