Chapter 17: The Calibration Triangle: Neutron →

Book IV established a single calibration anchor: the neutron mass m_n. From this one experimental input, the entire microphysical world was derived—electron mass, proton mass, coupling constants, dimensional units. But m_n lives in SI units, and the τ-framework is unit-free. The bridge between the unit-free τ-native quantities and the SI-measured world is a calibration pipeline. This chapter constructs the calibration triangle: a three-vertex diagram connecting the neutron (micro), the TOV limit (meso), and the minimal black hole (macro) through dimensionless ratios. The central result is that the calibration pipeline is internal to Category τ: no SI unit enters the structural relations. SI units are readout conventions—the τ-native calibration constant Ξ_τ is a well-defined ω-germ whose value is determined entirely by the axioms K0–K6 and the master constant ι_τ.