Template:POTD/2023-04-15

Leonhard Euler (15 April 1707 – 18 September 1783) was a Swiss mathematician, physicist, astronomer, geographer, logician and engineer. He founded the studies of graph theory and topology, and made pioneering and influential discoveries in many other branches of mathematics such as analytic number theory, complex analysis and infinitesimal calculus. Euler introduced much of modern mathematical notation and terminology, including the notion of a mathematical function. He is also known for his work in mechanics, fluid dynamics, optics, astronomy and music theory. This pastel-on-paper portrait of Euler was painted by the Swiss painter Jakob Emanuel Handmann in 1753, and is now in the collection of the Kunstmuseum Basel.Painting credit: Jakob Emanuel Handmann; image retouched by Bammesk