ABSTRACT
Quantum theory changed all that. According to quantum theory, at the molecular, atomic, and subatomic levels, energy can be exchanged only in discrete amounts when a system moves from one state to another. e fact that conservation laws are satisfied is a necessary but not a sufficient condition for energy exchange and the change of a system. e fate of the system is not determined exactly if initial conditions and forces are known. One can only talk about the probability that the system will follow this development or that; or it will do something or nothing. us, with the introduction of quantum theory, the study of the physical world changed from “deterministic” to “probabilistic.”
