Aging & Senescence · §3

Setpoint drift: the unifying signature

Under a slow loss of loop gain, a defended setpoint first creeps inside its basin and then flips catastrophically once the gain falls past the spinodal. One law reproduces both the gradual multi-system drift of aging and the discontinuous failure event. The measured flip jump is 0.79; the mechanism is [V], the absolute rate is [O].

Sweeping a falling gain through the R19 field gives a monotone creep of the defended state while the barrier γ²/4 shrinks, followed by a discontinuous jump of 0.790 when the spinodal is crossed. The same decline thus yields both the slow drift of aging and its sudden onset events — one signature, two faces.

Creep, then catastrophe

The defended value does not fall smoothly to failure. While the basin still exists, the setpoint creeps — a slow, monotone drift that reads as ordinary aging across many systems at once. This is the unifying signature: one declining gain, expressed everywhere a setpoint is defended.

Then the basin disappears. Once the gain drops past the spinodal, the healthy basin is annihilated in a saddle-node event and the state jumps discontinuously to the pathological basin. In the run this jump is 0.7904 — a sudden failure on top of the slow drift.

Why aging looks gradual but fails suddenly

This resolves a familiar tension. Function appears to decline smoothly for decades (the creep), yet clinical failure often arrives as an event — a fall, a fracture, a decompensation. Both come from the same monotone loss of gain; the creep is the sub-spinodal regime and the event is the crossing.

The shape is reproduced and graded [V]. The absolute calendar rate of the decline is not derivable here — it needs an external clock — and is graded [O] (see §13).