Time Travel: Your Opinion

[Dexter Morgan]

I don't know if there is a thread like this or not. This is NOT to discuss if it is possible, just your idea on it.

For me, I would love to go back to the past, but never the future. It would ruin so much in life. For example, if you had a girlfriend you really liked and went into the future and saw you two weren't together, wouldn't that just break your heart and make you think it would be pointless to keep on going with your current girlfriend?

Plus, there's the technology issue. If you went and flew around in a hover car and visited aliens, when you came back all of our current technology would seem stupid. More than likely you would want to go back to the future to mess around with that technology, but then you would leave your family and friends behind.

 

[victra♥]

I'd love to be able to time travel but if it were possible, it would be abused by so many people. Imagine if we were at war; if a country were to lose that war, they could time travel back in time before the war and try again, continuing to do so until they have their way. Thats just a time travel problem involving the past. With time traveling to the future, Dictators or Ultra-Nationalistic countries could time travel far into the future, figure out how to built all the new technology we have then (or take some of it), come back and take over the world. However, time traveling could be good as well i suppose, but all the better points of time travel would be pretty trivial.

 

[Eriatarka]

I don't see why time travel into the past isn't possible if traveling faster that the speed of light is indeed how it is done, the speed of light is just an arbitrary speed which you need to exceed, there's no force in existence which limits how fast a body can travel. (To the best of my knowledge anyway, I'm open to correction from someone more learned.) Sorry I know you said this thread isn't to debate whether it's possible or not.. couldn't help myself.

From what I believe though, time travelling into the future at a rate any faster than 1 second per second is impossible. The effect of someone travelling back in time would not create paradoxs or anything of the kind, merely their actions would cause everything from the point back to which they travelled to be 'rewritten', with the differences between the pre-travel 'reality' and the post-travel 'reality' based soley upon the actions of the time traveller in the past, and whatever knock on effects their actions might have. Even if their actions caused a future in which they themselves are not born or do not go back in time at all, the time traveller will not cause any paradoxs or any 'rips in space' or whatever, because (I believe) they remain independent of their past self, and they continue to exist on whatever part of the time-line they are conscious at, their origin not erased or anything, because it.. already happened, even though it technically didn't.. (?)

Anyway, for a less sciency point, if time travel is ever achieved, I'd say that we have already seen the effects of it, things that have already happened have had the effects of a time-traveller changing the past already taken into account.
I should probably go and get a degree in hyper-advanced physics or something before I try tackling this stuff again..

 

[Ørion]

I agree with Janitor, if they could get at this technology, it could be used to create a 1984ish society. It does have good points though, it would allow the world to find out the exact history of things, especially of events that happened centuries ago that the world does not have sufficient documentation on.

 

[victra♥]

It does have good points though, it would allow the world to find out the exact history of things, especially of events that happened centuries ago that the world does not have sufficient documentation on.

Oh that's right, i almost forgot. With time travel, it could finally prove whether Jesus was real and if he really did perform all those said miracles as well as Adam, Eve, Noah, and all the other characters mentioned in the bible. As well, the big debate between Creationism and Evolution could finally be answered if we traveled far enough back in time to the beginning of Earth which would too end the debate about the age of the Earth. Not only Christianity, but time traveling back into the past could really answer a lot of questions about religion.

 

[SkylerOcon]

Time Travel is a stupid idea. Everybody whose pursuing it is just idiotic.

Not to say that it isn't possible. We'll probably figure out how. But the thing is that, traveling in time brings such a high risk of changing the future (for better or for worse) that it's not worth trying to do so in the first place.

Let me be the first to say that I wouldn't like it if the Axis won World War II.

 

[AltF4]

Well, time travel in the way you're thinking of it ("Back the the Future" kind of time travel) IS impossible. So tough nuggets. It doesn't really matter what you think would be cool. I don't see any debate here.

 

[Eor]

I have a question for this, if you travel back in time to where you didn't exist, wouldn't you be creating matter in that time frame? Isn't that going to blow up the universe or some other doomsday scenario?

