Time Travel?

Question

Everyone seems to think that traveling back in time can't happen.
Why is that? Also, how would you prove it impossible?

Answer 1

Time was created by man. Who is to say it even exists in the way we percieve it?

Answer 2

Boy, some interesting and complex answers here. I was always taught that time is relative. Take the premise that two people are walking along parallel lines 40 feet apart, but one is 40 feet in front on the other. The person at the back throws a ball to the person in the front. To a person stood at the end of the lines, the ball appears to travel 40 feet in a particular time, the distance between the two lines. To the two people on the lines, the ball will travel approximately 60 feet, (across the diagonal), in exactly the same time. To the people standing at the end of the line, time has travelled slower, because the ball took the same time to travel a shorter perceived distance. The astronauts that went to the moon ended up two minutes younger than if they had stayed on earth. You can't travel back in time, but you can distort it.

Answer 3

Who said it wasn't impossible?
Saying it impossible is completly redicously for one reason. Those old McDonalds commercials, where they say "Hey it could happen" were for the most part right.

The Grandfather theory is based around the idea that there is one universe in our universe, and that the 4 dimensions that define our universe are finite to a degree that can be measured.
The four dimensions of course being the 3 dimensions involving 3 dimensional figures, length, width, and height, which can be defined as a constant. Then we have the 4th, which is time, which moves in a linear fashion foward. These are the ideals that our idea of Space itself revolve around. This would be a perfectly good way of thinking about things, if it were true. As far as we can tell right now, is that space, the 3 dimensions that can be defined as a constant, happen to be constantly defined as infinite.

Yes folks, it just keeps on going.

Now since it keeps on going, it isn't a matter of whether or not something is happening than what the probabilty of finding it are in a certain area. When I say area, I say a set, bounded off piece of space limited in all 4 dimensions.
Hope ya'll are still following.

So its like picking a point on a 4 dimensional graph paper. So you pick your first point and its point A. Now to make Point A easier to perceive, we'll call it the first Battle of the Marne in France during WWI on a planet called Earth in a galaxy called the Milky Way, or at least called that by its current inhabitants. Now we'll bring point B into the situation which is now. Now since space is infinite, you can't say that eventually if you start from Point B that eventually, if you know where your going you won't hit Point A. You just have to travel far enough to get there.


So is back time travel possible? Yes, of course it is, it jus involves vast distances that are on some level incalcuable. Infinite Probability, and maybe you've been waiting for me to say it, Infinite Improbability, can prove the grandfather paradox wrong because it is not going back in the time you expierenced to kill your grandfather, it is going back to anothers. This could also be described as I think, string theory or something similair, but this always seemed the easiest way to think about it to me.

Answer 4

They used to say if you travel faster then light, you would change your time. But you wouldn't have to go anywhere only maybe vibrate or have a wave form pass through you. I believe you can by moving into another dimension. Some people do this in, out of body experiences. But we need to in the body. I think this can be done with high voltage "static", and a lot of machinery?. Or maybe not as much machinery as you might think. I was once told by a reliable sauce that there's enough electrical energy in a vinyl disc the size of an old L.P to power a flying saucer for more then a year. Its just knowing how to extract and use it. Time has been likened to a tree, if you go back along your branch and start another, the two branches of time, will still exist along side each other.

Answer 5

Time travel is possible. For example, an object traveling at high speeds ages more slowly than a stationary object. This means that if you were to travel into outer space and return, moving close to light speed, you could travel thousands of years into the Earth's future.

Physicists (and mathamatitions) today are still trying to prove that traveling back in time is impossible, but so far they can't.

Answer 6

Time travel is not supposed to be possible but who knows what the future will bring? But it is possible to slow time.
Experiments have show that if you are in orbit travelling at high speed time goes slower than on earth. This was proved by synchronising two caesium clocks on earth and taking one up into space. After a week there was a difference of two seconds between the clocks, Even thought they are very accurate and keep very precise time

Answer 7

The honest answer is we just don't know yet. I myself would like to believe that some day we could but i am not a one theory guy, so this is a theory which me and a friend came up with. It may be impossible because in order to time travel an infinite amount of energy is required, and in order for us to have this we must have an infinite universe but the universe is not infinite therefore it must be impossible (theory).

Answer 8

Because for time travel to be possible, every single instance in all of the past would have to still exist, as would all events that are going to happen in the future. This would also mean that the future is also mapped out, in which case everything is simply going to happen no matter what - including an individual travelling back in time, if it were actually possible.

Answer 9

"Time travel" is bastardized terminology, meaning that it isn't a legitimate term. The term implies that one travels through something called time, and that isn't what is done.

But excepting "time travel" as the term for what you are speaking of, some people will say that it is possible but that there is a problem with an object surviving intact through the process. Others say it's impossible because it would create a paradox involving causality (cause and effect), usually citing some form of the grandfather paradox. The grandfather paradox basically states that if you were to travel back to when your father's father was an infant and killed him, then your father would never have been born and so you would never have been born either, thereby making it impossible to have traveled back to when your grandfather was an infant. Extensions of the grandfather paradox include taking anything that exists at a future date and placing it at a past date. However, the grandfather paradox doesn't work because causality isn't adversely affected by "time travel". The grandfather paradox treats causality as a circular event instead of a cascading event. The original cause of an effect does not need to continue to exist after the effect comes into existence, nor does it need to be made to come into existence again. That you won't be born again after killing your grandfather doesn't erase that you had been born once.

Others will argue that "time travel" disrupts the law of Conservation of Energy, which is wrong as well, misquoting it as "Energy can neither be created or destroyed". Firstly, they neglect to add "in a closed system" to that quote and secondly, the Universe is not made up of sections of space divided by time.

I'm constantly telling people "The Universe is the totality of existence". Let's say that you want to be at the southeast corner of Main street in your home town at 6:23 a.m. PST on May 2, 1969. You don't travel through time to get there, you simply go to where that exists in the Universe.

Answer 10

good question

maybe someday it will be answered but I will tell you (may already know)

that time travel is in a way a fact

the faster you go twords the speed of light the more time slows down..
how did they prove it

atomic clock on earth and one on the space shuttle

space shuttle velocity in space is around 17,000 mph nothing near that of light but the clocks were a fraction of a second off meaning one had slowed down ie.. the space shuttles time


traveling back in time is another story...

to me: you can think of time as on different parrellel lines.. one can go a little quicker/slower then the other

so I guess if you could travel at the speed of light for a year that you could come back to earth and the times would be off but you could never actually go from present and then back to past

but then again you have the theory of worm holes

and it may seem outrageous but things get really amazing and hard to belive when you get into the science of quantum physics

question everything that you think is real basically

Answer 11

Because of the paradoxes it could give rise to - like going back in time and killing your grandfather before he had children.

The many worlds interpretation (and it is the most sensible one even if it has far out implications) of quantum mechanics neatly solves this little dilemma.

Modifications to the past would place you in a parallel timeline and it would be next to impossible to get back home because travelling in to the future would send you in to a different future in a different universe from the one you came from.

You asked why people believe its impossible and thats the reason - for people who believe in a single timeline then being able to travel in to the past would give rise to such paradoxes. You can't prove time travel impossible and the best of our theories at the moment say that it is indeed possible.

Check out The Fabric of Reality by Deutsch or The Fabric of the Cosmos by Greene.