If, as is likely, while you are reading this article you endure the persistent heat wave, know that the prediction we have just made, with a good chance of being right, owes much to a pioneering Russian mathematician, Andrei Markov, who died on July 20, 1922 He defined the so-called Markov chains, or chains of probabilities of random events. In a few words, he put figures to the influence of the present on the future.
The mathematical milestone of this professor at the University of Saint Petersburg serves men of the time and epidemiologists of the 21st century. Remember the projections of the peak of the pandemic? Without Markov they could not have been done. But he was not interested in applications, but in poetry: he achieved his formula after analyzing Pushkin's poem Eugeny Onegin. Sciences and letters, more connected than it seems.
