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 need for the traveler to experience the intervening period (at least not at the normal rate). Any technological device – whether fictional or hypothetical – that would be used to achieve time travel is commonly known as a time machine.
Although time travel has been a common plot device in science fiction since the late 19th century and the theories of special and general relativity allow methods for forms of one-way travel into the future via time dilation, it is currently unknown whether the laws of physics would allow time travel into the past. Such backward time travel would have the potential to introduce paradoxes related to causality, and a variety of hypotheses have been proposed to resolve them, as discussed in the sections Paradoxes and Rules of time travel below.
Read more about Time Travel: Theory, In Physics, Time Travel To The Future in Physics, Philosophical Understandings of Time Travel
Famous quotes containing the words time and/or travel:
“The greatest waste of time he knew of was to count the hours—what good can come of it?—and the greatest illusion in the world, to lead one’s day by the sound of the clock, and not by precepts of common sense and understanding.”
—François Rabelais (1494–1553)
“You are wonderful. I love and honor you.... [ellipsis in source] Lead your own life, attend to your charities, cultivate yourself, travel when you wish, bring up the children, run your house. I’ll give you all the freedom you wish and all the money I can but—leave me my business and politics.”
—Eleanor Roosevelt (1884–1962)