Timetravel

[Nerve Misfire]

like 12 Monkeys there is another interesting time travel movie. Donnie Darko, whioch also deals with time travel.

[Freedan]

I like the split dimensions theory, seems the most likely from options.
But of course they currently say you can only travel forward in time, so you could not effect your own existance, since you'd've long since been born

[amlthrawn]

I know this is kind of off-topic (you are talking about time travel paradoxes and such), but this is a cool article:

A User's Guide to Time Travel

Its sort of a high-level overview of time travel theories from the post-Einstein era. The tounge-in-cheek fine print for each theory is rather humorous.

[Fixer]

amlthrawn, I love the way you post. Keep it up, man. Great material.

[Jeriwen]

wouldn't it be a lot nicer to make time travel just a experience where you have no effect on the past whatsoever?
then you won't have to worry about stepping on a bug in the past and when you get back to "your" time everything has gone down the tubes.

[Ender_Wiggin]

A book and a movie to contribute

Pastwatch -- by Orson Scott Card

People of the Future are in deep trouble. They are running out of food, they can't support the people of earth. They have this unique system that allows them to SEE what happened in the past. Not alter it, mind you. Well one of them discovers that someone DID tamper with it. Someone from a different future. So they're last desperate attempt to fix their future is to send a group of people into the past (such as their predecessors did) to alter just a few things and make a better future. They succeed. The old future is blinked out in an instant and a new one replaces it. So in this scenario, the past isn't always the same. It can be changed to suit our needs

Movie: The Time Machine

At the end when he's talking to the leader of the underground people, he gets an answer to his question.
***SPOILER*****

If Emma hadn't died, then he would have had no reason to build his time machine to save her. In this version, we CANNOT change the past. It is set in stone.

***END SPOILER

Yeah I mostly repeated what others have already said but I just thought I'd pop that in

[RyuuNoSenshi]

Hmmm...Time Travel, the subject of thousands of debates, arguments, and murder threats. ;

Now mind you I haven't read all of the posts on this, cause I don't have enough caffeine or energy to read them all now. I probably will later on though.. lol

Anywho to the subject at hand. Now mind you this is personal opinion seeing as we don't currently have the technology to travel more than a few fractions of a second in the future(via super sonic jet...or other fast moving body).

First I must say that everything in this universe is relative. Time, space, gravity, laws(relative to your country), color(relative to different people, color blind people see no color, blind people don't see anything so color is meaningless) and so on. With this said I can begin.

First interesting theory in Temporal Mechanics(fancy term for the way time works ^^;; ) is the temporal causality loop. This occurs when our hypothetical time traveler does something in his voyage that would void the creation of his time machine(i.e. he kills his parents before he was born). He is then trapped in a loop that affects his local area of space and time. That area of space-time would loop from when he killed his parents till he went back in time, over and over(unless something unrelated to him and his time machine inadvertently ends the loop). That point in space time wouldn't be allowed to progress forward in time until the loop ended. But the rest of the universe would continue on a normal path. This way the universe could protect the Space-Time continuum from damage(comparable to the way space-time bends in the presence of mass or energy, if it didn't do this space-time would suffer huge ruptures and all hell would break loose).

Now I don't believe that time is set and everything is destined and that trying to change it would only affect the process not the outcome. For instance I site the example of the Twilight Zone episode where the guy tried to kill Hitler, but his gun refused to fire. We know that our laws of physics are fairly solid relative to our reference of Earth, going back in time couldn't void those laws(this would require a major change in most of the known universe). So the man's gun would have to fire, because to do otherwise would stop basic chemical reactions from occuring. So I believe it's very unlikely that our universe is already set and that nothing is unchangable. But until we have the technology we can only speculate.

I personnaly don't believe in destiny in the common sense. Destiny is just the not knowing what lies beyond our current temporal reference frame. If we knew all the choices that we made throughout our lives and their consequences we'd do some things differently. But in the end no man can know the outcome of everything, because just as you can only know a particle's direction or momentum, never both, you can never know the consequences of everything(and beside what fun would it be if you knew everything? There would be no thrill to exsistance).

To those who said faster than light travel is impossible, you might want to rethink that. Though it is impossible for an object with mass to travel faster than light in a vacuum(it can though exceed light in other mediums), the term faster than light travel is more of a relativistic play on words. For instance say we have a photon traveling along, and it encounters a bend in space-time generated by some odd stellar body. The bend in space-time folds space in such a way that what uses to be a distance of 100,000 km is now only a 1000 km. To the distant observer, when our photon(or anything other particle for that matter)passes through this bend in space-time it will appear to have broken the oh so cherished speed barrier. But in actuality it never did at all. Einstein was correct, an object can never exceed the speed of light in local space, but in relative(the observers space) things can easily break this limit, so long as they don't do it local(in their space). The shortest distant between two points will always be...zero.

Anyway that's my two cents...I need more caffeine....and pants! wooo! ;;;

[Reno]

Hm, my friend pointed something out to me about time travel on a trip to the Tyler Mall here in Texas. I asked a question about Time Travel and he stated later on that,"No substance on a genetic level can pass through time." So if something doesn't have a dna strand, it won't go through time. Clothes, vehilcle which you came on would disappear. Is this theory real or just some BS my friend said to sound smart? OH yeah, that would make sense since Arnold wasn't wearing clothes in T2, he was from the future.

[RyuuNoSenshi]

Well some people may say that, but when you come right down to it, matter is matter is matter. It all depends on your method of time travel. If in the process of creating a temporal distortion you generate a huge amount of a radiation, then it's unlikely that anything would make it through intact. But the beauty of time travel is it's possible to travel through time in a multitude of ways. Wormholes, traveling near the speed of light, and quite a few other ways. So unless your mode of temporal transit requires a huge amount of radiation to maintain the temporal distortion(which would kinda make that mode of time travel useless to humans anyway..) it won't affect the genetic structure of a living being.

[Shyknight]

Time travel? I don't believe it's possible. Everything is occuring in the same instant. The passing of time is only an illusion created by this physical world. But let's just say we ignore that and talk about the physical implications of time travel.

I also believe that there are infinite dimensions, and within those are infinite universes, and within that is infinite galaxies, and within that... well you get the picture. I don't think it ever ends.

SO, if you wanted to travel through time, you could simply find a way into a completely different dimension where it is still that time. You wouldn't really be travelling through time; you would be travelling through space, or perhaps the space between space. As my dad says you would simply 'change your cosmic address'. Needless to say, no human has the knowledge or the power to do this.

Sometimes I wonder what will become of our world's space exploration program. Wouldn't it be weird if, after over a thousand years of exploration, we finally come across a very distant alien civilization. They call themselves 'humans' and come from 'earth' in a galaxy called 'the Milky Way'.

Actually, it's strange to think about. If both of the Earths sent spaceships straight at each other, on the exact same course, then they would collide and destroy each other PRECISELY at the universe's line of symmetry. That is, unless they could slow down before that with the aid of telescopic vision and some sort of braking system.

In another dimension, I didn't write this post.

...but then again, in yet another dimension I did, and it was twice as long. heh.

[ChronoSword]

SO, if you wanted to travel through time, you could simply find a way into a completely different dimension where it is still that time. You wouldn't really be travelling through time; you would be travelling through space, or perhaps the space between space

That is basically the idea behind Micheal Crichton's Timeline. Read it, it is a good book.

[Sir Xander]

That it is, marvelous book indeed. Such is the theory that I believe in also. Since every possible event can have a near infinate number of answers, all of which can are interacted with by the near infinate number of choices made by the near 100 billion people (guestimated) who have ever lived on the earth in this timeline, would it not be rational for there to be places where you took the 'road not taken' in your own (ie this one) timeline? Makes your head hurt, does not it?

Also, to make this a little more fun, since in all of the infinate timelines exist in all times future and past, there is, I'm sure, one multiverse where Eve did not take the apple and we are all still living in the Garden of Eden....
And I'm going to find it. <crickets chirp> Blasted cynics... <trudges off stage>

[Nekra]

yeah, time travel my favourite subject.

ok firstly as some one pointed out the speed of light is subjective. and easy to move faster then, you can do it in a car if you wanted. before somebody flames me, hear me out.

as most of you know light is a Photon Particle, oscilating at a set frequency, this gives it the appearance of beign a wave even though it can travel through a vacume, ie without a medium which a wave requires to move.

however because it acts like a wave it is possible to defract it. defraction can hve the interesting effect of slowing down a wave. it is because of this defraction scientits have been able to slow down light to just 40 mph. which means that you can acceed it in yor car. :->

anyway back to time travel.
firstly as far as i can tell there are only two major forms of time travel effects.
1. trouser legs of time
by going back in time and changing something, you create a temporal split, ie instea of going one route it goes another, the easiest way to explain this, is to simply think about back to the future. this is the oen most people subscribe toand is most popular amongst hollywood films, more then likely because it offers a better plot line thent he secound.

2. Time is static.
few like to believe this, as they believe it takes away their sense of free will. that in reality time is set. if person a goes back in time, they always went back in time, and they always will go back in time and nothing they can do will change this. some disclaim this theory on the principle of microisation. that technology given tiem will become avalable tothe general public and therefore we would see evidence of their time travel.


Paradox : explained previously better then i could so i wont bother.

potential ways of breaking through time:
1. Travel at the speed of light(in a vacume) around the earth in the opposite direction to the earth rotation, and counterign every roation between now and the tiem you wish to go to. example of this would be BattleStar Gallatica when they reach earth. ignoring my previous comment of slowing down light. before we even go into it, lets just say that travelling at the speed of light is impossible. i cant remember exactly why, somethign to do with as you aprach the speed your relative mass is infinite requiring infinite energy to exceed it. if someone with more then a passin interest in physics would care to explain in greater detail that would be appreciated.

2. bending time
accepting the time is the 4th dimension, and is effected by gravity is the fundamental of this belief. scientists believe that a black hole which is spinning is basically dragging out space around it, and because time is simply the 4th dimension , it is also dragging around time. by entering one part of the event horizon, movign around slightly you can come out in another time. using this as the basis for their theory one group of scientists are attemptign to attain a similar effect with lasers, by creating a area of rotating time and space, if successful when they switch the machine on it might have particles from the future coming out.

while i'm writing this i just remebered a friend of mine pointing out that another group has done an experiemnt, where the particle came out before it had completely gone into a mist of some gas...i'll try and get mor einformation on that, he might have just been bull shittign me...

oh yeah, one of my pet hates but can i just point out that there is not enough matter in our solar system to produce a black hole.

and matter is energy. even you can change dimensions so that time becomes length, width or height, in theory you could move say a stpe to the right then move back into our dimensions and would have changed time, just remember that the longer you are there the further you woudl eb from your startig point, as tie in that dimension would eb distance in another.

one theory which means time travel would be impossible, is the one that matter can not exist in the same time twice, and any attempt would destroy the matter in both locations.

Time cops theory of no two matter can contain the same space at the same time, wouldn't work as the human body has a complete new set of cells every 7 years, so in theory you would have little to no mass similar to yourself if there was more then 7 years difference and chances are the skins cells which come into contact with each other arn't the same anyway.

in the terminator films you could explain the nakedness through the theory that for every gram of mass you send through you have to replace with a gram from the otherside and the power required to move the extra mass is astronomical, so they move the minimum amount possible...this is my own personnel theory from watching it.

[Nekra]

hmm maybe i got a bit carried away.....

[ChronoSword]

1. Travel at the speed of light(in a vacume) around the earth in the opposite direction to the earth rotation, and counterign every roation between now and the tiem you wish to go to. example of this would be BattleStar Gallatica when they reach earth. ignoring my previous comment of slowing down light. before we even go into it, lets just say that travelling at the speed of light is impossible. i cant remember exactly why, somethign to do with as you aprach the speed your relative mass is infinite requiring infinite energy to exceed it. if someone with more then a passin interest in physics would care to explain in greater detail that would be appreciated.

You are right about the fact that the relative mass increase to infinity requires energy comsumption to go to infinity. The closer you get to the speed of light, more energy gets diverted towards the inertia of the object making it harder and harder to provide the energy needed to achieve luminous speed. The reason that light can go do it obviously is because it is massless.

however because it acts like a wave it is possible to defract it. defraction can hve the interesting effect of slowing down a wave. it is because of this defraction scientits have been able to slow down light to just 40 mph. which means that you can acceed it in yor car. :->

Actually, i think they have found a way to freeze light. I deals with laser light to be specific. I forgot all of the specifics about it.