Birnbaum Zygmunt

Zygmunt Birnbaum - Personal data
Date of birth: 18th October 1903
Place of birth: Lwów
Date of death: 15th December 2000
Place of death:
Occupation: mathematician
Related towns: Lviv

Birnbaum Zygmunt (18 October 1903, Lviv – 15 December 2000, Washington) – mathematician, statistician, representative of the Lwów School of Mathematics.

Zygmunt Birnbaum's path to mathematics was a winding one. He was born on 18 October 1903 in Lviv in a family of entrepreneurs. He began his education in his hometown, but after the outbreak of the war in 1914, the family moved to Vienna. In 1918, the Birnbaum family returned to Lviv (Lwów during the Second Polish Republic)), where, in 1921, Zygmunt passed his secondary school leaving examination (“with distinction”) at the Henryk Sienkiewicz 10th High School.

He dreamed of mathematics, but the family decided that he would achieve more as a lawyer. After obtaining his high school diploma, he entered the Faculty of Law of the Jan Kazimierz University, and graduated in 1925. He even started an apprenticeship at his uncle's law firm, while studying mathematics at the same time. In 1929, he presented his doctoral dissertation (Steinhaus was the promoter) O jednoznacznie odwracalnych funkcjach analitycznych (On unequivocally reversible analytical functions). From that period Birnbaum remembered the discussions that took place during the frosty winter nights in the library room. Students and lecturers, with their backs next the stove's hot tiles, discussed mathematical problems without seeing each other. “Mathematics in this group of people fascinated by it was something of a fever” - he recalled. However, the poor family situation meant that he had to earn some extra money. As many before and after him, he taught mathematics in private schools and the Jan Kochanowski IX State High School in Lwów.

After obtaining his doctorate, he went to Göttingen, where he attended lectures by famous mathematical celebrities: Edmund Landau and Felix Bernstein. There he got interested in mathematical statistics and obtained actuary qualifications, using legal knowledge to calculate the probability of failure of particularly risky, long-term financial projects. He worked in Vienna at a large insurance company, Phoenix, earned a lot of money, but lacked contact with mathematics. So in 1932, when the opportunity came up, he became the representative of his company in Lwów (and on that occasion he also provided work to Ludwik Sternbach). “I took part in the life of the Scottish Café and seminars from time to time [...] the interest remained, but there was no time for research work”, he told Wojbor Woyczyński.

The company was declared bankrupt in 1937. Birnbaum left for New York, briefly worked as a correspondent for the Ilustrowany Kuryer Codzienny (Illustrated Daily Courier), then as a consultant and investment analyst, and finally became assistant of Bernstein who escaped from Europe from the oncoming Nazism. In 1939, he received a professorship at the University of Washington in Seattle (the reference letter was written by Albert Einstein himself). “At the University of Washington math department, statisticians and applied mathematicians were looked at as if they had dirt behind their fingernails. But we stubbornly developed a program of mathematical statistics, and in 1948 I founded the Statistical Research Laboratory, which for 25 years was financially supported by the naval research office” - he recalled.

For many years he cooperated with, among others the Boeing Advanced Research Center, testing the reliability of systems used in airplanes manufactured by the aviation company. He became the president of the international Institute of Mathematical Statistics, and for several years he also served as Editor of the Annals of Mathematical Statistic. But he was involved not only in science. He co-founded the first social insurance company in Washington state and fought against racial segregation.

In 1962, his book Introduction to Probability and Mathematical Statistics was published. It was translated into many languages.

In 1963 he came to Poland. In Zakopane, he met Steinhaus. "It was a very emotional rendezvous", he recalled. When he retired, Washington University's Department of Statistics began bestowing the Zygmunt Birnbaum award to the best PhD students continuing his research.

He died in Washington on 15 December 2000. Thanks to the bequest in the scholar's will, the award is still granted.


Mathematical concepts associated with the name of Zygmunt Birnbaum:

  • Birnbaum-Marshall inequality
  • Birnbaum-Orlicz space,
  • Birnbaum-Saunders distribution


Mariusz Urbanek


  • Woyczyński W. A.,Szukając Birnbauma, “Wiadomości Matematyczne" no 33 from 1997.


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