The Mechanical Origin of Atomic Structure: Field Entrapment and the 0.69ns Nucleation Window

This paper introduces the Universal Shell Theory (UST), a unified mechanical framework that redefines the atom as a pressurized 3D vessel formed by the wrapping of primordial 2D energy fields. By analyzing the mass-energy discrepancy in neutron beta decay, we identify a specific 0.69 nanosecond nucleation window during the Big Bang where the 0.138% primordial pressure drop occurred. The framework provides mechanical resolutions to three major "glitches" in modern physics: The Neutron Lifetime Puzzle: Resolves the 9-second "beam vs. bottle" discrepancy through dynamic compressive pressure (The Kinetic Corset). The Hubble Tension: Reinterprets cosmic expansion as "Atom Softening"—a mechanical redshift caused by the decay of the primordial field over 13.8 billion years. The Matter Cliff: Defines the terminal limit of the Periodic Table at Element 118 (Oganesson) as the point where the vacuum's tensile strength is exceeded.