We cant go back in time>>>>

[pretender]

My thoughts are, we cant go back in time, the reason for this is, it already happened, if this is so, time cant happen twice. If you dont agree, Why????

[[Tycho?]]

Nobody knows if time travel to the past is possible for not. There also is not a good general understanding of what would happen if it were possible. So who knows.

[Forensicmad]

I think that is correct. I find it extremely annoying when time travel is just thrown into films and whatnot without thinking about the literal aspects of it.

For example, the Terminator films. Nevertheless entertaining, they are just... well... wrong. It will take too long to go into the synoposis of the films

(see: http://en.wikipedia.org/wiki/The_Terminator)

Anyway, the point of it is that machines are sent back through time to kill (and protect) someone who later on in the future, becomes important. When they arrive from the future, they claim it is history to them (the future is their past).

 

Now, if that was true, there would have had to be one main/true timeline. The character would have had to survive by himself to get to the future and THEN send the machines back in time. In other words, he is sending machines back in time to protect himself when he has already completed the timeline with no interruptions yet apparently he wouldnt have survived without the machines. (I hope you are understanding this)

 

So, if there were machines there to kill and protect him which came from the future, he would have had to already completed the timeline and so render the necessity of sending the machines back pointless.

 

Its the same in the 3rd Harry Potter film/book when he saves himself with the patronus. He needed to have survived the whole timeline so he can reach the point to then go back in time and save himself. If the timeline is complete, going back in it is pointless and so the plot is corrupt (couldnt think of a different word)

 

So in reply to your comment, no we cannot (or shouldnt be able) to go back in time because as the French call it, it is the Perfect tense. It cannot be changed. If you want to go back in time and save yourself, you would have already had to survived the whole timeline without the aid of yourself and so going back is pointless.

 

Phew. Just my thoughts on the subject.

 

By the way, I am not putting down Harry Potter and the Prisoner of Azkaban or the Terminator films. They are both highly entertaining; just a little illogical in my eyes.

[Kedas]

My thoughts are, we cant go back in time, the reason for this is, it already happened, if this is so, time cant happen twice. If you dont agree, Why????

So we can go to the future because it hasn't happened yet?

[pretender]

Kedas

I guess its the same thing.. YUP.

If there is a future it must be the now, as it is ongoing, and the now is its past, so we are the futures past. that does not make any sense. so there is no past or present only, now.

[[Tycho?]]

All you guys are talking about are paradoxes. These have been a staple of sci-fi for what, like 70 years now. It does not follow that time travel is impossible because of it, since we dont know how such a paradox would play out in the real universe.

[Neil9327]

Time travel is possible forwards. All you have to do is to go to bed for a few days, and there you are.

 

Time travel backwards is not possible. Why? Because if you travel backwards you see the world as it was. But you already know (because you have memory) how it is going to be, from then to the point when you travelled back from. Since this has already happened, because you lived the first time through the time when it happened and witnessed it for youself, your entire actions will be consistent so as to repeat exactly what happened before. If you have any power to choose anything different then your surroundings will act against you to prevent this, and you know this to be the case as you witnessed this the first time round.

So time travel into the past is strictly on a read-only basis. But then we already know this as we have many abilities to read stuff from the past. Like this message for example.

[dehammer]

Forensicmad, not neccissary. in the potter book, he only survived because he had help from the future. if something had prevented him from returning, he would not have been there to aid him.

 

the terminator on the other hand cant happen. in order for the computer to send him back the first time, it had to have things happen that would not have been possible, if he not been sent back. then the second one came back, and destroyed the things the first left so there was no way the machine could be made, so it could not send him back the first time. then the third one came and created the situation that made it possble for the computer to do what it did. the loops on this was far too complex.

 

on the other hand, considering that we have ways of watching things that ppl dont recognize now, how do you know that when it happen the first time, you werent there watching it again from a distance.

 

Neil9327. there is a theory that memory is a form of time travel, and if you can utilize it right you can travel into any part of your past. so if that is correct, time travel can go into the past.

[iglak]

My thoughts are, we cant go back in time, the reason for this is, it already happened, if this is so, time cant happen twice. If you dont agree, Why????

using "it already happened" as an argument only prevents one from changing the past, not visiting.

 

it's still potentially possible to go back into the past, try to change something, and find out that you actually caused it.

or to try to change something, and have no effect on it.

 

saying "it already happened" means that you can go into the past all you want.

it's just that when the past was the present, your future self was there too, which means that everything has already reacted to it.

[SoFlaSS]

You also have the Grandfather Paradox. Which ponders the question that if you went back in time and killed your grandfather would you continue to exist or would you disappear the same moment he died. This is an intresting point, but does not state that time travel into the past is imposible. Time travel forward is quite easy all you need is speed. Granted we can't achieve a speed high enough to get very far into the future, but it is still possible. Going backwards how ever is a tricky beast to deal with. Some scientist suggest use of a worm hole, to move through space and time. While others suggest different uses of speed and physics. Time is not a solid constant that is unchangable, time and space are actually very flexible. The realm of time travel forward and reverse is not something of impossibilty, just something that needs some more advancements and time to work with.

[Dak]

I'm going to regret entering into a phisics discussion, but... can't you not go the the past simply becuse it doesnt exist anymore? wouldn't travelling to the past neccessetate re-organising the entire universe so that it was in the state it was, say, last tuesday?

[Kedas]

I travel to the future every day.

 

I get the train in the morning to go to work and at the evening I return home with the train. Didn't I just travel to the future? because my house has experienced more time than I have.

OK it's not a big diference but it is there.

[Cloud]

(I hope you are understanding this)

 

Wow - that was a pretty difficult thing to get across(put into words) - seriously.

