A doctor’s son in Breslau
Max Born was born on December 11, 1882, in Breslau, then in Prussian Silesia and today Wrocław in Poland. His father, Gustav Born, was a professor of anatomy and embryology at the University of Breslau; his mother, Margarethe Kauffmann, came from a family of Silesian textile industrialists and loved music. She died in 1886, when Max was not yet four, and his father later remarried. The family was Jewish by descent but thoroughly assimilated into the educated German middle class, and religion played little part in the household.
Born grew up surrounded by his father’s scientific friends and by the music his mother’s family cherished; he played the piano well all his life. At school he was not an obvious prodigy, but at university he discovered a gift for mathematics and an ability to move freely between pure theory and physical intuition that would define his career.
Göttingen and the mathematicians
After studying in Breslau, with summer semesters in Heidelberg in 1902 and Zurich in 1903, Born arrived in 1904 at Göttingen, then the world capital of mathematics. There he worked with Felix Klein, David Hilbert and Hermann Minkowski, and served for a time as Hilbert’s assistant. He took his doctorate in 1906 under Carl Runge, with a prize-winning thesis on the stability of elastic wires and tapes, and qualified as a university lecturer in 1909.
Minkowski drew him into Einstein’s new theory of relativity, and in 1909 Born published work on the relativistic “rigid” electron, a concept still called Born rigidity. In 1912, with Theodore von Kármán, he laid the foundations of the dynamics of crystal lattices, explaining how the vibrations of atoms in a solid determine its heat capacity. That work grew into a lifelong study of crystals and, decades later, into the classic Dynamical Theory of Crystal Lattices, written with Kun Huang and published in 1954.
Marriage, baptism and war
On August 2, 1913, Born married Hedwig “Hedi” Ehrenberg, daughter of a Göttingen law professor. Her family, too, was of Jewish background on her father’s side, but her father had become a practising Lutheran. Born, who regarded religious professions and churches as of no importance, refused to convert before the wedding. In March 1914, however, he was baptised a Lutheran, partly in deference to his wife and partly to ease his place in German academic life. The couple had three children: Irene in 1914, Margarethe (“Gritli”) in 1915, and Gustav in 1921.
In 1915 Born took up a professorship in Berlin, partly to relieve Max Planck of teaching, and there began a close friendship with Albert Einstein that would last until Einstein’s death. During the First World War he did military scientific work, including on sound ranging for artillery. After the war he moved to Frankfurt in 1919, exchanging posts with Max von Laue, and studied the energy of crystals with the chemist Fritz Haber, leaving his name on the Born–Haber cycle that chemistry students still learn.
The making of quantum mechanics
In 1921 Born returned to Göttingen as director of its Institute of Theoretical Physics, and he arranged for his friend James Franck to lead experimental physics alongside him. Over the next twelve years he made Göttingen one of the three great centres, with Copenhagen and Munich, of the new atomic physics. His assistants included Wolfgang Pauli, Werner Heisenberg and Pascual Jordan; Enrico Fermi and Eugene Wigner worked with him; and his doctoral students included J. Robert Oppenheimer, Maria Goeppert Mayer and Max Delbrück. With Oppenheimer he published in 1927 the Born–Oppenheimer approximation, still the starting point for calculating the structure of molecules.
In July 1925 Heisenberg gave Born a paper proposing a strange new way of handling atomic quantities. Born recognized that Heisenberg’s arrays of numbers obeyed the rules of matrix algebra, and with Jordan, and then with Heisenberg and Jordan together, he set out the first complete form of quantum mechanics, matrix mechanics. It was Born who found its central law, the commutation relation between position and momentum, pq − qp = h/2πi.
A year later, in a paper on collisions published in 1926, Born proposed the interpretation that made Erwin Schrödinger’s rival wave mechanics usable: the wave function does not describe a smeared-out particle, but gives the probability of finding the particle at a given place. The Born rule, that probability is given by the square of the wave function’s magnitude, became the bridge between quantum theory and every measurement made with it. It also broke with strict determinism. Einstein never accepted it, and in a letter to Born in December 1926 wrote that he, at any rate, was convinced that God does not throw dice. Their decades-long argument, conducted with deep affection, was later published as The Born–Einstein Letters.
