THE PROTON-PROTON WALL BETWEEN 0.84 fm AND 0.21 fm

A recurring ambiguity in proton-radius language is that the experimentally reported rms electric charge radius near 0.84075 fm is often treated as if it were the single literal size of the proton. In the present OUXSPACE wall model the interpretation is two-scale: the compact mass-defined core is the reduced Compton scale R_c = hbar/(m_p c) = 0.210308910051 fm, while the observed collider-facing wall or visible onset is R_W = 4 R_c = 0.841235640204 fm, numerically close to the CODATA proton rms charge radius. The model explains the apparent standoff by placing proton-proton interaction in a six-dimensional Schrodinger-type equation over visible space plus TERRA SPACE internal coordinates. I/Z logic is introduced as a bounded operator split between an open/permeable channel I_W and an impedance/closure channel Z_W. The quartic wall law C_W = (R_W/r)^4 then yields C_W(R_c)=256, I_W(R_c)=1/257, and Z_W(R_c)=256/257, meaning that a visible probe reaches a hard response front long before it accesses the compact core. The result is not a denial of scattering data, but a reinterpretation: the 0.84 fm scale is a wall-onset/readout radius, while the 0.21 fm scale is the compact core radius. Within this framework reactions are feasible only through non-zero field-field operator matrix elements in the extended six-dimensional channel; literal point-particle penetration below the wall is neither required nor expected.