Leonhard Euler stands as the most prolific mathematician in history, producing enough work to fill libraries. The Swiss genius revolutionized almost every branch of mathematics, from geometry to calculus, often while balancing a child on his knee. He standardized the symbols we use today and solved puzzles that had baffled the greatest minds for centuries. Furthermore, he continued to revolutionize science even after he went completely blind. Prepare to calculate the impossible with the man who saw the world in numbers.
Leonard Euler
He wrote more mathematics than any other human in history. His collected works fill over eighty large volumes. He produced papers so quickly that the St. Petersburg Academy continued to publish his work for nearly fifty years after he died.
Leonard Euler went blind but became even more productive. After losing sight in his right eye early in life, he eventually developed cataracts in his left eye, leading to total darkness. Remarkably, he dictated his formulas to scribes and produced roughly one paper every week during his blind years.
He invented the puzzle that became Sudoku. He created “Latin Squares,” a grid system where numbers appear only once in each row and column. Centuries later, puzzle makers adapted this concept into the game we play today.
He proved that you cannot cross the Seven Bridges of Königsberg. The city featured seven bridges connecting two islands, and locals wondered if they could cross every bridge exactly once without backtracking. Euler proved it impossible mathematically, birthing the field of Graph Theory in the process.
Leonard Euler standardized the notation we use for math today. He popularized the Greek letter $\pi$ for the ratio of a circle’s circumference, $i$ for imaginary units, and $\Sigma$ for summations. Without him, our math textbooks would look completely different.
He possessed a photographic memory. He could recite Virgil’s entire epic poem, The Aeneid, word for word. He could even tell you which line started and ended every page of the edition he owned.
Leonard Euler famously solved the “Basel Problem” when he was just twenty-eight. Leading mathematicians had struggled for decades to find the exact sum of the reciprocals of the squares. Euler shocked the world by proving the answer involved $\pi$, connecting infinite series to geometry in a way no one expected.
Frederick the Great called him a “mathematical Cyclops.” When Euler served in the Berlin Academy, the King mocked his visual impairment. Despite the royal bullying, Euler continued to churn out brilliant work for the Prussian court.
He discovered the “most beautiful equation in mathematics.” Euler’s Identity, $e^{i\pi} + 1 = 0$, combines five of the most important constants in math into one simple formula. Physicist Richard Feynman called it “the most remarkable formula in mathematics.”
He worked comfortably with children playing around his feet. Unlike many geniuses who demanded total silence, Euler famously composed complex theorems while holding a baby and surrounded by his other children. He fathered thirteen children in total, though only five survived to adulthood.
He tried to use math to explain why music sounds good. He wrote a massive treatise attempting to turn music theory into a part of mathematics. Unfortunately, critics joked that the work was too musical for mathematicians and too mathematical for musicians.
His last words were “I die.” On the day of his death, he was discussing the newly discovered planet Uranus and playing with his grandson. Suddenly, he suffered a brain hemorrhage, stood up, and uttered his final statement before losing consciousness.
Leonard Euler has a number named after him. The constant $e$ (approximately 2.718) is known as Euler’s Number. It appears everywhere in nature, from population growth to compound interest, serving as the base of the natural logarithm.
He calculated the orbit of a comet in three days to win a bet. Astronomers expected the calculation to take months of work. Euler focused so intensely on the problem that the strain reportedly caused the fever that destroyed the sight in his right eye.
Finally, a French mathematician famously said, “Read Euler, read Euler, he is the master of us all.” Pierre-Simon Laplace advised all students to study Euler’s work because he had already laid the foundation for almost everything they would ever encounter.
