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Experiment for precognition

  1. Apr 27, 2010 #1
    I'm sure there is a simple explanation as to why this wouldn't work, please enlighten me.

    Take a computer, which generates a random number. When the number is generated, a positron gun shoots out that exact number of positrons into a vacuum with a magnetic field. On the other end of the vacuum, a detector waits to read the number of positrons, then display that number.

    I'm torn on what would actually happen here. According to Feynman, anti mater moves backwards in time. However, under the same hypothesis, a PET scanner would return an image before the positrons were ever emitted, and that obviously doesn't happen.
  2. jcsd
  3. Apr 27, 2010 #2


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    I think the statement you are looking for is:

    Matter moving forward in time is indistinguishable from anti-matter moving backward in time. And vice versa.

    Anti-matter is routinely created in colliders, and it moves forward in time.
  4. Apr 27, 2010 #3
  5. Apr 27, 2010 #4
    Time flows horizontally from left to right in this diagram. The arrows do go forward in time.

    There is a mathematical manipulation which consists in identifying a particle moving backward in time with negative energy as an antiparticle moving forward in time with positive energy. It is the condition of energy positivity which assigns the proper time flow. Those particles moving backward in time are curiosities rather than physical.
  6. Apr 27, 2010 #5
    So, if I understand this correctly, if it were technically possible to send a positron backwards in time then we would be able to trap it in a wire in exactly the same way as we do with electrons. The problem is, it is technically impossible to send even a positron backwards in time...
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