Bohr declared that although there may be a reality underlying quantum phenomena, we cannot know what the reality is. It is accessible to human understanding only through the mediation of experiment and classical concepts. Consequently, generations of physicists were taught that there is no quantum reality independent of experimental result. And that the Schrödinger equation, while incredibly useful as a predictive tool, should not be interpreted literally as a description of reality.
Everett took the opposite view.
And:
Fifteen years after the thesis was published, Everett penned a letter (found in the basement) to Max Jammer, who was writing his book on the philosophy of quantum mechanics… [saying] “It seemed to me unnatural that there should be a ‘magic’ process in which something quite drastic occurred (collapse of the wave function), while in all other times systems were assumed to obey perfectly natural continuous laws.”
[By] 1954, Everett was not alone in his feeling that the collapse postulate was illogical, but he was one of the very few physicists who dared to publicly express deep dissatisfaction with it… Everett had hoped to reinvent quantum mechanics on its own terms and was disappointed that his revolutionary idea was experimentally unproveable, as the only “proof” of it was that quantum mechanics works — a fact which was already known.
(It wasn’t until decades later that David Deutsch and others showed that Everettian quantum mechanics does make novel experimental predictions.)
Passages from The Many Worlds of Hugh Everett III:
And:
(It wasn’t until decades later that David Deutsch and others showed that Everettian quantum mechanics does make novel experimental predictions.)