The Time Traveler's Convention

Interesting idea, neh?

But what would the ramifications of time travel be? Why haven't they visited us already? Wouldn't that make time all weird?

Thoughts?

Well I know that I wont attend it now, but if its a good do then I'll travel back to it someday.

Sorry, but I know too much about relativity to accept that time travel, as we know it, into the past is possible. And even if it were, wouldn't we have never heard of Hitler, seeing as someone would have killed him to prevent the Holocaust? Of course, if we hadn't heard of him, then nobody could have remembered to go back and kill him, which, of course, would mean that he lived, and we did hear about him, which caused somebody in history to travel back in time to kill him, which of course made it so that we hadn't heard about him, which...

I think Einstein said that, should time travel ever become possible, one would not be able to travel back to before when time travel was possible...

My thinking usually goes along the lines of, "If time travel is possible, then it shows that all 'present times' co-exist, and thus if we go back in time then we've already done it, so we can have no true effect on the past because we've already had an effect."

However, I do not believe that time travel, backwards, can be possible. According to relativity, it would require MORE than infinite energy to push something beyond the speed of light in order to get 'time' to seem to reverse.

Mmm, there are persuasive arguments against it. But I think it's terribly hubristic to claim we are absolutely certain it's impossible. Many of today's commonplace things would have been dismissed as utterly impossible by previous ages.

As the velocity of an object tends towards the speed of light the mass of the object tends towards infinity.

Force Required to Accelerate an object = Mass of Object * Accelleration Required

Extrapolating, this means that once your object is at the speed of light it has infinte mass the therefore requires infinite force to change its velocity thus it cannot be possible to either push it past the speed of light or to decellerate it afterwards (which is dangerous in itself).

Doesnt going near lightspeed only make time slow down for the object traveling? If so wouldnt going faster than light mean that time is going backwards for you but forward for the rest of the world, so you will still be in the future?

That is a difficult question to answer, partially because we can't travel that quickly. However, I would tend to agree with you, but I don't understand the mathematics of relativity very well, so I'm not completely sure.

I think that the faster one travels, the slower one's time goes in comparison to slower moving objects. I believe this was proven with two very sensitive and accurate clocks set to the same time. One was placed in a low area (a mine shaft or suchlike) and the other somewhere high (on a plane). Since the high one was travelling fast compared to the ground, and the low one was going slower than an object at ground level, when matched up, the slow (travelling) one was further on the the fast (travelling) one.

Maybe time travellors have a non interference policy like they do in Star Trek when they find time warps.

This is just my guess, but we can't travel through time because it's a dimension and makes us what we are. It's quite confusing to write down what I'm thinking so this may not be of much sense to anyone but you can't really travel through something that makes the world or the universe be what it is. It's like making something 2D, or maybe that's been done, I'm not sure.

I wonder if you could break the speed of time...

I'm not exactly an expert on the subject, but time isn't dead solid as a wall is. It's different for everything. You get two twins, put one on a fast moving (and hypothetical) spaceship, they will age very differently.

Time, in my understanding, is a spatial dimension, similar to left and right, or up and down, with the only special case being the direction of chaos, which causes events to tend toward disorder, and produces what we perceive as a "flow" of time.

Time travel has always fascinated me. I think JAneway on Voyager best described ny thoughts "Leave it be and don't try to understand it" or something of that ilk! Time travel as we think of it requires a linear time line, a known quanitity of some sort ie: why could we not travel into the future- because there is too much we don't know and some sort of stabiliser to enable us to observe without causing difficulties. Time travel sounds cool but in reality it could be very dangerous. I say leave it to the experts!

(P.S if this post makes no sense please ignore it!)

Something that people might be interested in is a book called The Light of Other Days. Basically, a method of creating wormholes that can be loked through is created, which allows people to look into the past (but not the future). Anyway, this allows, among horrific invasion of privacy, learning the truth about past events, such as what happened to Jesus, but it also allows every crime to be solved. Simply look back in time at the right place, and get a nice viewing of a murder, or suchlike. Basically, ruins society as we know it.

All this talk of relativity is probably irrelevant (pun fully intended) when talking about future-tech time travel.

If time travel were to be possible, it'll use technologies, and probably physics, that we're completely unfamiliar with. Like quantum baubles, or qarktastic underpants. For example, your QT underpants will contain a single confined quantum bauble, which, upon relaxation of the exotic matrix which confines it, warps the flux gradient of spacetime such that the flow of time not only inverts, but exverts, thus allowing the wearer to pop out anytime, anywhere, like a giant temporal waterslide.

I'll be at home awaiting my Nobel prize.

