Leonhard Euler (1707-1783)

Leonhard Euler was born in Basel, Switzerland, the son of a pastor. At age 13 his father sent him to the University at Basel to study theology, but Euler soon decided to devote himself tot the sciences. Besides theology he studied mathematics, medicine, astronomy, physics, and oriental languages. It is said that Euler could calculate as effortlessly as "men breath or eagles fly." One hundred years before Euler, Fermat conjectured that any number of the form 2^(2^n)+1 must be prime, and in fact it was known that for n from 1 to 4, the corresponding numbers in the sequence 5, 17, 257, and 65537. The fifth number, 4294967297 was also thought to be prime until Euler, with his phenomenal calculating ability, showed that it is the product of 641 X 6700417 and so is not prime. Euler published more than any other mathematician in history did. His collected works comprise 75 volumes. Although he was blind for the last 17 years of his life, he continued to work and publish. In his writings he popularized the use of the symbols for pi, e, and i. One of Euler's most lasting contributions is the development of complex numbers.