After Born’s Habilitation in 1909, he settled in as a young academic at Göttingen as a Privatdozent. In Göttingen, Born stayed at a
boarding house run by Sister Annie at Dahlmannstarsse 17, known as El BoKaReBo The name was derived from the first letters of the last names of its boarders: “El” for Ella Philipson (a medical student), “Bo” for Born and Hans Bolza (a physics student), “Ka” for
Theodore von Kármán (a Privatdozent), and “Re” for Albrecht Renner (a medical student). A frequent visitor to the boarding house was
Paul Peter Ewald, a doctoral student of
Arnold Sommerfeld on loan to
David Hilbert at Göttingen as a special assistant for physics.
Richard Courant, a mathematician and Privatdozent, called these people the “in group.”
From 1915 to 1919, except for a period in the
German army, Born was extraordinarius professor of
theoretical physics at the
University of Berlin, where he formed a life-long friendship with
Albert Einstein. In 1919, he became ordinarius professor on the science faculty at the
University of Frankfurt am Main. While there, the
University of Göttingen was looking for a replacement for
Peter Debye, and the Philosophy Faculty had Born at the top of their list. In negotiating for the position with the education ministry, Born arranged for another chair at Göttingen and for his long-time friend and colleague
James Franck to fill it. In
1921, Born became ordinarius professor of theoretical physics and Director of the new Institute of Theoretical Physics at Göttingen. While there, he formulated the now-standard interpretation of the
probability density function for ψ*ψ in the
Schrödinger equation of
quantum mechanics, published in July 1926 and for which he was awarded the
Nobel Prize in Physics in 1954, some three decades later.
For the 12 years Born and Franck were at Göttingen, 1921 - 1933, Born had a collaborator with shared views on basic scientific concepts - a distinct advantage for teaching and his research on the developing quantum theory. The approach of close collaboration between theoretical physicists and experimental physicists was also shared by Born at Göttingen and
Arnold Sommerfeld at the
University of Munich, who was ordinarius professor of theoretical physics and Director of the Institute of Theoretical Physics - also a prime mover in the development of
quantum theory. Born and Sommerfeld not only shared their approach in using experimental physics to test and advance their theories, Sommerfeld, in
1922 when he was in the United States lecturing at the
University of Wisconsin-Madison, sent his student
Werner Heisenberg to be Born’s assistant. Heisenberg again returned to Göttingen in
1923 and completed his
Habilitation under Born in 1924 and became a
Privatdozent at Göttingen - the year before Heisenberg and Born published their first papers on
matrix mechanics.
In 1925, Born and
Werner Heisenberg formulated the matrix mechanics representation of quantum mechanics. On July 9, Heisenberg gave Born a paper to review and submit for publication. In the paper, Heisenberg formulated quantum theory avoiding the concrete but unobservable representations of electron orbits by using parameters such as transition probabilities for quantum jumps, which necessitated using two indexes corresponding to the initial and final states. When Born read the paper, he recognized the formulation as one which could be transcribed and extended to the systematic language of matrices, which he had learned from his study under Jakob Rosanes at
Breslau University. Born, with the help of his assistant and former student
Pascual Jordan, began immediately to make the transcription and extension, and they submitted their results for publication; the paper was received for publication just 60 days after Heisenberg’s paper. A follow-on paper was submitted for publication before the end of the year by all three authors. (A brief review of Born’s role in the development of the
matrix mechanics formulation of quantum mechanics along with a discussion of the key formula involving the non-commutivity of the probability amplitudes can be found in an article by Jeremy Bernstein. A detailed historical and technical account can be found in Mehra and Rechenberg’s book
The Historical Development of Quantum Theory. Volume 3. The Formulation of Matrix Mechanics and Its Modifications 1925–1926.)
Up until this time, matrices were seldom used by physicists; they were considered to belong to the realm of
pure mathematics. Gustav Mie had used them in a paper on electrodynamics in 1912 and Born had used them in his work on the lattices theory of crystals in 1921. While matrices were used in these cases, the algebra of matrices with their multiplication did not enter the picture as they did in the matrix formulation of quantum mechanics.
Born, however, had learned
matrix algebra from Rosanes, as already noted, but Born had also learned Hilbert’s theory of
integral equations and
quadratic forms for an infinite number of variables as was apparent from a citation by Born of Hilbert’s work
Grundzüge einer allgemeinen Theorie der Linearen Integralgleichungen published in 1912. Jordan, too was well equipped for the task. For a number of years, he had been an assistant to
Richard Courant at Göttingen in the preparation of Courant and
David Hilbert’s book
Methoden der mathematischen Physik I, which was published in
1924. This book, fortuitously, contained a great many of the mathematical tools necessary for the continued development of quantum mechanics. In 1926,
John von Neumann became assistant to
David Hilbert, and he would
coin the term Hilbert space to describe the algebra and analysis which were used in the development of quantum mechanics.
