Time Travel

[Scribs]

OK, a recent discussion about faster than light travel in the "Voiles of a Distant Star" Thread, has got me thinking about time travel (again.)

Now, I am sure we all pretty much agree that it is unlikely to impossible to travel through time, but theoretically, if we could do you think we would be able to change past events. My friends and I came up with sevral different possible theories:

#1: If you go back in time your actions would change events at that time and thus change the future. (Sort of like in back to the future when Marty almost causes himself not to be born by disrupting his parents first meeting)

#2: If you go back in time you may interact with people and do things, but the consequeces of your actions will not change the future, but instead simply cause the future that you remember to happen. (In otherwords it would have been impossible for Marty to prevent his parents from meeting because if he was never born he could not have gone back in time and prevented their meeting)

#3: If you go back n time you head explodes. (Marty's head would have exploded) A friend of mine came up with this one. I didn't bother to argue with him about it.

So what do you think? I support theory #2 myself.

Sorry if this is not the right place for this thread.

[Syaoran]

have you heard about quontum jumping if so it might be posible to travel in time.

[LorentzForce]

Yes and no, but more of yes.

From your perspective, the future will change. But in others who were already in the future from where you came, their perspective won't change. Splitting time?

And I have a feeling that's why time travel backwards won't be discovered because we'll always be in the time frame where our past wasn't altered, because it already happened. Least resistance of change, perhaps.

[Mangafanatic]

I think we could change things, but I think we might mess them up so bad that the entirity of earth's population would die around the year 1905. Chaning the past=really bad idea.

[Heart of Sword]

I'd go back in time and show the people who wanted to kill all the wolves what's been going on lately with the explosion in deer and coyotes...I'd try to stop the killing from happening...

I'd also go back in time and see if historical Battousai looks like Kenshin in the anime.

(I wouldn't want to try going back though. O_O;;; I'd be terrified.)

[Jasdero]

Yeah.. I would try and change what happened in the past...

[AnsemK_R]

I think that if it was possible it would really mess up the universe, here's why.

You decide to stop WW2 by killing hitler when he was a little kid. WW2 then never happens. As a result when you are born you never even know who Hitler is, so you never go back in time to kill him. Since you don't go back in time history has to "reset" itself to play out a history with hitler in it. Then when you grow up you get the idea to go back in time and kill Hitler...etc.etc.

So regardless of whether it is possibly or not we shouldn't try.

"The past is not a package one can lay away." ~Emily Dickinson

[Doubleshadow]

I don't think so. People seem to envision time as a stream, but I think it is a more like a wave. You cannot go back and forth; once an instant of time has past it is no longer accessible by people because it no longer exists. Similiarly, people can not go forward in time because it does not exist yet. The only you that exists is the one that is in the position of time that is current. You can't tamper with the past because it is no longer there.

[Debitt]

Even though it may be possible in the future to alter/change/go back in time, from a general standpoint, I don't think meddling with time is a good idea. Cuts a bit too close to "playing God" in my eyes. And from a personal standpoint, even though I've had/am having some difficulties with my life, I don't think I'd want to go back in time and change anything. Even if I could change the things that have happened to me, I know that God's blessed me with so much more, and I wouldn't want to gamble His gifts for the one chance to fix one event in the past.

[AnsemK_R]

I just remembered something I read in a science book Hyperspace : A Scientific Odyssey Through Parallel Universes, Time Warps, and the 10th Dimension.

The book claims that there are several dimensions the 1st, 2nd, and 3rd everyone knows about (who hasn't heard the term 3-D?). Some scientists speculate that there could be a fourth-tenth dimension and that one of them maybe time. They even think they know what an "unfolded" 4th dimension would look like. The book explains this much better than I ever could, so I would advise you to take a quick look at it.

"What then is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know." ~Saint Augustine

[Ashley]

Ah, I'm a sucker for time travel movies. I love them! I think another theory could be that even if time travel *were* possible through whatever dimension, it would be impossible to change it. For example, take H.G. Wells' Time Machine (or in this case, the movie based on it). Alexander creates a time machine to go back and save his fiancee from death...except he never can do it. No matter what he does, she keeps dying. Then later we realize he cannot change the past because if he saved her, he never would have invented the time machine and thus he couldn't have used it to go back and save her. Same idea--if you tamper with the past at all you've altered your future and to do so would change the "present".

