  It is argued that by the end of the 1920s a quantum-mechanical model could
have been in place, that not only produces the atomic and molecular energy
levels of the many-body Pauli equation with Coulomb interactions and external
classical electro- and magneto-static fields without putting these interactions
in by hand, but that also accurately describes the interaction of charged
particles with electromagnetic radiation, in particular the transitions between
atomic or molecular energy levels associated with emission or absorption of
radiation. This model suggests a re-interpretation of Maxwell's electromagnetic
field equations on spacetime as quantum-mechanical expected values of wave
equations on time X configuration space for photons and electrons. The creation
/ annihilation formalism for photons emerges without invoking second-quantizing
the classical Maxwell equations, and without involving the concept of creation
/ annihilation, thus suggesting an alternative physical interpretation of this
formalism. Furthermore, the model suggests that Lorentz covariance of
macroscopic physics models emerges through a law of large numbers from a
fundamental microscopic model that is not itself Lorentz covariant.
