On April 25, 1903, Soviet mathematician Andrey Nikolaevich Kolmogorov was born. He was one of the most important mathematicians of the 20th century, who advanced various scientific fields, among them probability theory, topology, intuitionistic logic, turbulence, classical mechanics, algorithmic information theory and computational complexity.
On March 3, 1845, German mathematician Georg Cantor, creator of the set theory was born Set Theory is considered the fundamental theory of mathematics. He also proved that the real numbers are "more numerous" than the natural numbers, which was quite shocking for his contemporaries that there should be different numbers of infinity.