American Scientist

The End of the Certain World: The Life and Science of Max Born: The Nobel Physicist Who Ignited the Quantum Revolution. Nancy Thorndike Greenspan. x + 374 pp. Basic Books, 2005. $26.95.

The distinguished German and British theoretical physicist Max Born (1882-1970) was in the forefront of the two great revolutions in 20th-century physics—relativity theory and quantum mechanics. He was among the small number of mainly European theorists who created quantum mechanics during the 1920s. He contributed to the statistical, probabilistic, uncertain interpretation of quantum experiments known as the Copenhagen Interpretation. As the head of the Institute for Theoretical Physics at the University of Göttingen in Germany, Born helped to train a generation of the world's leading physicists, among them Werner Heisenberg, Wolfgang Pauli, Pascual Jordan, J. Robert Oppenheimer and Edward Teller.

Yet Born was among the last of those who led the quantum revolution to receive a Nobel Prize for his work; and he was, until now, among the last to receive the attention of a full-scale biography. Nancy Thorndike Greenspan has more than made up for that deficiency with The End of the Certain World: The Life and Science of Max Born. With the support of Born's family, Greenspan has drawn on Born's correspondence, his wife's diaries and a host of memoirs and secondary historical studies to provide an admirable, informative, highly readable account of this remarkable man and his extraordinary times.

The biography begins and ends with the Nobel Prize. Although Born did not, as the book's subtitle claims, "ignite the quantum revolution," he built the fire after Heisenberg provided the initial spark in 1925 with the discovery of a multiplication rule that Born recognized as matrix multiplication. Together with his assistants Jordan and Heisenberg, Born formulated the matrix version of quantum mechanics, which, when combined with Erwin Schrödinger's wave mechanics, provided the unified formalism of quantum mechanics. Born was the first to discover a fundamental component of quantum physics, the so-called commutation relation. He also formulated the statistical interpretation of Schrödinger's wave function, with the profound implications for causality and determinism so characteristic of quantum mechanics. "The motion of particles follows probability rules," he declared, "but the probability itself propagates in conformity with the law of causality." This view became a fundamental tenet of the successful Copenhagen Interpretation.

But the contributions of Born, who was shy and retiring, were soon forgotten, as Heisenberg and others eagerly promoted the new interpretation as an expression of the "Copenhagen spirit" cultivated by Niels Bohr. Reviewing the archival records, Greenspan found that Born did not receive strong support for a Nobel Prize. He was forced to watch in hurt dejection as the Nobel Committee awarded the 1932 and 1933 prizes to Heisenberg, Schrödinger and Paul Dirac for the creation of quantum mechanics. The oversight was finally corrected in 1954.

Born's darkening mood during the 1930s reflected the darkening world situation. It is here that "the end of the certain world" of the title finds its clearest expression (whether that was Greenspan's intention or not). It is especially in the personal life and tragic existence of this great man that this biography rises to heights of excellence. Although Greenspan's focus strays little from Born and his family, their story, pervaded by the same mood of sadness that pervaded their lives, is representative of countless others at that time.

Max Born was the son of a wealthy, highly cultured family of Jewish descent in the then-German city of Breslau. His mother died when Max was four, and his father, a physician and medical researcher, died when he was 17. An asthmatic, Max was physically and emotionally frail his entire life. His interests in mathematics and astronomy eventually brought him to Göttingen, a world center for mathematical research, where he discovered that his talent lay in the application of sophisticated mathematics to emerging problems in physics. He was among the first of a new generation of theoretical physicists.

With the advent of relativity theory, Born was the first to develop a relativistic theory of the rigid electron. The theory brought him into contact with Albert Einstein, first in 1909 and then again in Berlin during World War I. Born and his wife, Hedwig (Hedi), whom he married in 1912, remained close friends of the Einsteins. Their correspondence, frequently cited by Greenspan, is one of the treasures of 20th-century history.

By 1921, with Born head of theory and James Franck and Robert Pohl heads of experiment, Göttingen had become an important center for research in quantum physics. Under Born, intuitive young scientists such as Heisenberg, Pauli and Oppenheimer learned to apply mathematical rigor to atomic problems. Greenspan states repeatedly that this instruction was Born's greatest professional strength. Without that lesson from the master, the quantum revolution might well have arisen elsewhere.

But as quantum mechanics went on to success, Born grew ever more depressed, as was his inclination. He had good reasons: His family had lost its wealth to war and inflation, anti-Semitism was on the rise, and he was a target—even though, at Hedi's insistence, he had been baptized a Lutheran. And Hedi, as her diaries make clear, was carrying on a long-term affair, of which Born was aware, with a Göttingen mathematician, Gustav Herglotz. Matters grew worse on Hitler's rise to power. Born, now in his fifties, was eventually forced to resign his position. Göttingen revoked his doctorate, and the Reich revoked his citizenship.

Stateless and without an income, he found a temporary teaching position at the University of Cambridge. From there, he tried to help his students and others escape to safety. Amid all this, a miserable Hedi found it necessary to return periodically to Herglotz and Nazi-infested Göttingen for months at a time. Greenspan does not tell us how the frail Born managed to survive. But he did, eventually gaining British citizenship and a professorship in Edinburgh, one of only three permanent positions that went to German refugees in Britain during the 1930s.

Greenspan informs us that Born was disturbed to learn of British atomic-bomb research. He was not asked to join the work, and he counseled his brilliant former student Klaus Fuchs against such a step. Fuchs, of course, did join, becoming one of the most damaging Soviet spies of the era—another highly troubling event in Born's life. But Greenspan, after quoting Hedi's remark in her diary that she was upset about Fuchs, states only that "Max too was shaken."

Max was also shaken by the dropping of the atomic bombs on Japan. He worked tirelessly with Einstein, Bohr and other leading scientists for the control of nuclear energy and against what he saw as the perversion of noble science in the pursuit of hatred and destruction.

Born's attitude toward the Germans after the war was more ambivalent. After what the Nazis had done, including murdering some of his relatives, writes Greenspan, "he had a mountain of sorrow and anger to resolve." At first, he refused invitations to return to Germany, and his relations with Heisenberg and other German scientists remained cool. But Hedi insisted on returning—alone, if need be. Max finally relented. The promise of a German pension helped ease the decision. Despite Einstein's objections, Born became more forgiving of the German people. Hedi, now a Quaker, selected Bad Pyrmont, where German Quakers held their annual meeting, for their retirement.

Soon endowed with a Nobel Prize, Born continued for the next 27 years to work on quantum physics, prepare popular essays and oppose the use of science for weaponry. His life had come, at last, full circle. It is a powerful story, one that was repeated many times over (often with a less happy ending). It is well told by Nancy Thorndike Greenspan.