A kinetic interpretation of <i>E</i> = <i>mc</i>²

The Special Theory of Relativity (STR) has equalized resting mass with energy, the latter being proportional to the squared speed of light ( c ) ( E = mc 2 ). This value exactly doubles the kinetic energy of a mass moving at c speed ( E = 1/2 mc 2 ). Therefore, E = mc 2 could be kinetically explained within the framework of a previously described, four-dimensional (4D) universe ( U 4D ) where the 3D space in which we live ( U 3D ) moves at c speed along its fourth dimension. We have shown that the counterintuitive effects on kinematics and dynamics of the STR can be explained as a misperception of the 4D reality when projected to U 3D . Based on this universe model, E = mc 2 could be interpreted as the sum of the kinetic energy associated with the mass, due to its displacement together with U 3D along the fourth dimension, plus the variation of the kinetic energy of U 3D itself when the mass is either annihilated or created, due to the principle of momentum conservation. This kinetic interpretation of E = mc 2 provides a new framework for our understanding of the Universe through a new-Newtonian perspective. Importantly, our results provide a way to experimentally test our universe model and, additionally, to estimate the mass present in U 3D .