This technical note presents a parameter‑free derivation of a minimal ultraviolet (UV) length scale within the BRane Interface Substrate Model (BRISM), achieved entirely without using the gravitational constant G. The only dimensional input is the experimentally measured proton Compton wavelength. All other elements follow from BRISM’s internal interface geometry, including the fixed structural scale epsilon = 1/pi², the two‑sided Naimark–Stinespring completeness, and the transverse projection pattern associated with the U(1) → SU(2) → SU(3) → SU(5) embedding.The resulting UV minimal length numerically matches the CODATA 2022 Planck length with 99.9998% accuracy, despite the complete absence of any gravitational assumptions. The result is therefore not a gravitational definition of the Planck scale but a structural emergence of a Planck‑scale UV cutoff implied by BRISM’s internal geometry and a single infrared input.All BRISM papers on Zenodo >> Searchlist
Swen Carlo Heinze (Tue,) studied this question.