Principle of Least Action - Quantum Mechanics
http://edu-observatory.org/olli/Action/Week2.html



   PHOTON PROPERTIES
  
  
  
   HEISENBERG'S UNCERTAINTY PRINCIPLE
  
    Heisenberg's Uncertainty Principle | Veritasium
      https://www.youtube.com/watch?v=a8FTr2qMutA  (4+ min)



   PHOTON EMISSION
  


   HYDROGEN SPECTRAL LINES (in the visible range)
  



   BLACKBODY SPECTRA
  



  SOMETHING STRANGE HAPPENS WHEN YOU TRUST QUANTUM MECHANICS | VERITASIUM
    https://www.youtube.com/watch?v=qJZ1Ez28C-A  (33 min)

    EULER-LAGRANGE-EQUATION
  


    WHY USE THE PRINCIPLE OF LEAST ACTION
  


    LAGRANGIANS FROM VARIOUS BRANCHES OF PHYSICS
  
  


   QUANTUM ACTION PRINCIPLE 
  

  EINSTEIN - PHOTOELECTRIC EFFECT
    Concerning an Heuristic Point of View Toward the Emission and 
    Transformation of Light
    einstein1905_photoeff.pdf


  FEYNMAM LECTURE - The Principle of Least Action
  https://www.feynmanlectures.caltech.edu/II_19.html

       




  BOOK RECOMMENDATION
  QED: The Strange Theory of Light and Matter by Richard P. Feynman
    https://www.barnesandnoble.com/w/qed-richard-p-feynman/1102510617
    https://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/0691125759

    Feynman's bestselling introduction to the mind-blowing
    physics of QED--presented with humor, not mathematics

    Celebrated for his brilliantly quirky insights into the
    physical world, Nobel laureate Richard Feynman also
    possessed an extraordinary talent for explaining difficult
    concepts to the public. In this extraordinary book, Feynman
    provides a lively and accessible introduction to QED, or
    quantum electrodynamics, an area of quantum field theory
    that describes the interactions of light with charged
    particles. Using everyday language, spatial concepts,
    visualizations, and his renowned Feynman diagrams instead
    of advanced mathematics, Feynman clearly and humorously
    communicates the substance and spirit of QED to the
    nonscientist.





  
  


 
    sam.wormley@icloud.com