 

[Dexter Morgan]

You must talking about the Grandfather Paradox:

A man traveled back in time and killed his biological grandfather before the latter met the traveller's grandmother. As a result, one of the traveller's parents (and by extension, the traveller himself) would never have been conceived. This would imply that he could not have travelled back in time after all, which in turn implies the grandfather would still be alive, and the traveller would have been conceived, allowing him to travel back in time and kill his grandfather. Thus each possibility seems to imply its own negation, a type of logical paradox.

Consideration of the grandfather paradox has led some to the idea that time travel is by its very nature paradoxical and therefore logically impossible, on the same order as round squares. For example, the philosopher Bradley Dowden made this sort of argument in the textbook Logical Reasoning, where he wrote:

Nobody has ever built a time machine that could take a person back to an earlier time. Nobody should be seriously trying to build one, either, because a good argument exists for why the machine can never be built. The argument goes like this. Suppose you did have a time machine right now, and you could step into it and travel back to some earlier time. Your actions in that time might then prevent your grandparents from ever having met one another. This would make you not born, and thus not step into the time machine. So, the claim that there could be a time machine is self-contradictory.

Cite: http://en.wikipedia.org/wiki/Grandfather_paradox

 

[Kur]

There was a movie called "time machine" I think where this guy in the late 19th century is working on a time machine. His girlfriend ends up being killed and this causes him to finish the time machine for the one reason of going back and preventing her death. He builds the machine and goes back and stops his girlfriend from being shot, only to see her killed some other way. He tries again to save her but she dies in some other way. No matter what he does, she dies.

He eventually ends up far in the future and meets a super smart 'human' who reveals that the reason his girlfriend always dies is because if she hadn't died, he never would have built the time machine. The existence of a working time machine conflicted with the existence of his girlfriends life.


Now whether or not things would really work like this if a person were to travel back in time, no body knows for sure. Maybe the universe doesn't care if you kill your own grandfather because you already exist in a way that allows you to do the deed.

Perhaps once you begin to exist, your actions in the past can not undo you? In the (very hilarious) cartoon Futurama, the main character is his own grandfather as the result of accidental time travel.

 

[Crimson King]

"Time Machine" is a book by H.G. Welles. Nothing annoys me more than when someone refers to a book as only a movie. It's a pet peeve.

 

[AltF4]

Okay, fine. Time travel to the past has a couple obvious problems.


The principle of consistent histories. There must be only one unchanging and certain past. This is a requirement for causality. Thus, violation of this violates causality. What this means is that you cannot change the past. IE: The Giants must have either won the Super Bowl last year or lost. It cannot be both, it cannot be neither, and it cannot be anywhere in between. And whether or not they did cannot ever change.

But reverse time travel isn't strictly impossible, and reveals a very nasty side-debate. One of Free Will. (See the Free Will thread. Preferably the one started by me.)

You see, have you ever heard of an anti-particle? In an introductory Physics class, they might tell you this: "The vacuum of space is not empty. There is a very strange phenomenon where a particle and anti-particle pair will spring into existence out of nothing, zoom around, collide with each other and cancel each other out into nothingness again."

But that is not the whole story! What really is going on is that there is not two particles colliding. But rather one particle which moves in a closed infinite loop! It moves forward in time, reaches a certain point and turns back around and goes in reverse in time (at which point we observe it as an "anti-particle") back to the original moment and begins to move forward in time again.


The relevance of this is obvious: The particle travels back in time, but while in the past, it has no choice about where to go. It is bound to follow what already happened in the past.

Which leaves us with two possible scenarios:

a) You can travel into your own past, but while there, you do not have free will to do as you please. The laws of nature will force you to behave in such a way that anything you do while already have been done in the past. (Think Terminator 3)

b) You cannot travel into your own past, but rather an alternate past. Which you CAN alter. This isn't actually time travel at all, however! It would just seem like it to you because this alternate universe has objects and places similar to that of your past.

 

[Dexter Morgan]

You know what I've always found trippy?


Who's to say that someone, or some group of people aren't going back in time and altering the past continuously?

Someone from the future could be altering past events in history, and we would never even know it! We may have never really lived through our own memories. Well, technically, we would have had to live through them for them to be our memories, but these past events may not have been the first rendition of what happened.

Honestly, who's to say that Ben Franklin wasn't America's first first president? Franklin could have been cast originally to be our nation's first president, then some people from the future figured that Washington would have made a better president, gone back in time, and convinced Franklin to let Washington take the position?

