Dedicated to the Pole. Stefan Banachone of the most important mathematicians of the 20th century, today Google doodles. On this day in 1922, the influential mathematician officially became a professor.

Stefan Banach was the founder of modern functional analysis and one of the first members of the Lwow School of Mathematics. His main work was Theorie des Operations Lineaires (Theory of Linear Operations) in 1932. This was the first monograph on the general theory of functional analysis.

According to our calculations, today #GoogleDoodle in honor of the mathematician Stefan Banach!

Learn more about why he is considered one of the most influential mathematicians of the 20th century → https://t.co/hYnUP3UZKB pic.twitter.com/QtHmxYb51e

— Google Doodles (@GoogleDoodles) July 21, 2022

He was born in Krakow in March 1892 and studied at the 4th Gymnasium, where he worked on mathematical problems with his friend Witold Vilkos. After graduating in 1910, he moved to Lviv (modern Lviv). However, during World War I he returned to Krakow where he befriended Hugo Steinhaus, who later called him his “greatest scientific discovery”.

Because of his poor eyesight, Banach was declared unfit for military service and taught in local schools during the First World War. After Banach solved some mathematical problems that Steinhaus found difficult, they published their first paper together.

In 1919, along with several other mathematicians, Banach organized a mathematical society. In 1920, he got a job as an assistant at the Polytechnic Institute in Lvov and soon became a professor at the Polytechnic Institute and a member of the Polish Academy of Sciences. He organized the Lvov School of Mathematics, and around 1929 began writing The Theory of Linear Operations.

After the outbreak of World War II, Banakh became dean of the Faculty of Physics and Mathematics at Lviv University. In 1941, when the Germans occupied Lvov, all higher educational institutions were closed to the Poles. As a result, Banach was forced to feed lice blood for a living at the Rudolf Weigl Institute for Typhoid and Virus Research.

Although the work carried the risk of contracting typhus, it protected him from being sent to forced labor in Germany and from other forms of repression. When the Soviets recaptured Lvov in 1944, Banach refounded the university. However, when the Soviets evicted the Poles from the former Polish territories annexed by the Soviet Union, Banach prepared to return to Krakow. Before he could do so, he died in August 1945, having been diagnosed with lung cancer seven months earlier.

Some of the famous mathematical concepts named after Banach include: Banach space, Banach algebra, Banach measure, Banach-Tarski paradox, Hahn-Banach theorem, Banach-Steinhaus theorem, Banach-Mazur game, Banach-Alaoglu theorem, and Banach fixed point . .

^{According to Wikipedia, Google.com}