Paper III: The Substrate Field and the Cyclic Universe: A Unified Cosmology

This paper develops a complete cosmological model based on the substrate field theory introduced in Paper I. The substrate field is a physical medium with rigidity K and effective density rho0 that determines the speed of light. Using optical data, we previously obtained rho0 ≈ 4. 4e3 kg/m³ and K ≈ 4. 0e20 Pa. In this model, the universe is not expanding but is currently in a collapse phase: all matter falls toward a central mass. The observed redshift is a combination of three independent effects: (1) dissipative attenuation of light in the substrate, giving zdiss = exp (beta r) - 1 with beta = H0/c; (2) Doppler shifts from intrinsic motions; and (3) a geometric projection term due to the infall velocity gradient, which depends on the angle to the cosmic center. This three-component decomposition resolves Olbers' paradox (the night sky is dark because light has a finite mean free path) and eliminates the need for dark energy. Galaxy rotation curves and gravitational lensing are explained by substrate density gradients, removing the need for dark matter. The universal dissipation coefficient alpha ~ 1e-20, estimated from lunar orbital decay, also governs angular momentum losses in other celestial systems. The cosmic microwave background dipole is interpreted as follows: its direction (toward Leo) points to the cosmic center, but the observed speed of 370 km/s is our velocity relative to the CMB radiation field, not necessarily our absolute velocity relative to the substrate. The cyclic universe (expansion-collapse cycles driven by central fracture) avoids heat death and resets entropy. The model makes testable predictions, including directional clustering of high-redshift objects, a redshift dipole, and an additional inward lunar drift. Part III of the Substrate Field Theory series