The Birthday of Hans Geiger (1882) — The Mathematics of Radioactive Decay

Hans Geiger co‑invented the Geiger counter, a device that detects ionising radiation. The mathematics behind it is the Poisson distribution — it counts rare, random events (radioactive decays) over a fixed time. Geiger worked with Ernest Rutherford and later discovered the Geiger‑Nuttall law, which relates decay constant to the energy of emitted alpha particles. Understanding radioactive decay required differential equations (dN/dt = –λN) and statistics — mathematics that now underpins nuclear medicine, carbon dating, and radiation safety.