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I Time-travel and space displacement

  1. Feb 8, 2017 #1
    Is it possible for a time-traveller to correctly account for space displacement in order to appear in an exact point in space and time?

    I've been thinking about time travel lately, and realized that to re-appear in the exact spot you started your travel, or any spot you desire, you would have to calculate the displacement of your desired location. However, it seems impossible to calculate that exactly without an absolute frame of reference. How would a time-traveller be able to account for space displacement without having an absolute frame of reference?
  2. jcsd
  3. May 3, 2017 #2
    It seems to me as though you are using the word displacement in two different contexts. In the first context it sounds like "the difference between the initial position of something (such as a body or geometric figure) and any later position" which is one of the dictionary definitions (Merriam Webster). The other usage (where you use the phrase 'account for') sounds more like you are trying to determine the effect your theoretical travels would have on the past and/or future where you would be an added factor. Also I know this paragraph totally makes me sound like a dick, but I just want some defined terms so we can talk about time travel.
  4. May 3, 2017 #3


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    Apparently you have realized it is impossible to define any exact location without invoking points of reference. The best you can do is measure your angular offset and distance from no less than 3 unambiguous reference points. Even this would be imperfect as everything in the universe has peculiar motion and a finite lifespan.
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