Thermodynamic Gradient Cosmology – A Local Model for the Observed Expansion of the Universe (Second Edition)

The prevailing cosmological paradigm interprets the nearly linear redshift–distance relation of galaxies as evidence that the entire fabric of space has been expanding since an initial high-entropy event commonly referred to as the Big Bang. This paper advances an alternative view: the observed expansion is confined to the hot, energetically active domain that constitutes the observable universe, whereas remote, energy-poor regions beyond the photon horizon may remain static or contractive. The apparent Hubble flow is modeled as a consequence of local thermodynamic gradients. Zones of high temperature and energy density undergo metric dilation, while colder, nearly empty zones do not. This framework reinterprets cosmic expansion as a macroscopic thermodynamic process akin to heat diffusion, extended to astrophysical scales. It challenges the necessity of auxiliary constructs such as dark energy, the cosmological constant, or negative-mass antimatter, and outlines empirical signatures by which it can be tested. The universe, in this view, does not face an inevitable disintegration or "heat death"; instead, it self-regulates through expanding and contracting regions in pursuit of large-scale thermodynamic equilibrium.