Time Travel Help

I don't think anybody knows how one would look or what technology would drive it--current theories suggest that short of surviving a black hole or wormhole it's pretty much impossible to actually travel through time (that is, at a different rate or direction than we do now). There's also time dilation, I guess, which is an often-used science fiction trope. The gist of time dilation is that traveling near the speed of light makes time pass faster for you than everyone else relative to you, so if you take a long trip through space at fast sub-light speeds you'd also be traveling forward through time more quickly.

If you're doing time travel on a planet, make sure you remember that the planet is always spinning and orbiting the sun... so chances are, traveling to a different time and the same place would send you to outer space! So if you travel back or forward in time, it's a good idea to either mention complex calculations and travel through space as well, or do it gradually, like rewinding or fast forwarding a video tape, so that the objects being moved through time move with the planet as it orbits the sun.

There are also a number of different methods for time travel. You can go the more ordinary route as seen in the Back to the Future films, where you just pop in some other time and can do whatever you want, but it'll have consequences in the future. But you could also treat it in different ways--like, for instance, you could say that the universe doesn't like changes to the timeline and tries to correct them after you mess things up. Another possibility is that you can't actually send your body back in time, you can only hitch a ride in somebody else's head (in popular film/TV, see Quantum Leap).

Well, remember that traveling to the past is, as far as we know, pretty much impossible. But you can kind of wink that away as a trope and pretend it's doable anyway. Still, it's good to at least pay lip service to scientific accuracy, so as I said, your system needs to take into account the Earth's orbit and the fact that it won't be at the same place in the past as it is when you travel back in time in the present.

From what I've read, some think the "theory" lies in creating wormholes. Supposedly they can develop a machine which can create this, the problem being that it'd be so large they'd need to build it in space, and I believe they need to harness nuclear fusion before it'd even be possible to build it.

I was considering doing some more research on it and looking more into it. You can find a plethora of information on the theories if you search your local library's databases.

Besides, you don't need to know any of the science behind time travel to write it. Mark Twain's own version involved a character getting hit in the head and then waking up in medieval England.

OremLK said:

Well, remember that traveling to the past is, as far as we know, pretty much impossible.

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Aren't we underneath eight-minute old sunlight every day though?

Rent the movie "Primer". It's a low budget timetravel movie, but is the most realistic I've ever seen when it comes to showing the effects of causality.

What you'll most likely want to do, is use a multiverse style of time travel(the only type that is really supported at all by physics, at least if you want to go into the past). The idea is that when you travel back in time, you create an alternate reality. Thus you don't run into the causation issues that happens in a purely linear timeline.

As a fan of Diana Gabaldon's novels, I have to say that I think a time portal is more believable than a time machine. Think of a doorway rather than a material object which transports you from here to there. Or should I say from now to then.

Yeah, but the problem with a multiverse is that it's always going to be different, isn't it? So it's more or less traveling into an alternate time period rather than the one in our universe. For instance, you may decide to travel back to the time of World War II, but instead, in that universe, America loses the war.

OremLK said:

Well, remember that traveling to the past is, as far as we know, pretty much impossible. But you can kind of wink that away as a trope and pretend it's doable anyway. Still, it's good to at least pay lip service to scientific accuracy, so as I said, your system needs to take into account the Earth's orbit and the fact that it won't be at the same place in the past as it is when you travel back in time in the present.

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This is technically true but I only know of two stories that actually mention that, Macroscope and Timescape. You can get away with not mentioning it and if after your story is published some pedantic idiot enthusiastic fan brings it up, you can say "oh, well, I didn't want to get too detailed and techy, but the programming inside the machine takes care of all of that. It even knows when Daylight Savings Time was started in what area, so it can always tell you what time to set your watch to."

Cybernaught said:

Aren't we underneath eight-minute old sunlight every day though?

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Yeah, so ... ?

(I know you're getting at SOMETHING here, but I dunno what)

scarletpeaches said:

As a fan of Diana Gabaldon's novels, I have to say that I think a time portal is more believable than a time machine. Think of a doorway rather than a material object which transports you from here to there. Or should I say from now to then.

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Well, as the younguns these days say, "whatever." It might as well be a Tardis.

