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Is there lighter particle than photon?

  1. Feb 8, 2012 #1
    Hey guys I am taking 1st semester quantum chemistry.

    My first question is "is there lighter particle than photon?"

    second is "If we discover/ or use much lighter particle than photon, I wonder we can challenge Heisenberg

    uncertainty principle.

    I thought uncertainty principles is based on thought that photon electron interaction is significant when we try to observe some phenomenon.

    Thank you!
  2. jcsd
  3. Feb 8, 2012 #2


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    The mass of a photon =0, so the particle must have a negative mass.
    According to Diract hole theory, there is a sea of electrons with negative energy and mass which is however not observable. We only note when such an electron is excited to a positive energy and mass state and leaves a hole behind. This hole than behaves as a particle with positive mass, namely the positron.

    It has also been speculated whether particles with imaginary mass can exist. However, these would really violate special relativity and are therefore not believed to exist. You should find plenty of old threads on that topic searching for "tachyons".
  4. Feb 8, 2012 #3


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    When there is a number lower than zero..........
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