Ferdinand von Lindemann

The German mathematician Carl Louis Ferdinand von Lindemann is celebrated for his proof that π is transcendental, that is, π is not a root of any polynomial with rational coefficients. In 1873, the year Lindemann was awarded his doctorate, Charles Hermite proved that e is transcendental. Using methods similar to those of Hermite, Lindemann showed in 1882 that π is transcendental. His proof was based on Hermite's proof that e is transcendental together with the fact, proved by Euler, that e^πi = -1.

The problem of squaring the circle, namely constructing a square with the same area as a given circle using only a straightedge and compass, is one of the classical problems of Greek geometry. Lambert had proved in 1761 that π is irrational, but this was not enough to prove the impossibility of squaring the circle with straightedge and compass because some irrational numbers can be so constructed. Lindemann's proof that π is transcendental finally established that squaring the circle with straightedge and compass is impossible.

Lindemann studied first at Göttingen, then at Erlangen (where he earned his doctorate in mathematics), and at Munich. He also visited universities in France and England. He became interested in physics as it concerned the idea of the electron. He was a professor at the Universities of Freiburg, Königsburg, and Munich.

Lindemann was one of the founders of the modern German educational system. He emphasized the development of the seminar and in his lectures communicated the latest research results. He also supervised forty-seven doctoral students, including the famous mathematicians David Hilbert and Hermann Minkowski.