A QUANTITATIVE FORMULATION OF NEWTON 1ST LAW

In this paper mass-energy equivalence is adopted as an intrinsic characteristic of the physical world via the definition of inertial energy. Examination of this definition together with Newton's second law in a completely classical context immediately leads to the mass-velocity dependence, considered up to now as a footprint of the special theory of relativity (STR). Furthermore, the concept of inertial energy leads to a quantitative formulation of Newton's first law as a principle of conservation of inertial energy. In the absence of net external forces (produced by the rest of the universe as in Mach's principle), Newton's first law simply states that inertial energy is unchanged. In the presence of net external forces, final inertial energy equals initial inertial energy plus the external work performed upon the body. The formulation of Newton's first law proposed here also contains a principle for the induction of inertial forces, thus accounting for centrifugal forces and avoiding criticism regarding noncompliance with the action- reaction principle of Newton's third law. This theory does not rely upon speed of light invariance or Lorentz transformations, which facilitates the design of empirical tests to distinguish it from STR; some possibilities are mentioned. An immediate consequence of the present formulation of the principle of inertia is a correction to the classical Newtonian theory of gravitation (described in a separate paper). The correction accounts for both the deflection of photons in gravitational fields and for the shift of Mercury's perihelion.