The 0S2 Seismic Normal Mode as a Density-Profile Test of the Frame

This study computes the 0S2 spheroidal normal mode 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: model period 3291 s; model frequency 0.304 mHz; residual against the observed period 1.8 percent; elastic share of the restoring budget 66 percent; period shift permitted by the ceiling 9.33e-52 s. The standard geophysical account reproduces the measured behaviour of the free oscillations of the solid Earth 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. The mode period is a clean integral constraint on the density profile: it depends on the whole planet rather than on any single layer, so a ceiling that altered terrestrial densities by even one part in a thousand would move the period by an amount modern spectra would resolve, and no such displacement is present. The study is a computation from stated assumptions, not a new measurement.