Leonhard Euler in Berlin (Q5920460)

In 1741 Euler followed the prestigious offer by Friedrich II, the new king of Prussia, to come from St. Petersburg to Berlin and help construct a new Royal Academy of Sciences. Euler was in Berlin 25 years and returned in 1766 to St. Petersburg. In the present paper first the two persons are characterized who were, without any doubt, most important to Euler's everyday life in Berlin: the king Friedrich II and the president of the academy Pierre-Louis Moreau de Maupertuis. The latter was not continuously present in Berlin; his stays were interrupted by long periods of absence. Thus Euler was in fact running the academy in all practical terms while formally he was only director of the mathematical class. Euler had 13 children but only his three sons Johann Albrecht (1734--1800), Karl Johann (1740--1790), and Christoph (1743--1808) survived him. Besides his nice house in Berlin, Euler owned an orchard and a farm in Lietzow (now Charlottenburg); on the farm his mother lived as a widow until her death. When Friedrich II called Euler to Berlin he probably did not know of his enormous energies extending to everything in his neighbourhood that offered possibilities for an effective treatment. Euler worked on a unification of the two societies (de Sciences, founded in 1700 by Leibniz, and de Belles Lettres) and was successful on 24 January 1744 when the new Académie Royale des Sciences et des Belles Lettres was founded in the Berliner Stadtschloss. Euler quickly built a sound basis for what was to become probably the most fruitful period of his life. Specially Euler's works in Practical mathematics are treated. In the paper there is the List of books which Euler has written or published while he was in Berlin, among them his ``analytic trilogy''. In Berlin he conceived his educational masterpiece, a collection of 234 letters to a German princess on questions of physics and philosophy. In the conclusion Euler is characterized as an exceptional human being and a singular scientist and mathematician, to be compared only to Archimedes, Newton, and Gauss.