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Feynmans Path Integral for single Electron?

  1. May 11, 2004 #1
    I had a Feynman Documentry of some early work Feynman done with a statement that there:Was a likelyhood of only being a single Electron? or words to that effect?

    Can anyone enlighten me to some data giving some insight?

    If true can any serious buff give me a handwave to the actual work that Feynman was doing around this era?

    Thanks..this will be much appreciated!
     
  2. jcsd
  3. May 11, 2004 #2

    ahrkron

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    IIRC, I read that comment on Gribbin's "In search of Schroedinger's cat", referring to the fact that the QFT representation of antiparticles is equivalent to their regular-matter counterparts, only going backwards in time. If you take that literally, you can imagine electrons and positrons to be, all of them, the "now" time-slice of the same particle, that goes forward and backward in time just tricking us into believing that there are many of them.

    I don't think there is much more to it, since: 1. there is an asymmetry between matter and antimatter that may prevent such picture to be workable, and, mainly, 2. even if that was the case, it seems to me that it would provoke no difference in experimental predictions.

    ... but the mere possibility is intriguing.
     
  4. May 11, 2004 #3
    Many thanks ahrkron, this is exactly what I had thought, though not word for word.

    I think I have found a 'deeper', rather physical interpretation actually. Making the connection with Feynman's work, I have stumbled across something extrordinary (even for me!). But I would have to delve into Feynmans workings for some correlation, hense the request.

    Thanks again.
     
  5. May 11, 2004 #4

    robphy

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    From Feynman's Nobel lecture
    http://www.nobel.se/physics/laureates/1965/feynman-lecture.html

    "As a by-product of this same view, I received a telephone call one day at the graduate college at Princeton from Professor Wheeler, in which he said, "Feynman, I know why all electrons have the same charge and the same mass" "Why?" "Because, they are all the same electron!" And, then he explained on the telephone, "suppose that the world lines which we were ordinarily considering before in time and space - instead of only going up in time were a tremendous knot, and then, when we cut through the knot, by the plane corresponding to a fixed time, we would see many, many world lines and that would represent many electrons, except for one thing. If in one section this is an ordinary electron world line, in the section in which it reversed itself and is coming back from the future we have the wrong sign to the proper time - to the proper four velocities - and that's equivalent to changing the sign of the charge, and, therefore, that part of a path would act like a positron." "But, Professor", I said, "there aren't as many positrons as electrons." "Well, maybe they are hidden in the protons or something", he said. I did not take the idea that all the electrons were the same one from him as seriously as I took the observation that positrons could simply be represented as electrons going from the future to the past in a back section of their world lines. That, I stole!" - Richard P. Feynman – Nobel Lecture, December 11, 1965
     
  6. May 11, 2004 #5
    Amazing robphy!

    Better than I had imagined. Before I go and read the link, it seems to have orignated from Wheeler, if this is so then no wonder he is actually such a ponderous Genius!

    Many thanks again.
     
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