obs_age_Gyr
plain-language theorem explainer
Observed age of the universe is fixed at 13.787 Gyr for SI comparisons. Cosmologists cite this when matching RS-native predictions to Planck data. The definition is a direct numerical assignment with no computation.
Claim. The observed age of the universe is defined by the constant value $13.787$ Gyr.
background
RS derives all physics in native units with $c = 1$, $ℓ_0 = 1$, $τ_0 = 1$. Comparison to observations requires a calibration seam that bridges to SI units via the Planck scale, where $ℓ_P = 1/√π$ in native units but the SI meter and second remain external experimental inputs. This module supplies the SI anchors and conversion formulas for cosmological observables.
proof idea
Direct definition that assigns the constant value 13.787.
why it matters
This definition supplies the observed age anchor inside the SI calibration seam of the Cosmology module. It lets RS-native predictions be expressed against Planck 2018 data without introducing axioms. The module documentation states the SI values are CODATA-sourced and not RS predictions; the theoretical content resides in the ratios.
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