Post by sornmanee on Feb 25, 2013 4:52:36 GMT -5
Time travel is the idea of going back in time to the past or forward to the future. Time travel cannot be done with the technology we have now. However, physicists say that there is a chance that time travel will be possible in the future. The time machine idea first appears in 700s BCE to 300s CE literature, Story of Raivata in the Mahabharata. Many Science fiction, fantasy movies and television programs have been based on stories of people who travel through time. For example, the American movie "Back to the Future" tells a fictional story about a professor who builds a machine that can take people into the future or back in the past. The popular British TV program Doctor Who is about an alien who has adventures by time traveling. Any technological device that would be used to achieve time travel is commonly known as a time machine.
Albert Einstein developed a theory called Special Relativity. The ideas of Special Relativity are very hard to imagine because they aren't about what we experience in everyday life, but scientists have confirmed them. This theory says that space and time are really aspects of the same thing, space-time. There's a speed limit of 300,000 kilometers per second (or 186,000 miles per second) for anything that travels through space-time, and light always travels the speed limit through empty space.
Special Relativity also says that if a person gets close to going as fast as the speed of light, time will seem to move slower to the person. For example, if an astronaut and his rocket ship flew through space at the speed of light for one day, by the time he came back, it is possible that years could have passed.
There are three rules of time travel. The first one is there is a single fixed history, which is self-consistent and unchangeable. Even when parties travel back in time, the future they left cannot be changed. All events remain as fixed points in time. The actions of the traveler in the past have already become part of history. This known as the Nivikov Self-Consistency Principle as seen in The Terminator, Harry potter 3, and 12 monkeys. For example, you travel back in time to kill Adolf Hitler as a baby in order to prevent World War 2. So you replace him with an orphaned baby, so that the family wouldn’t noticed, but the replaced baby grown up to be Hitler himself.
Second, “Dynamic timeline”. This means changes to history are easy and can impact the traveler, the world, or both. Altered events in the past have definite impacts on the present. In some cases, any resulting paradoxes can be devastating, threatening the very existence of the universe. In other cases the traveler simply cannot return home. The extreme version of this (Chaotic Time) is that history is very sensitive to changes with even small changes having large impacts such as in Ray Bradbury's "A Sound of Thunder".
The third one is called “Multiverse”. In an infinite number of parallel universes traveling into the past causes a new divergent timeline from the first. Because of this, the traveller can do anything with impunity, and only the new timeline will be affected. This means the grandfather paradox can be avoided since even if the time traveler's grandparent is killed at a young age in the new timeline, he/she still survived to have children in the original timeline, so there is still a causal explanation for the traveler's existence.
I believe in the first rule the most and it probably the safest because the future would not change to something worse. In second or third rule the future may change. There was a good chance that the world would change to be better, but there also chance that it would be worse. Also, if you make a small change in the past, in the future may turn to something completely different. History is very sensitive to change. So if time travel or time machine is real I hope that the time traveler is wise and good. Otherwise, the world would be extremely chaotic. “If you change the future you change that past. The effect ripple outwards up and down the timeline” this quote is from one of my favorite video games, Final Fantasy XIII-2, and I also believe that. If you travel to the future and change it, the past would change too, because what you do in the past would affect the future. The traveler’s mind would go crazy, because it is very confusing and I think he/she wouldn’t be able to handle it. I have the feeling they most of the movies or video games that involved with Time travel would have sad endings. So I think that it would be best if you don’t change the future and let it be. In conclusion, if time travel is real it would be best that it is the fixed timeline, because the future or the past won’t change. But not changing the timeline is the best way. In other words, let the future be.
sources :
en.wikipedia.org/wiki/Time_travel
iwastesomuchtime.com/on/?i=56475
Albert Einstein developed a theory called Special Relativity. The ideas of Special Relativity are very hard to imagine because they aren't about what we experience in everyday life, but scientists have confirmed them. This theory says that space and time are really aspects of the same thing, space-time. There's a speed limit of 300,000 kilometers per second (or 186,000 miles per second) for anything that travels through space-time, and light always travels the speed limit through empty space.
Special Relativity also says that if a person gets close to going as fast as the speed of light, time will seem to move slower to the person. For example, if an astronaut and his rocket ship flew through space at the speed of light for one day, by the time he came back, it is possible that years could have passed.
There are three rules of time travel. The first one is there is a single fixed history, which is self-consistent and unchangeable. Even when parties travel back in time, the future they left cannot be changed. All events remain as fixed points in time. The actions of the traveler in the past have already become part of history. This known as the Nivikov Self-Consistency Principle as seen in The Terminator, Harry potter 3, and 12 monkeys. For example, you travel back in time to kill Adolf Hitler as a baby in order to prevent World War 2. So you replace him with an orphaned baby, so that the family wouldn’t noticed, but the replaced baby grown up to be Hitler himself.
Second, “Dynamic timeline”. This means changes to history are easy and can impact the traveler, the world, or both. Altered events in the past have definite impacts on the present. In some cases, any resulting paradoxes can be devastating, threatening the very existence of the universe. In other cases the traveler simply cannot return home. The extreme version of this (Chaotic Time) is that history is very sensitive to changes with even small changes having large impacts such as in Ray Bradbury's "A Sound of Thunder".
The third one is called “Multiverse”. In an infinite number of parallel universes traveling into the past causes a new divergent timeline from the first. Because of this, the traveller can do anything with impunity, and only the new timeline will be affected. This means the grandfather paradox can be avoided since even if the time traveler's grandparent is killed at a young age in the new timeline, he/she still survived to have children in the original timeline, so there is still a causal explanation for the traveler's existence.
I believe in the first rule the most and it probably the safest because the future would not change to something worse. In second or third rule the future may change. There was a good chance that the world would change to be better, but there also chance that it would be worse. Also, if you make a small change in the past, in the future may turn to something completely different. History is very sensitive to change. So if time travel or time machine is real I hope that the time traveler is wise and good. Otherwise, the world would be extremely chaotic. “If you change the future you change that past. The effect ripple outwards up and down the timeline” this quote is from one of my favorite video games, Final Fantasy XIII-2, and I also believe that. If you travel to the future and change it, the past would change too, because what you do in the past would affect the future. The traveler’s mind would go crazy, because it is very confusing and I think he/she wouldn’t be able to handle it. I have the feeling they most of the movies or video games that involved with Time travel would have sad endings. So I think that it would be best if you don’t change the future and let it be. In conclusion, if time travel is real it would be best that it is the fixed timeline, because the future or the past won’t change. But not changing the timeline is the best way. In other words, let the future be.
sources :
en.wikipedia.org/wiki/Time_travel
iwastesomuchtime.com/on/?i=56475