Janos Bolyai

Born: 15 December 1802
Dead: 27 January 1860
In: Târgu Mureș

Short description:

He was a Hungarian mathematician, one of the founders of non-Euclidean geometry — a geometry that differs from Euclidean geometry in its definition of parallel lines.
The discovery of a consistent alternative geometry that might correspond to the structure of the universe helped to free mathematicians to study abstract concepts irrespective of any possible connection with the physical world.

Wikipedia/other in-depth site