The central new result of this version is the geometric ratio cπ = α^ (61/10) / (4π A (4) ⁵) =1. 7734573703×10^-28 — the spacetime analogue of π, derived entirely from PA axioms. Justas π is forced by Euclidean circle geometry, cπ is forced by the 1+3 spacetime ℍ geometry andthe ℂ/ℍ Hurwitz boundary. It is identified concretely in the hydrogen atom as the ratio α/ (2π × d), where d is the diameter between the two antipodal electromagnetic vertices. The photoncrosses that diameter in exactly d Planck times at speed exactly 1. cπ is the completegeometric characterization of c. The value 299, 792, 458 m/s is its shadow in human units.
Mario Sorce (Sat,) studied this question.