Time travel

Time travel

Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space. Time travel could hypothetically involve moving backward in time to a moment earlier than the starting point, or forward to the future of that point without the...

 is a common theme in science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 and is depicted in a variety of media. It simply means either going forward in time or backward, to experience the future, or the past.
Time travel can form the central theme of a book, or it can be simply a plot device. Time travel in fiction can ignore the possible effects of the time traveler's actions, as in A Connecticut Yankee in King Arthur's Court

A Connecticut Yankee in King Arthur's Court

A Connecticut Yankee in King Arthur's Court is an 1889 novel by American humorist and writer Mark Twain. The book was originally titled A Yankee in King Arthur's Court...

, or it can use one resolution or another of the Grandfather paradox

Grandfather paradox

The grandfather paradox is a proposed paradox of time travel first described by the science fiction writer René Barjavel in his 1943 book Le Voyageur Imprudent . The paradox is this: suppose a man traveled back in time and killed his biological grandfather before the latter met the traveler's...

.
Although The Time Machine

The Time Machine

The Time Machine is a science fiction novella by H. G. Wells, published in 1895 for the first time and later adapted into at least two feature films of the same name, as well as two television versions, and a large number of comic book adaptations. It indirectly inspired many more works of fiction...

by H. G. Wells

H. G. Wells

Herbert George Wells was an English author, now best known for his work in the science fiction genre. He was also a prolific writer in many other genres, including contemporary novels, history, politics and social commentary, even writing text books and rules for war games...

 was instrumental in causing the idea of time travel to enter the public imagination, non-technological forms of time travel had appeared in a number of earlier stories, and some even earlier stories featured elements suggestive of time travel, but remain somewhat ambiguous.

• In ancient Hindu mythology
  Hindu mythology
  Hindu religious literature is the large body of traditional narratives related to Hinduism, notably as contained in Sanskrit literature, such as the Sanskrit epics and the Puranas. As such, it is a subset of Nepali and Indian culture...
  
  , the Mahabharatha mentions the story of the King Revaita
  Kakudmi
  Kakudmi was the King of Kusasthali, a kingdom beneath the ocean. He was the father of Revati, who married Balarama...
  
  , who travels to a different world to meet the creator Brahma
  Brahma
  Brahma is the Hindu god of creation and one of the Trimurti, the others being Vishnu and Shiva. According to the Brahma Purana, he is the father of Mānu, and from Mānu all human beings are descended. In the Ramayana and the...
  
   and is shocked to learn that many ages have passed when he returns to Earth.

• Urashima Tarō
  Urashima Taro
  is a Japanese legend about a fisherman who rescues a turtle and is rewarded for this with a visit to Ryūgū-jō, the palace of Ryūjin, the Dragon God, under the sea...
  
  , an early Japanese tale
  Japanese literature
  Early works of Japanese literature were heavily influenced by cultural contact with China and Chinese literature, often written in Classical Chinese. Indian literature also had an influence through the diffusion of Buddhism in Japan...
  
  , involves traveling forwards in time to a distant future, and was first described in the Nihongi
  Nihon Shoki
  The , sometimes translated as The Chronicles of Japan, is the second oldest book of classical Japanese history. It is more elaborate and detailed than the Kojiki, the oldest, and has proven to be an important tool for historians and archaeologists as it includes the most complete extant historical...
  
  (720).