This edition What has changed since 1999

The web edition retains the treatment in the 1999 thesis, with specific corrections and updated cross-references.

The order

In the thesis we started with Stern–Gerlach and the cascaded thought experiments to introduce the principles, following Feynman. The cascaded experiments, however, assume conditions such as coherent beam recombination that already require a theoretical interpretation. We therefore do not use them as proof of the principles.

We now start with the electron experiments and diffraction, performed in the laboratory. We assume the four principles stated in the introduction and derive the Schrödinger equation; diffraction allows us to determine the constant left undetermined. The Stern–Gerlach cards follow the derivation and illustrate the meaning of the principles.

The cards and notes

The diffraction card has been split into three: the experiment, the form of the evolution equation and the Hamiltonian. The Rutherford card has been split into two, separating the experiment from the scattering calculation.

The commutator proofs and the appendices to the scattering calculation have been moved to the notes, as has the calculation of hydrogen energy levels. The steps remain available in full, separate from the main treatment.

The new content

The card on complex numbers and state vectors, some explanatory notes and the simulated laboratories were added in 2026. The mathematical background precedes its use in the theory; the simulations allow the experimental conditions to be varied without replacing the original measurements.

The original 1999 order

To follow the order of the thesis, the current pages can be read in this sequence:

1. The Stern–Gerlach Experiment
2. Cascaded Stern–Gerlach Experiments
3. Experiments with Electrons
4. Electron Diffraction then the form of the equation and the Hamiltonian
5. The Rutherford Experiment then the scattering formula
6. Further Developments of the Theory
7. The Franck–Hertz Experiment
8. The Photoelectric Effect
9. Atomic Emission Spectra