Euler’s Death

On 18 September 1783, Euler was enjoying a lunch with his family in St. Petersburg. After the lunch, Euler engaged in a discussion with his colleague and friend, Anders Johan Lexell, a Swedish mathematician and astronomer who had been a close collaborator of Euler’s at the St. Petersburg Academy of Sciences.
The topic of their conversation was the newly discovered planet Uranus, which had been observed for the first time by William Herschel in 1781. The discovery of Uranus was a significant event in the scientific community, as it expanded the known boundaries of the solar system and challenged prevailing theories about the formation and structure of the universe.
Lexell, who was deeply interested in celestial mechanics, had been working on calculating the orbit of Uranus based on the available observational data. It is likely that he and Euler were discussing the implications of this new discovery and the challenges of determining the precise path of this distant planet.
In the midst of this intellectually stimulating discussion, Euler suddenly collapsed. He had suffered a brain hemorrhage, a severe and often fatal condition caused by bleeding in the brain. Despite the best efforts of his family and colleagues to revive him, Euler passed away shortly thereafter.