Epoch 14: Harmonic 600-cell (candidate, HOLD)
This archived page is the exact-byte provenance snapshot for the Epoch 14 pilot lab. It is
not the live interactive experience -- that is served by the gallery single-page application
at /ecosystems/mathematics_v14.html via the discovered epoch package
epoch14-harmonic-600cell-r1. This static snapshot documents, in isolation, the
mathematics the live lab renders.
Mapping
The 600-cell's 120 vertices have coordinates in ℤ[φ], the ring of integer
combinations a + bφ where φ = (1 + √5) / 2 is the golden ratio. For
the k vertices whose 4D-to-3D perspective projection lies nearest the camera at
any instant, this lab computes a chosen coordinate function of each vertex and normalizes its
exact algebraic value into [1, 2) by repeated doubling/halving by powers of two.
The resulting ratio belongs to the finite family
{1, φ, φ², 2, 1/φ, ...} (each value taken modulo the same normalization), and is
sounded as a partial over a 110 Hz base using additive synthesis. Rotation drives
glide (a vertex's ratio glides only when its occupied rank among the k nearest
vertices changes between control ticks) and amplitude (nearer vertices sound louder, subject
to a -12 dBFS ceiling).
Determinism
sonicTable(seed, rotationAngles, time) is a pure function, exported from
gallery/src/sonic/sonic-table.mjs and mirrored bit-for-bit in
gallery/scripts/sonic_render.py (numpy only). The same inputs always produce the
same table and the same rendered PCM SHA-256, in both the browser's additive renderer and the
offline Python twin.
Citations
- 600-cell: https://en.wikipedia.org/wiki/600-cell
- Just intonation: https://en.wikipedia.org/wiki/Just_intonation