Comments by "Lepi Doptera" (@lepidoptera9337) on "1. Quantum Mechanics—Historical Background, Photoelectric Effect, Compton Scattering" video.

  1. There are neither particles nor waves here. There are only quanta of energy. Quanta give rise to a number of phenomena. A large number of quanta of the FREE theory (free as in free of self interaction) can give rise to mean field theories that look a lot like classical waves. Individual charged quanta can undergo annihilation processes but those are NOT part of the free theory. In an annihilation process we have at least two quantum fields (the charged fermionic field and an uncharged bosonic field) that are interacting with each other. Totally different physics.
    2