  The precession of Mercury's perihelion is reinspected by the principle of
least action. The anomalous advancement of the apside line that is customarily
accounted by the theory of general relativity, is ascribed to the gravitational
effect due to the entire Universe. When the least action is written in the
Sun's frame of reference, the residual rotation is seen to stem from inertia
due to all bodies in the Universe. Since mass corresponds to a bound form of
energy, gravity, as any other force, can be described as an energy density
difference between a system of bodies and its surrounding energy densities that
are dispersed throughout the Universe. According to the principle of least
action the Universe is expanding by combustion of mass to radiation in the
quest of equilibrating the bound forms of energy with "zero-density
surroundings" in least time. Keywords: cosmological principle; energy density;
energy dispersal; evolution; gravity; the principle of least action
