Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space, either sending objects (or in some cases just information) backwards in time to some moment before the present, or sending objects forward from the present to the future without the need to experience the intervening period (at least not at the normal rate).

Although time travel has been a common plot device in fiction since the 19th century, and one-way travel into the future is arguably possible given the phenomenon of time dilation based on velocity in the theory of special relativity (exemplified by the twin paradox), as well as gravitational time dilation in the theory of general relativity, it is currently unknown whether the laws of physics would allow backwards time travel.

Any technological device, whether fictional or hypothetical, that is used to achieve time travel is commonly known as a time machine.

Some interpretations of time travel also suggest that an attempt to travel backwards in time might take one to a parallel universe whose history would begin to diverge from the traveler's original history after the moment the traveler arrived in the past. Time travel has been a common plot device in fiction since the 19th century, and one-way travel into the future is arguably possible given the phenomenon of time dilation based on velocity in the theory of special relativity (exemplified by the twin paradox), as well as gravitational time dilation in the theory of general relativity, it is currently unknown whether the laws of physics would allow backwards time travel. These events, often called time slippages, seem to occur randomly and spontaneously. Those who experience these events are often bewildered and confused by what they see and hear, and afterward are at a complete loss to explain them. And also a few stories from those who claimed that they are the real time travelers.

Any technological device, whether fictional or hypothetical, that is used to achieve time travel is commonly known as a time machine and a time traveler (American spelling) or time traveller (British spelling), sometimes known as a "chrononaut", is a person who engages in time travel.

In 1935, Air Marshal Sir Victor Goddard of the British Royal Air Force had a harrowing experience in his Hawker Hart biplane. Goddard was a Wing Commander at the time and while on a flight from Edinburgh, Scotland to his home base in Andover, England, he decided to fly over an abandoned airfield at Drem, not far from Edinburgh. The useless airfield was overgrown with foliage, the hangars were falling apart and cows grazed where planes were once parked. Goddard then continued his flight to Andover, but encountered a bizarre storm.

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