Disease as setpoint drift: the quadratic basin-collapse law

Disease on this substrate is a defended setpoint, clock, or instrument failing. A loop-gain drop d shrinks the attractor barrier as (g²/4)(1−d)², a quadratic basin collapse, raising the Kramers crossing rate. Glaucoma, AMD, myopia, presbycusis, cataract, diabetic retinopathy, and BPPV each instantiate one failure mode. Shapes are verified; absolute rates are open.

A single derived law governs the major non-rare diseases of the sense organs: residual barrier = (g²/4)(1−d)² under a loop-gain drop d, so the barrier collapses quadratically (1.00 → 0.25 at d=0.5 → 0.01 at d=0.9) while the relative Kramers crossing rate rises monotonically. Presbycusis is the special case of the Hopf amplifier pushed off criticality, collapsing the F^(1/3) gain. Shapes are [V]; per-disease anchors are cited [L]; absolute incidence is [O] (needs the noise scale).

Disease here is not a separate machinery from health — it is the same R19 substrate failing in one of a few shapes: a defended setpoint drifts, a feedback loop loses gain, an attractor is crossed, or a physical instrument breaks. This is the same substrate as carcinogenesis, viewed through the sense organs.

Why the attractor barrier collapses quadratically

A loop-gain drop d leaves an effective gain g(1−d) and a residual attractor barrier (g²/4)(1−d)²; the escape rate follows Kramers' exp(−B/D). Because the barrier depends on the square of (1−d), a partial loss of feedback shrinks the protective barrier faster than linearly, so risk accelerates as control degrades.

Seven major diseases, one substrate

Each major non-rare disease of the eye and ear maps to a single failure mode of this law, with its anchor cited and its absolute rate left open: