Time travel in movies and books - Looong Question:

[Crono]

Adhere yourself to a fixed location, and let the universe move around you forward or backward in time.

You can't "stop" time for the universe, just change your velocity relative to everything else. Up to (and including, if you happen to be EM) the speed of light.

Not sure of fiction that addresses both concepts.

 

[Gibsons]

Since time and gravity are sort of interrelated, maybe the time machine can't move outside the earth's gravity well, even if the machine moves in time. Another way to think about it is that it would/should take an enormous amount of energy to move the machine into orbit, you can't get that much out of a flux capacitor.

 

[sourceninja]

two ways to think about it.

1) a tunnel between two points in space and time. This is the most straight forward. If you are making a tunnel to the past, you are also making a tunnel to a point in space, if you can adjust one, why not the other?

2) Like rewinding a tape you are fixed with the planet as it travels backwards in time. Thus you don't need to worry about space. The bigger question here is how then can you travel further back in time then before you invent the time machine?

 

[JTsyo]

I'll tackle the 2nd point. Freezing time won't work. Whatever is at the boundary of frozen time, when moved would have infinite acceleration. When you reposition someone into different funny positions, you would be ripping them apart on the inside. You actually see this in computer simulations, you you specify a displacement right at the start of an run, you usually wreck the part that you tried to move.

 

[Monster_Munch]

The true solution has more to do with the nature of time than of physical position in the universe. Whereas some people view time as a line, others view it as a plane. Others still view it as any number of diverging passageways along a 3 dimensional matrix.

One main way of looking at it is that true time travel is impossible. When someone time travels in a movie, they are essentially traveling instead to a parallel reality where the time period they travel to hasn't happened yet. Think of it as jumping from one branch of reality to another, from one universe to another overlapping universe.

I saw a public talk recently from a famous physicist called Jim Al-Khalili. He said the same thing. If skynet sent a terminator back to kill Connor, it wouldn't actually change anything in the future since the terminator has gone to a different universe. But from the terminator's point of view it would have worked because in the alternate universe the events can play out differently.

 

[ioni]

While this has always bugged me as well, it hasn't been too big of an issue to me because it's in the realm of fantasy. You know what really bugs me? How come when an airplane flies West, it doesn't get to its destination ridiculously faster than when it flies East?

According to Wikipedia, the rotational velocity of the earth at its equator is 465.1 m/s. If you jumped out of a plane to sky dive, wouldn't you be able to see the Earth spinning? Wouldn't it be unlikely that you'd land in the field you jumped out over?

 

[Monster_Munch]

Not if the atmosphere is spinning at the same time.

 

[QuantumPion]

While this has always bugged me as well, it hasn't been too big of an issue to me because it's in the realm of fantasy. You know what really bugs me? How come when an airplane flies West, it doesn't get to its destination ridiculously faster than when it flies East?

According to Wikipedia, the rotational velocity of the earth at its equator is 465.1 m/s. If you jumped out of a plane to sky dive, wouldn't you be able to see the Earth spinning? Wouldn't it be unlikely that you'd land in the field you jumped out over?

For the same reason why you don't fly off in to space when you lift your feet off the ground. You are already spinning at the same speed as the Earth, and so is the atmosphere.

 

[LucJoe]

This should help you:

People assume that time is a strict progression of cause to effect, but *actually* from a non-linear, non-subjective viewpoint - it's more like a big ball of wibbly wobbly... time-y wimey... stuff.

 

[hoyaguru]

I'll tackle the 2nd point. Freezing time won't work. Whatever is at the boundary of frozen time, when moved would have infinite acceleration. When you reposition someone into different funny positions, you would be ripping them apart on the inside. You actually see this in computer simulations, you you specify a displacement right at the start of an run, you usually wreck the part that you tried to move.

Yes! I saw some stupid move where the main character could freeze time (with a watch, of course), and he of course used this power to help his friend win a dance competition, by moving the guy's body into the dance moves while the guy was frozen (or actually going real slow) in time. First thing I thought was, it would have killed him instantly. torn him limb from limb.

 

[Saint Nick]

I've been watching Back to the Future and some of the time travel stuff is really confusing.

 

[Paul98]

The funniest time travel in a movie has to be the original Christopher Reeve Superman movie.

He just flies fast enough in the opposite direction of Earth's rotation to stop its rotatation and have it spin in reverse, thus making everything go back in time.

If the Earth stopped rotating I think we would have a huge mess on our hands.

I think he was supposed to be flying faster than the speed of light, and that was supposed to make time run backwards.( aka the earth would stop rotating in one direction and start in the other direction if time was reversed) Not just because he was flying in the opposite direction of the earths rotation.

But that being said not even superman could fly faster than the speed of light.

 

[Paul98]

Please explain. Seems like a pretty important thing to me, unless you're going into fantasy and not science, which a lot of science fiction does. I know that sci/fi has to do these things to make the story worth watching, which is why we have the explosion noises in space, but there are exceptions, like Arthur C. Clarke's 2001. That movie had the most believable science ever seen, no noise in space, and it was a great movie.

If you were to get into a space ship travel to close to the speed of light, turn around and come back to earth. You will experience a much shorter trip than those that are on earth.

 

[Ichinisan]

If I recall correctly, Timeline (Michael Crichton) went with the infinite universes theory.

 

[SphinxnihpS]

Adhere yourself to a fixed location, and let the universe move around you forward or backward in time.

