Time Travel

[sheld0n]

Is it possible? If so, how does it work? What's your take on all the paradoxes?

An interesting story i heard, from a book (which i didnt get to read, sadly) is about this time travel organization that discovers that at one point in the future humans die out. So they send an expedition, and the explorer discovers a race of acid spitting butterflies who most likely dominated the planet. They attack him, but he escapes to his pod and returns back to his time. He explains everything to his boss, only to hear "whats this?" from a technician, who was pointing at empty cocoons inside the time machine.

So the butterflies were never really created, they existed thanks to the fact that they continued existing, so to speak.
Do you think thats possible? Or would they exist anyway?

Some say that travelling into the futre is impossible entirely, or that the future you'd go to is very unlikely to be the one that your world will experience. Einstein, on the other hand, argues that knowing enough variables is all it takes. What do you think about that?

Frankly, time travel is such a vast topic, feel free to bring up other problems/paradoxes related to it :)


Oh and i know John Titor is pretty much inevitable here, but half a year has passed and i dont see any civil wars yet (tho its possible that were simply nicer folks than those in his worldline).
It was a great read either way!

[Meltman]

Well, travelling into the future is pretty easy if you just do it Planet of the Apes stye and just go really really really really really fast. (As close to the speed of light as you can get) Of course, it's getting back that's the tricky part...

[sheld0n]

Well, youve got a point there, kinda like hibernation.

[Meltman]

Well, if we could find a way to survive the massive g-forces, we could technically do it awake too, just not for as long obviously...

[inkblaster]

I'm travelling through time right now, I just can't control it. That's the trick you see. ;)

[MikeKAY]

Titor had the perfect throwback, 2% variance between each reiteration of the multiverse. I suppose you could claim that would account for just about anything because 2% of the sum of our existence is a hell of a lot. His little game was well thought out, and fairly well covered for but in the end it was essentially bull****. Brilliant bull****, but bull**** none the less.

The entire multiverse theory, beyond Titor, is certainly an interesting subject though. I wonder if you went "faster" then the speed of light, would you fall out of our universe? :think:

[Bagman]

I was just reading in one of the many Discworld books about the Trolls' ideas about Time.

Trolls think we got all this Time thing backwards. If the past is all known, and the future is unknown, then why are we travelling into the future when we should be travelling thru the past. The way we are now, it's like we are walking backwards on a path, thus can only see where we already walked, when it would make more sense to turn around and walk the path as you can see it.

I know that answers nothing and is a silly theory, but I thought it interesting.

[Blue Bolt]

Of course there's the idea that time is just a condition of the mind, meaning there is no such thing as time at all, or at least not linear time. For all we know everything could be happening at once and we're just not able to percieve it that way. O_o

[sheld0n]

Blue Bolt, you mean like a book, where every part of the story exists at the same time, and we just read it word after word?
But if time can be altered by gravity, or velocity, wouldnt that mean that whole reality must be in our heads too?

Bagman, i really like the "walking a path backwards" analogy. I think its very accurate, though i dont see how the trolls could "walk forward" :)
It could be interesting though, not remembering your past, and knowing yourself by the things you will do.

MikeKAY, about Titor, i was always a fence-sitter, and although now im leaning to the skeptic side, i remain not entirely sure. There was no war, but the way the country got devided after Bush won the second elections, could have easily turned into a conflict, and Titor had no way to predict that.
So i really cant say it certainly must be BS.

ink, you wiseguy... :P

[Blue Bolt]

Blue Bolt, you mean like a book, where every part of the story exists at the same time, and we just read it word after word?
But if time can be altered by gravity, or velocity, wouldnt that mean that whole reality must be in our heads too?

Yeah, like a book. Time can be in some ways the creation of matter, of 3D space, much like gravity is a creation of matter. People nowadays are steadfast in believing that you cannot skip ahead pages in the story, you certainly cannot re-read the previous pages, and the gravity of the story determines how fast the page is turned. But if you simply step back from the book and look at the whole thing, you'll find out that those rules aren't necessary and you can "read" however you please. The concept of time falls apart. So how can something that feels real to us and can be "measured" and "altered" simply dissappear when you look at it from an outsider's view? What if time is just a condition? An illusion?

