Quantum Physics

Abstract

As any physics theory, classical mechanics has its limits of applicability, and there exists a class of phenomena that it cannot explain. One such limit is the relativistic one: when the velocities involved in a phenomenon are close to the velocity of light, c (c= 2.997 924 58 · 10¹⁰ cm/s), it is necessary to make use of the theory of relativity. Another such limit is the quantum limit: when the actions involved in a phenomenon are of the order of magnitude of the Planck constant, h = 2πħ (ħ = 1.055·10⁻²⁷ erg · s), it is necessary to make use of quantum theory.