Current cosmological models (Lambda-CDM) are facing a systemic crisis driven by high-precision observational data. The statistical discrepancy in the Hubble Constant (H0) has reached 5-sigma significance, while JWST observations of high-redshift galaxies reveal luminosities incompatible with standard formation timelines. This paper presents a falsifiable alternative framework: the Primary Energy (PE) Theory. We postulate that the physical vacuum is not an empty geometry but a material, viscous, and dispersive medium with a characteristic impedance Z0 ≈ 377 Ohm. We introduce a fundamental viscosity coefficient η ≈ 0.14 (approx. 14%). This parameter is derived independently from laboratory calculations of magnetic saturation (B ≥ 20 T) and is shown to be scale-invariant. Key results: Unified Physics: The single parameter η ≈ 0.14 unifies micro- and macro-physics. It explains both the "freezing" of time in extreme magnetic fields and the cosmological redshift. Resolution of Hubble Tension: The theory resolves the H0 discrepancy via a Variable Speed of Light (VSL) mechanism due to vacuum viscosity, without requiring Dark Energy. The "Tired Light" Mechanism: Redshift (z) is reinterpreted as cumulative energy dissipation: Formula: z = exp[(1 - η) * H0 * D / c] - 1 This model accurately fits Type Ia Supernovae data and explains the high surface brightness of early galaxies (Tolman Test). Thermodynamics: The Cosmic Microwave Background (CMB, 2.7 K) is explained as the equilibrium temperature of the vacuum medium heated by dissipated starlight. Proposed Experiments for Falsification: The theory makes precise, testable predictions that distinguish it from Standard Model physics: The "Muon-20T" Test: A nonlinear increase in muon lifetime in magnetic fields B ≥ 20 Tesla due to local vacuum saturation. Gravitational Waves: Frequency-dependent arrival times for gravitational waves (dispersion) from distant mergers. This framework offers a causal, material description of the Universe, eliminating the need for hypothetical entities like Dark Energy and Dark Matter.