Aging & Senescence · §12
Pathology: sarcopenia, frailty, cancer
The major non-rare aging diseases follow one derived law: g_eff = γ(1−d) shrinks both the barrier (drift) and the spinodal (catastrophe). Sarcopenia is monotone setpoint drift, frailty is an accelerating co-failure of many setpoints, and aging-as-cancer is the convex crossing-hazard rise (135× from age 30 to 90). Rare/monogenic forms belong to disease_wp.
A single derived law — an age-related loop-gain drop d lowering effective γ — generates three failure shapes: sarcopenia (defended force-state drifts down monotonically), frailty (critical drops spread across setpoints give an accelerating co-failure transition), and the convex 135× rise in crossing hazard that is aging-as-cancer-risk.
One derived law
Disease here is the failure of a defended setpoint on the R19 substrate. An age-related loop-gain drop d lowers the effective gain to γ(1−d); this shrinks the barrier (so the setpoint drifts) and the spinodal (so a fixed stressor can flip it). All three major failures are read off this one law.
Sarcopenia — monotone drift
As gain falls, the defended force-state creeps down monotonically and the barrier fraction shrinks toward catastrophe. The shape is [V]; the absolute calendar rate is [O].
| gain drop d | defended state | drift | barrier frac |
|---|---|---|---|
| 0.0 | +1.1681 | +0.0000 | 1.000 |
| 0.1 | +1.1019 | +0.0661 | 0.810 |
| 0.2 | +1.0310 | +0.1370 | 0.640 |
| 0.3 | +0.9540 | +0.2140 | 0.490 |
| 0.4 | +0.8689 | +0.2992 | 0.360 |
| 0.5 | +0.7716 | +0.3964 | 0.250 |
| 0.6 | +0.6534 | +0.5146 | 0.160 |
Frailty and multimorbidity — accelerating co-failure
Many setpoints decline together, each with its own critical drop (here spanning 0.28 to 0.58 across six systems). As the shared drop rises, the fraction of failed setpoints climbs in an accelerating S-curve — the frailty transition — rather than linearly. The co-failure shape is [V]; absolute prevalence is [O].
Aging as the cancer risk multiplier
The crossing hazard rises convexly with age, a 135× increase from 30 to 90 in relative units, reproducing the steep oncology age-incidence slope (the seam of §7). The convex shape is [V]; the absolute incidence is [O].
Rare and monogenic accelerated-aging syndromes (progeroid disorders) are not modeled here; they are owned by the disease whitepaper and enter this layer only as a cited rate parameter.