There's also the idea from Issac Asimov that even stepping on one blade of grass, one bug in the past would drastically alter the future. He wrote a novel on it...something about light and dark, I think...and it had to do with people going on a dinosaur hunt but having to stay on this one path.

If you're interested in time travel I *highly* recommend the book Timeline by Michael Criton. Don't cheat and see the movie, it's absolutely horrendous. But the book was awesome, and mentioned a lot of problems most people wouldn't think of (like clothing and dialect)

[Steve Racer]

I read Timeline myself. It was excellent, so I agree.

I don't see that anyone has mentioned the parallel universes theory. For instance, you could go back into the past at a certain point. At ANY point in time, the universe is splitting into a multitude of different universes (or paths in time) depending on what outcomes occur in each. For instance, if today you ate Cheerios for breakfast, there is an alternate reality where you ate Raisin Bran.

So, you could go back to your past to a point, but from then on you are in a parallel universe where YOU went back into the past. When you come back to the future, you could arrive at one that is on the new timeline that you set in motion (or not, actually.) This reminds me, has anyone seen Sliders?

Anyway here's a crappy text drawing:

timeline
.............. __original universe______
....split.../
---------<
.............\__changed universe_____

(arg HTML ate my spaces)

so the split would be where you changed things.

I haven't seen any articles about time acting like 'a wave' however. (Just don't say it acts like a particle too!) However, even if it did and 'now' is all we have, that does not mean we cannot access the past experientially, it may just make it harder to do so. The thing about science is it is always moving on, it used to be 'impossible' to fly.

In fact, I remember about a year ago, some scientists were able to send a PARTICLE back in time using a circular type accelerator device. I'll see if I can find the article again.

[Steve Racer]

http://www.csmonitor.com/2002/0516/p12s02-stss.html

http://www.wonderquest.com/TimeTravel.htm

These are a couple articles... similar to what I'm talking about. I can't seem to find the one about the particle but I think it may have involved this principle of Mallet's.

[Yahshua]

Yeah in my university libraries there is a book by Davies, P. C. W in the Physics-Astronomy library call How to build a time machine and I remember reading in the Scientific American about the issue of time travel there is actually research done by various people to see if it is possible for human to go back in time but the question come back to it is would you want to? And what is the outcome of it?

[Nate]

I don't believe changing the past is possible...theoretically. However, they have done studies on this, and it has been proven that the present DOES change the past. It was done with a flashlight and a series of slits cut into a piece of paper. It was in the book "The Dilbert Future," which I cannot find my copy of currently, so I can't give you the details, but it had to do with the pattern produced when the flashlight was shone through the slits, the information that was recorded, and how it affected the pattern that was displayed. It was really freaky and proves that the past can be affected by the present. Weird, eh?

[EireWolf]

There's also the idea from Issac Asimov that even stepping on one blade of grass, one bug in the past would drastically alter the future. He wrote a novel on it...something about light and dark, I think...and it had to do with people going on a dinosaur hunt but having to stay on this one path.

I would agree that changing the slightest thing, something we'd consider insignificant, could drastically change the future. If you think about a near-miss car accident... If you'd been going 1 mph faster/slower, you'd have been creamed. Or, conversely, if you'd lingered over breakfast just a few seconds longer, the accident wouldn't have happened. Stuff like that is interesting thought-fodder.

[Fsiphskilm]

You would end u

[Zedian]

That was a on a the spot concept utilizing a regurgitated pop star....your a sheer genious Volt. There is the paradox problem that could result from us traveling back in time....like the grandfather example. If you were to go back in time, and possibly change the relationship your grandfather may have had with your grandmother, that in turn would null the very existence of you. Gasp! And going back in time also has severe implications not just on yourself and your family tree but those people who encountered your grandfather as well. It would all get messy.

I think if, time travel were to go further than just scientific theory and be possible, going back into the past would be more feasible than the future. Unless God has like a 1,000 or so possible outcomes just lined up, and He just waits for us to make our next move so that can be the outcome we embark on....than I just don't see it. We can remember the past, from a cognitive standpoint that is too, thanks to our limited memory capabilities.

I've always envisioned time as a wave that flows in a direct motion, like an arrow almost and goes in the speed of light of course(Marty and Doc showed us that in Back to the Future).

