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Time Travel: Quantum Eraser Experiments

  1. May 10, 2005 #1
    Quantum mechanics has actually shown thru the quantum eraser experiments that we can rewrite the histories of photons, and that time is symmetrical. The best example of this is the translational interaction or pilot wave theory, where a particle future and particle past selves our in constant communication via FTL forms of electromagnetic wave. Any alteration to a particle whether in the past or the future would instanteously alter the present of that particle. This is supported by the most theories of quantum gravity.

    The formulas of such theories predict that the past, present, and future are only connected by series of relationship. Relativity limited the range of the interactions that we sense, but there is nothing to prevent events from being altered. Paradoxes at least in Godel case pointed to correctness of his theorem that all systems of logic is incomplete, the same goes with time travel. A paradox only exist if one cannot follow the chain of events that lead to the present, whether from the future or the past. Time travel can be paradoxical considering the quantum eraser experiment is a perfect example of this. By using a series of beam splitters and photon detector we can alter the course a single photon and then eliminating the path it has already travel, and force it to never have travel down that path. It's like climbing a ladder, then having someone pull the ladder away and finding that you never climb the ladder in the first place.

    Hence, by traveling backward in time you automatically cut/alter your time line. Einstein did not believe in time travel, even after Godel prove that it was possible! Instead you have the same universe just with a series of events that have been alter, the changes would be transmitted up the line to the future till it reach the point of your departure. All informations dealing with you are gone, any relationships or events that you have interacted with has change to show this effect. You yourself are uneffected, and if you travel back to your present you will find the entire world change as if you did not exist. You are now a man with no past.

    Now if an other time traveller would travel back in time and you cannot time travel, he could prevent your birth and you would cease to exist. But if you are time traveling at the time, you would be uneffected since no causal event can catch you. In the book "Time Travel in Einstein's Universe: The Physical Possibilities of Travel Through Time" by Richard Gott, Dr Gott explores a host of methods using configuration of vaccum. Cosmic strings and wormholes that show how an advance civilization could actually create a time machines.

    What does everybody else thinks?

  2. jcsd
  3. May 16, 2005 #2
    Shameless plug:

    http://marcus.whitman.edu/~beckmk/QM/qe/qe.pdf [Broken]
    Last edited by a moderator: May 2, 2017
  4. May 24, 2005 #3


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    'Which Path'

    Does constructing the experimental apparatus in such a way that the path of the photon can be determined eliminate the interference pattern or does it need to be actually measured in real time? What happens if it is simply recorded with say a 10% chance of being looked at later?
  5. May 24, 2005 #4


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    I don't think just having the apparatus so you COULD erase the information would work. You have to actualy do it to get the effect. Typically the eigenvalues are just two; do it or don't. Certainly one might contemplate a natural setup of the same kind, where the eigenvalues form a richer set, but then it would be hard to determine what would or could happen.
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