Observational Bounds on Field Kinematic Viscosity: Bayesian Inference of Continuum Field Entropy from GWTC-3 and the High-Frequency Predictive Horizon

**Preprint | Continuum Field Entropy Empirical Validation Series** Standard cosmological models treat the vacuum as a frictionless, empty geometry. The Continuum Field Entropy (CFE) framework redefines the Primordial Field as a non-Newtonian Cosserat continuum, where gravity emerges as a symmetric transverse trace-free (quadrupole) deformation. By sourcing macroscopic geometric perturbations with the Effective Tension-Entropy Tensor (Tμνeff), the CFE framework incorporates irreversible entropy flux into the propagation of gravitational waves. A fundamental consequence of this radiation reaction is a third-order time derivative drag term (Zsymω³) that enforces frequency-dependent thermodynamic attenuation. To empirically bound the symmetric dynamic impedance (Zsym) of the relaxed modern vacuum, we developed a 64-bit JAX-accelerated Hamiltonian Monte Carlo engine to analyze 15 binary black hole mergers from the LIGO/Virgo GWTC-3 catalog. By natively fitting the CFE drag parameter against absolutely calibrated IMRPhenomD baselines, we demonstrate that for low-frequency (~ 100 Hz) macroscopic waves, Zsym evaluates to a half-Gaussian distribution bounded near zero. By extending this analysis to the GW170817 binary neutron star merger, we pushed the empirical macroscopic test into the kilohertz (~ 1000 Hz) regime, successfully confirming that the resulting thermodynamic attenuation remains entirely sub-dominant to instrumental noise even at elevated frequencies. Furthermore, we simulate high-frequency injections to establish a predictive detectability horizon for next-generation observatories like Cosmic Explorer and the Einstein Telescope, defining the "Cosserat Divide" where the microscopic antisymmetric tensor (light) fully triggers continuum vacuum drag. **Project Integration:**This document is a standalone validation report. The underlying universal field equations, foundational axioms, and the complete multi-disciplinary validation framework can be found in the primary master manuscript (DOI: 10.5281/zenodo.20631794).