Letter to John Lighton Synge (9 November 1959), as quoted by Walter Moore in Schrödinger: Life and Thought (1989) ISBN 0521437679
It is not a breakthrough, it is just something we refuse to see, something that was known for a century.
"All is a wave" is the unifying principle. I am no mathematician, but the math needs to start with that fundamental principle.
The very notion of calling it "qunatum" physics is probably wrong since quantum is "a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents."
And if everything is a wave there are no discrete quantities beyond our definition of what constitutes the end, or borders, of the wave.
> Now, when I told my editor at Allen Lane about my own interpretation, he immediately said “It’s Many Worlds on steroids!” There is a grain of truth in that, ...
Dude, this is an answer to an entirely different question. He's proposing an interpretation of QM, which is independent from "how many fundamental particles".