Editing Openai/6897769e-4ee4-800f-aba5-69cca34f701c (section)

=== 1. Enormous numbers. The required pressure and tension are astronomically large compared with human scales. That’s expected: holding a single elementary charge together at femtometre radius against Coulomb repulsion needs extreme internal forces. Historically this is why classical models of charged particles required Poincaré stresses or new binding physics. ===
# Binding energy equals half the EM energy. The calculation naturally produces a splitting of total energy between the EM field and the mechanical surface energy, with the mechanical part exactly half when you take the thin-shell radius coming from equating UEM=Mc2U_{\rm EM}=Mc^2UEM=Mc2. That provides a clear geometric origin for the “half” factors in the simplified QAT picture.
# Poincaré stresses are necessary. The mechanical tension TTT is the phenomenological representation of whatever binding physics holds the shell (non-electromagnetic stresses, perhaps deeper quantum forces). Any realistic model must explain the origin of those stresses (QED self-energies, quantum vacuum effects, or new binding mechanisms). QAT’s surface manifold suggests a place where those stresses can live.
# Connection to gravity & mass. The tension energy EtensE_{\rm tens}Etens contributes to the surface stress-energy SabS_{ab}Sab. Via the Israel junction conditions (or in Newtonian limit via Poisson’s equation), this energy contributes to gravitational/inertial mass. In the simple toy model half the mass would be attributable to binding stress and half to EM field — interesting in the QAT picture where mass is an emergent boundary property.
# Quantum issues remain. This calculation is classical and illustrative. Quantum field theory (QED) changes the picture (renormalization of self-energy, electron structure at very short scales, spin). But the classical model shows how geometric and energetic bookkeeping can produce the half-radius and half-energy features you found appealing.