Classical behavior of macroscopic bodies from quantum principles: Early discussions (Q1841144)

The question before the authors is: how did the founders of quantum mechanics propose to link their microscopic world of wave-particles to the macroscopically observed world governed locally by the Newton-Euler equations? Initially the founders did not propose to answer this question, but Schrödinger's first attempts (1926) to describe electrons caused Heisenberg, Ehrenfest, Madelung, and others to attempt to answer this micro-macro question, with some initial success. There are about 65 references in the 54 footnotes. The writing makes the reading flow, and the topic easy to understand. One should note that the authors' use of ``the real part of the wave function'' is not the usual meaning of the real part of a function of a complex variable, but refers to its modulus. The identity of C. G. Darwin is equivocal or ambiguous: for non-biologists, there is George Howard Darwin (son of Charles), and Charles Galton Darwin (``grandson of the real Darwin'').