"Haven't done anything..."

This one makes me think of Sy and Judith:

Art Hobson offers new insights on Schrödinger’s cat

Before returning to my discussion of Planck's discovery of the quantum of action via his analysis of black-body radiation, I would like to provide a couple of links to Art Hobson's recent writings about the quantum superposition problem. Hobson is an emeritus physics professor, or I should say a retired physics professor, at the University of Arkansas in Fayetteville.

Schrödinger’s cat is supposed to be one of the main themes of this blog, so, yeh, it's about time I got around to writing something about it again.  Hobson discusses and claims to resolve the paradox of the quantum superposition of the live and dead cat by using the concepts of entanglement and correlation.  Here is the abstract of his arXiv.org article titled Resolving Schrödinger’s Cat:

Schrodinger's famous cat has long been misunderstood. According to quantum theory and experiments with entangled systems, an entangled state such as the Schrodinger's cat state is neither a superposition of states of either subsystem nor a superposition of compound states of the composite system, but rather a nonlocal superposition of correlations between pairs of states of the two subsystems. The entangled post-measurement state that results from an ideal measurement is not paradoxical, but is merely a coherent superposition of two statistical correlations at "zero phase angle," i.e. at 100% positive correlation. Thus the state of the radioactive nucleus and Schrodinger's cat is as follows: an undecayed nucleus is 100% positively correlated with an alive cat, and (i.e. superposed with) a decayed nucleus is 100% positively correlated with a dead cat. The superposition consists merely in the fact that both correlations are simultaneously true. Despite many published statements to the contrary, this superposition is not paradoxical. It is in fact what one expects intuitively.

Actually, the concept of simultaneity is in there too!

Hobson also discusses The Cat Problem on the Oxford University Press website advertising his new book, Tales of the Quantum: Understanding Physics' Most Fundamental Theory.

Another new book with a different take on The Cat Problem and on quantum physics in general is Qbism: The Future of Quantum Physics, by Hans Christian von Baeyer.  He's one of my favorite physics book writers but I don't have a copy of this new book yet, so I'm reserving comment.  One fellow who has commented on the book already is Kelvin J. McQueen, who doesn't think Quantum Bayesianism (Qbism) as described by von Baeyer is on the right track to resolve the "notorious paradoxes of quantum theory."

Then there's the new book by Gerard 't Hooft, the main man in the renormalization business (Physics Nobel Prize shared with former adviser and buddy M. J. G. Veltman in 1999), called The Cellular Automaton Interpretation of Quantum Mechanics.

Yow!  So many new interpretations lately of quantum theory.  I'm still working on mine!

For a relevant discussion of the hardest thing to understand about quantum mechanics--which is also its most characteristic feature--see the History and the Concept sections of the Wikipedia article on entanglement.