Richard Courant

Richard Courant (8 January 1888 – 27 January 1972) was a German-American mathematician renowned for his foundational work in partial differential equations, the calculus of variations, and mathematical physics. Educated under David Hilbert at the University of Göttingen, where he earned his doctorate in 1910 on Dirichlet's principle, Courant became a professor there and founded the Mathematics Institute in 1922, fostering a vibrant research environment until his dismissal by the Nazi regime in 1933 due to his Jewish ancestry. Emigrating to the United States in 1934, he joined New York University, where he built a premier graduate program in mathematics and established the Institute of Mathematical Sciences in 1946, renamed the Courant Institute of Mathematical Sciences in 1964.

Courant's key achievements include co-authoring the seminal Methods of Mathematical Physics with Hilbert in 1924, which became a standard reference, and developing, with Kurt Otto Friedrichs and Hans Lewy, the Courant–Friedrichs–Lewy condition in 1928, a critical stability criterion for numerical methods solving partial differential equations. His early contributions to the finite element method and emphasis on variational methods and physical applications influenced computational mathematics and engineering. Additionally, he co-wrote What is Mathematics? with Herbert Robbins in 1941, an accessible introduction that bridged rigorous ideas with intuitive understanding, enhancing public appreciation of the field.

Richard Courant was born on January 8, 1888, in Lublinitz, a small town in the Prussian Province of Silesia (now Lubliniec, Poland), to a Jewish family. His father, Siegmund Courant, was a textile businessman whose ventures often faced financial difficulties, while his mother, Martha (née Freund), managed family resources during hardships, including selling personal jewelry to sustain them.

As the eldest of three sons—followed by brothers Fritz and Ernst—Courant grew up in a household marked by internal tensions, particularly over the extent of assimilation into broader German society despite the family's Jewish heritage. These dynamics coexisted with an emphasis on intellectual development, fostering an environment where education was prioritized amid economic instability.

Nerina and Richard had four children: Ernest David Courant (born 1920), a particle physicist known for contributions to accelerator design; Gertrude Courant Moser (1922–2014), a biologist; Hans Courant (born 1924); and a fourth child whose professional details are less documented in primary accounts. The family maintained Jewish cultural traditions, such as observance of holidays, despite Courant's largely secular academic environment and the family's relocations from Göttingen to Cambridge and eventually New York in 1934 to escape Nazi persecution.