Time TravelFirst, to give you a better idea of ​​time, I'm going to use one of my personal theories. When you look at the sky at night, at the stars, what do you see? Do you think this collage of stars really exists? Most of them don't. When you look at the sky at night, you are seeing the past, because it takes an obscene amount of time for the light from these stars to reach the earth, and in that time, these stars may have disappeared. It works both ways. When an inhabitant, if there is one, of a planet around the star you are looking at looks at our sun, they are also seeing the past. So here we come to the main idea of ​​my speech - the possibility of different times and time travel. The main question here is: How to connect these 2 times? Well, the key is to go faster than the speed of light, which is 186,283 miles per second - or about the same as going around the earth seven times in one second. If you have trouble understanding that going faster will connect 2 times, I can put it more simply: movement slows down time. This was proven in 1971. That year, American physicists took 4 atomic clocks, left 2 on the ground, and placed each of the others in planes flying in opposite directions around the earth at 621 mph. When the planes returned, scientists were delighted to find that the clocks on the planes were a few billionths of a second slower than those left on the ground. (theage.com.au) Unfortunately, according to Einstein (which has yet to be disproven), you cannot reach the speed of light because whatever solid object you would use to do that (it's (ie: a spaceship), would create a vortex behind it that would create drag all matter... planets, stars, galaxies, etc. To put this into perspective, think about when ... middle of paper ... and the mother would have been born, meaning the time traveler would have been born and could indeed still go back in time and kill his grandmother . Preston has two solutions to this. The first is that you can't change the course of history, so the time traveler would have endless misadventures trying to kill his grandmother. The second is that when he killed her, he immediately created a parallel universe in which the young grandmother never existed and he was never born, but our original universe remains. Time travel seems to be reserved for science fiction movies, but it could have been invented in the future and the course of history has already been altered. As we sit here right now, all of our feelings, thoughts and memories could have been reset and we are in a different universe. Neither you nor I would have any memory of it.