Mercury's Perihelion Precession from a Radial Substrate Gradient

We present a substrate field model for the observed perihelion precession of Mercury, manifested as the 43 arc-seconds per century advance of its perihelion. In this framework, change is mediated by a finite background substrate whose locally supported Event Density (ED) is reduced by mass, producing a radially varying suppression field around the Sun. When Newtonian orbital dynamics are formulated within this non-uniform suppression field, the exponential response of suppression to the solar mass distribution generates an effective $1/r^3$ correction to the Newtonian force without introducing additional forces, adjustable parameters, or spacetime curvature. Using the Sun’s radial mass distribution, the model predicts a perihelion advance consistent with the observed value for Mercury, providing a dynamical explanation of the anomaly arising directly from the Sun-induced radial suppression gradient.