Authors: Brian Van DeMark
Just as physics existed outside of political and moral concerns, physicists lived on a plane above the nation-state. They
eschewed politics; they shunned chauvinism and racism (though not, in many cases, sexism); they preferred cooperation and
collaboration. They were cosmopolitan. Language posed no barrier because facts and concepts were communicated by mathematics.
Steeped in a common culture of rationalism and humanism, they believed there was one supreme reward for their work: the sense
of sharing in the building of knowledge. From this idealism, physicists derived the belief that their true identity was not
as a member of a nation or a class but as scientific searchers speaking to other searchers. They believed physics could flourish
only in an atmosphere of openness and freedom.
The personal ties among physicists were extraordinarily warm and close. Indeed, they were attracted to the discipline in part
because each of them enjoyed being engaged in a collective enterprise. The community was small enough, and intimate enough,
that everyone knew everyone else. They all hungrily read the latest scientific journals, but they learned more from talking
among themselves, and when not together they communicated constantly by mail and telegram. A physicist could do his work in
any country; and when he published the results of his work, they were read all over the world.
It was a time of great opportunity and optimism for all of the sciences, but physicists sensed it was an especially fertile
moment and harbored grand expectations of discoveries to come. Nuclear physics, especially, was a beehive of exuberant creativity.
The powerful new theory of quantum mechanics, developed by Werner Heisenberg, Pascual Jordan, and Paul Dirac in the 1920s,
had given the structure and behavior of the atom a mathematical base. Excitement grew as physicists applied the analytical
force of quantum mechanics to a wide variety of physical problems. The theory was such a departure from approaches of the
past and shed so much new light that it was as if explorers lost in the desert had been given a map, compass, and water.
Curious, intelligent, and ambitious, physicists journeyed from one research center to another in Europe: Berlin, Cambridge,
Copenhagen, Göttingen, Hamburg, Leipzig, Leyden, Munich, Rome, Zurich. A physicist simply decided where he wanted to go and
showed up there, unannounced, to witness discoveries and learn insights that excited and inspired him. In 1927 I.I. Rabi spent
several weeks at the Cavendish Laboratory at Cambridge observing the work of Ernest Rutherford, then went on to Copenhagen,
where Niels Bohr had his Institute for Theoretical Physics. When Rabi arrived in Copenhagen, he walked to the institute, rang
the bell, and said to the secretary who answered the door, “My name is Rabi; I’ve come to work here.”
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In this informal way, physicists learned new experimental techniques, absorbed new ideas, and made new friends.
This mixing of people and ideas brought European and American physicists into close contact with one another. The peregrinations
of one physicist, Hans Bethe, illustrate how the process worked. Funded by a Rockefeller Foundation Fellowship in 1931–1932—which
bestowed a generous stipend during the hard times of the Depression — Bethe traveled first to the Cavendish, then to Rome
to study with Fermi. Bethe had been a graduate student at Munich in 1927 when Rabi spent the summer there. While in Europe,
Rabi met Robert Oppenheimer and Edward Teller. Rabi and Oppenheimer formed a bond of friendship that grew stronger with the
passing years. (Between each of them and Teller, however, existed a subtle friction that would later become the stuff of high
drama.)
These transatlantic relationships were cemented through guest lectureships at American universities by distinguished European
physicists such as Bohr; pilgrimages that young American physicists made to the great European centers of physics; the prestigious
Solvay Conference held in Brussels, where the world’s top physicists gathered annually; meetings of the American Physical
Society at the National Bureau of Standards in Washington, D.C.; and a summer symposium on theory at the University of Michigan,
attended by such rising stars as Bethe and Fermi. Through such personal contacts, a powerful network formed.
As things were, no one had the time to do it all himself. But these close international links stimulated the interplay of
ideas, producing one of the most creative atmospheres that had ever existed in physics. Physicists seemed to know when someone
was doing interesting work, and almost every idea occurred to several scientists simultaneously. Physics attained a richness
and variety of approach — and most important, an expansion of knowledge — that it never would have attained if it had been
the work of isolated scientists. It was an immensely exciting time. Few noticed the shadows and thunder in the distance.
When the Nazi attacks on academics came, they initially affected the humanities more than the sciences. The exchange between
a professor of physics and a professor of literature at the University of Stuttgart in 1932 captured the mood of academics in Nazism’s
early days. “Well, Herr Pongs, how are you?” the physicist Paul Ewald asked. “How should I be?” the literature professor answered.
“I’m not a physicist. We have to ‘relearn’ our entire field, looking upon everything ‘
unter dem Evoelkischen Gesichtspunkt
’ [under the racial point of view].” “I really pity you,” said Ewald.
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Yet if physicists lived under the illusion that politics would never reach into the isolated realm of physics, it did not
last for long. Shortly after Hitler came to power, the Nazis issued an edict that the greeting
Guten Tag
(good day) be replaced by
Heil Hitler!
Jewish physicists saw their academic colleagues ridicule the edict at first. Then their colleagues began making a sloppy
Hitler salute, and gradually it became more formal. After a while their colleagues started crossing the street to avoid greeting
them. Physicists were no longer able to keep politics at bay.
The university community was changing, too.
Studenten Verbindungen
(fraternities) were increasingly nationalistic and anti-Semitic—foreshadowing the growing Nazi movement that would come to
power in a few years. Members of these fraternities spent their free time roaming the streets, where they could be heard howling
anti-Jewish slogans late into the night. They regularly searched out and beat up Jewish students or those who looked Jewish.
Before long, Jewish physicists became one of their favorite targets because physics was so dominated by Jews. Such insults
and coercion were part of the Nazis’ plan to “free” German education from the Jews’ “destructive yoke.” The Nazi Party took
control of universities and appointed
dozentenschaftsfuerhers
(faculty leaders) who would assemble physics professors and lecture them that there was no such thing as “objective” science,
that science was an outcome of “national feeling.” A vise was slowly closing.
The vituperation of Nazi academics toward Jewish physicists became increasingly aggressive and outlandish. “German physics?”
asked Herr Lenard of Heidelberg University. “‘But,’ it will be replied, ‘science is and remains international.’ It is false.
In reality, science, like every other human product, is racial and conditioned by blood.” Herr Tomaschek of Dresden’s Physics
Institute went further. “Modern physics,” he wrote, “is an instrument of [world] Jewry for the destruction of Nordic science….
True physics is the creation of the German spirit…. In fact, all European science is the fruit of Aryan, or, better, German
thought.” And then there was Herr Mueller of Aachen’s Technical College, who in a book titled
Jewry and Science
described a worldwide Jewish plot to pollute science and thereby destroy civilization.
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American physicists had an inside view of the tragedy befalling Jewish physicists in Germany. The physics grapevine carried
vivid accounts of Nazi persecution, dramatic stories of hasty departures, and desperate inquiries about faculty positions
outside of Germany. “We have been three days in Göttingen and the rest in Berlin, and had time to see and appreciate the effects
of the present German madness,” wrote one American physicist to a colleague back home. “It is simply horrible. In Göttingen,
it is quite obvious that if these [Nazis] continue for only two more years (which is unfortunately very probable), they will
ruin German science for a generation—at least.” Hitler didn’t care. He reportedly said: “If the dismissal of Jewish scientists
means the annihilation of contemporary German science, then we shall do without science for a few years.”
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(The irony of fate is that Hitler’s actions removed the one group of people who would have been able to provide him with
the instrument for the world dominance he so eagerly sought.)
One result of all this was the exodus of the cream of European physicists, the prominent and the promising alike. Eleven Nobel
laureates in physics left Germany in 1933 alone; one was Albert Einstein. They could not yet imagine the evil of the Holocaust
and it was not German anti-Semitism per se that drove most of them away; they had long been used to subtle prejudice in Germany
and elsewhere. Instead, it was more the fear, the expectation—almost the certainty—that the Nazis would get into a war and
that the physicists caught in Germany would have to work for Hitler.
That
idea was too much.
