Time Travel, Possible or Not?

[Iamdan]

*ends quote train*

 

 

Well if by someway you could travel into the past why couldn't you change anything? You are traveling back before something happened so you can change it since it hasn't happened. Unless you are going off the theory of fate. That no matter what you do you will end up doing what it was you were supposed to do for that event to take place. If the former is true though you couldn't return because the time you were trying to get to would no longer exist.

 

 

 

There are 3 theories (I know of) on time travel:

 

 

 

1. The grandfather paradox

 

 

 

2. If you bring in the rest of the dimensions with multiple futures, it makes changing your own future possible. It will fork into a parallel time stream, so the "you" in the time stream you move to isn't born, because you came from the other time stream where you were born.

 

 

 

3. You can't change the past, if you travel back in time then that was the natural sequence of events and you already traveled time to cause whatever happened but you can't remember because it hadn't happened to your present self yet. This is the one lost went with.

[Nenga]

Time travel is a paradox in itself isn't it?

 

 

 

To travel to a time before you existed means you don't exist yet and thus can't exist.

 

 

 

To travel to a time after you existed means you have already existed and have ceased to exist and thus can't exist.

 

 

 

 

You can exist, because it's your present self doing the traveling. If you travel to before you were born, you haven't been born yet in that time stream, but your present self has. The 'future' would become your present self's past because you have already grown up and traveled time.

 

They actually explained this really well on Lost.

 

Well I never watched lost.

 

You can travel back in time, you just can't change anything, because it's already happened, and nothing can change it.

 

I forget exactly how it works. but they did explain time travel really really well on lost.

 

Well if by someway you could travel into the past why couldn't you change anything? You are traveling back before something happened so you can change it since it hasn't happened. Unless you are going off the theory of fate. That no matter what you do you will end up doing what it was you were supposed to do for that event to take place. If the former is true though you couldn't return because the time you were trying to get to would no longer exist.

 

Because what you did in the past has already been recorded now. So killing a butterfly would keep things normal just like not killing a butterfly.

 

Well if you were recorded to have killed that butterfly then not killing it would change what happened. Though the 'rule of fate' kicks in again and you end up doing what you were supposed to do even if you were trying not to do it.

[Riku3220]

Well if you were recorded to have killed that butterfly then not killing it would change what happened. Though the 'rule of fate' kicks in again and you end up doing what you were supposed to do even if you were trying not to do it.

 

No, because then it would be recorded that you didn't kill it. Anything that happened in the past results in the future that we have now, because you've already done it. You can't change it.

[Nenga]

Well if you were recorded to have killed that butterfly then not killing it would change what happened. Though the 'rule of fate' kicks in again and you end up doing what you were supposed to do even if you were trying not to do it.

 

No, because then it would be recorded that you didn't kill it. Anything that happened in the past results in the future that we have now, because you've already done it. You can't change it.

 

 

 

If you killed it, then you were recorded to kill it. Then you are not recorded for not killing it.

 

 

 

So then you don't kill it and that's recorded.

 

 

 

You have to choose one or the other. Something can't be alive and still be dead.

[Riku3220]

Well if you were recorded to have killed that butterfly then not killing it would change what happened. Though the 'rule of fate' kicks in again and you end up doing what you were supposed to do even if you were trying not to do it.

 

No, because then it would be recorded that you didn't kill it. Anything that happened in the past results in the future that we have now, because you've already done it. You can't change it.

 

 

 

If you killed it, then you were recorded to kill it. Then you are not recorded for not killing it.

 

 

 

So then you don't kill it and that's recorded.

 

 

 

You have to choose one or the other. Something can't be alive and still be dead.

 

You can choose but whatever you choose you'll end up with the same result as that will be what's recorded.

[a_bert]

If time travel would be possible in the future, why hasn't our future selves presented themselves to us by now?

 

 

 

This.

 

 

 

 

 

I'd go to the Dark Ages. Hey Arthur, DID YOU REALLY EXIST?.. Wait.. put that axe down..

[Iamdan]

If time travel would be possible in the future, why hasn't our future selves presented themselves to us by now?

 

 

 

I forgot who came up with that, but they didn't think it through well. What about if doing that would mess something up? If someone came back in time someone might freak out and kill them. It could also become world news and mess something up.

 

 

 

Anyway, it could have happened and those people just haven't told anyone. Either because their future self told them not to, or they didn't want to end up in an institution.