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Assuming that time is some kind of linear doohicky, the suggestion that time travel is possible brings up a modified Fermi paradox, as Commie points out - wouldn't they already have visited us? And more to the point, assuming a near-infinite amount of future after time travel is invented, then that would mean a near-infinite amount of time travellers would be appearing in every single bit of time. So, therefore, if time travel had been invented in our future, we'd know about it, as we'd be knocking elbows with people in silver one-pieces left, right and centre.

Anyway, as we all know, time travel is only permissable if you're either a robot from the future, or somehow involved with a robot from the future. It's like one of them incontravertable thingamies.

Well, I must say that I think time travel is a very interesting subject that I don't quite understand.

You see, as far as reprocussions go, I think it's safe to say that there are two different schools of thought: fooling around in the past will alter the future (think Back to the Future if you will in which messing with Marty's parents' first meet alters his existence.)

The second is a (I think) less probable school of thought which says that anything that happens in the past was required to make the future as the time traveler knows it (something like I go back to the age of the dinosaurs and accidentally sneeze which spreads a virus that kills said dinosaurs off and blah blah blah which all leads up to PsychWardMike typing on Matazone as we know it.) It's a rather Buddhist way of thinking, I suppose.

I, however, would say the first is a tad more probable.

Now, on the subject of the ability to travel through time. Sure, I think it's possible. What kind of sci-fi dork would I be if I didn't? However, I'd wager it's got all sorts of strict laws in the future restricting its use (assuming.) Added to that, I'd wager that it's fairly expensive so that not many people could afford it.

But those are just social issues.

I don't know enough about physics to really comment, so I won't. Suffice it to say that I think it's possible because I firmly believe that when humans want to do something (for better or worse) they'll eventually do it.

I'd like to say though, that I think pan dimensional travel would be better than going through time. If the theory that since one dimension can exist everything has to exist (the infinite dimensional theory) is true, then logically there would have to be a dimension that one could travel to and mess about there.

I dunno. I'm probably rambling, but it's early and I've not had a lot of coffee yet. It's a half baked theory, but at this point, so is time travel.

That's not a bad point, the multiverse theory could, somehow, allow us to travel to other universes, each of which could have different laws of physics...which, I'm sorry to say, is impossible for me to imagine at this moment. I simply can't imagine a universe without protons, or energy, or inertia...it would be so different that we wouldn't be certain of getting back to our own home universe.

Maybe time travellers have visited us but the process unfortunately renders their memories completely blank, so not only can they tell us nothing about the future they are also can't remember how to get back there.

Time travel backwards is probably too risky, but I'm not talking about the grandfather paradox (kill your grandfather in the past, you father isn't born, so you're not born, so you can't kill your grandfather, so your father is born, so you are born and you kill your grandfather etc.) but the risk that changes that you make would render your future unknown. You might be able to go back in time, but when you go forwards again it's possible that everyone you've ever known or loved would be dead or strangers.

I came up with a solution to the grandfather paradox when I was about 14, and it turns out that it's the same one that Steven Hawking suggested. He's always been copying me, the scallywag... Anyway, essentially you become a single point of view and your reality creates its own timeline. The instant that you travel back in time you create a new timeline for yourself that differs from the past. Even if you only travelled back one year then immediately came forwards again without doing anything else, the reality that you are then living in is actually distinct from the one that you left even though you personally cannot tell the difference. To take this further, you could easily travel back in time and kill your grandfather because the timeline you are then in is not the one where your grandfather lived and continued your family tree. You as an individual have moved between timelines in a continuous motion, but you would be living in a different reality. Time travel is more about motion between realities than times.

I wouldn't recommend thinking about this too much. It makes your head go bendy.

The principle problem, I think, with discussing time travel is that English simply isn't up to the job. Which tense do I use when discussing an alternate future that I visited in my personal past? It all goes a bit mad after a while.

Another problem, if I travel one year ahead in time, or one year behind, where should my physical coordinates be? The earth is moving, the sun is moving, the galaxy is moving, and space is expanding. All those calculations would make my head hurt.

Mata, I think I get what you last post is saying: Is it that like that parallel universe theory in a way? Because if it's what I'm thinking it makes total sense to me. I really would like to get more engaged in this thread, I just have reall trouble writing down what I mean in a clear and understandable way. Dagnamit.

But those things all move predictably, don't they? So that just requires brute processing power, which nobody denies we'll have in abundance

The sun and earth move predictably, I'm not so sure about the movement of the galaxy, nor the expansion of space. The problem is that there is no absolute reference, so we can't fully know how we are moving through space.

The Gods Themselves contains multiple universes where various fundamental constaints (strong and weak forces, namely) are different. It's also quite a good book.

