Addendum to: The General Theory of Universal Granular Field Dynamics (Cosmological Metric Expansion and the Temporal Acceleration of Light Velocity)

This addendum paper extends the core formulation of "The General Theory of Universal Granular Field Dynamics" (Cross-Reference DOI: 10.5281/zenodo.20576126) from localized laboratory engineering to a macro-cosmological scale. By incorporating Friedmann’s cosmic scale factor \bm{a(t)} into the dynamic granular field density equation, this work derives a non-static, time-dependent velocity of light \bm{c(t)}. The core thesis establishes that the continuous metric expansion of the universe naturally rarefies the underlying quantum spatial fabric, thereby minimizing medium resistance over cosmological epochs. Consequently, the speed of light is revealed not to be an eternal, absolute constant, but an accelerating temporal vector governed by the evolutionary state of the cosmic medium. The paper provides the comprehensive mathematical derivations defining this temporal acceleration (\bm{c(t) = c_0 \cdot a(t)^{1.5}}) and outlines the precise empirical and observational pathways required for verification, including highly redshifted quasar spectral analysis (variations in the fine-structure constant \bm{\alpha}) and long-baseline planetary laser ranging using optical atomic clocks.