The rules that govern matter at small scales, and the century-long argument about what they mean.
12 topics · 16 curated works
No prior grounding assumed.
Nobel Lecture: The Wave Nature of the Electron
Louis de Broglie · 1929
Argues that matter, like light, has both a wave and a particle character, and that a definite wavelength should be associated with every moving…
+1 more at this level
Assumes you know the vocabulary.
The Scattering of α and β Particles by Matter and the Structure of the Atom
Ernest Rutherford · 1911
Derives the scattering formula for alpha particles off a concentrated positive charge and matches it against Geiger and Marsden's data, establishing…
+2 more at this level
Primary sources and full treatments.
Nobel Lecture: Exclusion Principle and Quantum Mechanics
Wolfgang Pauli · 1946
Traces the exclusion principle back to the two-valued, non-classical degree of freedom that would come to be called spin.
+10 more at this level
12 of 16 works
Louis de Broglie
Argues that matter, like light, has both a wave and a particle character, and that a definite wavelength should be associated with every moving electron.
20 pageslink checked 17 Sept 2026Notes on this copySixty Symbols
Has working physicists state plainly that the measurement problem is unresolved, and that the theory's predictive success has not settled what it says the world is like.
link checked 17 Sept 2026Notes on this copyErnest Rutherford
Derives the scattering formula for alpha particles off a concentrated positive charge and matches it against Geiger and Marsden's data, establishing that an atom has a small dense nucleus.
link checked 17 Sept 2026Erwin Schrödinger
Explains how treating de Broglie's matter waves as a genuine wave equation reproduces the discrete energy levels that quantum theory needed to explain.
14 pageslink checked 17 Sept 2026Notes on this copyCharles H. Bennett & Gilles Brassard
Proposes distributing a cryptographic key by encoding it in non-orthogonal quantum states, so that any eavesdropper's measurement necessarily disturbs the signal and reveals itself.
link checked 17 Sept 2026Wolfgang Pauli
Traces the exclusion principle back to the two-valued, non-classical degree of freedom that would come to be called spin.
13 pageslink checked 17 Sept 2026Tosio Kato
Gives the first mathematically rigorous proof that a quantum system changed slowly enough stays in its instantaneous eigenstate, putting the adiabatic approximation used throughout perturbation theory on firm ground.
Notes on this copyHugh Everett III
Argues that the wavefunction never collapses at all — every measurement outcome occurs, in a branch of the universal wavefunction relative to which the observer finds themselves.
24 pageslink checked 17 Sept 2026Notes on this copyJohn S. Bell
Derives an inequality that any theory of hidden local variables must satisfy, and shows quantum mechanics predicts its violation — making the EPR debate experimentally decidable.
6 pageslink checked 17 Sept 2026Notes on this copyRichard Feynman
Narrates how summing over every possible path a particle could take, weighted by the action, reproduces ordinary quantum mechanics and led to the diagrams that bear his name.
23 pageslink checked 17 Sept 2026J. E. Avron & A. Elgart
Proves the quantum adiabatic theorem holds even when the spectral gap the classical 1950 statement requires closes, extending Kato's rigorous result to systems with only a piecewise-differentiable spectral projection.
link checked 17 Sept 2026Notes on this copyWojciech H. Zurek
Argues that classical-looking outcomes emerge from quantum mechanics through the environment continuously monitoring a system, not through any new physical law at measurement.
50 pageslink checked 17 Sept 2026Notes on this copyThis subject genuinely sits in more than one domain. These fields approach the same ground with different methods.