Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B Why are Photons Massless?

  1. Dec 8, 2016 #1
    So according to QFT, fundamental particles are just excitations in their underlying fields.

    So the photon would correspond to an oscillation of the EM field.

    But it takes energy to excite this field. And E=mc^2. So therefore the photon should have some mass. Energy was put in to create it. That energy has to be concentrated somewhere.
  2. jcsd
  3. Dec 8, 2016 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

  4. Dec 8, 2016 #3


    User Avatar

    Staff: Mentor

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook