Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space.
History of Time Travel
History of Time Travel
- In 700s BC to 300s AC – Story of Raivata in the Mahabharata
- 200s to 400s AC – Story of Honi HaM'agel in the Talmud
- 720 AC – "Urashima Tarō" in the Nihon Shoki
- 1733 – Samuel Madden's Memoirs of the Twentieth Century
- 1771 – Louis-Sébastien Mercier's L'An 2440, rêve s'il en fût jamais
- 1781 – Johan Herman Wessel's Anno 7603
- 1819 – Washington Irving's "Rip Van Winkle"
- 1824 – Faddey Bulgarin's "Pravdopodobnie Nebylitsi"
- 1827 – Goethe Faust fragment
- 1828 – Hans Christian Andersen's Journey on Foot from Holmen's Canal to the East Point of Amager
- 1832 – Goethe's Faust: The Second Part of the Tragedy
- 1836 – Alexander Veltman's Predki Kalimerosa
- 1838 – Hans Christian Andersen's The Goloshes of Fortune
- 1838 – Missing One's Coach: An Anachronism
- 1843 – Charles Dickens' A Christmas Carol
- 1861 – Pierre Boitard's Paris avant les hommes
- 1881 – Edward Page Mitchell's The Clock That Went Backward
- 1887 – Enrique Gaspar y Rimbau's El anacronópete
- 1888 – H. G. Wells' The Chronic Argonauts
- 1889 – Mark Twain's A Connecticut Yankee in King Arthur's Court
- 1895 – H. G. Wells' The Time Machine
"Rip Van Winkle"
Washington Irving's 1819 story "Rip Van Winkle" tells of a man named Rip Van Winkle who takes a nap on a mountain and wakes up 20 years in the future, when he has been forgotten, his wife dead, and his daughter grown up.
Special and general relativity, suggest that suitable geometries of spacetime, or specific types of motion in space, might allow time travel into the past and future if these geometries or motions are possible.
Stephen Hawking has suggested that the absence of tourists from the future is an argument against the existence of time travel—a variant of the Fermi paradox. Of course this would not prove that time travel is physically impossible, since it might be that time travel is physically possible but that it is never developed (or is cautiously never used); and even if it is developed, Hawking notes elsewhere that time travel might only be possible in a region of spacetime that is warped in the correct way, and that if we cannot create such a region until the future, then time travelers would not be able to travel back before that date, so "This picture would explain why we haven't been over run by tourists from the future." Carl Sagan also once suggested the possibility that time travelers could be here, but are disguising their existence or are not recognized as time travelers.
the theory of general relativity does suggest a scientific basis for the possibility of backwards time travel in certain unusual scenarios, although arguments from semiclassical gravitysuggest that when quantum effects are incorporated into general relativity, these loopholes may be closed. These semiclassical arguments led Hawking to formulate the chronology protection conjecture, suggesting that the fundamental laws of nature prevent time travel, but physicists cannot come to a definite judgment on the issue without a theory of quantum gravity to join quantum mechanics and general relativity into a completely unified theory.
Time travel to the past is theoretically allowed using the following methods:
- Travelling faster than the speed of light
- The use of cosmic strings and black holes
- Wormholes and Alcubierre drive.