[Xizor12]

It's possible to travel forwards in time, but it's not practical, as you'd have to travel at something like 99.8% of light speed.

 

 

 

Going back, however, is impossible, as far as we know.

[Nenga]

Well if you were recorded to have killed that butterfly then not killing it would change what happened. Though the 'rule of fate' kicks in again and you end up doing what you were supposed to do even if you were trying not to do it.

 

No, because then it would be recorded that you didn't kill it. Anything that happened in the past results in the future that we have now, because you've already done it. You can't change it.

 

 

 

If you killed it, then you were recorded to kill it. Then you are not recorded for not killing it.

 

 

 

So then you don't kill it and that's recorded.

 

 

 

You have to choose one or the other. Something can't be alive and still be dead.

 

You can choose but whatever you choose you'll end up with the same result as that will be what's recorded.

 

Two possible events have two possible solutions. If you kill the butterfly it will have different effects than if you don't kill it.

 

 

 

Say your father stepped on a butterfly when he was younger and he st oped to scrape it off his shoe, and in those few seconds your mother came along and they started talking.

 

 

 

Now you go back into the past and kill that butterfly, your father doesn't scrape it off his shoe and keeps walking. So he never meets your mother, thus you arn't born. You arn't born and you are friends with someone. The someone kills themself and they were destined to become the smartest person on the face of the earth in all of history.

 

 

 

Yeah the last part was just thrown in but since you never killed that butterfly there are unlimited possibilities.

 

 

 

Just think how many alternate universes there must be if that is true though. One for every single space an animal could stand/fly in for the entire history of earth.

[Riku3220]

That's the thing. You can't change what's been recorded, you can only do what's been recorded.

[Nenga]

That's the thing. You can't change what's been recorded, you can only do what's been recorded.

 

But you are going back before it is recorded so thus you can do it. Again if that rule of fate doesn't come into play.

[Riku3220]

That's the thing. You can't change what's been recorded, you can only do what's been recorded.

 

But you are going back before it is recorded so thus you can do it. Again if that rule of fate doesn't come into play.

 

Anything you see today is a result that happened from the past. You going back in time would be included in the past so anything that you would do would end up as what we have today.

[Iamdan]

Here's something I find interesting:

 

 

 

If you fold a piece of paper into a loop, you can instantly move from 1 end to the other. If you add a twist to the loop, the 2d being can travel in the 3rd dimension, but will have the impression it's only moving in a straight line.

 

 

 

It's the same thing with time. We are 3d beings, and can move through time but it appears as a straight line to us. The 5th dimension is all the possible futures from that moment in time. If we were a 4d being we could move through time, just like we can currently walk up stairs to move in the 3rd dimension.

 

 

 

After you pass a certain point in time, a theory in quantum physics suggests that the possible futures in the 5th dimension that didn't happen are collapsed into the 4th.

 

 

 

Basically this means teleportation requires the folding of the 3rd dimension, time travel requires the folding of time through the 5th dimension.

 

 

 

Going by the physics theory, theoretically you actually can change the future. Imagine a point in time where you can do 1 thing or another. The first option leads to scenario A in the future, the second leads to B. You can travel to before that moment, and choose the second option when the time arises. Folding the 5th dimension through the 6th dimension (if it exists) will enable you to jump between the alternate realities instantly.

 

 

 

The thing is, a 2d being can't fold a piece of paper - only a 3d being can. This suggests that folding time by ourselves, and time travel, is impossible unless it happens by something in the 5th dimension causing it.

[Rebdragon]

Hey gais! Guess what, there's a reason it's called a "time paradox"! You know why? Because it's unsolvable for anyone, much less a bunch of preteens on a gaming forum!

 

 

 

Eureka! Now go be more useful and play D&D or something!

 

~[bS]~

 

NO NO NO.

 

 

 

PSEUDOSCIENCE.*

 

 

 

BAD.

 

 

 

*Scroll down, read the first review.

[Nenga]

That's the thing. You can't change what's been recorded, you can only do what's been recorded.

 

But you are going back before it is recorded so thus you can do it. Again if that rule of fate doesn't come into play.

 

Anything you see today is a result that happened from the past. You going back in time would be included in the past so anything that you would do would end up as what we have today.

 

Are we really getting anywhere with this "i'm right, you're wrong" stuff?

 

 

 

Anyway back to the argument.

 

 

 

Refer to my post that two possible events will have two possible outcomes.

