In particular, when you say that knowledge of particles makes something colder, makes it possible to extract work, you’ve gone back to the ideal observer.
I think emphatically not! To extract work, you’ve got to be inside the system, extracting it.
If you take the perspective of a logically omniscient perfect observer outside the system, the notion of “entropy” is pretty much meaningless, as is “probability”—you never have to use statistical thermodynamics to model anything, you just use the deterministic precise wave equation.
In particular, when you say that knowledge of particles makes something colder, makes it possible to extract work, you’ve gone back to the ideal observer.
I think emphatically not! To extract work, you’ve got to be inside the system, extracting it.
If you take the perspective of a logically omniscient perfect observer outside the system, the notion of “entropy” is pretty much meaningless, as is “probability”—you never have to use statistical thermodynamics to model anything, you just use the deterministic precise wave equation.