Sci.Physics.Foundations

That is the title of a recent short essay by David Mermin in the latest Physics Today magazine.

https://physicstoday.scitation.org/doi/ ... /PT.3.5027

I agree with him about that. I posted the following on Gill's Google group with the subject line, "LOL! Some day you guys will figure it out!",

But in the meantime, David Mermin says in a recent short Physics Today essay titled "There is no quantum measurement problem", "If a question is asked of the system -- called making a measurement -- then when the question is answered, the state changes discontinuously into a state that depends both on the state just before the question was asked and on the particular answer the system gives to that question."

I am assuming here that for an EPR-Bohm scenario, the system includes both A and B so a composite system. So, two measurements and two answers. What the heck would be the resulting state according to what Mermin says? Doesn't make sense for that scenario. After the two measurements, there is no state.

Suppose there is, instead of a cat inside Schrodinger's box notionally perfectly shielded from external environment, a high explosive charge. Instead of a radioactive source triggering breakage of a cyanide capsule, it triggers a detonator instead. So BOOM! At some prior indeterminable time, the perfectly sealed box and contents interacts abruptly with the wider environment, that earlier had zero knowledge of the goings on inside that box.

How does that scenario fit into the position that a fully isolated composite system containing it's own observer + observed, proceeds indefinitely in a deterministic Schrodinger eq'n way?

Must remember to double proof read before logging out! Here is a slightly reworded version of above post:

Suppose there is, instead of a cat inside Schrodinger's box notionally perfectly shielding contents from external environment, a high explosive charge. Instead of a radioactive source triggering breakage of a cyanide capsule, it triggers a detonator instead. So BOOM! At some prior indeterminable time, the perfectly sealing box and contents interacts abruptly with the wider environment, that earlier had zero knowledge of the goings on inside that box.

How does that scenario fit into the position that a fully isolated composite system containing it's own observer + observed, proceeds indefinitely in a deterministic Schrodinger eq'n way?

kev01 wrote: ↑Mon Jun 20, 2022 7:40 am Must remember to double proof read before logging out! Here is a slightly reworded version of above post:

Suppose there is, instead of a cat inside Schrodinger's box notionally perfectly shielding contents from external environment, a high explosive charge. Instead of a radioactive source triggering breakage of a cyanide capsule, it triggers a detonator instead. So BOOM! At some prior indeterminable time, the perfectly sealing box and contents interacts abruptly with the wider environment, that earlier had zero knowledge of the goings on inside that box.

How does that scenario fit into the position that a fully isolated composite system containing it's own observer + observed, proceeds indefinitely in a deterministic Schrodinger eq'n way?

What is the measurement being performed?
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FrediFizzx wrote: ↑Mon Jun 20, 2022 10:22 am What is the measurement being performed?.

https://en.wikipedia.org/wiki/Geiger_counter
First line uses word measure. So is not the Geiger counter (who's radioactive decay detection event triggers the detonator) counted as an observer?

kev01 wrote: ↑Mon Jun 20, 2022 8:42 pm

FrediFizzx wrote: ↑Mon Jun 20, 2022 10:22 am What is the measurement being performed?.

https://en.wikipedia.org/wiki/Geiger_counter
First line uses word measure. So is not the Geiger counter (who's radioactive decay detection event triggers the detonator) counted as an observer?

Sorry, it seems like a bunch of nonsense to me. I guess I am not getting what your point is.
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FrediFizzx wrote: ↑Tue Jun 21, 2022 7:17 am

kev01 wrote: ↑Mon Jun 20, 2022 8:42 pm

FrediFizzx wrote: ↑Mon Jun 20, 2022 10:22 am What is the measurement being performed?.

https://en.wikipedia.org/wiki/Geiger_counter
First line uses word measure. So is not the Geiger counter (who's radioactive decay detection event triggers the detonator) counted as an observer?

Sorry, it seems like a bunch of nonsense to me. I guess I am not getting what your point is.
.

Maybe I have misunderstood what Mermin was claiming under sub-heading "The quantum measurement problem" in the article you linked to and agreed with.
Forget it then.