Dismissal in 1933
When the Nazis came to power in January 1933, Born’s Lutheran baptism counted for nothing: under the new racial laws he was a Jew. In April 1933 the regime’s law for the “restoration of the professional civil service” began driving Jewish scholars from German universities, and in May Born was one of six Jewish professors at Göttingen suspended from duty. Franck had already resigned in protest. Born took his family to the mountains of South Tyrol in Italy and never taught in Germany again. His Göttingen tenure was formally ended in 1935.
The blow was compounded by a scientific slight. The 1932 Nobel Prize in Physics, awarded in 1933, went to Heisenberg alone for the creation of quantum mechanics; Born and Jordan were not named. Heisenberg wrote to Born in November 1933 that he had a bad conscience about it, since the work had been done in Göttingen by the three of them together.
Refugee scholar: Cambridge, Bangalore, Edinburgh
Born was offered a temporary Stokes lectureship at Cambridge, where he worked from 1933 to 1935 and, with the Polish physicist Leopold Infeld, developed the Born–Infeld theory of the electromagnetic field. He then spent six months at the Indian Institute of Science in Bangalore at the invitation of C. V. Raman. In October 1936 he became Tait Professor of Natural Philosophy at the University of Edinburgh, where he remained until his retirement in the early 1950s.
In Edinburgh he built a school of theoretical physics largely staffed by refugees from Central Europe, and he and Hedi worked tirelessly to help other scholars escape Germany and Austria. He became a British subject on August 31, 1939, the day before Germany invaded Poland. One of his Edinburgh assistants was the German refugee Klaus Fuchs, who later worked on the British and American atomic projects and in 1950 was convicted in Britain of passing secrets to the Soviet Union. Born himself refused to take part in weapons research. He was elected a Fellow of the Royal Society in 1939 and received its Hughes Medal in 1950.
The Nobel Prize and a return to Germany
In 1954 Born shared the Nobel Prize in Physics with Walther Bothe, receiving his half “for his fundamental research in quantum mechanics, especially for his statistical interpretation of the wavefunction.” Recognition had come nearly three decades after the work, by which time his probability interpretation had become the standard way physicists everywhere used the theory.
That same year the Borns moved back to West Germany, settling in the spa town of Bad Pyrmont, not far from Göttingen. It was a controversial choice for a man the country had expelled, but Born felt he could help rebuild German science on democratic foundations. With Emil Wolf he completed Principles of Optics, published in 1959 and still a standard reference.
Conscience in the nuclear age
Born’s final years were devoted to warning against nuclear war. In 1955 he took the lead in organizing the Mainau Declaration, in which Nobel laureates gathered at Lindau warned of the dangers of nuclear weapons, and the same year he signed the Russell–Einstein Manifesto. In April 1957 he was one of the Göttingen Eighteen, the West German nuclear scientists, including Otto Hahn and Heisenberg, who publicly refused to take any part in building, testing or deploying nuclear weapons when Chancellor Konrad Adenauer’s government considered arming the Bundeswehr with them.
He wrote widely on philosophy and the responsibility of scientists, arguing that the certainty claimed by fanatics, in politics as in science, was more dangerous than doubt. His family life was rich: his son Gustav became a distinguished pharmacologist in Britain, and his granddaughter, Irene’s daughter, was the singer and actress Olivia Newton-John.
Death and legacy
Max Born died in hospital in Göttingen on January 5, 1970, aged 87. He is buried in the city’s Stadtfriedhof, near Planck, Hilbert, Nernst and von Laue, and his gravestone bears the equation he had found in 1925, pq − qp = h/2πi.
Born’s legacy runs through all of modern physics and chemistry. The Born rule is used whenever a physicist turns a wave function into a prediction; the Born–Oppenheimer approximation underlies computational chemistry; his lattice dynamics shaped solid-state physics. His Göttingen school trained a generation that built quantum mechanics, nuclear physics and molecular biology. As a Jewish-born German scientist thrown out of the university he had made famous, he rebuilt his life in Britain, helped others to escape, and then returned to the land that had expelled him to argue, until the end, that science carried a moral responsibility.
Sources & further reading
Max Born, Wikipedia · Max Born, MacTutor History of Mathematics, University of St Andrews · Max Born, physics (1882 to 1970), University of Göttingen · Göttingen Eighteen, Wikipedia · Max Born, Wikiquote · Researched from the sources above and checked against them. Spotted an error? Tell us.
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