The Lesson of Quantum Theory

Graziano Cavallini, Marco Giliberti

Daniel M. Hausman

R. Michael Bokeno

Blind Review

The main philosophical lesson of holographic gravity is that spatiotemporal descriptions of a field theory may not be respected by observational reality. We apply this lesson to the correspondence principle, and then later justify the lesson (holographic correspondence) without necessitating such spatiotemporal deviations via the law of large numbers in statistics, applied to an average of n quantum measurements. Classical observables are considered to emerge as n approaches infinity. The averaging approach can be interpreted both as a generalization of Bohr's correspondence principle (large number limit) and Planck's correspondence principle (Planck's constant approaching zero). Holographic correspondence and the averaging approach are then re-analyzed in light of preceding works in the correspondence principle. A key consequential lesson is that we should not conflate the nature of fundamental theory observables with that of emergent theory observables, and once this confusion is avoided, the correspondence principle has a solid standing.

Hans Halvorson

I argue here that progress in understanding the lessons of quantum physics has been hindered by the tendency to cast Niels Bohr as a villain. Building on the work of Favrholdt, Faye, and Howard, I present a more accurate view of Bohr's proposal for the "epistemological lesson" of quantum physics. I then argue that several interpretive programs -- often presented as alternatives to Copenhagen -- are, after substantial conceptual work, arriving at a view that is notably similar to Bohr's. Using Maudlin’s formulation of the measurement problem as a foil, I argue that it relies on a notion of wave-function completeness that is inappropriate for a genuinely indeterministic theory, and one that Bohr consistently rejected. On Bohr's view, quantum theory permits concrete agents, situated within specific experimental contexts, to make objective descriptions, while refusing the demand for a single, context-free "description from nowhere".

Berthold‐Georg Englert