Also, what if in the first rendition of World War II, the Axis Powers won? Nazi Germany blows through Europe with their blitzkrieg, create an Aryan race of (most likely inbred) super humans, then spread their strong arm throughout the rest of the world, and wiped out all "impurities". Then, at some point, time travel was invented, and some renegade secret society of underground Jews got to it, or stole it, or stole the plans and built their own while destroying the one in Nazi Central, then used to get America to help the Allied Powers and win the war. We would never know that.

Time travel brings up some crazy f***ing scenarios.

 

[WuTangDude]

Or what if someone time traveled to the past to prevent the invention of time travel in the first place? Does that person disappear, since he would've made it so there was no way for them to be here?

Time travel is one of the craziest topics ever, and it's a personal favorite just because of how mind boggling it is.

 

[blazedaces]

AltF4, can I ask you a question concerning this phenomena (particle and anti-particle collision in a vacuum)?

It's a little hard for me to understand. I've read books such as "A Brief History of Time", but it's still a little confusing to me. If a particle and anti-particle are "created" and then collide does that mean that conservation of matter is being broken here (I don't think this to be true, but I've been asked and I didn't know how to answer so perhaps you will).

Now your explanation is the first I've heard of the anti-particle actually being the original particle travelling back in time... Could you elaborate on this? Without going into too much detail can you explain what leads one to this conclusion based on our observations?

I'm just very interested is all. If you think this requires a lot of further reading could you recommend some? Most books don't go into the math too much either, though I wish they did... Guess I can't do much about that beyond taking advanced courses in quantum physics or something of the like...

-blazed

 

[AltF4]

Let me explain something first:

The universe does not speak English. The universe deals entirely through the language of mathematics. In order to understand the universe, you must be well versed in its language. Any attempts to try to explain to you in English how the world works are necessarily going to be flawed. They are going to miss some aspect of the real truth. In order to understand the full story, you have to see the math for yourself.

Thus, sometimes science comes up with these really weird explanations for things! Like I'm sure you're familiar with the Wave-Particle Duality of Light. (If not, give it a look up on wiki) Scientists struggled for centuries (probably longer) trying to figure out whether light was a particle or a wave. The truth wound up being that it was both and neither at the same time!

You see, "wave" and "particle" are English words we humans use to gain a conceptual understanding of things. Light, as it turns out, happens to exhibit behavior exactly as if it were both a wave AND a particle. Even though our "common sense" understanding of those concepts says it impossible for something to be both a wave and a particle.

But light makes perfect sense in the mathematics of it all. Once you read the math, it all comes together.The universe is under no obligation to make sense to you. It is what it is. If the math works out, it works.




In a similar fashion, the particle phenomenon I mentioned to you earlier can be described "in English" in several ways. One way of looking at it is that there are two particles, which spring up out of nowhere and collide to cancel each other out. The other way of looking at it is as a single particle moving through a timespace loop. It moves forward in time, slows down and heads backward in time, then repeats.

Btw: the two particles don't just "disappear into nothing". They annihilate and produce other particles (such as photons) which go on to perform more mundane acts. Similarly, they are created by some event and use the mass from previous particles. Conservation is never violated.

It's often said "created out of nothing", which is a bit misleading I guess. But there's no such thing as "empty space" anyway, so...

 

[blazedaces]

Don't know if this requires a reply, but thank you for the insight...

-blazed

 

[Taymond]

One of the less-ambitious plans I've always had for purely-rhetorical time travel is just to "sit still" in time whenever it was time to sleep, and stop wasting so much of my time catatonic. There are, of course, much grander possibilities.

Is... is there a debate here at all, or..?

 

[Kur]

"Time Machine" is a book by H.G. Welles. Nothing annoys me more than when someone refers to a book as only a movie. It's a pet peeve.

And nothing annoys me more than people assuming things about me. I gave no reason for you to believe I was referring to a book as only a movie. I was referring to a movie.

I said there was a movie called "Time Machine" that is it. The rest of my post was based on the movie. I have never read the book so why would I refer to my experience of "Time Machine" as anything other than a movie?

I saw a movie.

 

[Firus]

If Time Manipulation, I'll call it, were possible, I'd want to do very little with it.