 

 

 

Lets take a more solid example: You go back in time and you kill baby Hitler. So because he is dead he still does what he would if he was alive?

 

 

 

It's the grandfather paradox.

[Laura]

That's the thing. You can't change what's been recorded, you can only do what's been recorded.

 

But you are going back before it is recorded so thus you can do it. Again if that rule of fate doesn't come into play.

 

Anything you see today is a result that happened from the past. You going back in time would be included in the past so anything that you would do would end up as what we have today.

 

Are we really getting anywhere with this "i'm right, you're wrong" stuff?

 

 

 

Anyway back to the argument.

 

 

 

Refer to my post that two possible events will have two possible outcomes.

 

 

 

Lets take a more solid example: You go back in time and you kill baby Hitler. So because he is dead he still does what he would if he was alive?

 

 

 

It's the grandfather paradox.

The better question to ask is, "If this occurs, why don't the others occur instead?"

[The Observer]

I believe that it is possible to travel forward in time by using a wormhole (for example), but travelling backwards in time is impossible as it's already been done. You can slow down time, but you can't really reverse it, can you?

[Lenin64]

If time travel would be possible in the future, why hasn't our future selves presented themselves to us by now?

 

 

 

I forgot who came up with that, but they didn't think it through well. What about if doing that would mess something up? If someone came back in time someone might freak out and kill them. It could also become world news and mess something up.

 

 

 

Anyway, it could have happened and those people just haven't told anyone. Either because their future self told them not to, or they didn't want to end up in an institution.

 

And this was in Back to the Future!

 

 

 

To clear up the paradox thing a little bit, hopefully: Your butterfly thing. You can't kill the butterfly that your father killed before. No matter how hard you try to, you will be unable to kill the butterfly because that's just not how it happened. You aren't changing anything by being there, either; history has recorded you being there already. If you tried going back in time to kill Hitler, you couldn't. Something would happen every time to screw up your efforts, because Hitler wasn't assassinated ever. But time back then did play out with you trying to kill him; it's not something new.

 

 

 

And why do people say we would know already? If you had a time machine, would you really unveil it before 2009? Compared to time machines, time before now is amazingly unadvanced. It may not be until the year 4000 that we invent time travel, they'd probably go to the year 3500 or something if they were going to make an unveiling. And 2009 would be ancient history nobody remembers.

[sphinxor86]

I have a degree in Theoretical Physics, and I'd like to add to this:

 

 

 

Prograde (ie: forward) time-travel (TT) is perfectly possible, not only possible but necessary: (as someone has already pointed out) we are all doing it right now. To get ahead of everyone else however, requires either passing through an extreme gravitational field (near a black hole for example) OR travelling very very fast. For a noticeable "jump" into the future, this speed has to be very close to the speed of light. But the principle holds for any increased speed, and in fact has been proved.

 

 

 

Scientists synchronized two atomic clocks (extremely accurate clocks) and put one on a Concorde from London to New York (back when they still had Concorde, at least I think it was Concorde, it may have been another plane). When they compared the clocks after the flight, the one left in London had recorded (ever so slightly) more time than the one on the plane. So the one on the plane had jumped ever so slightly into the future. (I'm talking miniscule fractions of a second here). To get anything a human would notice would require sizeable fractions of light speed.

 

 

 

Retrograde (ie: backward) TT is not strictly forbidden by physics. Any such attempts however require exotic (not yet observed, and extremely unlikely) ideas, such as negative or infinite energy. Or wiggling one end of a wormhole near a very strong gravitational source (not to mention that making a wormhole in the first place requires negative energy!). One common thing that arises from most of these ideas, is that you cannot go back further than the time of creation of the machine you are using to perform your retrograde TT.

 

 

 

So if I built a retrograde TT machine today, I could not use it to go back to before today... which defeats the point really, but it prevents some paradox issues.

 

 

 

My personal opinion is that retrograde TT is impossible, because you can always conceive of paradoxes. I feel that the universe must have some natural "paradox filter" built into its laws, but that's just an intuition.

[Nenga]

That's the thing. You can't change what's been recorded, you can only do what's been recorded.

 

But you are going back before it is recorded so thus you can do it. Again if that rule of fate doesn't come into play.

 

Anything you see today is a result that happened from the past. You going back in time would be included in the past so anything that you would do would end up as what we have today.

 

Are we really getting anywhere with this "i'm right, you're wrong" stuff?

 

 

 

Anyway back to the argument.