[ChairLegOfTruth]

CLoT Sez:

Timetravel within a continuua is relatively simple and, due to the uncertainty prinicple, anything that you haven't actually experienced, directly or indirectly, doesn't effectively exist until you do. So you can't go back and do anything to stop 9/11 but you could go back and stop Thomas Becket from being killed by the knights but History books would still record his death in the manner they did in your time; they're just wrong.

Travel between continuua (or Membranes as the fashionable physicist currently call them) is harder and typically requires transit through a connecting continuua... Of course, thanks to a variety of different things I am a continuum and thus can go where and whenever I like. ;)

[Meltman]

CLoT Sez:

Timetravel within a continuua is relatively simple and, due to the uncertainty prinicple, anything that you haven't actually experienced, directly or indirectly, doesn't effectively exist until you do. So you can't go back and do anything to stop 9/11 but you could go back and stop Thomas Becket from being killed by the knights but History books would still record his death in the manner they did in your time; they're just wrong.

Travel between continuua (or Membranes as the fashionable physicist currently call them) is harder and typically requires transit through a connecting continuua... Of course, thanks to a variety of different things I am a continuum and thus can go where and whenever I like. ;)

Would one of these variety of different things be fermented and consist partially of barley?

[ChairLegOfTruth]

Would one of these variety of different things be fermented and consist partially of barley?

Yes, yes it was. Rodney mixed me up a chrono-synclastic infundibulum disguised as a cocktail. I understand that the by-products of barley fermentation were involved. However alcohol was not, as I'm tea-total. ;)

[Rottweiler]

My personal opinion is that time travel, although fun to dream about, is complete CRAP. There's no such thing as the 'past.' The instant 'now' stops being 'now,' there is nothing but our memory of it. As for the 'future,' it is simply 'now' that doesn't exsist yet.

But if you'd like a better answer, the only form of time travel you can perform has one step: 1)WAIT - The 'future' will come to you. :)

[ChairLegOfTruth]

Let me rephrase myself.

You can go back and do anything as long as it doesn't change your know present.

http://news.bbc.co.uk/1/hi/sci/tech/4097258.stm

Interestingly I see no reason why, if you went back in time and changed something the result of which was unknown in your present and then looked it up when you got back, you'd not find evidence of your tampering. If that makes sense. :eyebrow:

[sheld0n]

Sorry but i dont buy that. It almost sounds as if that scientist guy was making fun of the journalist.

Clearly, the present never is changed by mischievous time-travellers: people don't suddenly fade into the ether because a rerun of events has prevented their births - that much is obvious.

This part here shows that the guy doesn't know in the slightest what he's writing about.
If "fading away", like we see it in the movies, was the only problem, then there would be no problem, because nobody would remember these people who ceased to exist.
The real paradox is that if you killed your father before your birth, there would be nobody there to kill him.

Quantum behaviour is governed by probabilities. Before something has actually been observed, there are a number of possibilities regarding its state. But once its state has been measured those possibilities shrink to one - uncertainty is eliminated.

No duh. :P

So, if you know the present, you cannot change it. If, for example, you know your father is alive today, the laws of the quantum universe state that there is no possibility of him being killed in the past.

Just because we observed an object in a certain state, does not mean that state cannot change.

"Quantum mechanics distinguishes between something that might happen and something that did happen," Professor Dan Greenberger, of the City University of New York, US, told the BBC News website.
[...]
In other words, even if you take a trip back in time with the specific intention of killing your father, so long as you know he is happily sitting in his chair when you leave him in the present, you can be sure that something will prevent you from murdering him in the past.
[...]
"You wouldn't be able to kill him because the very fact that he is alive today is going to conspire against you so that you'll never end up taking that path leads you to killing him."

So now laws of physics have a consciousness? Come on, how can you take that seriously.

I cant say i understand alot of quantum physics, but this is akin to Gremlins causing plane malfunctions...

[Charon]

My opinion of time is going to take a little bit of explanation.

So, bassically, the universe started with the Big Bang. Hydrogen goes boom, the whole universe begins to expand, racing across the universe yadda yadda yadda yackety schmackety. Soon enough planets and such are formed, including the Earth.

