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Did photon obey Uncertainity Principle?

  1. Jul 23, 2009 #1
    Photon has no mass.So when we apply Uncertainity principle to photon
    position*velocity*mass=greater than plancks constant
    So when we use mass as null,the equation implies that 0<h.
    That is h is negative.But h is positive.
    Please explain me this.
  2. jcsd
  3. Jul 23, 2009 #2
    The uncertainty relation follows from the commutation relation of the momentum and position operators. The photon does not carry a mass, but it does carry a momentum.
  4. Jul 23, 2009 #3
    This is not momentum. This is an approximation of momentum at low velocity. The correct dispersion relations for the massless particles as the photon is
    [itex]E=pc=\hbar\omega=\hbar c k[/itex]
    Last edited: Jul 23, 2009
  5. Jul 23, 2009 #4


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    The single-slit diffraction phenomenon is the clearest example of photons "obeying" the HUP.

  6. Jul 23, 2009 #5
    Thank you
  7. Jul 23, 2009 #6
    As far as we know, everything obeys quantum principles...including HUP...
  8. Jul 23, 2009 #7

    I refuse to obey your quantum principles ;)
  9. Jul 23, 2009 #8
    Thanks a lot
  10. Jul 24, 2009 #9
    A smart dope is in direct violation of my HUP.

    - Werner
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