I know it can't happen because we can then ultimately just change life to where all the bad stuff never happened, so those ominscience powers could potentially make us God...not good. But I still get a kick out of talking about it.

[Dante]

time... the main area of my physics research...

Here's my point of view, yes there are four dimensions (the fouth being time space-space). The shadow of a four-dimensional object would be 3 dimensional. You can find an image of a shadow here <dogfeathers.com/java/hyprcube.html>, it is called a hyper-cube. It is also called a tesseract

As for travel at the subatomic level, let me begin by stating that this world is governed by the laws of quantum mechanincs, (probability), thus theories that work here don't work in the regular size world. For instance, in this world I could shoot a toaster at a concrete wall and it could pop out on the other side (quantum tunnelling) Also, space time isn't smooth (if you get small enough) but rather a bumpy surface called quantum foam. Here when you move forward one really small step you go backward or forward in time by random amounts. And space is more like a 4-d maze than a 3-d plane.

As for looking back in time, you can do that already. Just look at the sky, everything you see is old to ancient. The image of the sun (if you look at it) is eight minutes old. And the stars you are seeing in the sky may not even be there anymore. From a purely scientific point of view this is where scientist get huge dates back in time for the beggining of the universe. Of course, God could have put the photons there to begin with and just make everything look really old... but I'm not here to argue big bang stuff, I'll ask God when I see him and just do the best I can with the data I'm given.

Also heres a cool thought, other than the future, past and present there is something called otherwhen (or spacelike). This is neither of the above and we have actually done experiments where particles are in otherwhen. Check it out under spacelike, or lightcones under google.

Actually though if I had a time machine I wouldn't have worry "what" I would do with it seeing as how I could go back in time and ask God myself. He would know why in the universe I was given such abilities and I wouldn't have to worry about the results.

Later
Pascal

[Technomancer]

A cautionary tale: join the Campaign for Real Time (I'll let you figure out the source!)

Time travel is increasingly regarded as a menace. History is being polluted.

The Encyclopedia Galactica has much to say on the theory and practice of time travel, most of which is incomprehensible to anyone who hasn't spent at least four lifetimes studying advanced hypermathematics, and since it was impossible to do this before time travel was invented, there is a certain amount of confusion as to how the idea was arrived at in the first place. One rationalization of this problem states that time travel was, by its very nature, discovered simultaneously at all periods of history, but this is clearly bunk.

The trouble is that a lot of history is now quite clearly bunk as well.

Here is an example. It may not seem to be an important one to some people, but to others it is crucial. It is certainly significant in that it was the single event which caused the Campaign for Real Time to be set up in the first place (or is it last? It depends which way round you see history as happening, and this too is now an increasingly vexed question).

There is, or was, a poet. His name was Lallafa, and he wrote what are widely regarded throughout the Galaxy as being the finest poems in existence, the Songs of the Long Land.

They are/were unspeakably wonderful. That is to say, you couldn't speak very much of them at once without being so overcome with emotion, truth and a sense of wholeness and oneness of things that you wouldn't pretty soon need a brisk walk round the block, possibly pausing at a bar on the way back for a quick glass of perspective and soda. They were that good.

Lallafa had lived in the forests of the Long Lands of Effa. He lived there, and he wrote his poems there. He wrote them on pages made of dried habra leaves, without the benefit of education or correcting fluid. He wrote about the light in the forest and what he thought about that. He wrote about the darkness in the forest, and what he thought about that. He wrote about the girl who had left him and precisely what he thought about that.

Long after his death his poems were found and wondered over. News of them spread like morning sunlight. For centuries they illuminated and watered the lives of many people whose lives might otherwise have been darker and drier.

Then, shortly after the invention of time travel, some major correcting fluid manufacturers wondered whether his poems might have been better still if he had had access to some high-quality correcting fluid, and whether he might be persuaded to say a few words on that effect.

They travelled the time waves, they found him, they explained the situation - with some difficulty - to him, and did indeed persuade him. In fact they persuaded him to such an effect that he became extremely rich at their hands, and the girl about whom he was otherwise destined to write which such precision never got around to leaving him, and in fact they moved out of the forest to a rather nice pad in town and he frequently commuted to the future to do chat shows, on which he sparkled wittily.

