TIME TRAVEL

# TIME TRAVEL

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## TIME TRAVEL

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1. TIME TRAVEL PLEASE NOTE: This PowerPoint is intended to be remodeled for the purposes of SlideFest.

2. Layman’s Artist Depiction “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).” Source: http://en.wikipedia.org/wiki/Time_travel

3. In theory, time travel has been around for a long time. 700 BCE: The Mahabharata (Ancient India) 200s to 400s CE: The Talmud 1819: “Rip Van Winkle” by Washington Irving 1895: The Time Machine by H.G. Wells Source: http://en.wikipedia.org/wiki/Time_travel

4. Time Travel in Two Directions “Some theories, most notably special and general relativity, suggest that suitable geometries of space-time, or specific types of motion in space, might allow time travel into the past and future if these geometries or motions are possible. In technical papers, physicists generally avoid the commonplace language of ‘moving’or ‘traveling’through time ('movement' normally refers only to a change in spatial position as the time coordinate is varied), and instead discuss the possibility of closed time-like curves, which are world-lines that form closed loops in space-time, allowing objects to return to their own past. There are known to be solutions to the equations of general relativity that describe space-times which contain closed time-like curves (such as Gödel space-time), but the physical plausibility of these solutions is uncertain.” Source: http://en.wikipedia.org/wiki/Time_travel

5. Time Travel to the Past “The theory of general relativity does suggest scientific grounds for thinking backwards time travel could be possible in certain unusual scenarios, although arguments from semi-classical gravity suggest that when quantum effects are incorporated into general relativity, these loopholes may be closed.” Source: The Quantum Physics of Chronology Protection by Matt Visser “This confusing.”

6. Time Travel to the Future Special and General Relativity state that time passes more slowly as you approach the speed of light. So if one twin were to travel a very far distance at a very high speed, he would age more slowly relative to his twin on Earth. When he returned home thousands of years in the future, he would have aged very little, while his twin would have grown very, very old. So in this sense, time travel is theoretically possible. “Nice Beard, Bro.”

7. Time Travel via Wormholes Wormholes are a hypothetical warped space-time which are permitted by the Einstein field equations of general relativity. In theory, a wormhole might allow information to travel from one point in space-time to another point in space-time. Source: http://en.wikipedia.org/wiki/Time_travel

8. So what do really smart people think? Stephen Hawking suggests that the absence of time travelers from the future shows that their existence is unlikely. Carl Sagan once suggested that time travelers could be here but that they are disguising their identities. What do you think? Source: http://en.wikipedia.org/wiki/Time_travel

9. Traveling to the Future No one knows what the future looks like, but here’s some of the things a time traveler can expect: Robots Cyborgs Flying Cars Jetpacks Aliens A Larger Sun A Smaller Moon More Robots

10. Thank You! And safe time travels.