The Qi Medium Cosmological Model: A Testable Fluidodynamic Hypothesis for Redshift, Polarization, and Dark Matter

The standard ΛCDM model faces several unsolved fundamental problems, such as the nature of dark matter and dark energy, the fine-tuning of the cosmological constant, and inconsistencies with high-redshift observations. This paper proposes a self-consistent, testable scientific hypothesis based on a universal, massless, incompressible fluid medium named Qi. In this framework, light is treated as a transverse wave perturbation in the Qi medium; cosmic redshift is attributed to viscous damping by Qi vortices; polarization is explained by the collective helicity of vortex clusters; and galactic rotation curves are explained by large-scale stationary vortex shells. The model reproduces mainstream cosmological observations without introducing dark matter or dark energy and provides four falsifiable predictions for next-generation observational facilities. This hypothesis represents a unified fluid-dynamic approach to fundamental physics and cosmology.