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2 photons, same starting point/time, same end point

  1. Feb 3, 2016 #1
    How would 2 photons with the same starting point& time and same end point view each other's positions, time and distance from start to end point. I recognize this is likely a bad question, so any input would be helpful.
     
  2. jcsd
  3. Feb 3, 2016 #2

    jtbell

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    It is. Photons don't have "point of view" like massive objects do. This is because an object's "point of view", in technical terms, is a reference frame in which the object is at rest. However, no such reference frame exists for a photon.

    https://www.physicsforums.com/threads/rest-frame-of-a-photon.511170/
     
  4. Feb 5, 2016 #3
    Yes, that is why I mentioned likely bad question.
    How can this question be changed so the time and path of the 2 photons can be fully addressed?
     
  5. Feb 5, 2016 #4

    Nugatory

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    It's easy to describe the paths followed by the two flashes of light, and how those paths will appear to any possible observer. That's a complete description of the physical situation.

    There is no "point of view" in which either of the flashes is at rest, nor even moving at any speed other than c relative to the observer.
     
  6. Feb 5, 2016 #5

    Ibix

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    Further to Nugatory's comment, you also need to specify something about the path the light pulses follow. If they start at the same point at the same time and arrive at the same point, are they taking the same route? If not, do they arrive at the same point at the same time? Do they bounce off mirrors? Or are you thinking of gravitationally lensing?
     
  7. Feb 11, 2016 #6
    I was pondering: Same starting point, same end point, same path, simultaneous within allowable uncertainty. Basically identical signals overlapping in all possible aspects.
     
  8. Feb 11, 2016 #7

    Nugatory

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    Electromagnetic radiation superimposes, so for all observers this is going to be a single more intense flash of light moving from the starting point to the end point at speed c.

    The question about how things would look from the point of view of an observer moving along with that flash of light is still ill-formed, for the the reason that jtbell gave above.
     
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