James Clerk Maxwell published in 1861 his theory about electromagnetism which resulted in his famous set of equations describing mathematically plane waves and spherical waves. But it is impossible to describe with Maxwell's equations non plane waves like a Laser beam or the projection of an arbitrary slide on a screen. Only in "Quantum Light Theory" it is possible to describe (and solve) mathematically the propagation of a Laser beam or any other unique wave pattern like the projection of an arbitrary slide (or film) on a screen.
“Quantum Light Theory” has been based fully on Isaac Newton’s concepts and early ideas about beauty, harmony and equilibrium. The most important concept in QLT is his third law. “The law of Equilibrium”. Newton’s third law of Equilibrium has been extended in QLT into a 4-dimensional Equilibrium in which the Equilibrium in time (the fourth dimension) represents the fundamental relativistic quantum mechanical “Dirac Equation” which is a better presentation in quantum physics than the Earlier presented Schrödinger Equation which is only valid at relative low velocities.
4-Dimensional Equilibrium based on Newton's Third Law
The Propagation of Light is more complex than Maxwell's Equation can describe Introduction to Quantum Light Theory