IMS President Krzysztof (Chris) Burdzy, in conversation with Bernoulli Society President Adam Jakubowski

On September 8th, 2021, Krzysztof Burdzy became the President of the Institute of Mathematical Statistics (IMS). The next day Adam Jakubowski obtained the “Bernoulli Book” — the symbol of presidency of the Bernoulli Society for Mathematical Statistics and Probability (BS). Both presidents of the sister societies grew up in Poland and graduated from college in the 1970s, majoring in mathematics. Later, their career paths were completely different but each one was representative of a large segment of the Polish scientific community in their generation.

A.J.: What is the probability that the BS and IMS would have presidents of Polish origin at the same time?

K.B.: Your question gives me an opportunity for a shameless plug and for a display of Polish pride. I have published two books on the philosophical foundations of probability, titled The Search for Certainty and Resonance. According to the followers of de Finetti, symmetries in probability are subjective, so I am free to apply a symmetry in the form of equally likely events as follows. The current world population is about 7.7 billion and the current Polish population is about 38 million. Hence, the probability that the Presidents of BS and IMS would be Polish in 2021 was

(38 million / 7.7 billion)2 2.43548659 × 105.

According to the followers of von Mises, probability is equal to frequency. Out of 85 IMS Presidents preceding me, three were Polish: Jerzy Neyman, Bill Birnbaum and Mark Kac. Hence the probability of a Polish IMS President in 2021 was 3/85 0.03529. None of the 24 BS Presidents preceding Adam was Polish. It follows that the probability of a Polish BS President in 2021 was 0/24 = 0. The probability that both Presidents of BS and IMS would be Polish in 2021 was 0.03529 × 0 = 0. If you, the reader, do not like these probability calculations, please read my books on the philosophical foundations of probability.

A.J.: You applied the same method as Alexander the Great when he cut the Gordian knot. I would rather expect you to construct a suitable configuration space of paths representing our scientific lives and to calculate the probability of a coupling — the coincidence in time of our presidencies.

The calculation could be simplified by the fact that the model has a fixed point—I have been anchored at the Nicolaus Copernicus University in Toruń, Poland, for almost fifty years now (but with many international collaborations and professional travel). My attachment to Toruń was so unusual in the 1980s, when many Polish mathematicians emigrated, that when I was a Humboldt fellow in Göttingen, people used to ask me whether I was the last probabilist in Poland. I was not, of course, but the question illustrated well those times.

K.B.: Indeed, I went to college in Lublin, Poland, and then I successively jumped to Wrocław, Poland; Berkeley, California; San Diego, California; Lublin, Poland; West Lafayette, Indiana (the home of Purdue University); and finally Seattle, Washington. Polish mathematicians emigrated not only in the 1980s. A number of them emigrated between the two World Wars, despite the fact (or because of the fact?) that this period was the heyday of Polish mathematics. The former Polish IMS Presidents, Jerzy Neyman, Zygmunt William (Bill) Birnbaum and Mark Kac, obtained their PhD degrees in Poland. In this sense, they were Polish. They were also American, having spent most of their lives in the US, and the last two were Jewish. All three were born before Poland re-emerged in November 1918, after more than a century of partitions. The last two scientists obtained their doctoral degrees in Lwów, a city then in Poland, now in Ukraine. The lives of all three researchers illustrate well the turbulent events of the twentieth century.

A.J.: Our concurrent presidencies, an extremely improbable event, are best explained by a conspiracy theory. Our friend, Jerzy Zabczyk, a member of the Polish Academy of Sciences, pointed out that everything goes back to 1923. That year two papers were published in Fundamenta Mathematicae: Antoni Łomnicki’s “Nouveaux fondements du calcul des probabilités” and Hugo Steinhaus’s “Les probabilités dénombrables et leur rapport à la théorie de la mesure”. Both papers influenced the axiomatic approach to probability theory as presented in the seminal Kolmogorov’s short book Grundbegriffe der Wahrscheinlichkeitsrechnung. Moreover, Steinhaus was the PhD adviser of both Birnbaum and Kac (while Neyman’s adviser was Wacław Sierpiński at the Warsaw University). If you put these facts together, everything becomes clear!

Our random walk in the space of historical events has brought us to the early 1920s. That was an exciting period for probability theory. In 1922 the direct part of what is nowadays called the Lindeberg–Feller Central Limit Theorem was published. Lindeberg’s result was obtained by a new method that is still of interest. In 1924 Khintchine’s Law of the Iterated Logarithm appeared in (once again) Fundamenta Mathematicae. These are just two of many examples of fundamental developments in that golden age of probability theory.

I plan to make the preparation for the celebrations of centennials of the above milestones in probability theory one of the main undertakings of my presidency. In particular, I am going to encourage organizing conference sessions placing the above cornerstone results in a historical context.

What will be the goals of your presidency?

K.B.: I am afraid that my plans pale as mundane undertakings compared to your flirtation with grand historical events. The IMS faces a number of challenges of systemic nature. Among these are diversity, equity and inclusion issues; expanding our connection with various communities comprising “data science”; improving our appeal to junior researchers to enlarge our membership base; invigorating our outreach efforts via social media and other means; and reviewing our special lecture guidelines.

I have a feeling that we have somewhat different attitudes, styles and plans — this is good news. I hope to have regular conversations with you so that I can use your complementary ideas as an inspiration. Best wishes for your presidency!

A.J.: It was great talking to you. Best wishes!