Is (theoretical) timetravel possible without automatically creating a paradox?

[Joe]

I do not think that Time Travel to the future or the past is possible. The reasoning is farily simple in this case.

PAST: One cannot travel to the past, because the past has already been set in stone. If one were to travel back in time, it would fundamentally alter the timeline. Even if that person stood still and spoke and did nothing, that would STILL have a ripple effect, like all actions do. This would change that with is already certain, and as such everything in the present could be changed. Since the past is solid, one can't alter the rock without shattering it.

FUTURE: One can't travel to the future, because the future has not been set yet. You could die tomorrow, next week, or in two hours. To travel anywhere beyond that would, in theory, kill you. And once you've crossed the barrier between life and death you can't come back. Likewise, traveling to the future would bring few results, again, because it's fluid. And, even if travel to the future Were possible, you wouldn't be able to come back to the present. Since the present is set in stone, already, and your return would again alter that which is set in stone.

[Sinister]

Technically, time travel is a natural occurrence. People are convinced that time is iron-clad. That it is as a clock. One second is one second for everyone. But the truth is that Time and Space are relative to certain degrees of speed.

In theory time should slow the closer you get to a black hole, for instance...or the closer you get to the speed of light. Such speeds are not available to humans, of course. But then, as you rejoin normal speeds you would rejoin normal time. And thus having achieved a...form of time travel.

But if you're referring to Back to the Future or other Sci-Fi mediums. I have nothing to contribute.

Most everything that can be said about Time travel, has been. The bottomline is, it's not possible at the moment... But it's not impossible.


As for Paradoxes. Paradoxes are often flaws in logical conceptualization. But until someone has tried it, who can say?

-Sin

[RagnaToad]

In theory time should slow the closer you get to a black hole, for instance...or the closer you get to the speed of light. Such speeds are not available to humans, of course. But then, as you rejoin normal speeds you would rejoin normal time. And thus having achieved a...form of time travel.

I don't quite understand what you mean with "time should slow...".
It's not because you move faster through space, that everything else moves faster through time.

Personally I don't believe in the matter of "time". There is only this moment that is real, not the moment 1/1000.000th of a second ago, that is a moment gone forever. Neither is there something as a "future".

Many people see "time" as a timeline on which we are but one little dot. The thing is, time is just an abstract term for us to use to easily refer to situations "in the past" i.e. situations that are no more. The term "future" is used to describe what will happen according to someone's logic, but it's not written in stone or anything. There is no destiny.

The native Americans believed that the people "in the past" were still alive, but just in the past. I disagree. You would have to see time as a timeline on which there is no absolute "now". If you know what I mean? We would simply be the past's future and the future's past. It's just weird to assume that this situation is not more existent than a situation which is no more...

I do believe looking back in time is possible.
In fact, we already do, don't we? What is the ability of sight? Light reflects on an object, e.g. a person you're talking to, travels a meter to your eye and falls into your eye and voila, sight is a fact.
Light may be incredibly fast, but it still has A speed. So it takes a while for the light, reflecting on something, to reach your eye.

Why don't we notice it? Because light is extremely fast. We WOULD notice the "delay" if, say, light were somewhat slower than our thinking.
Imagine someone moving in front of you, you try to hit him, and you can, because what you see may not be what happens when the light reaches your eye, but the difference in time between something actually happening and you being able to see it, is not noticeable by our brains.
(Whereas for sound, which can be slowed down in thin air or various curcimstances, you often see something happening, only for the sound to arrive later. Think about an F-16 flying over, flying faster than the speed of sound. You hear him being a couple of hundred yars behind where he actually is, right?)

Just to illustrate "looking" back in time is what we already do, but travelling is a totally different thing. I wouldn't want to know how easily a paradox could be created...

[Sinister]

I don't quite understand what you mean with "time should slow...".
It's not because you move faster through space, that everything else moves faster through time.

Personally I don't believe in the matter of "time". There is only this moment that is real, not the moment 1/1000.000th of a second ago, that is a moment gone forever. Neither is there something as a "future".

Many people see "time" as a timeline on which we are but one little dot. The thing is, time is just an abstract term for us to use to easily refer to situations "in the past" i.e. situations that are no more. The term "future" is used to describe what will happen according to someone's logic, but it's not written in stone or anything. There is no destiny.

The native Americans believed that the people "in the past" were still alive, but just in the past. I disagree. You would have to see time as a timeline on which there is no absolute "now". If you know what I mean? We would simply be the past's future and the future's past. It's just weird to assume that this situation is not more existent than a situation which is no more...

I do believe looking back in time is possible.
In fact, we already do, don't we? What is the ability of sight? Light reflects on an object, e.g. a person you're talking to, travels a meter to your eye and falls into your eye and voila, sight is a fact.
Light may be incredibly fast, but it still has A speed. So it takes a while for the light, reflecting on something, to reach your eye.

Why don't we notice it? Because light is extremely fast. We WOULD notice the "delay" if, say, light were somewhat slower than our thinking.
Imagine someone moving in front of you, you try to hit him, and you can, because what you see may not be what happens when the light reaches your eye, but the difference in time between something actually happening and you being able to see it, is not noticeable by our brains.
(Whereas for sound, which can be slowed down in thin air or various curcimstances, you often see something happening, only for the sound to arrive later. Think about an F-16 flying over, flying faster than the speed of sound. You hear him being a couple of hundred yars behind where he actually is, right?)

Just to illustrate "looking" back in time is what we already do, but travelling is a totally different thing. I wouldn't want to know how easily a paradox could be created...

I simply stated time slows in relation to speed. "In relativistic contexts, however, time cannot be separated from the three dimensions of space, because the rate at which time passes depends on an object's velocity relative to the speed of light and also on the strength of intense gravitational fields, which can slow the passage of time." That is relativity. How I choose to word what we all know happens, isn't relevant. Time travels in different frequencies at certain speeds, on which assertion I am correct according to most astrophysicists. The twin that is flying around the galaxy near the speed of light for ten years, could well stop and come back home to a brother who has aged twenty years.

Not only time, but matter as well. A meter stick going the speed of light will be shorter than a meter stick I hold in my hand on earth, by principle.


As to expound on the rest of your post... I quite agree. We, Taoists have a saying that the man who comes home and sits down in his chair, is not the same man who woke up and left home in the first place. There is no future. No one has ever lived two days at once, so how can their be a tomorrow.

People like to look at time the way they look at music, dragging the past to make sense of the present and assuming the future to establish a pattern. If the music doesn't follow the pattern set by the past, it's just a lot of jumbled noises. You have to follow the flow of notes to catch the greater meaning. Taoists don't live like this. We live only second to second.