Conceptual objections to the Bohr atomic theory — do electrons have a “free will” ?

Carl E. Behrens

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".

ROBERT K. NESBET

In 1926, Schrödinger [365] recognized that the variational theory of elliptical differential equations with fixed boundary conditions could produce a discrete eigenvalue spectrum in agreement with the energy levels of Bohr's model of the hydrogen atom. This conceptually startling amalgam of classical ideas of particle and field turned out to be correct. Within a few years, the new wave mechanics almost completely replaced the ad hoc quantization of classical mechanics that characterized the “old” quantum theory initiated by Bohr. Although the matrix mechanics of Heisenberg was soon shown to be logically equivalent, the variational wave theory became the standard basis of methodology in the physics of electrons. The nonrelativistic Schrödinger theory is readily extended to systems of N interacting electrons. The variational theory of finite N -electron systems (atoms and molecules) is presented here. In this context, several important theorems that follow from the variational formalism are also derived.

John Hendry

Henry Pierce Stapp

Jan Faye

I: Hoffding as Mentor.- I.- 1. Harald Hoffding, His Life and Thought.- 2. Hoffding and Bohr Senior.- II.- 1. The Ekliptika Circle.- 2. Bohr and William James.- 3. Bohr and Kierkegaard.- 4. The Student Bohr on Formal Logic.- III.- 1. The Friendship.- 2. The Years Around 1927.- 3. Hoffding on Complementarity.- IV.- 1. Hoffding's Theory of Knowledge.- 2. Totality as a Category.- 3. Hoffding's Philosophy of Mind and Psychology of Free Will.- 4. Hoffding on Biology.- 5. Analogy and Scientific Progress.- II: Bohr and the Atomic Description of Nature.- V.- 1. The Principle of Correspondence.- 2. The Search for an Interpretation.- VI.- 1. Complementarity.- 2. Quantum Mechanics and Psychology.- 3. Bohr on Biology.- VII.- 1. The Objectivity of Knowledge.- 2. The EPR Discussion.- 3. The Conditions for Description.- VIII.- 1. Bohr and Realism.- 2. Hoffding on Reality.- 3. Objective Anti-Realism.- Epilogue: The Legacy.- Notes.