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One theory I have herd for the grandfather paradox is that if you try to kill your grandfather then something will go wrong. (the gun will misfire or you will hit him but won’t kill him) Like how in time machine when he builds the time machine to save his girlfriend but she just dies another way because otherwise he wouldn’t build the time machine to save her.
Not a theory I like but an interesting solution

That's fatalism, and is philosophical, not scientific. There would be NO scientific reason for that to happen.

It is very closely related to parallel universe theory, but I think that a tangent universe might be an easier idea to think of: like out timeline having tributaries that people could go down without realising it.

The grandfather paradox assumes a single timeline that is Reality, but it looks to be far more likely that there are many realities depending on many factors. Without a single unifying Reality the grandfather paradox becomes pretty meaningless (although remains a great device for sci-fi writers ). Unlike Pgrmdave, I think that there are reasonable arguments for a single timeline, but I think the arguments for mutliple ones are stronger.

I do find it amusing that in the thread about abortions Pgrmdave is saying that he doesn't believe in free will, but here he is saying that fatalism is false. You can't have it both ways!

As a close friend of Dave's, I should tell you that Dave is very prone to arguing devil's advocate for EVERYTHING. He likes to argue, so he'll assume the opposite stance on every subject (save, I suspect, a few) that comes up in conversation. Gets a bit irritating some times, but on the whole, it's actually a fairly endearing quality of his. At least we're never without a source of conversation.

(It does make his personal views a bit hard to figure out sometimes)

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I didnt say it was scientific and thats why I dislike it

I am not argumentative...well...not all the time

I try to play devil's advocate for many reasons, mostly to get people to think about their positions, and to force me to think about mine. However, on this subject, I have multiple, conflicting views, so I pick and choose which one seems appropriate at the time.

No, determinism is not fatalism. Fatalism is the idea that we have free will, but our choices don't matter. Determinism is the idea that we don't have free will.

Are you sure?
http://www.cogsci.princeton.edu/cgi-bin/we...1&word=fatalism
fatalism -- (a philosophical doctrine holding that all events are predetermined in advance for all time and human beings are powerless to change them)

That sounds pretty similar to me.

Going back to a long time ago in this thread...

PWM, why do you think that the theory of your actions being able to change the future as we know it more probable? To me, it seems sufficiently obvious that since you were in the past, which has already happened, that your actions would just feed into the existing timeline.

fatalism -- (a philosophical doctrine holding that all events are predetermined in advance for all time and human beings are powerless to change them)

determinism -- ((philosophy) a philosophical theory holding that all events are inevitable consequences of antecedent sufficient causes; often understood as denying the possibility of free will)

The differences are that in fatalism, humans have free will, but it does not matter. Fatalism, as I understand it, is like - "No matter what I do, I'll die, be it in a car accident, or of cancer, or from old age". Determinism, as I understand it, is like - "Given the previous events within the universe, I will be killed at 2:45 pm by the car driven by Mr. Smith."

Fatalism is like saying that our choices don't matter. Determinism is scientific theories taken as far as possible, and makes us more like computers than people with free will who simply can't really make any significant impact like fatalism claims.

They still sound pretty similar to me... Although possibly equally flawed because they are based on pre-Einsteinian physics.

Actually, according to our current physical theory (both the Standard Theory and M Theory) Time Travel is indeed possible through wormholes, which end up being a sort of rip between dimensions, of which time is the fourth (there are eight others, three of which we deal with normally. So says M theory, anyway.). According to the theory, a wormhole could (only could, mind you, not necessarily would) open up. Theoretically, because a wormhole has no dimensions, travel would be instantaneous. Ahh, but there's one problem: It would take a quadrillion times as much energy as we are currently able to produce. That's 1,000,000,000,000,000 times as much, in case you were wondering.

No only that, but a wormhole would have so much gravity to be able to work fully, that all matter travelling through it would be ripped apart into its basic particles, kinda dangerous.

Mata, relativity doesn't go against determinism, but quantum mechanics may or may not. Determinism denies randomness, and quantum mechanics seems to display randomness.

I was referring to quantum mechanics, which does seem to cause problems for determinism and fatalism.

Well, it took place a couple of days ago, and no time travellers announced themselves

Maybe they all missed our reality by a couple of microseconds so were invisible to the naked eye...

Time travel is now theoretically possible, apparently

It seems to me Commie that the article is flawed. It doesn't take into account that if a person's past was erased and they never existed, people in the present would have never known them to begin with, thus negating the ablility to notice a change; a change should change the future without anyone noticing. Hell, for all I know just a second ago a time traveler went back and had my friend John's parents meet. That would have created my friend so that up until just a few seconds ago, I'd have never had a friend named John but now that all is changed my life altered in such a manner that John does exist and he and I are going to play video games tomorrow.

