(quantum-mehcanics:history:origin-matrix-mechanics)=
# Origin of matrix mechanics

Experiences:

* Quantization in light-matter interaction:
   * 1900, Planck radiation law: $h$ as a mathematical trick to fit experimental data of black-body radiation; thermodynamics model followed 
   * 1905, Einstein work on photoelectric effect: $h$ is not a mathematical trick

* Light dispersion, as a light-matter interaction process:
   * 1900, Lorentz-Drude model for classical dispersion
   * 1913, Bohr atomic model
   * 1917, Einstein derived Planck law from thermodynamic equilibrium between atoms and radiation
   * 1914-24, Ladenburg work on quantization of dispersion law, matching Lorentz-Drude (classical model) and Bohr-Einstein (quantum model) in the classical limit

* Heisenberg matrix mechanics
   * ...
   * [Modern reinterpretation of Heisenberg mechanics](quantum-mechanics:history:heisenberg-reinterpretation)