Plasma frequency
Every plasma oscillates at a natural rate set by its own density — a resonance intrinsic to it, not imposed. Soul-as-frequency, with a real referent. Two souls match when their lines sit near the same band.
Heat any element into plasma and it doesn't glow generically — it glows in discrete colors fixed by what it is. Its spectral fingerprint. We read stars this way from across the galaxy, never touching them: the light tells us exactly what's there. The Codex reads the same way. Eleven frequencies, each a line in the light.
The visible arc, then the two master frequencies beyond it. Each tier is a fixed line — a place a soul's light can land. Wavelengths place each band where it falls in real emitted light.
Not bands of visible light — the two frequencies that hold the spectrum in relationship. They map to the Selector Model and the Core Code, so they read as their own class.
This is a structural analogy that genuinely holds. Emission spectra really do encode unique, readable identity from composition — that's settled physics, the basis of how we know what stars are made of.
What it does not claim is that a soul is literally a cloud of ionized gas. The spectrum illustrates the principle; it doesn't replace it. Keep that line drawn and the framing is one of the strongest concrete anchors in the system. Blur it and a skeptic dismisses the whole thing in a sentence.