Stefan Banach A FAMOUS POLISH MATHEMATICIAN Krystyna Ceszkiel

Stefan Banach A FAMOUS POLISH MATHEMATICIAN Krystyna Ceszkiel Przemysław Mazur

Stefan Banach ªStefan Banach - one of the 20 th century's most important and influential mathematicians. Banach was one of the founders of modern functional analysis ªHe is considered to have been one of the three greatest Polish scientists along with Nicolaus Copernicus and Maria Skłodowska-Curie.

Stefan Banach ª He was born in March 30, 1892 in Krakow as the illegitimate child of Katherine Banach and Stefan Greczka (a servant and a soldier). He grew up in a foster family of a laundry owner – Franciszka Płowa and her daughter, Maria Puchalska. ª He was graduated from high school in 1910, with grade "mature", but apparently had serious problems to even be admitted to the baccalaureate. He almost got eight negative notes. Joint action of his maths teacher and a catechist saved him. The first one thought that Banach's a genius, the other probably wanted to get rid of him.

Stefan Banach ª He chose to study mechanics at the Lviv Technical University (Polytechnic), because he believed that mathematics has already reached a top level of development and there was virtually nothing you could discover in mathematics. After a few years, he came to the conclusion that he was mistaken. ª After graduation he worked in a bookstore in Cracow. At the same time he studied mathematics as a self-taught learner (autodidact). In Lviv he earned money by tutoring and as an extra in the opera. After four years he received the so called „half-diploma”. ª In 1914, when the World War I started, he wasn’t enlisted into the army. That was because he had poor eyesight and was left-handed. Instead, he worked as a supervisor for the construction of roads.

Stefan Banach ª He attended maths lectures at the university in Krakow. Once, when sitting on a bench in the Planty, he was talking to someone about the Lebesgue’s integration. Then Hugo Steinhaus showed up. It was him who got Banach a job as an assistant at the Technical University of Lviv. Among the duties of an assistant was also taking care of a newly born daughter of the professor. ª Banach did not care much about his work: he often worked in cafes writing in pencil on the tabletop. Only because a certain assistant noted all his mathematical statements and proofs, Banach’s work was published (in French): „Sur les opérations dans les ensembles abstraits et leur application aux équations intégrales” (On operations in the abstract sets and their application to integral equations); Fundamenta Mathematicae

Stefan Banach A few interesting facts: ª He had a "strong" head. ª He was a spendthrift. ª During the Second World War he was a lice feeder at the Institute for the Study of Typhus and Viruses of prof. Rudolf Weigl. That allowed him to get a document that effectively protected him from the repression of Nazi occupants. ª He died on August 31 st, 1945 in Lviv, of lung and bronchitis cancer: all his life he smoked like a chimney. ª Everything he did, he did with passion and „to the bottom”.

Stefan Banach Some concepts you may find in encyclopaedias and math textbooks: ª Banach space, ª Integral of Banach, ª Banach limit, ª Banach algebra, ª the Banach–Tarski paradox.

Hugo Steinhaus ª Hugo Steinhaus [1887 -1972] creator of Lviv and Wroclaw school of mathematics, creator of the department of applied mathematics, ª eminent popularizer of mathematics and aphorist, ª the discoverer of Stefan Banach’s talent (he used to say that Banach was his greatest mathematical discovery), ª Steinhaus used to say about Banach: „Geniusz – gen i już” (Genius – gene and that’s it) a cartoon of Steinhaus by Leon Jeśmanowicz

Bibliography ª Mariusz Urbanek „Genialni. Lwowska Szkoła Matematyczna” ª http: //pl. wikipedia. org/wiki/Stefan_Banach ª http: //kielich. amu. edu. pl/Stefan_Banach/mis 2. html

The Maths Tower of the University of Wrocław http: //muzeum. uni. wroc. pl/plan-zwiedzania/wieza-matematyczna/

The Maths Tower of the University of Wrocław ª Imperial Staircase leads to the Maths Tower, whose premises are today used as an exhibition space of University Museum. The observation deck gives visitors the opportunity to enjoy the panorama of the city. The tower was an Observatory founded in the late eighteenth century. It was opened in 1791 by Longinus Anton Lorenz Jungnitz, a professor of Wroclaw Leopoldina, an avid naturalist, physicist and astronomer. ª After adopting Mathematical Tower terrace for tourism this place became one of the favourite tourist places in Wroclaw. A beautiful panorama of the city stretches away from there. Not too much height (approx. 42 m) makes all visible objects, including church towers and modern skyscrapers, easy to identify. ª Given its astronomical function the name of the tower (the Mathematical Tower) may seem confusing. It bears this name because it was one of the three planned towers. There was the Bell Tower planned over the Imperial Gate, and the whole building had to be slightly longer in an eastern direction, and in that wing there was an Astronomical Tower planned.

The Institute of Mathematics, Univ. of Wrocław

Mathematical Wroclaw. Hedge maze in the Brochowski Park in Wrocław - the largest maze garden in Poland. (Photo courtesy of the company Agrobud-Wroclaw) source: http: //www. mmm. uni. wroc. pl/

Time for a brain teaser What a didelph! If a parrot costs € 21, a cat only € 12 and a crocodile € 30 then how much would a didelph cost? This exercise comes from MMM („Magazyn Miłośników Matematyki” – a mathematics enthusiasts magazine) published by Wrocławskie Wydawnictwo Oświatowe in 2004.