After reading A Sound of Thunder by Ray Bradbury, it's sort of hard to want to go to the past. When I think hard, there are little things that would totally have changed my life. If I had never joined these forums, I never would've realized how annoying Sakurai was about making us play the way he wants us to, I never would've been woken up to how screwed up gaming has become, and I'd still be blissfully, but ignorantly, playing Brawl and games like Wii Fit without even realizing how they've killed gaming. Heck, if I had never become friends with someone who had Super Smash Bros for N64, who knows if I ever would've gotten that much into Nintendo or Smash Bros for that matter, and in turn, would I have joined this forum? Maybe not. Things could go so wrong here that I'd never want to go into the past. There are some things I wish I could change, some things I've done I wish I hadn't, but if I changed them, would I ever learn the lesson? Could that change my entire life? Yes. So I wouldn't want to do it.

I wouldn't want to go to the future either. While I do, it's like when I spoiled everything for myself in Brawl. The option was out there and I couldn't wait any longer to find out the roster and everything, but once I actually found everything out, it was a huge disappointment. And that was a bad thing for a video game. Imagine if it happened with my entire life. If things turn out badly, you'd want to kill yourself. If things turned out well, you'd probably end up screwing up and changing your future. So the future would be a bad place to go as well.

The only thing I'd like to do is pausing time. As Taymond brought up, pausing time for sleeping. That may be simple, but it's a GREAT idea. I hate having to sleep. I hate sleeping in, I hate going to bed. If I sleep in past 10 o' clock (on days that I can), I feel like I've wasted my day away. Meanwhile, when I get up much earlier (again, on a free day), I feel overjoyed because it feels like 2PM and it's only 10AM. There are also many other uses for time stopping.

But even so, there are consequences. Given the ability for anyone to stop time, it could be disastrous. People could stop time, go into a store, steal something, leave the shop, and start time again. There are endless possibilities of things going wrong.

So the only thing I'd WANT to do is stop time, and even that would be completely and utterly disastrous. No time manipulation for me, I suppose. Realistic or not, I don't particularly like the idea.

 

[Uncle_Donkey]

I have a half-baked idea about how time travel could be achieved. I admit it makes some unfair assumptions and is quite ridiculous, but it's fun to think about it.

My college physics textbook says in the chapter about entropy that entropy is what gives direction to time. It is why a popcorn kernel can pop but not unpop, even though matter and energy would still be conserved. So if we could develop a device that could manipulate entropy, then time could be altered. We would change the polarity to go back in time and change the magnitude to speed up or slow down time. Through localized entropy manipulation, we could construct a time machine by manipulating entropy on the outside of the craft and keeping it constant inside the craft.

Localized entropy manipulation would have other applications outside time travel. If you drop your grandmother's antique vase for example, you could set up a localized entropy manipulation device around the pieces and turn the entropy value to negative something, and the vase would reassemble itself. Pretty cool I think.

 

[AltF4]

Yea... it doesn't work like that.


The definition of Entropy varies wildly depending on who you're talking to and what you're talking about, but generally it's considered kosher to speak of it as the amount of disorder in something. It has been observed that this disorder has a clear inclination to tend to increase over time. Thus, it can help us distinguish direction in time.

For example: If I had two pictures, one with a vase and flowers in it, and another with a shattered vase on the floor, you can use the concept of entropy to help assign the order of these objects in time. It is very likely that the broken vase came second. However it is not strictly always true. It is conceivable that the vase was created originally "shattered", and was only later put together as a full vase.

A well known thought experiment to demonstrate this is hydrogen atoms bouncing randomly in a container. Imagine that they start in a highly disordered state. Eventually, through their random interactions, they will reach a position where they perfectly align into a grid. So over time, we have decreased entropy!

So change in entropy is generally a good indication of direction in time, good enough (with few enough exceptions) that we can use it fairly frequently without problem.


But changing entropy does not change time! If your room is dirty and you clean it you have decreased the entropy in your room, but certainly didn't travel back in time while doing it now did you?

 

[Jack Kieser]

AltF4Warrior, you're awesome. That has to be the best explanation of entropy I've ever heard; I'm totally writing that down for when I get asked about it.

