Johann Carl Friedrich Gauss

Born in Brunswick, Gauss stunned teachers by summing integers 1‑100 aged 10. His *Disquisitiones Arithmeticae* (1801) founded modern number theory; he proved the constructibility of the 17‑gon, introduced modular arithmetic and quadratic reciprocity. As director of Göttingen Observatory, he predicted Ceres's orbit with least‑squares, pioneered Gaussian distribution and, with Weber, measured Earth's magnetic field, inventing the heliotrope for geodesy. Gauss worked privately on non‑Euclidean geometry yet published cautiously, epitomising rigorous proof.