Leonhard EulerLeonhard Euler, (born April 15, 1707, died Sept.
18, 1783), was the mostprolific mathematician in history. His 866 books and articles represent aboutone third of the entire body of research on mathematics, theoretical physics,and engineering mechanics published between 1726 and 1800. In pure mathematics,he integrated Leibniz’s differential calculus and Newton’s method of fluxionsinto mathematical analysis; refined the notion of a function; made common manymathematical notations, including e, i, the pi symbol, and the sigma symbol; andlaid the foundation for the theory of special functions, introducing the betaand gamma transcendal functions. He also worked on the origins of the calculusof variations, but withheld his work in deference to J. L.
Lagrange. He was apioneer in the field of topology and made number theory into a science, statingthe prime number theorem and the law of biquadratic reciprocity. In physics hearticulated Newtonian dynamics and laid the foundation of analytical mechanics,especially in his Theory of the Motions of Rigid Bodies (1765). Like his teacherJohann Bernoulli, he elaborated continuum mechanics, but he also set forth thekinetic theory of gases with the molecular model.
With Alexis Clairaut hestudied lunar theory. He also did fundamental research on elasticity, acoustics,the wave theory of light, and the hydromechanics of ships. Euler was born in Basel, Switzerland. His father, a pastor, wanted hisson to follow in his footsteps and sent him to the University of Basel toprepare for the ministry, but geometry soon became his favorite subject. Throughthe intercession of Bernoulli, Euler obtained his father’s consent to change hismajor to mathematics.
After failing to obtain a physics position at Basel in1726, he joined the St. Petersburg Academy of Science in 1727. When funds werewithheld from the academy, he served as a medical lieutenant in the Russian navyfrom 1727 to 1730. In St. Petersburg he boarded at the home of Bernoulli’s sonDaniel. He became professor of physics at the academy in 1730 and professor ofmathematics in 1733, when he married and left Bernoulli’s house.
His reputationgrew after the publication of many articles and his book Mechanica (1736-37),which extensively presented Newtonian dynamics in the form of mathematicalanalysis for the first time. In 1741, Euler joined the Berlin Academy of Science, where he remainedfor 25 years. In 1744 he became director of the academy’s mathematics section. During his stay in Berlin, he wrote over 200 articles, three books onmathematical analysis, and a scientific popularization, Letters to a Princess ofGermany (3 vols. , 1768-72). In 1755 he was elected a foreign member of the ParisAcademy of Science; during his career he received 12 of its prestigious biennialprizes.
In 1766, Euler returned to Russia, after Catherine the Great had madehim a generous offer. At the time, Euler had been having differences withFrederick the Great over academic freedom and other matters. Frederick wasgreatly angered at his departure and invited Lagrange to replace him. In Russia,Euler became almost entirely blind after a cataract operation, but was able tocontinue with his research and writing.
He had a phenomenal memory and was ableto dictate treatises on optics, algebra, and lunar motion. At his death in 1783,he left a vast backlog of articles. The St. Petersburg Academy continued topublish them for nearly 50 more years.
