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

Does an EM wave bend in a B-field?

  1. Aug 29, 2010 #1
    I read somewhere that Thomson (1897) concluded that the electron was not an EM wave because it bended in a magnetic field and that it had been proven that EM waves did not do this. Is this true?
  2. jcsd
  3. Aug 29, 2010 #2
    Why would a wave bend in a magnetic field?

    A CHARGE will experience a force, but the E&M wave is a "wave", a propagating electric-magnetic field. They can superpose.
  4. Aug 29, 2010 #3
    Indeed, but my confusion arose from this: if in QM an EM wave is interpreted as a probability wave, just like an electron is interpreted as a probability wave, then due to the latter statement, a probability wave can experience a B-field. Now indeed a photon has no charge, but an EM-wave does have an E-field, so it might intermingle? And if it doesn't, is the reason a photon doesn't bend in a B-field because it has no charge, or more fundamentally that it is a wave?
  5. Aug 29, 2010 #4
    I can't explain it at the QM level, but I know that fields can superpose (shown by the linearity of Maxwell's equations).

    True that electron is interpreted as a wave, however I don't think we can say "electron is a wave, photon is a wave, they're the same". Obviously the electron has a charge and it behaves differently than other waves on the larger scale. That's probably the reason, I'm not sure.
  6. Aug 30, 2010 #5
    If a photon could be bent in a magnetic field it would have to have its own B field or E field for this to happen .
  7. Aug 30, 2010 #6
    cragar: isn't that exactly what a photon has?
  8. Aug 30, 2010 #7
    Then why cant a photon emit photons.
  9. Aug 30, 2010 #8
    Field wave and probability wave are different.
    Probability wave is more of a mathematical construct than physical reality (although it depends on interpretation). It contains all information about physical state.
    EM field is a fundamental field of nature. It is definitely out there, waving happily, making light, radio waves and other nice things. (Unlike probability wave, which is gone once you look at the particle.)
  10. Aug 30, 2010 #9
    That's what I thought at first, but I read that Bohr interpreted an EM wave as a probability wave. Was Bohr wrong the first time around?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook