Anything for Science : UNCERTAINTY: The Life and Science of Werner Heisenberg, <i> By David C. Cassidy (W. H. Freeman: $29.95; 669 pp.)</i>

<i> Kevles is a frequent contributor to Book Review</i>

Seven years after winning the Nobel Prize for elucidating the “uncertainty principle,” a basis for the new quantum mechanics, physicist Werner Heisenberg (1901-1976) was working night and day to provide Hitler with a nuclear chain reaction.

The question of why such a brilliant physicist--one of the giants responsible for the 20th-Century scientific revolution and a man who had worked and co-authored papers with Jewish colleagues--remained in Hitler’s Germany pervades “Uncertainty,” David Cassidy’s definitive biography of Heisenberg.

This is an important book. Cassidy has probed Heisenberg’s role during the Third Reich: how he came to it, and how he rationalized it afterward. For the role of the biographer, he tells us, is to bring together three lives: the subject, the author and the reader.

As a subject, Heisenberg fascinates, because of his scientific genius and because of the highly controversial issue of whether he actually helped Hitler’s nuclear effort or sabotaged it. While others have described Heisenberg’s science, Cassidy alone has sifted the record and brilliantly detailed Heisenberg’s actions.


The author was drawn to Heisenberg because his grandparents were victims of the Armenian genocide. He wanted, he says, to “comprehend the nature of genocide, dictatorship, and the hold of mass persuasion over people’s minds.”

This reviewer is especially concerned with the way some scientists rationalize their research, distinguishing their “responsibilities to science” from their civic roles. They see science as pure and transcendental, quite apart from the people who devise it.

Cassidy describes the political background of late-19th-Century Bavaria and the rapid rise of the Heisenberg family into the self-satisfied, but not altogether secure, academic elite. He also describes vividly and with great understanding the confusion that swept over Germany as World War I left it ostracized internationally and an abortive Marxist-Soviet coup in Munich created political chaos. The latter had a searing effect on 17-year-old Heisenberg, who helped put it down.

Though never a Nazi, Heisenberg was sympathetic to Nazi romanticism and its appeal to youth. Almost until his marriage in 1937, a youth group was the center of his social life.


All the while, he excelled at mathematics and physics with men many years his senior, such as Niels Bohr and Max Born. Yet he could not have ignored the political atmosphere around him. While a student in Munich, he was disappointed when Einstein declined to lecture there in 1923 because of threats from anti-Semitic students, and he was in Munich during Hitler’s abortive beer-house putsch in 1924.

Cassidy shows how Heisenberg separated political events entirely from the intellectual challenge of grasping the paradoxes of the new quantum mechanics. This new physics was in part an effort to explain the nature of the particles that make up the atom: to explain how light acts sometimes as waves and sometimes as particles. Cassidy cautions us that Heisenberg’s work is hard to understand without mathematics (it is hard even with mathematics).

Atomic particles do not follow the laws of Newtonian mechanics because they are perturbed by the very process of measurement. Thus we cannot exactly know an electron’s velocity and location. “The more precisely we determine the position,” Cassidy writes, “the more imprecise is the determination of velocity, and vice versa.” What we can do is calculate the probability of where a specific particle will be.

When Heisenberg received his doctorate at age 23, he had already done some of the work for which he would win the Nobel Prize. And he accomplished this feat during some of the most trying years in German history.


In hindsight, it is clear what he could have done to make a difference. As Cassidy describes Heisenberg’s decision to walk a narrow line as a physicist in the troubled ‘20s and ‘30s, he traces the series of moral compromises Heisenberg made to feed his academic and social ambitions, decisions that turned out to be a Faustian bargain.

Quantum mechanics is theoretical physics, and theory was anathema to the Nazis who won power in 1933. The Nazis called theory and mathematics “Jewish science,” and attacked Heisenberg as a “white Jew,” an Aryan with Jewish thoughts. His chief opponent was Philipp Lenard, another Nobel Laureate, and his defender was Hitler’s henchman, Heinrich Himmler (whose mother was a friend of Heisenberg’s mother). When he did not win the academic post he coveted at Munich, Heisenberg worked hard to validate his Aryan credentials.

While under fierce attack from scientific enemies and encouraged by emigres to live in the United States, Heisenberg clung to the belief that National Socialism was not all bad. As late as 1933 he wrote, “Much that is good is now being tried, one should recognize good intentions.”

Jewish physicists who could leave did, and so did non-Jews like Erwin Schrodinger, who left because of “poor working conditions.” But Heisenberg conferred with Max Planck, already an elder statesman in physics, and decided to remain and guard German science for the future, as if he could protect “Science” without protecting the human rights of scientists.


Cassidy tells us that at the outbreak of World War II, Heisenberg picnicked over the border in France and, gazing back into Germany, murmured that he could not abandon such a beautiful country. But four years later, at news of the Russian army’s approach, Heisenberg sent out feelers to see if he could still emigrate to the United States. He did not want to live in a Communist country, not even if it was Germany. What drew his loyalty in Germany was the comfort of his privileged social and professional position.

Although throughout the Hitler years, Heisenberg did not push anyone into harm’s way, he did little to help people in trouble. In Poland, as the populations of the Lodz and Warsaw ghettos were decimated, he did not raise his voice but went on working on Germany’s fission project.

During the war, Jewish physicist Samuel Goudsmit, who had emigrated to the United States from Holland, wrote Heisenberg to ask him to save his parents, who were en route to Auschwitz. When they met in 1945, Goudsmit, having lost his parents to the gas chambers, could only stare incredulously at his former friend. But in his obituary of Heisenberg 30 years later, Goudsmit noted, “He was one of the greatest physicists of our time . . . . In my opinion, he must be considered to have been in some respects a victim of the Nazi regime.”

Cassidy doesn’t quite agree, but he leaves the reader to judge. In the end, Heisenberg’s science is inspiring. His life is not. He was too much a man of his time and place, a man whose extraordinary gifts demanded he take a stand, where being ordinary and banal was simply not good enough.


BOOK MARK: For an excerpt from “Uncertainty,” see the Opinion section, Page 3.