Shear Cannot Be Outrun by Spin: The Constant Ratio of Anisotropy to Torsion Energy in a Contracting Bianchi I Universe

The numerical check confirms the analytic expectation: with the spin density chosen for equality at unit scale factor, the ratio of the spin term to the shear term equals unity at every sampled scale factor, from a = 1 down to a = 10^-6, and the script records the ratio as constant (True). The aligned spin number density required for equality at the reference epoch is 1.334e+29 per cubic metre, against a reference shear energy density of 8.300e-20 J/m^3. Set beside a present cosmic baryon number density of about 0.25 per cubic metre, the requirement exceeds the available baryonic spin carriers by a factor of 5.334e+29. No amount of subsequent contraction changes any of these figures, because numerator and denominator are multiplied by the same factor of a^-6 at every step. The study is a computation from stated assumptions, performed by the accompanying script; it is simulated, not measured.