The murder of Walther Rathenau had a look that was to become increasingly common in the twentieth century. The foreign minister was riding in an open car when another automobile pulled alongside and the occupants began blasting. The two cars swerved, one from panic, one from hatred. The shooters preached the text that underlies all thug politics: Shaddap. This means you. We can do without your ideas. Rathenau had been warned frequently that there were plans to assassinate him, but he refused to take them seriously. Shortly after that killing an attempt was made against another prominent Jew, Maximilian Harden, a journalist, essayist, publisher, and radical socialist. Although Harden survived his attack he retired from public life and left for Switzerland. Force was replacing rumor as the source of authority in Berlin.
The story of science, art, and other fruits of imagination is more burdened with efforts to silence creators than we commonly recognize. Although silencing, say, a physicist because he is a Jew, and a pacifist, and a democrat makes the physics part seem accidental, it is the general open-mindedness necessary to the successful creation of ideas that makes thugs so angry. A British mob in Birmingham made clear their willingness to do without further thought from the chemist, oxygen’s discoverer, and religious radical, Joseph Priestly. They hated
him for his broadmindedness, not for his oxygen, but the broadmindedness led to oxygen. Thugs stormed his home and destroyed his library, his laboratory, and the rest of his place. Shut up, shut up, be silent was the message that sent Priestly fleeing into the night when thugs thought he was too sympathetic to the French Revolution.
Across the channel, in Paris, the man who explained the importance of Priestly’s oxygen was also spotted by thugs. They saw the chemist as the revolution’s enemy and architect of the wall that forced all goods to enter Paris through tax collection points. They hated Lavoisier for his cleverness, not his theory of fire, but of course the cleverness was foundation to his theory. No more from that brain was their thought as they chased him down the city streets.
Einstein ducked down an alley, too, and stayed quietly out of view in his apartment at 5 Haberlandstrasse. He had never lacked for scientific or political courage, but he was not foolhardy. With brutes roaming the boulevards, he lay low. Yet guests did come over to play music with him. Professional musicians enjoyed playing with the famous host. His apartment featured a music room where he and guests would play while Elsa listened through open double doors. Einstein loved his violin, playing the notes straight, with no vibrato. “Skreek-skreek-skreek,” was the way the pianist Rudolph Serkin recalled the sound, and Einstein loved every minute of it. It was as distracting and seductive as fame, a pleasurable way to lay by his quest for sense. If Einstein ever idolized anything—in idolatry’s formal sense of worshiping a human creation—it was music.
In the noisy, boisterous world beyond Einstein’s apartment, a whole civilization was crossing a Rubicon. Anything-goes open-mindedness was going to war with ferocious hatred of the different. In poetry, 1922 was the year T.S. Eliot published The Wasteland and Rilke, “in a creative fit,” as Peter Gay described it, scribbled down his Sonnets to Orpheus and the Duino Elegies. In prose, Joyce’s completed Ulysses was printed and another volume of Proust’s great work rolled off the presses. Musically, it was the year Louis Armstrong quit a riverboat band to settle in Chicago and begin transforming jazz into an art form. Meanwhile, hatred for all such mental liberties was organizing. On the day Rathenau was murdered, Canadian readers awoke to find
two stories about Italian fascism in the morning’s Toronto Star. The reporter was Ernest Hemingway. The first story related an interview with Benito Mussolini, who told the newspaper representative, “We are a political party organized as a military force.” Hemingway’s second story described the members of this military force as “black-shirted, knife-carrying, club-swinging, quick-stepping, nineteen-year-old potshot patriots.” As for the suggestion that anything more than banality underlay fascism, in a later report Hemingway wrote, “Mussolini is the biggest bluff in Europe. If Mussolini would have me taken out and shot tomorrow morning, I would still regard him as a bluff…. Study his genius for clothing small ideas in big words.”
While Einstein stayed hidden, the struggle between big ideas and big words took shape. Einstein’s enemy in physics and politics, Philipp Lenard, was unmoved by Rathenau’s murder. The German Republic proclaimed a day of mourning for its slain minister, but Lenard said the Jew had been “justly” killed and he insisted on giving his regular physics lecture.
