Voltaire and Frederick the Great mocked him; Catherine the Great of Russia employed him; Mathematicians revere him. His name was Leonhard Euler. The son of a Protestant minister, Euler was born on this day, April 15, 1707, in Basel, Switzerland.

Euler showed early promise in math, a promise that was amply fulfilled. Gathered together, his works fill sixty encyclopedia-size volumes! He was a founder of analysis and made major advances in arithmetic, geometry, trigonometry and calculus. His symbols are used to this day. The Euler constant, Euler numbers, Eulerian integrals and other mathematical forms are named for him.

Euler almost didn't make it into math. His father wanted him to be a minister. But Euler knew what he was best at and pleaded to be allowed to switch courses. His father finally agreed. Euler remained a staunch Calvinist all his life.

Catherine I invited the young man to Russia. She promised him a teaching job at the Academy of Sciences in St. Petersburg. But she died before the job was given to him and Euler's circumstances forced him to consider taking a position in the Russian navy. Fortunately the Academy came through and Euler's brilliance was not lost at sea. He married and had a family. Friends were astonished at the way he could produce high-caliber work with squirming children on his lap and shoulders.

Frederick the Great invited the now-renowned mathematician to
Prussia. But Frederick and Voltaire, both of whom hated Christianity,
mocked Euler for his "simple" beliefs. In spite of their nastiness,
Euler published *Letters to a German Princess,* a book combining
science and faith and written for his pupil, Frederick's niece.
Translated into seven languages, it was widely read throughout Europe.
Despite the luster that Euler lent to the Berlin Academy, Frederick
turned against him. Euler returned to Russia.

Disasters now stalked him. His house burned. Fortunately his papers were saved. His wife died. He had lost sight in one eye solving a problem in three days which most mathematicians expected to take a month. Now a cataract formed on his other eye. Surgery restored his sight, but both eyes became infected and he was in such excruciating pain that he said only his faith in God enabled him to bear it. When the infection cleared, he was totally blind.

Then, in one of the greatest achievements of all time, he solved some of the most difficult problems of all mathematics on the blackboard of his mind, dictating the solutions to friends. Euler remains one of the greatest geniuses mathematics has ever known.

Bibliography:

- Bell, E. T.
*Men of Mathematics.*New York: Simon and Schuster, 1937. - "Euler, Leonhard."
*Dictionary of Scientific Biography.*Edited by Charles Coulston Gillispie. New York: Scribners, 1970. - Graves, Dan.
*Scientists of Faith.*Grand Rapids, Michigan: Kregel, 1996. - Guillen, Michael.
*Bridges to Infinity; the human side of mathematics.*Los Angeles, California: Tarcher, 1983. - Kanigel, Robert.
*The Man Who Knew Infinity; a life of the genius Ramanujan.*New York: Washington Square, 1991; p. 205. - Newman, James R.
*The World of Mathematics.*New York: Simon and Schuster, 1956, especially volume 1, pp. 148ff and volume 1, pp. 573ff. - Russell, Bertrand.
*Wisdom of the West.*New York: Fawcett, 1964; p. 112. - Various encyclopedia articles.

Last updated May, 2007.