Bohr's Measurement Obsession

Bohr predicting to Pauli the outcome of a spinning tippy top experiment. 

• Physics is not about how the world is, it is about what we can say about the world. (Niels Bohr)
• Everything we call real is made of things that cannot be regarded as real. (Bohr)
• If quantum mechanics hasn't profoundly shocked you, you haven't understood it yet. (Bohr)

Bohr as the Grandfather of the Copenhagen Interpretation CI of the theory of Quantum Mechanics QM together with Born and Heisenberg, was obsessed with the role of experimental measurement based on a conviction that the purpose of QM is to predict the outcome of experiments. This may seem a bit strange since what is the point of predicting the outcome of an experiment, when you anyway are going to preform the experiment and so learn the true outcome. Instead of learning anything about the outcome you could of course use the prediction to test the theory. If the prediction is wrong, the theory is wrong (or the experiment is not performed correctly). 

More generally one may say that the role of a theory is to allow prediction of actual events, not only those in the lab. Like the collapse of a bridge under too heavy load performing a finite element simulation of the action of the bridge. Or computational QM simulation of the folding of a protein from a DNA-sequence to find its action in the body by   

But to Bohr that was far into the future and so the focus was a laboratory setting preferably as simple as possible (but often as puzzling as possible), like the double-slit experiment. Then the act of measurement became paramount, and this is where quantum mechanics differed from classical mechanics, since the very act of observation could now influence the outcome by interaction instrument-observed phenomenon. In particular this came to expression by the probabilistic aspect of CI with a state prior to observation (Schrödinger's cat) supposedly being in a superposition of many possible states with the act of observation singling out one into actuality, referred to as "collapse of the wave function".  

So Bohr became obsessed with observation in experimental laboratory settings including interference from the observer, to be compared with computational simulation of a process like protein folding without interference from experimental measurement. Bohr would thus limit the role of QM to prediction of experiment outcomes, while the broader role of QM would be computational simulation of real processes without interference from observation during the simulation. This moves the focus from lab measurements with interference to computational simulation without measurement and interference. 

A main headache of CI is the idea of the state of an object prior to observation (is the cat dead or alive?) as undetermined until the observation, when somehow possibility is made into actuality. How can we be sure that the cat is neither dead nor alive prior to observation and only is decided to be either way at the moment of observation? Is it just like a dice prior to throw has the possibility of 1 to 6. This connects the question of "hidden variables" supposedly answered negatively by the Nobel Prize in Physics 2022. 

All the problems of the CI of QM originate in the multi-dimensionality of the wave function over configuration space arising because of a formal mathematical generalisation of Schrödinger's equation from one electron to many. Nothing says that this is the correct generalisation. Rather the opposite by being a too easy catch.