Space Displacement Theory: A Mechanical Framework for Gravitational Acceleration, Refractive Lensing, and Non-Singular Stellar Collapse

Current gravitational paradigms rely on the geometry of an abstract four-dimensional spacetime continuum to describe gravitational acceleration. This paper proposes an alternative, purely mechanical framework: space is a foundational, physical medium characterized by zero baseline mass and zero viscosity. Rather than existing within a vacuum, baryonic matter interacts directly with this spatial medium as a physical lattice or "sieve". When macroscopic mass aggregates, the cumulative effect physically displaces the surrounding spatial medium, generating a localized 3D Spatial Density Gradient. This paper details the macroscopic, microscopic, and ultra-dense boundary mechanics of this model, offering intuitive physical mechanisms for gravitational lensing, frame dragging, the equivalence principle, and non-singular black hole event horizons while resolving the Vacuum Catastrophe and the Black Hole Information Paradox.