Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Does any one know how does paradox fits in to time travel?

  1. Jun 2, 2003 #1
    does any one know how does paradox fits in to time travel??
    Last edited by a moderator: Feb 5, 2013
  2. jcsd
  3. Jun 2, 2003 #2
    It would allow you

    to go back and kill your parents before you were born.
  4. Jun 2, 2003 #3


    User Avatar

    Re: It would allow you

    WHOA! Thats narcisstic and heavy, dude.
    But i thought about it a few times when I was cool, just kidding. I luvs ya mom and dad.
    Dx :wink:
  5. Jun 2, 2003 #4


    User Avatar

    Re: It would allow you

    that's probably the simplest and most obvious paradox of time travel, if you went back and killed them, then you couldn't exist to go back in time, and then you couldn't really have killed them, because you wouldn't exist!

    i read an article in popsci or sciam about this, there was something about shooting a ball into a loop-shaped wormhole so it came out and deflected off itself.
  6. Jun 2, 2003 #5


    User Avatar

    Didn't you guys learn anything from those tacky Back to the Future movies?
  7. Jun 3, 2003 #6
    Another paradox would be if I travelled foward in time, and read a paper by S.Claus about, for example, how to cure cancer. I then return to the present. I then tell my best friend S.Claus about what I read and he goes away and rights a paper on it.

    The knowledge came from apparetly no where.
  8. Jun 3, 2003 #7
    Anyone think of a paradox with going forwards in time, but not involving ever going back?
  9. Jun 3, 2003 #8
    I've never heard of one.

    I suppose it just adds to the argument that we can go forward but not backwards. Like how there are no time travelers from the future around just now.
  10. Jun 3, 2003 #9
    You should see the first post in this thread, eastsidecrew.

    Welcome to the PFs, by the way.
  11. Jun 5, 2003 #10
    Think about the guy that travels to the past and kill his father...

    I believe he will not dissapear at all. In his "line of time", the journey to the past to kill his father is a future event, posterior to his born, so he is going back in time to everyone else except himself.

    His future will be going to the past.

    I believe he could kill his father in the past, it will be no "real" past. The fact of killing his father will not change the previous past of that guy, he really borned, then went to the past and killed his father.

    Imagine you kill someone right now. Does it means this guy never existed because he is not present anymore?. I see killing your father in the past is the same thing. You borned, went to the past and killed your father, so you changed the past. All events between that moment and the journey to the past are only in your head and your live. They existed to you, but you "killed" them, so anybody else know. Going to the past is like "erase" the future you lived, but from your point of view, all movements you'll make into time (past, future...) will be a "time line" as the normal time that everybody feels.

    The same happens going to the future. You are not travelling to the "real" future, because it will be the future that will be without you from the present to that moment. If you take an information from that future, and then go back and put this information into knowledge, it will seem to become from you. As killing your father, you are only the guy who knows that information in the world. You're changing the things that you've seen from that moment to the future you saw. This time-line will only exist into your head, but it doesn't mean that it happened (at last, to you).
  12. Jun 5, 2003 #11
    cla your point is valid if you believe that for each desicion another universe is creating. But if you don't then killing your father will stop you ever being concieved and therefore you couldn't go back to kill him.

    If you do believe the multiverse theory then it becomes even more complicated. You would have to travel to a multiverse that was created from an earlier decision, as some mulitverses will be relatively new. So providing you could jump to one that was created long enough ago to allow you to travel before your birth, and you kill your father, only that multiverse and any ones created from that one, you will have killed your father. So returning to your own time and your own multiverse you would find your father was still alive.

    Presumable if you believe that though you then believe there are multiverses out there that your father was never even born.

    p.s. I'm not even sure if multiverse is a word but universe can't be right!
  13. Jun 5, 2003 #12
    What i believe is not exactly the multiverse theory.

    It's more likely "adaptative time" or something like that.

    If you were able to travel in time, the sequence I imagine is something like this:

    You born in 1960 (for example)

    You hate your father in 1985, and decide to ERASE him from the history, so you go back in time to 1950.

    You kill your father in 1950. Then, if you continue living from here, you'll be a person that nobody knows where you came from. Only you know you borned on 1960 (or should born 10 years later, hehe), but obviously, you'll never born in 1960 from here (due to the change you have just made).

    Now, imagine you regret yourself for killing your father, and go back to 1985 trying to stop yourself going to the past. The 1985 you'll go is no more the one you started the trip. It's the 1985 since you killed your father, so nobody knows you have travelled in time and killed your father, in fact, nobody knows you. You'll not find yourself on 1985, because you travelled to 1960 and changed things.

    The only way you have to save your father is going to the past, to some moment before you killed him (1945 for example). Then, doing nothing more, you just jump to 1985, this 1985 would be the same as if you have not travelled, because in fact, it's like if you have travelled to 1945 and then to 1985, touching nothing.

    So, you can make all the strange things you want, and visit all the possible futures from this actions (trying not to be killed in the proccess, hehe). To restore the time-line you want, you'll have to go to a moment before you did the actions you don't desire, and then go back to a moment after you started the time travel. (do you know how the tool HYSTORY works in PHOTOSHOP?... something like this)

    Every jump to the past makes this past convert into present, and erase the rest of the future that you know it happened from that moment. It's time that have not happened (and will not happen) to anybody else.

    If you travel to the future, it will be the same as if you just have dissapeared for that years.

    Another interesting thing is that there can only be one time-traveller, the time traveller that goes more into the past makes the rest of the time travellers depend on his actions. Maybe this deeper-past-time-traveller will change the time in a way that the other possible time travellers will not travel. The time-travel possibility depends of this deeper-past-time-traveller.

    To me, It's similar to multiverse theory, but with a collapsing of the multiverses into only one time-line on every time travel.
  14. Jun 5, 2003 #13
    From that point of view, all paradoxes dissapear, only the strange thing that the universe will be different from every option changed when you make time-travel remains... But in fact you're the only person that knows it on all universe. So, to the rest of the universe, nothing have changed (neither the time structure). To the universe, all that history you can told about the things you have made to time and universe is just an invention of your brain.

    And my vision of time is not like this of linear way to see it. I think it's like a book written by ourselves, but we forget we wrote it, and just read it, thinking we make elections, but in fact the elections are only the way we see time. Time as we understand it is just an illusion, the same way that we say that the universe has not justice. We are applying a human concept to the universe that the universe doesn't know about. The "justice" of the universe is something that depends of our point of view of the universe.

    The same with time experience.

    Election is the way we read the book of life, but not the way the book exists. We see time to be linear, one way, and going from past to the future, but i think this is just a human point of view of time, and i think time (if really exist) is something much more complex and strange.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Does any one know how does paradox fits in to time travel?
  1. How does time exist? (Replies: 36)

  2. How does one pronounce (Replies: 15)