Five identical-sized tissue populations sit side by side, one per age group, all exposed to the same claimed dose at the same time. Each population is a grid of instanced cells that divide continuously; every division is a chance for a radiation-induced mutation to be locked in and passed on. The only thing that differs between clusters is the age-dependent scaling factor applied to that shared dose — younger tissue divides faster and has far more remaining lifespan for a damaged cell to matter, so its effective damage rate (and the fraction of cells shown red) is visibly higher even though every cluster absorbed the identical dose.
damageRate(age) = base(D) × scale(age)
base(D) = k · D (k ≈ 5.5%/Sv, linear no-threshold)
scale(age) = exp(θ · (age − 30) / 10) (θ ≈ −0.3, BEIR VII-style)
- Claimed dose — the absorbed dose, identical across all five clusters; raising it speeds up damage accumulation everywhere at once.
- Highlight age group — outlines one cluster (infant, child, adolescent, adult, elderly) and reports its numbers in the panel; it does not change the simulation, only which cluster is measured.
- Cell colour — green cells are undamaged; a cell flips to red when a division roll lands inside its damage probability, then fades back over time as the tissue turns over — a stand-in for repair and replacement, not permanence.
- Division pulse rate — younger clusters visibly pulse and flip colour faster; this mirrors the higher division rate and higher damage probability of tissue with more remaining cell divisions ahead of it.
Real-world relevance: this is the mechanistic reason pediatric imaging protocols cap dose aggressively and why the same accidental exposure is treated as far more serious in an infant than in a retiree — not a different hazard, the same hazard scaled by how much biological future is exposed to it.