Max Born

Max Born, a German-British theoretical physicist born on 11 December 1882 and dying on 5 January 1970, played a key role in shaping quantum mechanics. His work also advanced solid-state physics and optics, and during the 1920s and 1930s he oversaw the research of many prominent physicists. In 1954, he and Walther Bothe jointly received the Nobel Prize in Physics, awarded for Born’s fundamental quantum mechanics research, particularly his statistical interpretation of the wavefunction.

Born began his university studies in 1901 at the University of Breslau, later moving to Heidelberg and Zurich before arriving at the University of Göttingen in 1904. There, he encountered the mathematicians Felix Klein, David Hilbert, and Hermann Minkowski. His doctoral thesis, which won the university’s Philosophy Faculty Prize, examined the stability of elastic wires and tapes. In 1905, he started working with Minkowski on special relativity, then wrote his habilitation thesis on the Thomson model of the atom. A 1918 meeting in Berlin with Fritz Haber sparked a discussion about how a metal and a halogen form an ionic compound—this later became known as the Born–Haber cycle.

During World War I, Born initially served as a radio operator, but his expertise soon shifted him to sound-ranging research. Returning to Göttingen in 1921, he secured a second professorship there for his longtime colleague James Franck. Under Born’s leadership, Göttingen grew into a world-leading physics centre. In 1925, he and Werner Heisenberg created the matrix mechanics formulation of quantum mechanics. The next year, Born introduced the now-standard probability density interpretation of ψ*ψ in the Schrödinger equation, the work that earned him the 1954 Nobel Prize.

Born’s influence extended through his students and assistants. Those who earned their PhDs under him at Göttingen included Max Delbrück, Siegfried Flügge, Friedrich Hund, Pascual Jordan, Maria Goeppert Mayer, Lothar Nordheim, Robert Oppenheimer, and Victor Weisskopf. His assistants included Enrico Fermi, Werner Heisenberg, Gerhard Herzberg, Friedrich Hund, Wolfgang Pauli, Léon Rosenfeld, Edward Teller, and Eugene Wigner.

When the Nazi Party took power in Germany in January 1933, Born—born into a Jewish family—was suspended from his professorship at Göttingen. He emigrated to the United Kingdom, taking a position at St John’s College, Cambridge, where he wrote the popular science book *The Restless Universe* and the textbook *Atomic Physics*, which soon became standard. In October 1936, he became Tait Professor of Natural Philosophy at the University of Edinburgh. There, with German-born assistants Ernst Walter Kellermann and Klaus Fuchs, he continued his physics research. He became a naturalised British subject on 31 August 1939, one day before Germany invaded Poland and started World War II in Europe. Born remained in Edinburgh until 1952, then retired to Bad Pyrmont, West Germany. He died in a Göttingen hospital on 5 January 1970.

Born was born in Breslau (now Wrocław, Poland) on 11 December 1882, into a family of Jewish descent. He was one of two children of Gustav Jacob Born, a professor of embryology at the University of Breslau, and Margarethe Gretchen Kauffmann, who came from a Silesian industrialist family. His mother died when he was four, on 29 August 1886. He had a sister, Käthe (born 1884), and a half-brother, Wolfgang, from his father’s second marriage to Bertha Lipstein. Wolfgang later became an art history professor at City College of New York.

Born first attended the König-Wilhelm-Gymnasium in Breslau, then entered the University of Breslau in 1901. Because German universities allowed easy transfers, he spent summer semesters at Heidelberg in 1902 and Zurich in 1903. Fellow students Otto Toeplitz and Ernst Hellinger told him about Göttingen, and he went there in April 1904. There he found the mathematicians Klein, Hilbert, and Minkowski, quickly forming close ties with Hilbert and Minkowski. Hilbert, after Born’s first class, recognized his exceptional ability and chose him as lecture scribe—a role that put him in regular, valuable contact with Hilbert, who later became his mentor by appointing him as the first unpaid, semi-official assistant. Born’s stepmother Bertha, who knew Minkowski from dancing classes in Königsberg, introduced Born to him, leading to invitations to Sunday dinners at Minkowski’s home. Born also often saw Minkowski at Hilbert’s house while performing his scribe and assistant duties.

Born’s relationship with Klein was more difficult. In a seminar on elasticity run by Klein, Carl Runge, and Ludwig Prandtl, Born was required to present a paper. Though not keen on the topic, he presented one that used Hilbert’s calculus of variations to find the most stable configuration for a curved wire with both ends fixed. Impressed, Klein invited him to submit a thesis on the stability of elastica in a plane and space—a subject Klein favoured—which Klein had arranged as the topic for the university’s prestigious annual Philosophy Faculty Prize. Entries could also serve as doctoral dissertations. Born declined, since applied mathematics was not his preferred area.