QED

[steve_bank]

Looks like I am a bit behind the curve.

A quantum they behind EM wave fields? Photons are the quantization of EM fields. QED describes the interaction between photons and electrons in matter.

Basic antenna theory, an electron moving through a wire gives rise to photons. Photons hutting a wire gives rise to electrons in motion. EM field mappings in terms of E and H do not change.

https://en.wikipedia.org/wiki/Quantum_electrodynami

In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved. QED mathematically describes all phenomena involving electrically charged particles interacting by means of exchange of photons and represents the quantum counterpart of classical electromagnetism giving a complete account of matter and light interaction.

In technical terms, QED can be described as a perturbation theory of the electromagnetic quantum vacuum. Richard Feynman called it "the jewel of physics" for its extremely accurate predictions of quantities like the anomalous magnetic moment of the electron and the Lamb shift of the energy levels of hydrogen.[1]:Ch1

 

[bigfield]

Basic antenna theory, an electron moving through a wire gives rise to photons. Photons hutting a wire gives rise to electrons in motion. EM field mappings in terms of E and H do not change.

I understood antenna operation easily enough with plain old classical electromagnetism, where it's simple to visualise a signal being generated by pushing electrons back and forth along a wire.

No particle physics required.

 

[steve_bank]

So, what is the practical use for QED or is it just academic? QM has practical applications.

Is QWED the only model for photon-electron interaction in matter?

For me the practical l QM view of absorption in a detector is absorption occurs when the energy of the photon equals the band gap energy or voltage of the material. So, QED reduces the transfer to electrons to a series of prop abilities, The Feynman Diagram.

As to proof, on the face of it, it appears to be bootstrapping. A measurement of one constant is needed to measure a second constant.