You can't "stop" time for the universe, just change your velocity relative to everything else. Up to (and including, if you happen to be EM) the speed of light.

Not sure of fiction that addresses both concepts.

Where is a fixed location in the universe? Fixed relative to what, the center of the universe that does not exist?

Pick a point in you room and look at it, did you see it get bigger? Well it did.

 

[jhu]

Another thing that ties into this is "freezing time". There are many books and movies where the time traveler has a device (which usually for some reason is in the shape of a clock or wristwatch) that, once a button is pushed, everything around them is frozen in place. They can go about their business without being seen, yet never seem to do the first thing all of us would do in this situation, which is to undress every good looking woman in view.

Cashback

 

[SphinxnihpS]

Time and space are the same thing, sillies. What 1905?

 

[SphinxnihpS]

If I recall correctly, Timeline (Michael Crichton) went with the infinite universes theory.

Yep, this solves all the paradox problems, but destroys the plot because now your effects from time travel have no effect in the universe you are from. You can go back in time and kill your father, but when you get back home, he's still there to beat your ass!

 

[Clemenza]

Wow

This.

 

[SagaLore]

Time Travel Relative Position:

A lot of time travel mechanics involve very strong electromagnetic and gravitonic interactions. The traveler will be "fixed" within the Earth's field at all points in time. I hypothesize that the higher the deviation of time traveled, the more your position would drift as to match the magnetic poles during that timeframe. This means that time travel could never occur in space - only within fields generated by large mass that has existed within the window of possible travel.

Time Stop Local Interaction:

Time actually doesn't stop, but is slowed down. If it actually stopped, the traveler would not be able to see since photons aren't moving, and any movement would be extremely viscous as the local atmosphere would be pinned in place as soon as the traveler is not directly contact it. The person wouldn't be able to breath and the body would overheat really fast. At this point their only way to survive in this condition is to be inside a suit, and to see they would need some kind of tachyon based sonar. This means that to interact locally, time actually would have to just be really slowed down, and everything you see would be doppler shifted. People in real time would be able to see you as if you were a subliminal message being displayed within a video with a poor refresh rate, unless you stood very very still, in which case you would be a blur.

 

[gorcorps]

Please explain. Seems like a pretty important thing to me, unless you're going into fantasy and not science, which a lot of science fiction does. I know that sci/fi has to do these things to make the story worth watching, which is why we have the explosion noises in space, but there are exceptions, like Arthur C. Clarke's 2001. That movie had the most believable science ever seen, no noise in space, and it was a great movie.

Don't know why I get worked up about this stuff, except I feel like I have to be wrong and it's REAL obvious to everyone else why I'm wrong, to the point that no one even bothers to talk about it. I've never even tried to write a sci/fi story, but I'm guessing that the authors have to just leave stuff like this out or the story wouldn't work, but I would think someone would address it sooner or later.

He's saying that if they built a vessel that can accurately travel through time, then building one that can also move around is easy. We already make shit that can move... if you figure out time I'm pretty sure you'll have movement down pat to the point of (like you said) it's trivial and not worth talking about.

 

[Paladin3]

The subject is somewhat addressed In Piers Anthony's book "Bearing an Hourglass", where the main character Chronos travels in time with the help of a magic hourglass. At one point in the book he also travels through space by selectively moving himself slightly out of sync with the Earth's rotation and orbit as he travels in time.

 

[hoyaguru]

Cashback

Yes, I wathed a little of this a while ago, didn't think it was very good. There was also a book that came out a few years ago called I think "The Fermata", about a guy who could suddenly stop time for everyone around him, so he of course used this power to have sex with any woman he wanted (never read the book, but this is what I read in reviews). I don't want to picture what would have happened if this were somehow possible.

 

[hoyaguru]

Time Travel Relative Position:

A lot of time travel mechanics involve very strong electromagnetic and gravitonic interactions. The traveler will be "fixed" within the Earth's field at all points in time. I hypothesize that the higher the deviation of time traveled, the more your position would drift as to match the magnetic poles during that timeframe. This means that time travel could never occur in space - only within fields generated by large mass that has existed within the window of possible travel.

Time Stop Local Interaction:

Time actually doesn't stop, but is slowed down. If it actually stopped, the traveler would not be able to see since photons aren't moving, and any movement would be extremely viscous as the local atmosphere would be pinned in place as soon as the traveler is not directly contact it. The person wouldn't be able to breath and the body would overheat really fast. At this point their only way to survive in this condition is to be inside a suit, and to see they would need some kind of tachyon based sonar. This means that to interact locally, time actually would have to just be really slowed down, and everything you see would be doppler shifted. People in real time would be able to see you as if you were a subliminal message being displayed within a video with a poor refresh rate, unless you stood very very still, in which case you would be a blur.

I can't say I agree with your first point, but the second is very interesting, points out a few things I've not thought of. It's like the invisible man movies and books, if a person were able to make himself invisible, he'd be totally blind, as photons would have no eyes to go into.

I guess if time were just slowed down or stopped, that would mean every atom in the air would also be slowed or stopped, and that would make movement for the person not affected (the only one who can move) impossible, in effect freezing him in time as well. An outside observer wouldn't be able to tell who was frozen in time, and who the time traveller was.

 

[Ichinisan]

Yep, this solves all the paradox problems, but destroys the plot because now your effects from time travel have no effect in the universe you are from. You can go back in time and kill your father, but when you get back home, he's still there to beat your ass!

Well, you could "return home" to an alternate reality in which your past actions *did* have an effect.