The Elastic Vacuum Revisited: Classical Foundations, Historical Vindication, and Open Problems in Vacuum Mechanics

Paper VIII in the Vacuum Mechanics series. Derives the fine-structure constant alpha = MK/(4pi) as a theorem of MacCullagh-Larmor elasticity theory, closing the foundational gap where Paper I postulated this relationship. Demonstrates that the hierarchy problem's seed (31.6x) follows from Green's compression-to-shear coupling ratio. Shows 137 is the unique integer consistent with four independent observables (alpha_s, m_H, M_Planck, dark matter ratio). Confirms topological stability of fermions (B=1, pi_3(S^3)=Z) and predicts all classical null experiments (Michelson-Morley, Lodge, Fresnel drag) quantitatively. Synthesizes contributions from MacCullagh, Green, Larmor, Lorentz, Fresnel, Kelvin, Stokes, Poincare, and Dirac, showing the 19th-century aether programme was abandoned for the wrong reasons. Includes honest accounting of 7 failures and 7 open problems. v2: Corrected constraint windows (Table 2-3), fixed "zero failures" claim to reference Section VIII's 7 documented failures, replaced Trouton-Noble with Fresnel drag in abstract, fixed "orders of magnitude" phrasing, corrected alpha_s/m_H/DM constraint ranges to match computation, removed draft artifact in Section I, qualified alpha derivation claim. No changes to results or conclusions.