These years and exile did not destroy the physicists’ intellectual and emotional bonds to the best of German culture, which
was deeply ingrained in their thinking and feeling, but did profoundly, personally demonstrate to them that unfathomable evil
could take hold of a civilized society. They had gone into physics to escape, and now they had to escape to do physics. And
it was still not clear whether they had escaped the hangman’s noose, or whether the rope had just temporarily loosened.
Leo Szilard lived on the edge of the maelstrom as a researcher in nuclear physics at the Kaiser Wilhelm Institute in the Berlin
suburb of Dahlem. A brilliant, sensitive, and intuitive genius who imagined things no one else had imagined before—and could
peer into the future as few others could—Szilard was in Dahlem when Hitler took power as chancellor of Germany on January
30, 1933. With the coming to power of the Nazis, Szilard sensed a new chill more potent than Germany’s damp and biting winter
air. As the situation for Jews in Europe grew darker, the streets of Dahlem seemed to him more and more like a maze, a trap.
Szilard’s ideas often appeared bizarre and remote from reality because his thinking was so far ahead of others’. Such foresight
was not restricted to physics. His colleagues at the Kaiser Wilhelm Institute thought civilized Germans would not tolerate
anything really rough happening under Hitler, but Szilard was not so sure. One night he saw a Nazi torchlight parade end in
a square near the institute. A huge pile of books gathered there was put to the torch, and as the flames engulfed them, more
books were thrown on the pyre. Among the books tossed into the flames were works of “Jewish physics” by Einstein. As Szilard
watched the barbaric spectacle, he remembered that a century earlier the great German Jewish poet Heinrich Heine had written,
“Wherever they burn books they will also, in the end, burn human beings.”
Szilard possessed a rare combination of concentrated thinking—often about the future—and readiness for immediate action. He
reacted to the rise of Nazism by packing his suitcases and keeping them close at hand. He was used to picking up and leaving
when things fell apart: he had grown up a Jew in early-twentieth-century Hungary.
Szilard was born in 1898 in the Garden District of Budapest, a neighborhood of wealthy Jewish merchant families who stood
just one step below the Magyar nobility in the hierarchy of Austro-Hungarian society. Budapest was one of Europe’s most cosmopolitan
cities; it had the second-largest Jewish population, after Warsaw. Horse-drawn droshkies carried silk-gowned women and their
counts in red uniforms and furred hats to the grand palace of Emperor Franz Josef while coffeehouses teemed with intellectuals
espousing socialist revolution. The Hapsburg Empire’s official tolerance and rich mixture of nationalities had allowed Jews
such as the Szilards to find a home, but beneath the cosmopolitanism lurked a powder keg waiting to explode.
Szilard’s mother, Tekla, was a frank and honest woman who taught her son to be candid. “I made up my mind” at an early age,
he later wrote, “that if I had to choose between being tactless and being untruthful, I would prefer to be tactless.”
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As an adult, his outstanding characteristic was not to be deterred by conventions of the time. Although Szilard’s mother
was Jewish, she practiced what she called her “natural religion,” which was loosely based on the teachings of Jesus and which
she conveyed through vivid parables. As a result, her son developed a strong moral and ethical sensibility, and a deep aversion
to violence. He later said that his “predilection for saving the world” was traceable to the stories his mother told him.
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Tekla and her husband, Louis, argued often in front of their son, who increasingly exhibited a trait quite likely fostered
by their chronic disagreement: a tendency to worry. Playmates kidded Szilard for worrying too much, but he seemed unable to
stop thinking about dangers. Intensely inquisitive, and perhaps a bit terrified about endings and abandonment, he was always
jumping ahead to the next assignment in school. Most boys his age strove to fit in, but Szilard was—and would forever be—independent
and irreverent. His sense of humor also helped him alleviate tension and neutralize opponents, and he cultivated an ironic
wit.
Szilard’s interest in physics surfaced when he was a teenager. At about the same time, he found himself drawn to politics
as well. “Ever since I was 13,” Szilard recalled later, “I was interested in physics and in public affairs but I kept these
two things in water-tight compartments and it never occurred to me that these two interests of mine would ever meet.”
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