In 1928,
Albert Einstein nominated Heisenberg, Born, and Jordan for the
Nobel Prize in Physics, but it was not to be. The announcement of the Nobel Prize in Physics for
1932 was delayed until November
1933. It was at that time that it was announced Heisenberg had won the Prize for 1932 “for the creation of quantum mechanics, the application of which has,
inter alia, led to the discovery of the allotropic forms of hydrogen” and
Erwin Schrödinger and
Paul Adrien Maurice Dirac shared the 1933 Prize "for the discovery of new productive forms of atomic theory". One can rightly ask why Born was not awarded the Prize in 1932 along with Heisenberg – Bernstein gives some speculations on this matter. One of them is related to Jordan joining the
Nazi Party on May 1, 1933 and becoming a
Storm Trooper. Hence, Jordan’s Party affiliations and Jordan’s links to Born may have affected Born’s chance at the Prize at that time. Bernstein also notes that when Born won the Prize in 1954, Jordan was still alive, and the Prize was awarded for the statistical interpretation of quantum mechanics, attributable alone to Born.
Heisenberg’s reaction to Born for Heisenberg receiving the Prize for 1932 and to Born for Born receiving the Prize in 1954 are also instructive in evaluating whether Born should have shared the Prize with Heisenberg. On
November 25, 1933 Born received a letter from Heisenberg in which he said he had been delayed in writing due to a “bad conscience” that he alone had received the Prize “for work done in Göttingen in collaboration – you, Jordan and I.” Heisenberg went on to say that Born and Jordan’s contribution to quantum mechanics cannot be changed by “a wrong decision from the outside.” In 1954, Heisenberg wrote an article honoring
Max Planck for his insight in 1900. In the article, Heisenberg credited Born and Jordan for the final mathematical formulation of matrix mechanics and Heisenberg went on to stress how great their contributions were to quantum mechanics, which were not “adequately acknowledged in the public eye.”
Those who received their Ph.D. degrees under Born at Göttingen included
Max Delbrück, Walter Elsasser, Friedrich Hund, Pascual Jordan, Maria Goeppert-Mayer, Lothar Wolfgang Nordheim, Robert Oppenheimer, and
Victor Weisskopf. Born’s assistants at the University of Göttingen’s Institute for Theoretical Physics included
Enrico Fermi, Werner Heisenberg, Gerhard Herzberg, Friedrich Hund, Pascual Jordan, Wolfgang Pauli, Léon Rosenfeld, Edward Teller, and
Eugene Wigner. Walter Heitler became an assistant to Born in 1928 and under Born completed his
Habilitation in 1929. Born not only recognized talent to work with him, but he let his “superstars stretch past him.” His Ph.D. student Delbrück, and six of his assistants (Fermi, Heisenberg, Goeppert-Mayer, Herzberg, Pauli, Wigner) went on to win
Nobel Prizes.
In a letter to Born in 1926, Einstein made his famous remark regarding quantum mechanics, often paraphrased as "The Old One does not play dice."
In 1933 Born emigrated from Germany. He had strong and public pacifist opinions; moreover, though Born was a Lutheran, he was classified as a "Jew" by the
Nazi racial laws due to his ancestry, and was thus stripped of his professorship. He took up a position as Stokes Lecturer at the
University of Cambridge. From 1936 to 1953 he was Tait Professor of
Natural Philosophy at the
University of Edinburgh. He became a
British subject and a Fellow of the
Royal Society of London in 1939.
Born had a dislike for
nuclear weapons research, but he still acknowledged “it might be the only way out.” Much of the theoretical power behind the development of the first atomic bomb was due to many of those surrounding him at Göttingen and working on
atomic physics and quantum mechanics: three of his Ph.D. students (Maria Goeppert-Mayer, Oppenheimer and Weisskopf), three of his assistants (Fermi, Teller, and Wigner), the Director of the Second Institute for Experimental Physics (James Franck), and
David Hilbert’s assistant (
John von Neumann).
Max and Hedwig Born retired to
Bad Pyrmont (10 km south of
Hamelin (
Hameln)) in Germany, in 1954.
Born was one of the 11 signatories to the
Russell-Einstein Manifesto.
Born died in
Göttingen, Germany. He is buried there in the same cemetery as
Walther Nernst, Wilhelm Weber, Max von Laue, Max Planck, and
David Hilbert.
rss feed