The Volumetric Pendulum

Standard cosmological models often struggle with absolute end-states, predicting either infinite expansion (Heat Death) or mathematical singularities (Big Crunch). The Volumetric Coupling Hypothesis (VCH) offers a physical, mechanical alternative. By treating space as a pressurized fluid (P_min) and mass as maximum-density droplets (P_max), this paper models the universe as a closed-loop thermodynamic pendulum. We introduce the Leads-Swap Theorem, demonstrating how the physical limits of fluid incompressibility and spatial surface tension force the dominant cosmological vector to swap mechanically between contraction (1/R^2) and expansion (1/R). Furthermore, this paper establishes a precise mechanical symmetry between the subatomic and macroscopic scales. We propose that the 1/137 fracture limit governing nuclear fission is mechanically identical to the macroscopic shattering of the primordial V_min state (the Big Bang). This unified framework provides a classical fluid-dynamic solution to the Cosmic Microwave Background (CMB) Horizon Problem without requiring unproven inflationary fields, presenting a complete, cyclical mechanics for universal oscillation.