Pietro Cataldi

Pietro Cataldi (1548–1626), Italian mathematician. He taught in turn in Florence, Perugia and Bologna, devoting much of his life to teaching and writing mathematical works, more than thirty of which are attributed to him. His work covered several fields: he studied computing square roots using infinite series and made a significant contribution to the study of continued fractions, of which he was one of the earliest proponents in the European mathematical tradition. He also compiled astronomical tables, notably tables of sunrises in Bologna, reflecting an interest in practical astronomy. In geometry, he devoted himself to the study of geometric transformations and, following the efforts of many mathematicians before him, attempted to prove that Euclid's fifth postulate—the parallel postulate—is a logical consequence of the first four, thus anticipating developments that would lead to non-Euclidean geometries.