Janus Bolyai (December 15, 1802 - January 27, 1860) was a mathematician known for his work in non-Euclidean geometry. He was born in in a Translyvanian town of Klausenburg. He is the son of another well-known mathematician Farkas Bolyai.
By the time he was thirteen years old, he had mastered calculus and other forms of analytical mechanics. His father was the one who taught him. He studied at the Royal Engineering College in Vienna. He was so focussed on Euclid's parallel postulate, that his father wrote him letters begging him to forget about it. However, Janus persisted and finally came to an understanding that the postulate is independent of the other axioms of geometry and that different consistent geometries can be constructed on its negation.
