1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Do photons have mass?

  1. Jun 12, 2015 #1
    I read the FAQ about photons not having mass: Do photons have mass?

    But De-Broglie's equation says that wavelength=Plank constant / mass x velocity

    inserting values in the above relation we find the mass of a photon having certain wavelength
    Last edited by a moderator: Jun 14, 2015
  2. jcsd
  3. Jun 12, 2015 #2


    User Avatar
    Gold Member

    You wrote the debroglie equation for a massive particle (where you can write its momentum as p=mv which is not correct for the photon). You should use instead [itex] \lambda= \frac{h}{p}[/itex].
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - photons mass Date
B Reasoning for photon having no mass Jan 14, 2018
Why the photon has no mass? Jan 10, 2017
B Mass of a photon Jul 4, 2016
Presumed mass content of photon as gravitational source Feb 10, 2016