Absolute Time and Dynamic Cosmic Medium as an Alternative Foundation of Cosmology

This paper presents an alternative cosmological model based on the existence of absolute time and an immutable spatial container filled with a dynamic medium. In contrast to General Relativity (GR), which interprets gravity as the geometric curvature of spacetime, this model describes gravitational phenomena as the result of the interaction of matter and light with a gradient in the properties of this medium. A key postulate is universal braking: the medium affects all fundamental forces and physical processes identically. This explains the observed synchronization of diverse clock types (atomic, nuclear, mechanical) without invoking the concept of relative time. The paper demonstrates the model's mathematical equivalence to GR in classical tests (Mercury's perihelion, gravitational lensing, redshift) but proposes a distinct prediction for free-motion dynamics: the existence of measurable cosmic drag. As a crucial empirical test, we propose a re-analysis of data from the Pioneer and Voyager missions, which could confirm or refute the existence of this drag and, consequently, the medium itself.