Hi people,

I was sitting on the train today and my mind started to wonder to time travel (you know, the norm:) anyway my thinking was this...

Forgetting about Einstein's theory of relativity for one moment, my mind stumbled across an unexplainable idea as to why time travel is impossible, it also led to another philosophical question. However my station arrived and I had to cut the thinking short but it went something like this...

If (backward) time travel were possible, then it would be safe to assume (would it not?) that by now there would be at least a few people claiming to be from the future? If that were so does time travel mean that we are all leading a linier life. Is everything that we do already bound to happen, because if time travel were real it would also be safe to assume that right now people are living on planet earth 200 years into the future? So is there any such thing as spontaneous actions?

Just a thought,

-Rhys

Many physicists and philosophers have thought on this very issue. The many worlds concept allows that if a time traveler went back in time it would only be logically consistent if they went into a different time line.

Paradox occurs in any time travel concept where you are able to go back in time to your own time line and change an event that would preclude your being born ect ect ect.

what if there was no paradox, that each time someone went back in time, a new reality was formed, so that whatever was changed didn't affect the timelines? so if i went back in time, and killed my great-grand father, it would not make me disappear, but make it where i wouldn't be born in that reality...

Yup, but if there is only one reality, time-line, ect ect, then you seemingly cannot avoid paradox.

With all due respect, young people need to read more. This has been the subject of science fiction novels and short stories for decades.

there would never be a paradox to avoid...both timelines would continue as normal

yea, your right, if there was only 1 timeline... i misread it before i typed...

paradox, can't live right now 200 years in the future

makes sense but for that you would have diferent timelines and probably with diferent versions of the same person in it.People changing the future and creating new timelines where other people could also change the future. Imagine the number of timelines you would need to make it possible. Now im confused

the way i look at is like this... say 10 people all went to different points or times in the past... no matter what they did, there would be 11 different timelines... the one they came from, and 1 new timeline for each of the ten people. if you went back in time and changed my history, it would only affect the new timeline you created by going back, not the one you left, the one i am in...i would never see anything change, other then the fact you were gone.

just my interpretation of it anyway....

but by being gonne wouldnt you change the timeline you left even for a while? say you didnt go to a place you needed to be because you were in the past and because of it someone went in your place and changed their future because of it. Both timelines would change, the one you left and the one you created by leaving. Now im confused again haha

i look at it a little differently... i don't think anything could ever change this timeline, no matter what anyone does by going back in the past... there can be an infinite number of timelines.... so ours would always be safe...the idea of someone going back in the past and killing a monkey and wiping humans out sounds absurd to me...JMO

Moe, if there are choices for timelines, then Stefi is right, the situation leads to a mayhem of incompatible timelines, yet they have to co-exist in the universe. If, however, as you say in the next sentence, there is no infinite number of possible timelines, but there is only one possible timeline, which incorporates people already travelling back and forth in time, then you are right, the only one possible timeline figures in the zig-zags, and the chain of causality is not disturbed.

And if you ask why, I say, just becausality.

this is just my thinking, nothing scientific about it... but the timelines are separate from each other, none will ever have anything to do with the other, other than the fact someone from this timeline created it...other than that, we would never know they existed.

Thank you now im less confused

You mean, the universe is indivudalized, different for everyone?

So you say that when I meet you, and I see it that way, you may be not meeting me at the same time and in the same place?

You mean, each of us has a private, own little universe, where we have the luxury of having our own timelines?

And in my universe, in which my timeline is independent from other people's timeline, and in your universe, in which you have your own timeline, independent completely from other people's timelines in their own little individual universes,

then if you and I meet in my universe, and I and you meet in your universe, then it's complete coincidence? Because in my timeline it is possible for me to meet someone different from you, say, Kark, while you meet me in your universe.

I can accept that. But I can't accept ONE universe, which everyone occupies, and having independent timelines in it for us all each individually, as if the others did not exist.

Because if everyone is in one universe, then we each exist; but to appear as not existing, which can happen only if the person does not exist, that means that each person exists and does not exist at the same time and at the same respect.

This is absurd, reductio ad absurdum. In Socrates' times this was the only logical way of disproving someone else. The next step came with Aristotle, who developed syllogisms.

Let's do it with syllogisms.

1. Each human has his own timeline.
2. Each timeline requires its own universe.
---------
3. Therefore each human has his own universe.

=================

4. There is only one universe.
5. In one universe only one timeline can exist.
-----------
6. Therefore humans, each individually, can't have differing timelines.

Youve been watching Futurama, havent you?

Hmm.. I was reading about all this on google. Some scientists say that small particles time travel to future when they are near to speed of light. They travel 2 mins into future.. Thats a short time. There is a possibility of travelling to future but not past. So, the question arrises- if u travel to future 5yrs from now n you killed urself, will you be alive.??

Ash you are asking for it! now the confusion will start again
Now the question: Yes on the timeline you created when you leaved the past. Or is it future? see confused again!

Wait.! Its all confusing. Lets say i travelled to future from 2011.. I travelled to 2020.. So, its obvious that there wont be any trace of me in 2011, my parents would be looking for me.! So, in 2020, i killed the future Ash(not me)., will i be alive or i will dissapear in thin air.?? This question cant be answered. Maybe messing with the timeline destroys that dimension.