Or something like that. I think that if you're going to argue the quantum mechanics rule for this, you have to do two things: acknowledge a higher power governing the universe and completely discredit the infinite dimensional theory.

Well, if you actually did kill your parents in the past, it would not alter reality when you returned, your parents would still be alive as it would simply create an alternate universe in which they were killed.

The Multiverse, as it's called.

I'm going to sound horribly un-scientific, but: there's on theory of branching realities, right? Parallel universes for different probabilities. The idea being that they all start out at a common point, and deviate when there are different possible outcomes for an event. So some would deviate early on and not resemble our reality in the least, whereas others might deviate at the point during which some world leaders decide whether or not to declare war, or when I had a bagel today rather than tuna. In other words, if you could pick the right dimension, it would be possible to travel to the "past". Still, going by this theory there would necessarily be an infinate number of parallel realities due to the massive number of events in the world within even a minute, each of them with nearly limitless possibility and probability. So it's viability as a means of time travel would really be bunk.

I'd like to cite Invader Zim's thoughts:

If you go back in time to destroy your arch enemy, he won't be your arch enemy anymore so you won't go back in time to destroy him, but then he will be your enemy so you will go back and destroy him, but then he won't be *head explody*

Ahem.

The infinite dimensional theory, so far as I'm aware, is that if one universe can exist in a way, then all possible universes must exist on top of it in different dimensions. So for the first infinity or so, you have minor changes. An oak tree in this reality had one less leaf. One grain of sand is moved an inch to the left. But after all of that, bigger things occur. Say Einstein never existed in one reality. Then after infinity of those or so, you have really messed up stuff... physics are reversed. Black is white. All that jazz. Like I said, what is possible must occur.

Saying that time travel is really dimension skipping is just silly, though. That's the approach taken by Dragon Ball Z and no matter what school of physics you subscribe to, every rational law states that Dragon Ball Z being correct is completely impossible!

Firstly I apologise if this deviates from the discussion too much but I've only recently started to consider time travel and the theories related to it, as the result of something so completely unconnected that I shall leave it well alone for the moment.

Im currently reading a book dealing with the concept of time travel, and although its fiction I am curious to find out exactly how much factual detail the author actually incorporated. The book by the way is Timeline by Michael Crichton.

Basically it looks at the idea of time travel as tapping into multiple dimensions on the level of quantum foam, something I understand to be smaller than protons and all rippled and frothy as a result of the universes birth.
(would that be this multidimensional thingy you're talking about?)

As I stated this is new to me so please be patient, espescially if Im getting it all backwards and if I am tell me I wish to learn!

In order to 'travel' a person is basically scanned and duplicated then projected like a fax through this foam to another dimension, one close enough to be virtually identical to the persons own, just at a different point in the timeline. Simultaneously at the sending end the persons body is destroyed whilst the exact duplicate appears in the target dimension/time. However, retrieving the traveller is apparently impossible, instead the returning traveller is actually another version of the person from somewhere were they do know how to reconstitute. So the returning traveller is actually a completely different person, with the differences between the two dimensions being so minute as to be indistinguishable, to all intents and purposes the returning person is the same.

I think that makes sense although trying to articulate it clearly and think about it is turning my head into knots which is convoluted at the best of times. Also at about this point my ears started steaming and I think something inside broke.

In this novels theory it raises the point that the grandfather effect has so many variables working against it that it is not possible. To go back and change an event would mean that billions of factors would have to come together to allow a person to succeed. Therefore the necessary similarities between the two dimensions to make travelling possible would also render it impossible to significantly alter an event. Also I think that with time not running as a flow in this theory even if it did happen the point of origin would remain unaffected.

Well this is from a fictional novel and therefore most probably wrong but I find it an intriguing concept. That to travel I would have to die and be replaced but Id never know and carry on as if nothing had happened yet it wouldn't be me (sort of).

Ok I now have lost myself but I still think its a fascinating idea and I have a niggly feeling its got alot to do with quantum mechanics. Feel free to save me from myself please!

I have a problem with multi-dimensional theories, merely because it leads to strange paradoxes in space and idea. Where do these dimensions physically exist? We can easily see how a two dimensionaly universe can co-exist with others, because we can stack them in three dimensions, but the third dimension, stacked in the fourth dimension, simply produces what we perceive as 'time'. Perhaps then the answer is in time's 'time', so to speak. However, I think that the existance of time's greater dimension would produce results closer to 'chance', or 'god', than multiple existances, although I have a difficult time explaining it to anybody.