Time travel impossible?

[soMe_RandoM]

well what do you think
if you do this:
you go back to save ur GF from dying But no matter what you cant change it.

you time travel back in time before you go into the room.
you then baricade the room from stoping your self from getting into room
but it fails.

you go back intime to suicide your self as being murded is an larger payout from insurance for your family and you want to die
but shot miss and you spend some time in prision for attempted murder.

you go back in time to shag brittney, but when you do you then dont have an recall of the event as it never happen

you go back in time to stop ur parents from shaging as you are the brother of some one like hitler that massed killed alot.
but it fails. (it was motive)

so what u think imposible for anything other than sight seeing and you where sent by force? as since it not the reason you are in the past thus meaning what ever done stays that way>?

[rubikscube]

well what do you think
if you do this:
you go back to save ur GF from dying But no matter what you cant change it.

you time travel back in time before you go into the room.
you then baricade the room from stoping your self from getting into room
but it fails.

you go back intime to suicide your self as being murded is an larger payout from insurance for your family and you want to die
but shot miss and you spend some time in prision for attempted murder.

you go back in time to shag brittney, but when you do you then dont have an recall of the event as it never happen

you go back in time to stop ur parents from shaging as you are the brother of some one like hitler that massed killed alot.
but it fails. (it was motive)

so what u think imposible for anything other than sight seeing and you where sent by force? as since it not the reason you are in the past thus meaning what ever done stays that way>?

Why can't you save your gf?

How does it fail?

Third one I just don't get the point. It's a statement.

[RCIX]

I favor the "it always happened" theory of time travel: if we ever time traveled, then those events we caused would already have been integrated into our version of history, so we can do what we like when we go back (as it already happened, thus no polluting the timeline).

[Frozen Critical]

Time travel is totally impossible , Even with SCIENCE , the only way you can time travel is in your mind

[eRe4s3r]

Time travel is impossible - because traveling back would involve generation of infinite energy.

Why? You take a battery from the past - reload it in the future and leave it in the past - that means you just spend energy in the past that does not exist, and thus would need to be generated out of thin air. And time travel would thus require *more energy* than all the universe contains at a given point in time - a paradox.

Since magical energy does not exist - time travel is absolutely impossible.

[zebramatt]

Travel into the future at an accelerated subjective rate is theoretically possible according to present theories of time dilation - but people rarely mean that when they talk of 'time travel'. Indeed, it's arguable that for the subject travelling forward through time this actually equates to little more than a time perception effect much like that achieved in organisms capable of altering their metabolic rate through hibernation and the like.

So then, time travel to the past. Although eRe4s3r outright claims it impossible, present thinking on the nature of exotic energy-generated traversable wormholes and their interaction with time dilation effects does present a relatively popular case for such time travel into the past. It's well-known so I shan't go into it but basically: jump in a really-very-fast ship; generate one end of your traversable wormhole on board; generate t'other end somewhere else, stationary and a fairly long way away; now get your really-very-fast ship going really-very-fast-indeed, approaching the speed of light no less; wait quite a long time; et voila one end of your wormhole is now subjectively in the future (the stationary one) and the other's subjectively in the past (the one moving quite quickly). Or you use gravity-based time dilation to a similar effect.

Anyway, the point is, time travel of this variety isn't much good to anyone either, because you almost certainly would have to keep the two ends of the wormhole very far apart - making infringements of causality entirely impractical. I did read one theory on how you'd still be able to meet yourself if you set up elaborate series of wormholes but it was all a little bit convoluted.

So is there anything else? Well, current quantum theories do include some rather esoteric provisions for time travel but it's somewhat akin to speculating on the possibility of blue peanut butter by including it in a theory of the psychology of mayfly...

[RCIX]

Time travel is impossible - because traveling back would involve generation of infinite energy.

Why? You take a battery from the past - reload it in the future and leave it in the past - that means you just spend energy in the past that does not exist, and thus would need to be generated out of thin air. And time travel would thus require *more energy* than all the universe contains at a given point in time - a paradox.

Since magical energy does not exist - time travel is absolutely impossible.

Ah, but what about the theory (afaik, it may be mine, but it might not) that the law of conservation of energy is four dimensional? as in, as long as a system maintains the same total amount of energy measured over time as well as space (in this case, it would be energy in the battery * amount of time we're looking at), then the law of conservation of energy is not broken.

