Viazminsky, Caesar P
September 7, 2019
The equivalence of inertial frames as sites of one physical world implies that a system of intrinsic units of length, time, mass and charge should be defined in terms of basic constituent physical blocks that have the same identity in all inertial frames. It was shown in earlier papers that the consistency of the concept of time with motion in space requires time and distance to be of the same dimension, and thus measured by the same unit. The arising reduced system of units reveals that mass and energy are only different facets of one entity, and results in the well-known mass-energy equivalence formula as a natural consequence.