Now Red Shift dictates that the universe is expanding, we all know this. It's still moving away from us (or rather we're moving with it and it just seems like it's moving away from us from where we're sitting.) So the universe is still being hurled outwards from the impact of the Big Bang.

But one day, it's going to stop. And scientists all over the world think that once it's stopped, it'll retract. So, if the universe begins to retract, all the stars in the universe burn out, and every living thing in the universe dies, we'll all just retract back to the matter we were originally made of, where the big bang started it all off.

So, all the matter returns to the space in which it was originally, in exactly the same form it was originally. (and there's absolutely nothing to say it will be, but again there's nothing to say it won't be either.)

And then something causes another big bang. The universe expands, everything happens exactly the same as it did the first time.

But was it the first time?

If everything remained the same when this happened again, then the earth would be formed in exactly the same way. Thus, everything on the earth would happen exactly the same way, and in turn, humans would exist in exactly the same way, doing exactly the same things, on exactly the same time line. Meaning this thread could have been discussed millions of times before. You and I could have lived our lives infinite times in exactly the same way, and we'd never know it. We'd be... well, doomed, as such, to live our lives over, and over as the universe expanded, and retracted and expanded, and retraced. Time would simply be on a loop.

So time travel, do I think it's possible? In theory, yes, because time's just a loop, so all you'd have to do is exit the loop at some point, and re-enter it at another. What would the consequences of doing such a thing be? I don't know. But, if my theory was correct, and someone did manage time travel, well then that self same person will have acheived time travel millions of times before, and it would just be another part of the universe that constantly repeated itself.

Strange theory, I know, and I'm not sure if I really believe it... but it's just one of my random late night musings. Take it for what it's worth. :)

[sheld0n]

Well, Charon, i will agree with you up to the point where you say something like our planet will be recreated after another big bang.
Considering the sheer ammount of planets in the universe, one that's similar to ours forming again is statistically reasonable.
However, i personally doubt that life would be born on it, much less our copies who would re-experience the events happening presently.
Unless you believe in an extremely hardcore version of destiny :p

But thats just my opinion.

Btw, get a die and throw it three times exactly the same way, and see if the roll is always the same, or not.

[Charon]

Well that's the thing. Destiny would be real in the most extreme sense. Because you'd be living out a completely pre-determined life. However, it's just a theory, i don't fully believe it myself.

[MikeKAY]

Ah! A vision! I see heavy drinking in your future! :p

[Krypto]

You and I could have lived our lives infinite times in exactly the same way, and we'd never know it.

Wonder if it would explain Deja Vu. And dreaming about something before you do THE EXACT same thing the next day.

[8 Ball]

I'm personally a believer that this wasn't the first big bang (if it was what came before?) but I'm doubtful that the universe plays out the exact same way every time. During those crucial first few seconds a few particles out of place and the whole thing goes in the crapper :P By the way if you haven't read it get "A short history of nearly everything" this stuff is covered in a chapter :D.

As to the main question, is time travel possible? Techincally yes by approaching near the speed of light time slows down for you and remains the same for everyone else (I think that's how it goes...I ain't no big time head thinker person y'know) but time itself isn't constant so it may be hard to manage, apparently it speeds up closer to large sources of gravity (like the earth) and again slows the farther away you are. Though it's unlikely to ever be possible in a practical sense for a loooonngg time. And most of these theories always seem to cover going forward...noone has a clue how to go back :P.

[MikeKAY]

Wonder if it would explain Deja Vu. And dreaming about something before you do THE EXACT same thing the next day.

Pfft, I have been doing that while completely awake since I was twelve.

[Krypto]

And most of these theories always seem to cover going forward...noone has a clue how to go back

Of course, that's because time's not real! :p
Obviously we can travel into the future, because we do that every day.

I'm a firm believer that there is no way to travel back into the past, because time doesn't exist. It's nothing more than a unit of measurement created to help manage our lives. It's all in our heads. ;)

[Solario]

Light travel throughout the universe, so, I'm lead to believe that is, if we move faster than light, we should be able to witness the events of the past but nothing else.

