Apollonius of Perga

(c. 262 bc–c. 190 bc) Greek mathematician

Apollonius moved from his birthplace Perga (now in Turkey) to study in the Egyptian city of Alexandria, possibly under pupils of Euclid. Later he taught in Alexandria himself. One of the great Greek geometers, Apollonius's major work was in the study of conic sections and the only one of his many works to have survived is his eight-book work on this subject, the Conics. Apollonius's work on conics makes full use of the work of his predecessors, notably Euclid and Conon of Samos, but it is a great advance in terms of its thoroughness and systematic treatment. The Conics also contains a large number of important new theorems that are entirely Apollonius's creation. He was the first to define the parabola, hyperbola, and ellipse. In addition, he considered the general problem of finding normals from a given point to a given curve (i.e. lines at right angles to a tangent at a point on the curve).

Apart from the geometrical work that has survived, Apollonius is known to have contributed to optics – in particular to the study of the properties of mirrors of various shapes. This work, however, is now lost.