From Student to Professor

Inside the Church of Saint Roch when it was used as a
military hospital for the Prussian Army during the Franco-Prussian War.

During my process of completing Plücker’s Neue Geometrie des Raumes I met Alfred Clebsch, a fellow German mathematician. He who would be someone I would work together with in near time after University of Bonn. He is also the one that helped me develop my thesis for my doctorate degree after Plücker. I spent the years of 1869 and 1870 visiting Göttingen (where Clebsch was located), Berlin, and Paris. In addition to Clebsch, I became closely acquainted with Sophus Lie, who is a Norwegian mathematician. We met in Berlin and moved to Paris to study new findings in the mathematics there. However, the rising tensions between Prussia and France caused us to leave in July, 1870. In Germany, we refer to the war as 70/71 as it took place during those years. I felt the need to serve for my country and volunteered for the army. I did not serve in the frontlines, but instead in the medical corps. I was released early as I was infected with typhoid fever. But the war ended in January 1871 (with a German victory); only 6 months after it started. I am now thankful for my short time and position in the war, because it anything were different I might not have lived to become a professor.  

Shortly after the war and my recovery, I was appointed as a lecturer at Göttingen. Although, not a long-term position, this can be considered the start to my long life as a professor and mentor to my future students. My first full position as a professor happened when I was 23 years old at University of Erlangen in 1872. This was due in part of the tremendous support of my mentor, Clebsch.  Here, I developed the Erlangen program that uses group theory and projective geometry to characterize geometries which turned out to be one of my major achievements. This program ended all confusion between what is considered Euclidean geometry and what is considered non-Euclidean University. This was only the start to my contribution to mathematics.   

A portrait of me at Leipzig University. 

The University of Erlangen did not have many mathematics students. I strived to teach more pupils. Thus, I moved to Munich to teach at Technische Hochschule in 1875 and stayed until 1880. At this technical college, I had many more students studying mathematics and I dedicated myself to their understanding of mathematics. Most were engineers, as it was a technical college, but I also taught geometry classes for future teachers. (I should shortly mention that I married my wife, Anne Hegel, in 1875 as well.)

In 1880, I took a professor position at Leipzig University teaching geometry. My time spent here profoundly changed my life, as my health deteriorated in 1882 which followed with a spout of depression in the following two years. I was overworked and it was impossible for me to continue my work while teaching. It proved difficult to keep up with my research, my teachings, and my own learnings. I tried my best to keep up with new mathematics and to discover new things, but I fell behind during those years. I remember writing in my notes that, “My great productivity is entirely over”. Things would change for the better for me though.

I knew I needed a change, so I found my way back to Göttingen and accepted a position at the university in 1886. I would stay there until I retired in 1913. I accomplished many things during my final years as a professor, but wish to tell you about my accomplishments at another time. Please read my next posting to know more about my contributions to the mathematics community and my work done at the various points of my life.

References:

Chislenko, E and Tschinkel, Y. (2007). The Felix Klein Protocols. American Mathematics Society. Retrieved from https://www.ams.org/notices/200708/tx070800960p.pdf

Felix Klein. (2012). Famous-Mathematicians.com. Retrieved from http://www.famous-mathematicians.com/felix-klein/

Halstead, G. (1894). Biography: Professor Felix Klein. The American Mathematical Monthly. Retrieved from http://www.jstor.org/stable/2969034

O’Connor, J and Robertson, E. (2003). Felix Christian Klein. MacTutor History of Mathematics Archive. Retrieved from http://www-history.mcs.st-andrews.ac.uk/Biographies/Klein.html

Schubring, G. (2000). Felix Klein. The First Century of the Internet Commission Mathematical Instruction (1908-2008): History of ICMI. Retrieved from

http://www.icmihistory.unito.it/portrait/klein.php#bib

Pictures from 

McCallum, J. (2008). Military medicine. Santa Barbara, Calif.: ABC-CLIO, p.126.

Schubring, G. (2000). Felix Klein. The First Century of the Internet Commission Mathematical Instruction (1908-2008): History of ICMI.