 

I think Back to the Future works a bit better. Atleast there's some incarnation of a time-machine involved. The lesson learnt here -

 

"Stick with the stereotype." No-one's gonna argue.

 

Anyways - In regard to kedas's - "I travel to the future everyday"

 

Yes, that's strange (but true).

 

Wouldn't it also work if you went backwards (and hence travel back in time)

(Obviously it would be miniscule but if you went backwards at the speed of light - is this theorically possible?)

[JustStuit]

Wow - that was a pretty difficult thing to get across(put into words) - seriously.

 

I think Back to the Future works a bit better. Atleast there's some incarnation of a time-machine involved. The lesson learnt here -

 

"Stick with the stereotype." No-one's gonna argue.

 

Anyways - In regard to kedas's - "I travel to the future everyday"

 

Yes' date=' that's strange (but true).

 

Wouldn't it also work if you went backwards (and hence travel back in time)

(Obviously it would be miniscule but if you went backwards at the speed of light - is this theorically possible?)[/quote']

If you went "backwards" at the speed of light your time would speed up relative to the normal lower-speed reference time frame, but remain unnoticably changed to you. The direction of which you travel will not have effect on the time dialation.

[pcs]

My thoughts are, we cant go back in time, the reason for this is, it already happened, if this is so, time cant happen twice. If you dont agree, Why????

 

Your argument fails because:

 

1) You equivocate on the definition of time. Your first use expresses time as a coordinate axis which we can traverse. The next use lays out time as a process mapped onto some coordinate system.

 

2) "Time can't happen twice" is a premise; it doesn't follow from "it already happened."

[mimefan599]

Wouldn't it also work if you went backwards (and hence travel back in time)

(Obviously it would be miniscule but if you went backwards at the speed of light - is this theorically possible?)

 

Distance has no direction, or at least speed doesn't. The direction has nothing to do with how fast you go therefore it would not change the direction of time in which you travel. Absolute distance cannot go backwards.

 

In our present knowledge of the universe, we couldnt determine an answer, because we still don't know the true nature of time, nor exactly how we travel through it, or if it is just something we made up. Either way, einstien helped get us to understand a little more about the nature of time, but there is still plenty of knowledge we have you to attain, so you should hold that thought for another 40 to 50 years or so.

 

Perhaps when you travel back in time, you are not on the same timeline at all, I know im going into kind of shaky ground, but the grandfather paradox could be solved if we simply traveled back to a different timeline than our own and killed a version of our grandfather. Just an idea formed from our limited knowledge.

[cougarboxxer]

well isnt it supposedly that if you were to travel back in time then youre universe wouldn't be altered just the one you entered meaning that that alternate universe that would be the singularity that made it original so maybe then that universe consisted only for the possibility of you traveling back in time. as to the terminator movie i bet they didnt put a whole lot of thought into to that because the money maker was the action.

[dehammer]

there is a theory (some say crankcase, but who really knows, the wright bothers were called cranks) that all of time exist in a single point, and its only the perception that makes it appear to flow. that means the big bang, and the final entroy occured simultaniously. everything in between was just percieved to happen in order. according to this theory, to travel in time, only perception must be altered.

 

another theory is that if you were to go into the past, you might change things, but unless you were extreamly agile about it, something would happen to make it seem the same. example is that if you went back into to stop booth from assisnating president lincon, some else would kill him, perhaps accidently, and booth would get the blame.

 

its all theory, until someone gets hurt.

[Saryctos]

Time travel is impossible because it implies that time exists as an entity.

[ecoli]

I'm going to regret entering into a phisics discussion, but... can't you not go the the past simply becuse it doesnt exist anymore? wouldn't travelling to the past neccessetate re-organising the entire universe so that it was in the state it was, say, last tuesday?

 

How do you know it doesn't exist anymore.

 

It's been postulated that time, rather like space, is on a continuum, and that it, also like space, is curved. So, by creating wormholes, it might possible to travel through a shortcut past curved time.

[Dak]

How do you know it doesn't exist anymore.

 

It's been postulated that time' date=' rather like space, is on a continuum, and that it, also like space, is curved. So, by creating wormholes, it might possible to travel through a shortcut past curved time.[/quote']

 

I dont know as such... it just seems to me that the universe exists in an ever-changing state, and that once the universe has changed -- once something is 'in the past' -- it no longer exists, as there are no records being kept. In fact, I can't see how or where the information for past 'configurations' of our universe could be stored, so I dont see how the past could still exist in any way.

[ecoli]

I dont know as such... it just seems to me that the universe exists in an ever-changing state, and that once the universe has changed -- once something is 'in the past' -- it no longer exists, as there are no records being kept. In fact, I can't see how or where the information for past 'configurations' of our universe could be stored, so I dont see how the past could still exist in any way.

 

just because you can't imagine it being there doesn't mean it isn't. Humans can't conceptualize quantum mechanics, yet we know it exists.

[aguy2]

My thoughts are, we cant go back in time, the reason for this is, it already happened, if this is so, time cant happen twice. If you dont agree, Why????

 

My argument against the possibility of physical time travel is a lot more prosaic than the others presented in this thread. My argument is based on the assumption that individual point particles cannot exist twice at the same time. If this assumption represents the actual case, then the only possibility open for physical time travel would necessitate the instantanous transposition into the future of the atoms that are going to be part of the body going back in time.

 

If it proves to be impossibile for a physical body to travel back in time, would this also preclude the possibility of transmitting information and patterns back in time? I would tend to think that the case for information time travel might be a 'different bag of beans' altogether.

aguy2

[pretender]

If we are saying that time travel is a possibility, and I don't.. we are then saying our life is mapped out and we follow the future, and what we are doing now has already happened. I just cant believe that. I think what is now is now. no past, no present, just the now

[ashennell]

Isn't being cryogenically frozen just the same as travelling forward in time?