 

 

 

Refer to my post that two possible events will have two possible outcomes.

 

 

 

Lets take a more solid example: You go back in time and you kill baby Hitler. So because he is dead he still does what he would if he was alive?

 

 

 

It's the grandfather paradox.

The better question to ask is, "If this occurs, why don't the others occur instead?"

 

I think my original thoughts on time travel are lost lol. I don't think it possible to travel to the past. I gave an argument against future time travel but it was a really weak one that I don't even consider a credible argument.

[mmmcannibalism]

Prograde (ie: forward) time-travel (TT) is perfectly possible, not only possible but necessary: (as someone has already pointed out) we are all doing it right now. To get ahead of everyone else however, requires either passing through an extreme gravitational field (near a black hole for example) OR travelling very very fast. For a noticeable "jump" into the future, this speed has to be very close to the speed of light. But the principle holds for any increased speed, and in fact has been proved.

 

 

 

if I may request, can you explain the effect of gravity on time?

[Riku3220]

That's the thing. You can't change what's been recorded, you can only do what's been recorded.

 

But you are going back before it is recorded so thus you can do it. Again if that rule of fate doesn't come into play.

 

Anything you see today is a result that happened from the past. You going back in time would be included in the past so anything that you would do would end up as what we have today.

 

Are we really getting anywhere with this "i'm right, you're wrong" stuff?

 

 

 

Anyway back to the argument.

 

 

 

Refer to my post that two possible events will have two possible outcomes.

 

 

 

Lets take a more solid example: You go back in time and you kill baby Hitler. So because he is dead he still does what he would if he was alive?

 

 

 

It's the grandfather paradox.

 

It wouldn't work that way. Hitler died commiting suicide. If someone had gone back in time and killed Hitler then we wouldn't be where we are right now. You might be saying that you can change the present but you can't because going back in time would keep the present normal.

 

 

 

Take this example:

 

You want to go back in time 5 years ago and tell yourself that you're you from the future. Obviously if you had retained that memory you would know that would travel back 5 years, in 5 years.

 

You don't have that memory because didn't happened, since it didn't happened it will never happen.

 

 

 

I suppose that's what I should've said from the start, "Because it didn't happen it will never happen."

[sphinxor86]

if I may request, can you explain the effect of gravity on time?

 

 

 

 

 

I'll try:

 

 

 

In General Relativity (GR), acceleration and the effect of gravity are identical concepts. In fact in GR, the force of gravity is a "myth", and its all the geometry of spacetime that causes acceleration that we feel as gravity.

 

 

 

So back to black holes, black holes are areas of extreme gravity, and by the same principle extreme acceleration areas. The geometry of such a region is very distorted. Now near the black hole the space part of spacetime stretches (think of water down a plug-hole or a heavy object on a rubber sheet), andthe time part of the spacetime stretches.

 

 

 

You travel (litreally) through a region where time is stretched (compared to the outside world) and so time elapses much more slowly in this region, and when you leave it, time contracts back to normal (and so passes at the familiar rate), and you have jumped into the future.

 

 

 

This also means that your feet are younger than your head, time passes more slowly for your feet (compared to your head).

[mmmcannibalism]

if I may request, can you explain the effect of gravity on time?

 

 

 

 

 

I'll try:

 

 

 

In General Relativity (GR), acceleration and the effect of gravity are identical concepts. In fact in GR, the force of gravity is a "myth", and its all the geometry of spacetime that causes acceleration that we feel as gravity.

 

 

 

So back to black holes, black holes are areas of extreme gravity, and by the same principle extreme acceleration areas. The geometry of such a region is very distorted. Now near the black hole the space part of spacetime stretches (think of water down a plug-hole or a heavy object on a rubber sheet), but the time part of the spacetime contracts. (that's just the way spacetimes work)

 

 

 

You travel (litreally) through a region where time is compressed (compared to the outside world) and so time elapses much more slowly in this region, and when you leave it, time stretches back to normal (and so passes at the familiar rate), and you have jumped into the future.

 

 

 

This also means that your feet are younger than your head, time passes more slowly for your feet (compared to your head).

 

 

 

k tyvm; as a one liner as gravity increases time slows down correct?

 

 

 

If I ever go back in time I am commiting myself to talking to myself about how im going to talk to my self.

[sphinxor86]

I had to double check that, I made an error is exactly what I said (but edited it)

 

 

 

But yes as a one liner, more gravity, slower time goes.