Are Maxwell's Equations True at the Quantum Scale?

[aliens123]

Newtonian mechanics is considered an extremely valid "approximation" for large objects whose speed relatively small (compared to the speed of light).

But, we generally acknowledge that they aren't "true," even though they are still useful. My question is are Maxwell's equations similar in this respect? In other words, I know that at a certain scale they are useful, just like Newtonian mechanics is, but I was wondering if they are still "true" at the quantum scale.

There are times when we treat a photon as a wave and times when we treat it as a particle. When we are treating individual photons as waves do Maxwell's equations still hold? Or are they just approximations for large amounts of photons?

 

[mfb]

My question is are Maxwell's equations similar in this respect?

Yes. They are the macroscopic approximation of quantum electrodynamics. They work when individual photons are not relevant, although they can sometimes be used for single-photon experiments as well (in parts where the quantization is not relevant, e. g. in mirrors and similar optical elements).

 

[Nugatory]

Maxwell's equations are true as long as you're posting in the Classical Physics subforum.

(Although it might be better to say that the Classical Physics subforum is the one where Maxwell's equations are true).