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Why time traveling (To the past) is impossible.

  1. May 9, 2005 #1
    I figured if anyone would understand my theory it's you. Now for one I'd like to make it clear I don't believe in time travel. I believe if you go faster then light (If you can..) you'll rip through the space-time countiuem and slip into a pocket dimension, it folds around you. And you're in a brand-new universe. (Think Sliders but much more lonely..)

    Now why is time-travel then impossible? Because traveling to the future requires faster then light speed. Time is measured by speed. The past has already gone. Therfore logic would dictate I'd have to move SLOWER then space-time to "make the clock move backward" and I believe it would be more impossible to go that slow rather then that fast. Because I would have to be having a net-loss in time, negative time, it defies logic. Therby I denounce anymore thought on the idea of traveling to the past to change ANY future..
  2. jcsd
  3. May 9, 2005 #2
    You have race with space time and beat it to make the clock move backward...
  4. May 11, 2005 #3
    to get to the speed of light it takes an infinite amount of energy. Not possible. Read up on the twin paradox will help a little.
  5. May 11, 2005 #4


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    Ok, apart from a few poetic liberties you took, it is true that if you go faster than light, according to special relativity in a naive formulation, you should go back in time. However, first you need to acquire an INFINITE amount of energy, which you can never obtain (there's only a finite amount of energy available in all of the visible universe). So this is then solved: you cannot go faster than light, so what happens when you do doesn't matter.

    But there is ANOTHER way of going "back in time", at least according to GENERAL relativity. General relativity allows you certain solutions which have, what is called, closed timelike curves. This means that if you follow them, at a reasonable speed (that's the "timelike" part) you'll end up at the same EVENT (= space + time point) after a finite time on your watch.
    Now, first of all, it is not because the equations of GR allow you such solutions, that these are also present somewhere in our universe. There are people who proposed the postulate that we should restrict ourselves to solutions of the GR equations which do not contain such closed timelike curves. Second, one can wonder what it means to go back to the "same spacetime event" when your watch did count a finite amount of time forward (proper time). Finally, quantum theory might mix in with this and change what exactly it means to be on the same spacetime event. You might indeed just end up in another branch of the wavefunction.

    There is a simple reason for not being able to travel to your OWN past and do something, which is well known: it is the "what if I kill my own grandfather" paradox.
  6. May 11, 2005 #5
    There are many flaws in this 'theory'. First of all you are talking about exceeding the speed of light. For you to do so, you'd have to be able to acquire a 'bigger then infinite' amount of energy. This is clearly impossible.

    Secondly, the brand new universe aspect. How can you be sure this happens ? I assume you think that because of the large energies that are recquire, spacetime will be curved very severely and this is the 'wrapping around you' part, right ? Well, anyhow it does not really matter because of the above energy argument. You cannot adopt these macaroni-type dimensions alla String Theory for these reasons. If you have this much energy, the entire space time continuum has to wrap around you, also the Kaluza Klein type dimensions that make up every space time point

  7. May 11, 2005 #6


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    Personal theories are not welcome on this site.

    - Warren
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