Andrey Nikolaevich Kolmogorov (Russian: Андре́й Никола́евич Колмого́ров) (April 25, 1903 - October 20, 1987) was a Soviet mathematician and computer scientist. He made major advances in the fields of probability theory and topology. Born in a Russian family in Tambov, he worked early in his career on intuitionistic logic, and Fourier series. He also worked on turbulence, classical mechanics, and information theory; and was a founder of algorithmic complexity theory which is often referred to as simply Kolmogorov complexity theory.