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Time Travel

  1. May 24, 2005 #1


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    Hi folk,
    In the various literature I have read relating to time travel there always seems to be an assumption that if one travelled in time from a time machine located in say one's own living room one would reappear in the same living room (site thereof) either in the present or the future. Is there a reason for this? I'd have thought if you travelled in time then your spatial coordinates would remain unchanged and so you would reappear in the same place but because the universe in in constant motion you would be in a different part of the universe. This would mean that without any time dilation issues resulting from near light speed travel etc you could travel enormous distances by simply staying put. In effect you could visit any part of the universe which has ever passed through the co-ordinates we now occupy. This would also make paradoxes less likely.
  2. jcsd
  3. May 26, 2005 #2
    I understand what you are saying, and I never ever thought to look at it that way. It makes a lot of sense, but I thought of one thing that would keep you in the same spot. If you look at time and space as the same thing, when you went backwards or forwards in time, you would follow the same curvature of spacetime that you would if you went through it normally. Picture a piece of toilet paper going down the drain when you flush the toilet. That would be us moving through spacetime. no matter how fast, or how slow, or whether time is moving backwards or forwards, it follows the same path. I think if we were to move along that path with control, at any time we chose, we would land on the spot we wanted. Time is the moment. Each point in space is only determined by where things were at the time. I don't know if this makes sense, I really wish I could take a physics class.
  4. May 27, 2005 #3


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    Time is one dimension of the 4 dimensions of spacetime. Moving in one dimension shouldn't neccesitate a movement in any of the other three no more than moving in a flat plain should affect your elevation. For instance if you imagine the universe as a travellator and time to be represented by it's movement and you were to suddenly jump to a different point on the travellator you would have travelled through time but would no longer be standing on the same spot. To remain in the same position relative to the the travellator (which equates to the generally accepted view of the effects of time travel) you would have to make the entire travellator jump with you. Interestingly this would mean that the ideas by some physicists regarding black holes being used as time machines wouldn't work because as soon as you shifted in time you would find yourself outside the singularity and thus outside your time machine. To stretch this concept further perhaps it is quantum fluctuations in time that accounts for the phenomenon of quantum tunnelling
  5. May 27, 2005 #4
    Please dont discuss all this here or you will be banned. Form what you are saying; it is clear that just by time travelling we will instantly find the absolute speed of earth in the universe and thats rightly so because at each next interval of time earth would have travelled far form what it was when you started the time travel.

    So please stop all this and let scientist here think they are right and there is no such thing as absolute speed.
  6. May 27, 2005 #5


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  7. May 27, 2005 #6


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    It is 100% due to creative license. The story is interested in movement through time, but the plot will concentrate on events that happen in the same spatial place - from a human perspective, that's Earthbound geography. Dealing with the consequential relocation does nothing to help the plot.

    How much sense would H.G. Wells' story make if, when he stopped his time machine 800,000 years in the future, he found himself floating 2000 light years or so below the galactic plane?
  8. May 27, 2005 #7


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    HG Wells creative licence is understandable but why do scientists such as Richard Gott and Stephen Hawking take the same licence when writing non-fiction? They too write of time machines without spatial displacement.
  9. May 27, 2005 #8

    I think that if you tried to travel in time you would end up in a parallel universe with its own time line.

  10. Jun 16, 2005 #9
    Time travel is too dangerous for scientists to even consider. You have to take into consideration the Butterfly Effect (not the movie). Your mere presence in the past could dramatically change the present you came from.

    EDIT: Besides, according to Einstein's theories on time, time is impossible.
  11. Jun 16, 2005 #10


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    I don't know what you mean by this. Time is a dimension in Einstein's relativity theories. In general relativity there are solutions that allow "closed timelike curves" (CTCs), aka trips to the past and back. But these solutions require strange conditions, and are not likely to be implemented in the real world any time soon, if ever.
  12. Jun 16, 2005 #11
    dang... it was supposed to be "time travel is impossible".
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