Spatial-Causal Geometry (SCG) Spatial-Causal Geometry (SCG)Spatial-Causal Geometry (SCG) is a unified geometric framework for physics developed by D. J. Hallman. It derives all physical law from a single physical substrate: the electromagnetic permittivity \(\varepsilon_0\) and permeability \(\mu_0\) of free space. Their product \(\varepsilon_0\mu_0 = 1/c^2\) is not a constant — it varies with gravitational potential, confirmed daily by GPS and established experimentally by Pound and Rebka in 1959. That variation is gravity. Everything else follows.
The framework has one field equation: $$\mathbf{a} = c^2\,\nabla\ln(\varepsilon_0\mu_0)$$ and one geometric invariant: $$\gamma_{\rm cause} = \frac{2}{\pi}\,E(-1) \approx 1.2160$$ the arc-to-closure ratio of any propagating oscillation in any c-constrained medium — as substrate-independent as \(\pi\). From these two quantities, derived without additional postulates: the proton-to-electron mass ratio, the Bohr radius, the neutron mass, the fine-structure constant, galactic rotation curves across 175 galaxies, gravitational lensing, and the physical origin of charge, spin, and matter dominance.
The Higgs field is \(\varepsilon_0\mu_0\). Maxwell had it in 1865.
Every result in this framework is a consequence of these five sentences.
D. J. Hallman is an independent researcher. All works are published open-access through Zenodo under a CC BY 4.0 license. Full publication list: Zenodo · ORCID 0009-0000-1710-3549 · Contact: SCG@azfn.com