He never got around to writing the poems, of course, which was a problem, but an easily solved one. The manufacturers of correcting fluid simply packed him off for a week somewhere with a copy of a later edition of his book and a stack of dried habra leaves to copy them out on to, making the odd deliberate mistake and correction on the way.

Many people now say that the poems are suddenly worthless. Others argue that they are exactly the same as they always were, so what's changed? The first people say that that isn't the point. They aren't quite sure what the point is, but they are quite sure that that isn't it. They set up the Campaign for Real Time to try to stop this sort of thing going on. Their case was considerably strengthened by the fact that a week after they had set themselves up, news broke that not only had the great Cathedral of Chalesm been pulled down in order to build a new ion refinery, but that the construction of the refinery had taken so long, and had had to extend so far back into the past in order to allow ion production to start on time, that the Cathedral of Chalesm had now never been built in the first place. Picture postcards of the cathedral suddenly became immensely valuable.

So a lot of history is now gone for ever. The Campaign for Real Timers claim that just as easy travel eroded the differences between one country and another, and between one world and another, so time travel is now eroding the differences between one age and another. "The past," they say, "is now truly like a foreign country. They do things exactly the same there."

[Fsiphskilm]

I think the problem here is,

[LorentzForce]

Technomancer: It's...

[spoiler]Hitchhiker's Guide to the Galaxy![/spoiler]

Don't know exactly which book though. I need to borrow them from the library again.

[JediSonic]

For me, it comes back to the granfather paradox Zedian mentioned:

1) You go back in time
2) You kill your grandfather before your parents were born
3) Your parents are never born
4) You were never born because your parents didnt exist
5) You did not exist to go back in time
6) Your grandfather wasn't killed because you werent there to go back and kill him
7) Your parents are born
8) You are born
1) You go back in time
etc.

Also, the story Ashely was thinking of is "A Sound of Thunder", by Ray Bradbury (not Asimov). It was a short story but there's a movie of it coming out this winter

[Ashley]

Also, the story Ashely was thinking of is "A Sound of Thunder", by Ray Bradbury (not Asimov). It was a short story but there's a movie of it coming out this winter

That's it. Sorry, I was close, right? XD I'm not much of a big sci-fi reader, actually. >.>

[SpikeSpiegel306]

I think that you may be able to go back in time. Quantum Theory and Wormhole Connectivity along with the String Theory strongly point towards the possibily, but I think that if you changed the past it would cause a brach off universe and not affect your directly. In other words, another universe would be created where what you had changed became reality and when traveling back to the current times there is a risk that you could cross to the branch off universe by accident.

[Nate]

Heh. I recognized what Technomancer had posted right when I read it. One of my favorite books ever.

[Scribs]

Wow! Poeople seem to be getting into this, big time! I hadn't realy thought about the alternate universe concept...

I don't have time to post an indepth responce right now, but tomoroow i will formulate one.

Lots of people seem to be going with poll option 3!

[Cognitive Gear]

yes... well I don't know if anyones heard of this theory.... *brain freezes over*

what is it called..... well... nm what its called.... basically what it says is that the past is unalterable. and because of this, if you were to go back in time, a blade of grass would be like a razor blade to you, and rain would be like bullets. this is due to your inability to alter the past. Its an odd theory, but valid nontheless.(well, at least as valid as a theory about time travel can be)..... Obviously, this has its problems, but the Alternate Universe is filled with so many philosophical questions.... I dont wanna to touch that one.....

[Azier the Swordsman]

Heh... I know I'm not supposed to be here right now, but I figured I'd pop in and catch up on things a little bit. Actually, I love talking about stuff like this. Anyone consider the theory from Stephen King's The Langoliers? Even if you could go back in time, there may be buildings, cities, trees, ect. but there wouldn't be any human life anywhere. Everything would be deserted. Nothing works. Food and drink have no taste. Everything would be inoperable. This is because the 'past' is only a reflection of it's former self, but it no longer really exists. Just like being in a photograph.

It's another interesting theory to chew on.

Anyways, gotta go. See everybody in a few months!

[Slater]

wow, this is a really kewl looking thread... I'll be getting into all this kewl stuff about time and light and stuff in a few months in Physics and I'll be sure to report then
but pretty much the one thing I've heard so far is this: Time is not a constant, but rather, the speed of light is. Time bends around the speed of light so that c remains the constant and not t.