I think it is quite telling that Planck's principle was formulated by a physicist. https://en.wikipedia.org/wiki/Planck's_principle https://en.wikipedia.org/wi

I think it is quite telling that Planck's principle was formulated by a physicist. https://en.wikipedia.org/wiki/Planck's_principle https://en.wikipedia.org/wiki/Planck's_principle Though probably Planck was at the time still under the impression of the C.G. Barkla affair.