Deterministic Measurement of a Quantum Systems

This a preparation of the next post on RealNucleus vs Standard Model/QCD.

Standard Quantum Mechanics StdQM says that measurement of the state of a quantum mechanical system like an atom/molecule or nucleus necessarily interferes with the outcome of the measurement. This is called "collapse of the wave function into a definite eigenstate" which happens with a certain probability during the measurement process, from an indefinite state in superposition of eigenstates described by the wave function prior to measurement. This is viewed as maybe the deepest mystery of StdQM still today 100 years after its formation. It is contrasted with measurement of a system of classical mechanics which can be done with insignificant interference with the measuring device. 

Yet measuring the spectrum, as the set of eigenfrequencies of an atom, always gives the same result with precision set only by the measuring device. No probability, no collapse of the wave function, no indeterminism, essentially no quantum. The same as recording the set of frequencies generated by plucking a guitar string using an app on your mobile. Same string, same frequencies. 

How is this possible? It is made possible by a phenomenon of resonance which is analysed in a context of blackbody radiation as Computational BlackBody Radiation. The measurement of the spectrum of a system like an atom or guitar string, is made by subjecting the system to periodic forcing of varying frequency as input and observing a peak in the response of the system to signal that an eigenfrequency of the system is close to the forcing frequency. In this procedure there is massive interference with the system through the forcing, while the reaction of the system revealing its eigenfrequencies can be viewed to be independent of the procedure and so expected to always give the same result. We thus find no principal difference as concerns spectrum of an atom and a classical system like a guitar string.  

But there is a difference between a classical mechanics guitar string and an an atom in the sense that the tone generated by a guitar string as a superposition of eigenfunctions as the wave form (which depends not only on the string but also on the plucking technique) can be listened to/measured, while the wave function/form of the atom as superposition of eigenfunctions cannot be observed, only the spectrum of the atom as the set of eigenfrequencies.  

How important is then interaction by resonance as determinism also in a quantum system? There are good reasons made as Computational BlackBody Radiation to view all interaction as somehow monitored by resonance. Listening to the tone/wave form generated by a plucked guitar string thus involves recording individual resonances (and amplitudes) by the ear which are then synthesized in the brain back to a wave form. It seems reasonable to expect that interaction between quantum system also primarily is monitored by resonances and then in a deterministic way and then not directly by wave form interaction.

Reducing measurement of a quantum system like an atom to resonance, makes it deterministic and circumvents the roulette game of "collapse of the wave function". Moreover, if interaction between quantum systems relies on resonance, then it can also be deterministic.