Universe Expansion Is Not Eternal: Finite Heat Death and a Turning Point in 4.5 Billion Years — A Theory of Time Derived from the Spatial Autodynamicity Field Ψ (Independent Report)

Mainstream cosmology assumes dark energy is a cosmological constant, leading to eternal accelerated expansion and an everlasting heat death. Based on the SGCU framework, this paper proposes a radically different picture: dark energy originates from the dynamic potential of the spatial autodynamicity field Ψ and is currently decaying. Ψ is the sole intrinsic property of three‑dimensional space. We show: · Cosmic expansion will stop in a finite time. Fitting supernova and BAO data yields a decay index n = 1.8 ± 0.1 for the dark energy density ρ_DE ∝ a⁻²ⁿ. Consequently, expansion stops in about 40–60 billion years (best estimate 45 Gyr) and then turns into slow contraction. · Time is fully derived from the rate of change of Ψ. Physical time flow is proportional to Ψ̇; gravitational time dilation arises from the shielding of background evolution by a local strong Ψ gradient. · The heat death is only a finite transition – a “finite heat death” – after which the universe contracts, bounces, and starts a new cycle, not an eternal frozen state. This prediction is testable: if dark energy does not show significant decay within the next decade, the theory is falsified. Current DESI hints (a ~3.2σ deviation from w = −1) are qualitatively consistent with decaying dark energy.