Cybernaught said:

Yeah, but the problem with a multiverse is that it's always going to be different, isn't it? So it's more or less traveling into an alternate time period rather than the one in our universe. For instance, you may decide to travel back to the time of World War II, but instead, in that universe, America loses the war.

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Well, not neccesarily. You could have America lose in the alternate universe if it moves the story forward, but there doesn't have to be anywhere near that big of a change for it to be an alternate universe.

According to one quantum physics interpretation, alternate universes are created at the rate of zillions* per second, and many are so close to identical you can't tell the difference (a BIG difference would be a coin flip landing heads up rather than tails up) .

What the alternate universe thing does is allow time travel without a causality violation (look what that link forwards to!). If you go back and kill a grandparent before your parents were conceived, then you 'no longer exist' and were never born in that universe. But your grandparents lived on in the universe you came from.

The thing is, we don't know how to change to other universes. At least, not that we know of (I'm thinking of a Larry Niven story where they've been using transporters on Earth, but the MC works for a company experimenting with transporting between Earth's surface and Earth orbit).

You can read a few (dozen) books to educate yourself on some of the known and speculated-on science, as well as SF that uses time travel to see how it's often done, but I think you might as well "just write it" (some section of your story where time travel is actually done), post it to SYW and take suggestions about what to change or how to do it.

But if you want to learn some of the ways it's been done before, here's some fiction that includes time travel that I think might be instructive:
"A Sound of Thunder" Ray Bradbury. Short story (really!), I strongly suggest you click the link and read it.
"The Number Of The Beast" Robert Heinlein
"Timemaster" Robert L. Forward
"Timeline" Michael Crichton
I know I've read quite a few others that don't immediately come to mind.

* Zillion is actually a technical term. A very technical term. You can trust me.

Causality is a real boogeyman in any time travel story.

WATCH PRIMER ALREADY! It pretty much shows why it would be a bad idea to have time travel in a linear time line, and what you would have to do to minimize the effects of your meddling(and this is with a time machine that can only let you go back to the point that it was turned on, it doesn't let you go completely back to the past).

With the alternate realities, you're effectively traveling back in time, but causing a "fork" in the timeline. Our history proceeds as it already did, but when you travel back, you cause a fork in the road, and create an alternate reality. In fact you could travel back like this, and meet yourself if you wanted to, or kill your parents consequence free.

The point being, that with the multiverse set up, you don't run into the real nightmare that is causality.

Dommo said:

...and this is with a time machine that can only let you go back to the point that it was turned on, it doesn't let you go completely back to the past...

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Reminds me of Dean Koontz's Lightning. That was a headf*** of a book to read. Lord knows how he wrote it.

Why is this in Science Fact and not Science Fiction?

http://video.google.com/videoplay?docid=3909854615539675694

Here you guys go. This is "Primer" and is a must watch for anyone who even wants to attempt time travel on a linear timeline. This pretty much sums up why, even if I figured out how to do it, why I'd be highly reluctant to ever want to try to travel back(although I might give myself information through time travel, by say putting a recorded message and putting in the time machine, so that it would pop out at a fixed time every day).

dclary said:

Why is this in Science Fact and not Science Fiction?

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Presumably the OP wanted the facts on time travel, though admittedly those facts don't apply well to most fiction about time travel. Perhaps Robert L. Forward's stories would be the best in that regard, but he was a really smart scientist who put a lot of scientific knowledge into his fiction work, so it appeals mostly to techies like me.

It's like what Stephen Hawking said his publisher told him while he was writing "A Brief History of Time" - every equation he adds to the book will cut the number of readers in half. The super-techy stuff doesn't sell well.

Hmm. The individual interactions of subatomic particles are indistinguishable as far as time going forwards or backwards (as in Feynman diagrams), but entropy (as in thermodynamics) points the arrow of time one way for macroscopic events (such as mixing two different colors of paint - unmixing the paints requires each molecule to follow a path that's perfectly legal in physics, but them all unmixing is so hugely improbable as to be regarded as impossible). Perhaps if we could be shrunk down really small, even much smaller than Rachel Welch and crew in "Fantastic Voyage," we could "go back in time" and still follow all the laws of phyics.

If you use this, please reference me by calling this the Bradley Time Reversal Mechanism.

