Nikolas Lvanovich Lobachevsky (§¯§Ú§Ü§à§Ý§Ñ́§Û §ª§Ó§Ñ́§ß§à§Ó§Ú§é §­§à§Ò§Ñ§é§Ö́§Ó§ã§Ü§Ú§Û£¬ English Nikolas Lvanovich Lobachevsky) (December 1, 1792 - February 24, 1856) was a Russian mathematician and one of the early discoverers of non-Euclidean geometry.

Lobachevsky entered the University of Kazan in 1807, obtained a master's degree in physics and mathematics in 1811, and stayed there to work. He was appointed assistant professor in 1814, promoted to additional professor in 1816, and became permanent professor in 1822. From 1818, Lobachevsky began to hold administrative positions and was the first to be elected to the Kazan University School Committee. In 1822, he served as a member of the New School Building Engineering Committee and in 1825 was elected chairman of the committee. During this period, he also served as chairman of the Department of Physics and Mathematics twice (1820-1821, 1823-1825). Due to his outstanding achievements, in 1827, the University Committee elected him as President of Kazan University. After 1846, he served as deputy superintendent of the Kazan School District until his death.

When Lobachevsky tried to prove the axiom of parallelism, he found that all previous proofs could not escape the error of circular argument. Therefore, he made the assumption that an infinite number of straight lines could be made parallel to the known straight line through a point outside the line. If this assumption was denied, the axiom of parallelism was proved. However, not only did he fail to deny this proposition, but he used it to deduce with other propositions in Euclidean geometry that had nothing to do with the axiom of parallelism, resulting in a logically sound new geometric system - non-Euclidean geometry, which was later called Roche geometry.

The founding of Roche geometry played a huge role in the development of geometry and mathematics as a whole, but it did not attract much attention at first until 12 years after Lobachevsky's death. Lobachevsky also made some achievements in mathematical analysis and algebra.

Comments: I don't understand Euclidean geometry, but I respect non-Euclidean geometry