AbstractWe propose that the universe operates as a single, continuous non-equilibriumenergy-processing system, where thermodynamic constraints on energy flow and in-formation transfer are conserved across scales—from ion-mediated biological systemsto stellar fusion and galactic structure. Within this “systems cosmology” framework,we hypothesize that the vacuum is not an empty void but a structured medium witha non-zero refractive index. This medium imposes a small but measurable geometricdrag on light propagation over cosmological distances.To test this hypothesis, we analyzed high-precision time-delay measurements fromfive strong gravitational lens systems (HE 0435-1223, RXJ 1131-1231, PG 1115+080,WFI 2033-4723, and DES J0408-5354). Standard general relativity attributes time-delay residuals to gravitational potential and geometric path differences under theassumption of a perfect vacuum (n = 1). Our analysis reveals a strong linear correlationbetween observed time delays and geometric path differences alone.We derive a global geometric drag constant, α ≈ −17.94 days/arcsec2, which fitsthe observational data with high statistical significance (> 40σ). This constant impliesa consistent “optical viscosity” inherent to the cosmic medium. If the vacuum istreated as a refractive medium (n > 1), observed high-redshift anomalies—such as theextreme pressures (109 K cm−3) reported in the Sunburst Arc—can be reinterpretedas volume illusions caused by refractive compression rather than intrinsic physicalextremes. These findings suggest that a portion of the “missing mass” attributed todark matter may represent unaccounted refractive latency within a structured vacuum.