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Defined future

  1. Jan 29, 2006 #1
    Many people heard about aproaches for time machines.
    Particularly I'd like to discuss Stephen Hawking's thought, that a time machine is impossible because otherwise we would have tourists from the future, unless we can't go back to time before a time machine was made.
    I think everyone took this idea under attention, but I'd like to discuss it aloud. What if there is no tourists from the future because there is no defined future ahead of us? Maybe We are the past, present and the future, not anyone else. Our acts and deeds define and make future, not defined future causes us to do something. Time machine is definitely passible and we can go back to what ever time we want, but first we have to build it, it's not built somewhere far in the future. What do you think about it?
  2. jcsd
  3. Jan 29, 2006 #2
    Well, I don't really believe in time travelling into the past..
    Seems to me that time is just matter in space moving, so the only way to travel back to the past is to take a picture or use a video camera.
    We can capture the past, when it is the present, but we can't force the entire universe, or a bubble in the universe, to "rewind" all its particles and mass back to an earlier state.

    Well maybe you can, but if you could, the future and the present would no longer exist.
    I mean think about it, if you imagine the universe as tons of tiny small baseballs boucning around in a room, you can capture the states and coordinates of all the balls, but then a split second later they would all be bouncing somewhere else again.

    Likewise if you imagine particles in space to have coordinates, not subatomic particles but the most fundamental and basic particle that exists, liek a string, if you imagine that they move and bounce around in space, tjhen you can capture their coordinates at any given moment, but, if you rewind all the particles back to their earlier state, then all particles who are rewinded would no longer be in the present. (they can only exist in one place at one time, thus having to "choose" between the present, the past or the future, but in reality those are all the same except the future.)
    Unless you have unlimited universes on unlimited timelines, but that's too far fetched in my opinion.
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