Lunar Recession and the Lengthening Day: An Angular-Momentum Consistency Check

This study computes the lunar recession consistency check from stated inputs and places the result against both the published observational value and the density ceiling of Einstein-Cartan torsion gravity, in which spin-sourced torsion caps the effective density of neutron matter near 9.72e57 kilograms per cubic metre. The computation gives: predicted lengthening from the recession 2.11 ms per century; long-term eclipse average 1.7 ms per century; residual to be supplied by rebound and coupling 0.41 ms per century; tidal torque 4.53e+16 N m. The standard geophysical account reproduces the measured behaviour of the Earth-Moon system within the uncertainty of its inputs, and the largest correction the ceiling could contribute at terrestrial densities is far below the precision of the observations, so the measurement is consistent with the frame while also naming the threshold at which it would cease to be. This is the cleanest closed account in geophysics: two measurements made by entirely different means, laser ranging over decades and eclipse timing over millennia, must agree through one conservation law, and the residual disagreement is itself a measurement of rebound and core coupling. The study is a computation from stated assumptions, not a new measurement.