2I Foundations: The Geometric Origin of Dimensionless Constants

Abstract. From the single axiom I AM I — self-reference that closes — spatial dimension D = 3 emerges as the unique non-trivial solution to the Borwein-class threshold equation D(D+1) = 2·D!. The icosahedron, the maximal Platonic solid in three dimensions, then yields the dimensionless constants of physics from its integer counts. The fine structure constant α⁻¹ = e⁵ − 6√3 − 1 + 1/66 agrees with CODATA 2018 to seven significant figures — four icosahedral terms, no fitted coefficients, full experimental precision reached in [2]. The Euler–Mascheroni constant γ derives from the same scaffold to 66 digits, and the glass transition threshold 1/41 = 2.439% emerges from the icosahedron's interior threshold V + E − 1…