Time travel

This slide is about time travel

1. Time Travel Md. Mahbub Hasan ID: 151012 Dept: EEE

2. “ Time travel  is the concept of moving between different points in  time  in a manner analogous to moving between different points in space, generally using a theoretical invention known as a  time  machine .Nature also allowed us Time Travel through Wormhole,Blackhole,Crossing speed of light(theoretically).” What is Time Travel

3. What Exactly is Time? Most people think time is constant. Physicist Albert Einstein showed that it was merely an illusion. Time depending on one’s speed through space. Einstein declared time as the fourth dimension. Time only provides the coordinate direction, which only moves forward.

4. • Einstein's theory of special relativity describes that the speed of time depends on how fast you are moving relative to something else  • Ex. If someone in a spaceship flies around the earth at the speed of light, that person would age much slower than a person back on earth  • Theory of general relativity states that gravity can bend time. Einstein's Theory of Special & General Relativity

5. One possibility of traveling back in time would be to travel even faster than the speed of light, but even then it is shown in Einstein's equations that one's mass & length must infinitely be 0. However, other scientists are optimistic about that it may be done . Possibilities of Time Travel

6. Through Wormholes WORMHOLE a shortcut connecting two separate points in spacetime that could connect extremely far distances such as a billion light years or more, in theory, different points in time. • Create a wormhole between different points in space time  - Space-time is a four-dimensional fabric that when bent, causes gravity . • But wormholes collapse fairly quickly & would only work for tiny particles. • Technology to even create a wormhole goes beyond anything we have today.

7. • A black hole is a large amount of matter squeezed into a small area; its gravitational pull is so strong that even light can’t escape it • Fly a spaceship quickly around the black hole to make the big rotating structure • Would have to travel at the speed of light for this method to work Black Holes

8. But some physicist claimed that the machine used for time travel can fall apart for the gravitational pull of the blackhole . This picture shows that how light bend near a blackhole for strong gravitational pool. Black Hole from movie- INTERESTELLAR

9. Time Machine A machine in which people or objects can be transported into the past or the future. Though, at present it’s only exists in science fiction stories & movies. If a true time machine would ever invented, it can only travel forward not backward. Because if it is capable to travel back in past, it may create some inconsistent loop(paradox). Which physics doesn’t allowed. Time Machine from movie- Back to The Future

10. Grandfather Paradox The main problem with Time Travel is the time travel theory is unable to answer some paradoxes. paradox is a statement or concept that contains conflicting ideas. The grandfather paradox is a proposed paradox of time travel. Considering this paradox time travel can not be possible. Grandfather Paradox: If the time traveller goes back in time and kills his grandfather before he meets his grandmother. As a result, the time traveller is never born. But, if he was never born, then he is unable to travel through time and kill his grandfather. This creates inconsistent a loop. That can never be answered by our theoretical physics.

11. References Websites- https://en.wikipedia.org/wiki/ Time _ trave www.space.com/21675- time - travel .html http://www.dailymail.co.uk/home/moslive/article-1269288/STEPHEN-HAWKING-How-build-time-machine.html Image Courtesy- www.google.com/images Movies- INTERESTELLAR(2014) Predestination(2014) Back to the future Trilogy(1985,1989,1990)

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