Now, I have a quick question. Earlier, the Grandfather's Paradox was brought up; I've been thinking about that a lot since then, and I have to ask... doesn't that paradox make a big assumption, namely that there is a 'right way' for the order of events to be in? For instance, let's say I go back in time and, through an unfortunate series of events, my actions cause my grandfather to get hit by a car. My grandfather dies, thus my father is never born (this is my paternal grandfather; not like it matters : P ), and thus I am never born. I cannot go back in time, so I begin to phase out of existence.

Here is our first assumption: we really don't know what would happen to me had this series of events took place. We assume that I would phase out of time because there is no direct line of causation resulting in my birth... but would that really matter? There would be a direct line of causation leading to my existence in that time period (the past), however, and that is all that matters. We have no reason to assume (other than our own flawed mythology on 'time travel') that I would disappear from existence. Of course, this is all conjecture and is completely dependent on the method of time travel used; for instance, if I used a Chronosphere to travel back in time (Red Alert 2 version, when they worked out all the kinks), then my mass would have been transferred by the device to the past. My grandfather's demise would be irrelevant because the device is my direct causation in the past (of course, the device is programmed to revert the user to the present in the case of such paradoxes, but that is neither here nor there). If I used H.G. Wells' time machine, then my mass would be structurally the same before, during, and after time travel (because it only affects the speed at which the subject travels in relation to his/her surroundings), so such an action may very well cause a paradox.

Which brings me to the second assumption: that a paradox would be caused in the first place. We assume, for instance, that there is a single timeline, and that the events in that timeline are concrete (as was said earlier, a sports team can either win or lose, but it can't be both and it can't be neither). Why do we assume this, though? Let's say that my grandfather's demise, caused by me, does cause me to cease to exist. My ceasing to exist is directly caused by my grandfather's demise; however, what is the direct cause for my grandfather to come back to life? It isn't my ceasing to exist, because I am now taken out of the equation; we have no reason (again, outside of our flawed mythology) to assume that time would 'revert' to anything, because in order to assume this, we'd also have to assume that there is a 'something' to revert to! Who's to say that it can't be that I just cease to exist, and my grandfather stays dead? Unless there is something to directly influence events that would bring my grandfather back to life, I say it is much more logical that simply nothing would happen: I would cease to exist and time would continue in its altered path.

 

[Dark Hart]

I'll put my two cents here as well.

The first thing about time travel is this: You can't go back in time the second you build a time machine. You can only go back in time as far as when the time machine was first turned on. Why? Here's an example:

Mr. Brown is building a time machine. (Bear with me). He finishes building it, and turns it on at... 10:00PM, on the dot, on June 10th, 2004. That's as far as he can go back, he can only go as far back as 10:00PM, on the dot, on June 10th, 2004. Why, because the time machine didn't exist before then. If he wants to go through the time machine on June 10th, 2005 @ 10:00PM on the dot, he can only go as far back has the year earlier because that's when he turned it on.

Make sense to anyone, or is it just me?

 

[Stroupes]

Make sense to anyone, or is it just me?

Not if you can get the machine to move in other dimensions.
Otherwise, based on chronology, you couldn't.

 

[Vro]

Your idea can make sense, you just didn't explain it fully. Can he not bring the time machine to 2003 because it didn't exist at that time (breaking the law of conservation: matter from nothing)?

 

[Dark Hart]

Well, I'm talking based on just chronology. I'd have to imagine that if someone or some group was to build a time machine, they would start with chronology because it would be so much harder to find a way to move into other dimensions that way. Actually, in general now that I'm thinking about of it.

Your idea can make sense, you just didn't explain it fully. Can he not bring the time machine to 2003 because it didn't exist at that time (breaking the law of conservation: matter from nothing)?

No you couldn't being that the time machine didn't exist yet. In my example, he can only travel as far back as June 10th, 2004 @ 10:00PM.

 

[Vro]

Moving into a different dimension is different from traveling time.

 

[Stroupes]

Well, I'm talking based on just chronology. I'd have to imagine that if someone or some group was to build a time machine, they would start with chronology because it would be so much harder to find a way to move into other dimensions that way. Actually, in general now that I'm thinking about of it.

No you couldn't being that the time machine didn't exist yet. In my example, he can only travel as far back as June 10th, 2004 @ 10:00PM.

Well, like Alt said, the most apparent way to get around chronology, would be to travel to a alternate existence, perhaps one where there existed a time machine in 1980. If travelling to another existence were even possible with a time machine

 

[Stroupes]

Moving into a different dimension is different from traveling time.