Hindsight makes it seem odd, but Germany in 1921 was seen by some as a haven from thug politics. For years Berlin had been absorbing refugees fleeing the Bolshevik catastrophe. Jewish peasants had recreated a shtetl on Berlin’s outskirts while Russian nobility settled in Berlin proper. Vladimir Nabokov was among the refugees who thought Germany looked better than home, and who knew personally that murder had become a popular tool for shaping the future. Nabokov’s father had been slain that spring at a public meeting of Russian émigrés. The question before the floor had been what to do about communism’s successful entrenchment back home. During the evening two monarchists tried to shoot an ardent republican. They were poor marksmen and killed Nabokov senior instead. The battle between openness and close-mindedness had become a war.
Open-minded Germany still reigned on the day of the Rathenau murder and the country’s middle class was mostly horrified by the assassination. The people’s indignation made the nationalist movements fall back on the defensive, and naturally some on Germany’s political left called for silencing the right. The chancellor told the Reichstag, “The enemy is on the right—here are those who drip poison into the
wounds of the German people!” and he began introducing legislation to “protect the republic” by silencing extremists. The world had become a remarkable garden in which some people were creating unknown flowers while others were determined to rip out all new blooms as though they were weeds. Blows from all sides followed. In Heidelberg, on Rathenau’s day of mourning, parading workers saw the lights in Lenard’s classroom and, knowing nothing of his thoughts about the photoelectric effect, burst into his class, grabbed him by his clothes and frog-marched him out the building. They were prevented from tossing him off a bridge only by the intervention of more humane mourners.
How, faced with such murder, was open-minded expression supposed to triumph over narrow-mindedness organized as a military force? All these generations later, of course, the question is hardly suspense-filled. We know that the close-minded militarists were finally defeated by the creative societies, which were slow to rouse, but unstoppable once angered. We know, too, that fascist ignorance paid a terrible price for embracing silence. Many of the dreamers in this story would eventually move abroad, where they contributed their talents to the other side. Einstein famously settled in Princeton, New Jersey, where for a time his neighbor was the refugee-novelist Thomas Mann. Max Born would end up teaching in Edinburgh. Ilse Rosenthal-Schneider, the philosophy student who chatted on the tram with Einstein, spent the last half of her life in Australia. Erwin Schrödinger, who figures prominently later in this story, went to Dublin, while the Dutchman of great merit, Peter Debye, skipped to Cornell in New York State. The musicians who played in Einstein’s music room typically ended up in New York City or London. Even Bohr would make a daring wartime escape from occupied Denmark to America. Meanwhile, the fate of the university at Göttingen showed what happens when banality takes charge. The university’s mathematics school had looked like a kind of perpetual-motion machine that spewed out ideas in an endless show of fireworks, but Göttingen ran out of fuel as soon as the Nazis put an end to the imaginative life.
The long view, however, misses the fears of daily life. In the summer of 1922 thuggery was getting away with murder, literally. Imagi-
native people were being killed and silenced. German, Austrian, and some neutral scientists were banned from international conferences. Rathenau’s murder shook Einstein to the depth of his soul. It foreshadowed a long assault on Jews and humanism, and Einstein knew it. At the same time, Bohr was troubled by the larger world’s suppression of German science. Isolated Germany was developing its own distinct theory of the atom and quanta. The first Solvay conference had moved quanta to the heart of European physics, but time had eroded that universality. Poincaré died in 1912, before his newfound enthusiasm for the quantum revolution could take deep root in France. Britain’s leading quantum scientist was a brilliant physicist named Henry Mosely, but British interest in quanta faded after he died violently on the Turkish front. Only in Germany had the pace and breadth of work with quanta accelerated.
So Bohr made a one-man show of openness toward Germany. When Rathenau was assassinated, Bohr had just completed a triumph in Göttingen. Over a two-week period he gave seven lectures at the “Eldorado of erudition” as Einstein jokingly designated the university. It was a great event for the school, the students, and the scientists who remembered those two weeks as the Bohr Jamboree, or Bohr Speakathon, or however you choose to translate Bohr Festspiel. The most promising young physicists in Germany made their way to Göttingen to hear Bohr, partly because he was a great physicist and partly because he was a great physicist who had come to Germany when many Auslanders would not even shake hands with men like Max Born, Arnold Sommerfeld, and Max Planck. Bohr knew that his broadmindedness about ideas stamped “Made in Germany” kept him in the game. An alliance was developing that linked the scholars of Copenhagen, Munich, and Göttingen in a shared approach that took the Bohr atom for granted and saw no use for Einstein’s hypothetical light quanta.
