0
$\begingroup$

In this forum I've often read that EM radiation does not consist of photons (ie be emitted from accelerated electrons in an antenna rod) and that photons are only excitations of an already existing EM field. How can one connect this with the Standard Model of physics, where photons are particles? Would a different model of quantum theories negate the existence of photons?

$\endgroup$
  • $\begingroup$ In what forum have you read that? Are you perhaps misinterpreting statements to the effect that the relation between a macroscopic EM wave and individual photons is complicated as saying the EM wave doesn't consist of photons? $\endgroup$ – ACuriousMind Oct 6 '16 at 11:21
  • 1
    $\begingroup$ @ACuriousMind: physics.stackexchange.com/questions/283291/… $\endgroup$ – HolgerFiedler Oct 6 '16 at 11:43
  • 1
    $\begingroup$ That question dealt with a constant electric field, not EM radiation. $\endgroup$ – Jon Custer Oct 6 '16 at 12:51
  • 1
    $\begingroup$ @Jon The first sentence is about EM field which is something very different from an electric field. $\endgroup$ – HolgerFiedler Oct 6 '16 at 14:12
  • 1
    $\begingroup$ "The first sentence is about EM field which is something very different from an electric field. " Who told you that? The words 'electric field' mean 'the components of the electromagnetic field tensor that behave in the way described by electrostatics in the frame of reference we're using'. In other word the electric field is a subset of the electromagnetic field (albeit a frame-dependent subset). $\endgroup$ – dmckee --- ex-moderator kitten Oct 6 '16 at 15:27
0
$\begingroup$

The SM (standard model) is in comparison to the QFT (Quantum field theory) as newtonian physics is to special relativity. It is still applicapble, but contains more information. So when you ask if it would negate the existance of photons, the answer is no. It is just written in a different format. For all purposes within the standard model, photons still exist, as they do in QFT, but there they simply exist as excitations:

For a general overview of QFT see: https://en.wikipedia.org/wiki/Quantum_field_theory

$\endgroup$
  • 2
    $\begingroup$ I don't think your analogy is quite correct. I think a better one is that the standard model is to QFT as the model of the solar system is to Newtonian mechanics. $\endgroup$ – Sean E. Lake Oct 6 '16 at 12:52

Not the answer you're looking for? Browse other questions tagged or ask your own question.