Talk:Measurement problem

message: The current article has this paragraph:
* Bohr offered an interpretation that is independent of a subjective observer, or measurement, or collapse; instead, an "irreversible" or effectively irreversible process causes the decay of quantum coherence which imparts the classical behavior of "observation" or "measurement".
I believe this is incorrect. I believe this is actually (at most) Rosenfeld's rationalization, not something Bohr ever said. But I don't have access to the primary ref (Bohr collected works) @ReyHahn WDYT? Johnjbarton (talk) 22:35, 30 April 2024 (UTC)
replies: text: I got access to the book. The page referenced is a letter from Bohr to Pauli where Bohr discusses measurement. I will take a look, but I need a few days.--ReyHahn (talk) 00:02, 3 May 2024 (UTC)
thread_title:  Bohr paragraph with refs. 

message: I recently deleted an unsourced section on Schrodinger's annoying cat. Since then I have found references for the Cat in the context of the measurement problem:
* Peres, Asher. "Schrödinger's immortal cat." Foundations of physics 18.1 (1988): 57-76.
* Bell, John. "Against ‘measurement’." Physics world 3.8 (1990): 33.
* Schlosshauer, Maximilian. "Decoherence, the measurement problem, and interpretations of quantum mechanics." Reviews of Modern physics 76.4 (2005): 1267. "A book has never been observed to be in a state of being both “here” and “there” si.e., to be in a superposition of macroscopically distinguishable positions, nor does a Schrödinger cat that is a superposition of being alive and dead bear much resemblence to reality as we perceive it."
* Bub, Jeffrey. "Why the quantum?." Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 35.2 (2004): 241-266. "This is the measurement problem, or the problem of Schrodinger’s cat (where the cat plays the role of a macroscopic measuring instrument): it is impossible to extend the Hilbert space theory as a noncommutative mechanics to include the black box measuring instruments."
So there are plenty of refs to rebuild a section with that title. Johnjbarton (talk) 22:44, 1 May 2024 (UTC)
replies: text: I have no objection to your deleting that unsourced section.  But I think the article certainly should have a section on the thought experiment.  Whether or not there are any current physicists who believe that any of the interpretations could result in an alive/dead cat superposition, the experiment was historically used to discuss the measurement problem, is a great way of explaining wavefunction collapse to general readers, and today is constantly referenced in articles about the subject.  And of course today the question raised by the cat, whether a macroscopic object or system can be in a superposition, is no longer hypothetical, it has been shown to be possible.  The issue has extreme practical importance: that is what is required to create a quantum computer.  --ChetvornoTALK 19:01, 2 May 2024 (UTC)
replies: text: Thanks.  I will work on a Cat section. Johnjbarton (talk) 01:38, 3 May 2024 (UTC)
replies: text: Ok I put something back with refs. I will add more based on other refs shortly. Johnjbarton (talk) 19:59, 6 May 2024 (UTC)
replies: text: Looks great! --ChetvornoTALK 05:23, 8 May 2024 (UTC)
thread_title:  The cat