"Are There Quantum Jumps?", Schrödinger's Censored Chapter in "What Is Life?"

When Erwin Schrödinger’s book “What Is Life?” was republished, it was without a chapter titled “Are There Quantum Jumps?” available at this link.

Here is an excerpt:

Schrödinger’s concerns have not been entirely laid to rest:

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Schrödinger’s What Is Life? was originally published in 1944. The chapter in question, “Are There Quantum Jumps?”, seems to argue (based upon a quick skimming, not detailed examination of the argument), that quantum phenomena are fundamentally wave-like in nature, and the apparent observation of single particles only occurs at very high energies where their wavelength (wave packet size) is so small as to appear localised. This is pretty much the same as the contemporary view of quantum field theory, in which the field is fundamental and particles are a localised excitation of the field.

Quantum field theory only began to emerge in the mid-1950s and was not on solid ground until the standard model was developed in the 1970s, explaining the behaviour of the strong interactions.

Virtual particles were introduced in quantum mechanics to explain particle interactions, but Schrödinger appears to dismiss them as bookkeeping tricks to fix computations, much as astronomers invented epicycles to explain the discrepancies between their assumed circular orbits of planets and moons and the observed orbits (which turned out to be elliptical).

But shortly after Schrödinger wrote, the discovery of the Lamb shift in the spectrum of the hydrogen atom provided direct physical evidence for the existence of virtual particles, in this case due to polarisation of the quantum vacuum by the electric charge of the hydrogen nucleus (proton). This phenomenon was not predicted by the Dirac equation, but was explained by vacuum energy fluctuations, which are a virtual particle effect. This was eventually modeled theoretically by the Schwinger-Feynman-Tomonaga quantum electrodynamics, in which virtual particles played a fundamental role.

I don’t know the story of Schrödinger’s chapter being removed from What Is Life?, but it may have been that based upon subsequent discoveries in quantum electrodynamics, he considered it dated and, since it wasn’t central to the main topic of the book, better omitted. Schrödinger lived until 1961, and although he remained dubious of wave-particle duality, I haven’t heard of subsequent arguments against the existence of virtual particles which, by that time, were considered the explanation of numerous physical phenomena.


Has the muonic hydrogen proton radius tension/puzzle been resolved?

I’m tempted to go do a Mathematica implementation of Randell Mills’s model of the bound electron as a classically non-radiating (ref H Haus and Goedeke) charge current surface. From that structural definition of the electron he claims to calculate the muonic hydrogen Lamb shift (and all “quantum jumps” as continuous changes between non-radiating configurations).

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