This paper presents a complete physical alternative to metric expansion. Instead of stretching spacetime, we show that redshift can be explained by informational decay of photons as they propagate through a vacuum containing a growing equilibrium field. The model is built from established thermodynamics (Landauer’s principle), radiative physics, and the verified behaviour of photons as carriers of energy and information. Using the Informational Luminosity Law (ILL), we derive the exponential decay relation 1 + z = e^λd, where λ ≈ H₀/c emerges naturally, not as a fitted parameter. This mechanism reproduces redshift, accelerated redshift, galaxy collisions, the CMB uniformity, the Hubble tension, and Tolman-test behaviour — without expanding space and without invoking dark energy, inflation, or exotic new physics. We provide observational consequences, thermodynamic derivations, and a suite of falsifiable predictions. Physicists, cosmologists, and researchers interested in the information-theoretic structure of the universe are warmly invited to examine, challenge, or validate the predictions. Independent verification of λ is the critical next step. All supporting works — including the Grand Synthesis and 13 foundational papers on the Diffusion of Information Hypothesis and Informational Cosmology — are available below.
Nathan et al. (2025) studied this question.