A cosmological basis for E = mc2

Abstract

The Universe has a gravitational horizon with a radius R-h = c/H coincident with that of the Hubble sphere. This surface separates null geodesics approaching us from those receding, and as free-falling observers within the Friedmann-Lemaitre-Robertson-Walker space-time, we see it retreating at proper speed c, giving rise to the eponymously named cosmological model R-h = ct. As of today, this cosmology has passed over 20 observational tests, often better than Lambda CDM. The gravitational radius R-h therefore appears to be highly relevant to cosmological theory, and in this paper we begin to explore its impact on fundamental physics. We calculate the binding energy of a mass m within the horizon and demonstrate that it is equal to mc(2). This energy is stored when the particle is at rest near the observer, transitioning to a purely kinetic form equal to the particle's escape energy when it approaches R-h. In other words, a particle's gravitational coupling to that portion of the Universe with which it is causally connected appears to be the origin of rest-mass energy.