The Neutron Magnetic Moment from The Ultimate Relativity: A Proton-Electron Oscillator Model Grounded in Four Ontological Postulates

We derive the magnetic moment of the neutron from first principles within the four-postulate framework of The Ultimate Relativity. The neutron is modelled as a proton-electron bound system. The four postulates - Space, Pair, Time, and Measurement - directly resolve all three classical objections to this model: (i) the Space Postulate identifies the neutron as a single spatial restructuring of zero net charge, resolving the binding energy objection; (ii) the Pair Postulate assigns a superluminal shadow of opposite angular momentum to the orbiting electron, resolving the spin objection; and (iii) the Measurement Postulate requires every detection event to be a particle-shadow coincidence at the midpoint of their separation, which identifies the effective orbital radius as r_eff = lambda_C/2 = hbar/(2 m_e c), resolving the factor-of-two ambiguity in the magnetic moment. The resulting expression gives mu_n/mu_N = -1.913042, matching experiment to better than 1 part in 10^4. The result is obtained with no free parameters: the effective orbital radius is fixed by the Compton wavelength of the electron, not by fitting. We compare with the quark model, chiral perturbation theory, and lattice QCD, and discuss the implications.