Not necessarily.
When you get up to the higher dimensions, like perhaps 6-10, your "timeline" of life starts to loop back to your past, and, possibly, alternate realities.


http://www.tenthdimension.com/medialinks.php

 

[Dark Hart]

Well, like Alt said, the most apparent way to get around chronology, would be to travel to a alternate existence, perhaps one where there existed a time machine in 1980. If travelling to another existence were even possible with a time machine

That would be traveling to an alternate dimension, wouldn't it. That kinda breaks my whole point.

 

[Stroupes]

That would be traveling to an alternate dimension, wouldn't it. That kinda breaks my whole point.

Traveling to an alternate reality, for our sake of understanding, one where there exists a time machine before you create one, would eliminate your limit of only "traveling to the point where you created the time machine," because, in the alternate reality, you already created it at a previous time, meaning you could also travel to THAT point in time, as well.

 

[Vro]

The video you showed me is interesting. How accurate are these representations of dimensions? Are they purely theoretical? Everything seemed to be perfectly normal knowledge until he represented the third dimension as a fold. The concept is interesting, in that a two dimensional figure wouldn't realize. But they idea that you can unfold the dimension and move about seems to be very challenging.

 

[Stroupes]

The video you showed me is interesting. How accurate are these representations of dimensions? Are they purely theoretical? Everything seemed to be perfectly normal knowledge until he represented the third dimension as a fold. The concept is interesting, in that a two dimensional figure wouldn't realize. But they idea that you can unfold the dimension and move about seems to be very challenging.

Well, that's the way my physics teacher explained it(the first four dimensions) himself, and he's a Physics major. The info in the video seems to match, so I'm assuming it's all pretty accurate.
As for being theoretical, I'm just guessing that it is, unless there has ever been an experiment that involved other dimensions. Which, to my limited knowledge, there isn't.

 

[Dark Hart]

Traveling to an alternate reality, for our sake of understanding, one where there exists a time machine before you create one, would eliminate your limit of only "traveling to the point where you created the time machine," because, in the alternate reality, you already created it at a previous time, meaning you could also travel to THAT point in time, as well.

Well, in my eyes, and alternate reality would be another dimension. Whether that's a correct statment or not, it's how I think.

But they idea that you can unfold the dimension and move about seems to be very challenging.

Well, you can technically fold dimensions, why not unfold them?

 

[Vro]

But a lot of those ideas seem to be theory. The video itself linked itself to The String Theory. All the information seemed credible up to the fourth dimension, as you yourself agreed. The rest just seems to be speculation.

That would also mean that instead of traveling to a different universe, it would be the same one with a different time-line. And that just wrecks my limited understanding of time. Is time linear or indefinite or even real?

 

[Stroupes]

That's true, I don't think anybody knows what happens past the fourth dimension. It has to be speculation, since there isn't indisputable proof of what goes on in the outer dimensions.
As for myself, they seem to be possible explanations of what occurs past the fourth dimension.

That would also mean that instead of traveling to a different universe, it would be the same one with a different time-line.

That would seem to be the case. But, if you could get there, would there really be much difference?

Is time linear or indefinite or even real?

I would most likely assume that time is definately indefinite, due to the choices you make having different outcomes.

 

[Vro]

But, if you could get there, would there really be much difference?

I guess not, should the tenth dimension video hold true. It'd be the same you, in the bigger picture, just moving around. Time seems to be almost the same as space, in terms of mobility.

I would most likely assume that time is definately indefinite, due to the choices you make having different outcomes.

This assumes determinism is incorrect. I like to believe in free will and that my choices branch out my future. However, I can't ignore a very logical argument, like determinism, completely.

 

[Dark Hart]

That would also mean that instead of traveling to a different universe, it would be the same one with a different time-line. And that just wrecks my limited understanding of time. Is time linear or indefinite or even real?

In a different universe, the time may be different just because of all the different possibilities.

 

[Stroupes]

I like to believe in free will and that my choices branch out my future.

I probably worded my last statement wrong, but what you said is what I meant.
Anyways, my main point is that I believe it is possible to loop back to an alternate past, or reality, and it could be like time travel. But...dimension travel.