Abstract: | Classical Schr?dinger and Dirac equations have been derived from Brownian motions of a particle, it has been shown that the classical Schr?dinger equation can be transformed to usual Schr?dinger Quantum equation on applying Heisenberg uncertainty principle between position and momentum while Dirac Quantum equation follows from it’s classical counter part on applying Heisenberg uncertainty principle between energy and time without applying any analytical continuation. |