Dommo said:

Causality is a real boogeyman in any time travel story.

WATCH PRIMER ALREADY!
...

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I'm watching the first couple minutes here, they're using these logic analyzer clips and poking around with an 8-pin dip (my guess is it's a serial eeprom) - how old is this thing anyway? Just about everyone's gone to surface mount now...

Anyway, I'm already having to suspend my disbelief, because we've got these four "engineer-types" around a table, and they're all, every one of them, wearing not just dress shirts, but TIES.

Where I live--which happens to be where that movie was filmed--lots of stodgy engineer types wear button-up dress shirts and ties to work.

SPMiller said:

Where I live--which happens to be where that movie was filmed--lots of stodgy engineer types wear button-up dress shirts and ties to work.

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i.e. "Not California"

People who live in Not-California are crude and uncivilized. I'm not even sure they exist.

scarletpeaches said:

Reminds me of Dean Koontz's Lightning. That was a headf*** of a book to read. Lord knows how he wrote it.

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Yeah, I read a simmilar russian book. Keeping track of all the different timelines was harder than a colledge course

Well, anyway, even the this scenario doesn't eliminate the Grandfather Paradox (killing your own grandfather).

Another option is to say that everything that happened already happened (including time travelers). This creates all sorts of paradoxes, but it eliminates the need for multiverse (think Terminator 1)

Re

Well, the closest idea that we have to bringing time travel into reality is about still a hundred years from being possible. BUT, the idea is plausible to many in the scientific community.

First, according to Einstein, the universe is comprised of an interwoven fabric of space and time, called spacetime. Whenever matter or ENERGY is present then the fabric warps creating gravity (just imagine a bowling ball in a trampoline, with the trampoline representing spacetime and the ball being a planet).

Now, considering that our universe warps where matter or energy is present thus creating gravity, one scientist created a thought experiment. If we can warp spacetime, then we can warp time. Considering that light is energy and warps spacetime, then if we were to cause something like a photon to travel in a circular path at high enough of a velocity, then perhaps we can create some kind of portal where we can travel forward or backward in time.

Yeah yeah yeah. I know its crazy. But hey, that's science.

When you go back in time, you're going back earlier into a timeline that already exists. By doing so, you just overwrote everything that happened afterwards. If you killed your grandparents before your parents were conceived, then the timeline will continue and the you that was born will never exist. However, the you that went back in time is just fine and dandy, if a little psychopathic, because you were outside that timeline you just annihilated by going back in time.

No multiverse or anything. Say you go back to July 20, 1967 at 9:31 AM, just as an example. Everything at 9:32 on has been annihilated, but slowly rebuilds itself as you come in at 9:31, and thusly an entirely new 9:32 is made that never existed before, but is pretty much identical in every way, with the exception that you are now there, and the timeline will remain identical, since nobody else knows about this annihilation, except for any direct or indirect changes you make. In other words, you destroy it and then build it back.

To travel into the future, you simply cease to exist for X amount of time.

Just my two cents.

now this is a bit un-proven, okay a lot un-proven. but i remember reading an account from of roman soldiers in a battle that was interrupted by (as closely as i can paraphrase from memory) "Two silver birds that roared at each other with the might of thunder and cast bolts of lighting until one was destroyed."

now i don't know about you, but that sounds a lot like fighter jets. which is where the relevancy comes in. the space time continuum is a location of times and places. it spread into infinity both ways. The way i picture it is, that the continuum, is not continuous. since it is based on a system of place And Time, we are in a different part of the continuum than we were just a second ago.

Which means that if two sets of continuum intersect, then you would be able to time travel. so if they can get two continuum frames to intersect, then they would be able to move through time.

another way is to leave the continuum. it would be like a book of graphs, each one shows a different time, and each one a different place, the travel would be like turning the pages. so if you found a way to step out of the continuum, while taking enough with you to experience time, then not only could you step back into the continuum any where you want, but any when

with the trampoline example, if you were standing on the trampoline, and jumped off, you would no longer be on the continuum, but when you landed again, you would be in a new spot, and a new time, without traveling the space between.

wow, its one thought after another, after another, after another. well, i hope i made more sense to all of you than i did to my self.