[sheld0n]

I'm a firm believer that there is no way to travel back into the past, because time doesn't exist. It's nothing more than a unit of measurement created to help manage our lives. It's all in our heads. ;)

Do you want to say something like the theory brought up by Blue Bolt?
Because from your wording, it would rather seem that in your opinion, if it wasnt for watches, everything would be happening at once.
Its a common thing to mistake the units of time that we invented, with the actual order and process of time, that is generally believed to exist on its own.
Kind of like saying that lenght doesnt exist because we invented centimeters, you know.

Maybe it is like Blue Bolt said, that our brains subconciously percieve only parts of reality, which creates the illusion of time, but as possible as it is, it remains quite an exotic theory. Which is why its so interesting and im glad he posted it. :cool:

Solario, you know? I never thought of that! All we really need is a very good telescope and a spaceship to percieve past through distance! Brilliant! Where did you get that?

[sheld0n]

On a completely different note, here's one of the many things that Douglas Adams has to say about time travel in one of the chapters from Life, Universe and Everything:


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."

[Solario]

Solario, you know? I never thought of that! All we really need is a very good telescope and a spaceship to percieve past through distance! Brilliant! Where did you get that?

I was actually discussing Wormholes and the possibility of using them to travel into the past with them, when it suddenly hit me. It was more of a "that's strange..." than "Heurika!" kinda moment though. As with most theories and ideas.

[suburbanhell]

MikeKAY, about Titor, i was always a fence-sitter, and although now im leaning to the skeptic side, i remain not entirely sure. There was no war, but the way the country got devided after Bush won the second elections, could have easily turned into a conflict, and Titor had no way to predict that.
So i really cant say it certainly must be BS.

Well didn't Titor say civil war broke out in 2008...we still have a little time for that...

[sheld0n]

Well, sub, i went back and checked, heres a quote:
America will soon be engaged in civil war with itself; a civil war that we'll see the beginnings of during 2004 and 2005, escalating until it is indisputable by 2008 and "will consume everyone in the US by 2012"

So we were both partially right. The fights start in 2005, but by 2008 the armed conflicts between the law enforcement and the people will grow on such a scale that it will be safe to call it a war.

Sol, so you came up with that? Neat! I think its an awesome idea, man.

And about wormholes that move you back in time, well, i thought about that a little bit. Wouldnt it necessarily mean that time must have at least two dimentions?

[Blue Bolt]

I always think of a highway when we're talking about a 2-dimentional time. There's the one lane that travels toward the future and away from the past, and then there are the other lanes that you can switch onto, either the right or left lane. Those lanes could translate to other universes. So, basically you're traveling across universes with almost no change in time. :p

[Half Life]

Who is Titor?

[ChairLegOfTruth]

John Titor (http://timetravelportal.com/viewtopic.php?t=41&postdays=0&postorder=asc&start=0) was a guy who claimed to be a time traveller from 2036 (or thereabouts).

[Sun-Scarab]

my idead on time travel..
well on the effects of time travel anyway:
i think its like water. on hit ripples out, & youre a ripple, so to go back thru time, you cut back thru dimensions to the start, but that myabe just cancel out the first ripple, that leaves you backin that first start point & since your out of sync with that time you wont be effected but the erased passed that wont go beyond that point.
its like wondering if time travel is done on earth does it really effect the rest of the universe.
maybe not all ripples maek it to the edge of time. just a thought.

[Rottweiler]

Wow.. did I just get totally ignored? LOL

[Blue Bolt]

My personal opinion is that time travel, although fun to dream about, is complete CRAP. There's no such thing as the 'past.' The instant 'now' stops being 'now,' there is nothing but our memory of it. As for the 'future,' it is simply 'now' that doesn't exsist yet.

But if you'd like a better answer, the only form of time travel you can perform has one step: 1)WAIT - The 'future' will come to you. :)

Heh, I'm not going to agree or disagree simply because I don't know enough about time. No one does honestly either. Try to ask people to define time, and you get a different answer or sometimes no answer at all. Is it a dimension? Is it simply a form of measurement? There's no solid proof to make any one claim valid :p It's funny though how time travel is crap but you admit we're all moving through time, or time is moving through us :o

[Rottweiler]

It's funny though how time travel is crap but you admit we're all moving through time, or time is moving through us :o

Well I'm among the same human race that has as little an idea of time travel as the rest. Time exsists, but it doesn't 'travel' nor we through it... just my guess.