So then, time travel to the past. Although eRe4s3r outright claims it impossible, present thinking on the nature of exotic energy-generated traversable wormholes and their interaction with time dilation effects does present a relatively popular case for such time travel into the past. It's well-known so I shan't go into it but basically: jump in a really-very-fast ship; generate one end of your traversable wormhole on board; generate t'other end somewhere else, stationary and a fairly long way away; now get your really-very-fast ship going really-very-fast-indeed, approaching the speed of light no less; wait quite a long time; et voila one end of your wormhole is now subjectively in the future (the stationary one) and the other's subjectively in the past (the one moving quite quickly). Or you use gravity-based time dilation to a similar effect.

You actually don't have to do that. If you use a particle accelerator (or some other device capable of propelling a wormhole to extreme speeds), and spin the wormhole around really really fast, then it slows in time relative to you and after you stop spinning it you can go back in time. That's assuming that you can actually move wormholes, and that they're effected by time dilation.

[rubikscube]

you get infinite energy from the future, which will power your infinite energy using time machine, creating a paradox about making a time machine

so when ever we do get infinite energy, it will jumpstart the time travel age

[eRe4s3r]

There is no such thing as infinite energy - because the Universe and with that i mean all galaxies and everything in between is finite and decays - thats called Entropy - http://en.wikipedia.org/wiki/Entropy . That is the current state of knowledge, anyhow.

Wormholes are theoretical constructs and not proven nor a scientific fact. The only thing Wormholes would *at best* allow is FTL travel (and only between 2 points and only 1 way) but time travel is not travel in the physical sense. Also wormholes would have a hard time to exist for more than a nano second due to their massive power requirements ;p

The first law of newton only applies to vacuum 0-grav travel - it doesn't really work so well in reality because space is not empty - space is actually pretty damn full dark matter and dark energy and theres a high chance that it will cause drag if we fly through it. Although inner solar system is relatively empty because of the planets and sun

The vital law of motion is : III. For every action there is an equal and opposite reaction.

Traveling back in time would thus require an equal opposite reaction which amounts to more energy than exists in the universe ^^

Why? Because Universe you leave is State 1 - You revert it back to State 0 (which means everything, the entire universe) - Now 2 states exist so you just duplicated the energy of the entire universe - to do that you would need more energy than exists because the older the universe gets the more it decays (the galaxy expands and cools down = decay of energy = entropy). Time travel BACK in time is physical thus impossible

FTL travel would be possible - if, and only if theres a secondary space or dimensional plane we don't know about (ie outside real space)

[zebramatt]

Did you not understand the theoretical concept of time-dilated traversable wormholes or are you simply choosing to ignore it? 

[eRe4s3r]

That isn't a experimental proven theory So i chose to ignore it.

There is no point to fantasize - reality is where we live in and in reality, black holes exist, and wormholes do not (so far, anyway). The Theory that tries to fantasize about Wormholes is based on the 0.01% that we know about black holes. And we know nothing about black holes - we can't even explain the current state of the universe with ANY physics model, neither Quantum Mechanics nor Standard Physics. Which means that all our quantum based theories about things in space are flawed by default and our standard physics understanding of them is thus faulty as well.

I am fairly certain that if your theory proves true , the uses for humans of that kind of time "travel" would be nill. If we don't discover FTL travel in the next 200 years there will be no human race left to contemplate over time travel or creation of wormholes anyway.

Which is not to say that Doctor Who style time travel would not be totally awesome to have  But if given the choice between that and FTL - i'd take ftl

[Dragon]

The argument of "time travel must be impossible because we have not seen any time travelers" is another point against it.....

[rubikscube]

most "super natural" stuff like wormholes and other blackholes we can actually use for our needs is not going to come till we get out of this stupid solar system (jk it's great, though it's getting hot over here )

[RCIX]

The argument of "time travel must be impossible because we have not seen any time travelers" is another point against it.....

That doesn't deal with the class of time travel machines that can't travel to before they were made (like said time-dilated wormholes)

eRe4s3r, i get the feeling you look at time as an artificial construct (as in, it's something we humans invented to make it easier to do things regularly), in which case you're right and time travel is impossible. However, if time is a separate dimension, then it might be possible to travel back along it (to an earlier state, as you said), without any duplication of energy.

[zebramatt]

That isn't a experimental proven theory So i chose to ignore it.

Oh good, I thought for a second there you and I might not actually exist within the same perceptual reference, which would be immensely frustrating (if that is, it were possible) to say the least.

There is no point to fantasize...

Of course there is!