Philippe Emmanuel Le Corbeiller (January 11, 1891 – July 24, 1980) was a French-American electrical engineer, mathematician, physicist, and educator. After a career in France as an expert on the electronics of telecommunications, he became a professor of applied physics and general education at Harvard University. His most important scientific contributions were in the theory and applications of nonlinear systems, including self-oscillators. Career in France Son of author and politician Jean-Maurice Le Corbeiller and his wife Marguerite Dreux, Philippe entered the École Polytechnique in 1910, training there in engineering and the mathematical sciences. During World War I he served in the French Signal Corps, earning the croix de guerre and joining the staff of Marshal Ferdinand Foch. After the war, Le Corbeiller worked on telegraphy and radio systems. In 1926 he completed a doctorate in mathematics from the Sorbonne. His dissertation was on the arithmetic theory of Hermitian forms. Written under the supervision of Charles Émile Picard, Le Corbeiller's dissertation built upon the work of the then recently deceased Georges Humbert. From 1929 to 1939, Le Corbeiller served in the French ministry of communications (Ministère des Postes, Télégraphes et Téléphones) as a research engineer and taught at the École Supérieure d’Électricité (Supélec). From 1939 to 1941 he was technical and programming director of the French national broadcasting network (Radiodiffusion nationale). He also obtained a licence in philosophy from the Sorbonne in 1938. Move to Harvard Le Corbeiller and his family moved to the United States in 1941, fleeing the German occupation of France. Le Corbeiller spent the rest of World War II at Harvard University, teaching electronics to US Army and Navy personnel. After the war, he became a lecturer in applied physics at Harvard, and in 1949 he was promoted to professor of both applied physics and general education. Elected fellow of the American Academy of Arts and Sciences, the Acoustical Society of America, and the Econometric Society, Le Corbeiller was also a member of the American Physical Society and the American Association for the Advancement of Science. Scientific and educational work Le Corbeiller's research interests spanned several branches of pure and applied mathematics, as well as electromechanics, control theory, acoustics, and economics. He was a friend of Dutch physicist Balthasar van der Pol, whose work on the nonlinear theory of self-oscillating dynamical systems (see van der Pol oscillator and relaxation oscillator) Le Corbeiller extended and applied to problems