Einstein returned the compliment by being skeptical about the intricate details of Bohr’s atom. True, its experimental success was impressive and surely must mean something, but there were still many contradictions and unsolved puzzles. Eighteen hundred years earlier the astronomer Claudius Ptolemy had said, “Theoretical [physics]
should rather be called guesswork than knowledge … because of the unstable and unclear nature of matter.” All these centuries later the nature of matter was still unclear. Bohr had made some brilliant guesses—intuitions, his disciples called them—but was he right?
Ptolemy himself had described the heavens, and his method allowed for wonderfully accurate calculations of eclipses and astrological relationships. His theories were developed when the physical nature of the night sky was almost a total mystery. It consisted of a show in which lights moved and varied in brightness. Everything known or guessed about the structure of the cosmos came from carefully observing and measuring the motions and changes in the brightness of those lights.
Didn’t they know that the stars and planets were places, separate objects with their own landscapes or features? No, not really. As late as Galileo’s time the Holy Roman Emperor was asking the court astronomer if he thought the moon might be a mirror that reflected part of the earth’s surface. The ancients knew only those moving lights and their changes in brightness. Beyond that it was all “Twinkle, twinkle little star, How I wonder what you are.”
How much of Bohr’s atom was as fictitious as the crystalline spheres that were once said to carry the planets around the earth? The only thing anybody really knew about atomic behavior concerned the frequency and intensity of the light that atoms absorb and emit. Bohr talked about an atom’s orbiting electrons and the distortions of these orbits caused by electric and magnetic fields, but these theoretical motions were based on observed changes in the frequency and intensity of atomic light. Nobody had seen an electron moving around an atom.
Yet Bohr was building a great following in Germany. Physicists to the political left of Lenard and Stark packed his lectures and heard the Danish visitor explain that chemistry’s periodic table of the elements made sense. Fifty years earlier, Dmitry Mendeleyev had produced a chart that organized the elements into groups with shared chemical properties. Mendeleyev’s table, however, was much like an inexplicable equation or system of categories. It had its uses, but only after Bohr’s lectures did it become clear that quantum physics suggested a meaning
that lay behind the periodic table. Bohr’s idea was that electrons can share orbits so that an atomic “solar system” has several “planets” following the same route—as though the earth had a twin sailing the same course around the sun. Bohr said that the number of electrons in the outermost orbit determines an atom’s chemical properties and he showed that chemicals listed in the periodic table as being similar shared the same number of outer-orbit electrons. It was a wonderful example of finding physical meaning behind factual order.
It is entertaining to speculate on how many people in the audience actually understood Bohr’s lectures. Despite his brilliance, he was remembered as a “divinely bad” speaker. His voice was weak and carried only to the front rows. Even worse, he was rethinking his way through his lectures as he spoke, so nothing came trippingly or directly. Audiences were commonly more bewildered than enlightened by his words.
The smartest quantum people, however, knew what he was talking about. Werner Heisenberg was a bright student in Munich who had come to Göttingen just to hear Bohr. He reported, “Each one of [Bohr’s] carefully formulated sentences revealed a long chain of underlying thoughts, of philosophical reflections, hinted at but never fully expressed. I found this approach highly exciting; what he said seemed both new and not quite new at the same time…. We could clearly sense that he had reached his results not so much by calculations and demonstrations as by intuition and inspiration, and that he found it difficult to justify his findings before Göttingen’s famous school of mathematics.”
Bohr’s distaste for math was his most distinctive trait. It is common in populations as a whole but unusual among theoretical physicists. He did not like the way mathematics encouraged people to believe abstractions were real. Mathematical formulas tend almost inevitably to propose abstractions underlying appearances, while natural languages force ideas to stay closer to the surface, and Bohr wanted to understand surfaces. Einstein was the opposite, treating his abstractions with utmost seriousness and even saying that hυ, which combines an uncountable number (h) with an abstract property (υ), is something that actually bangs about and causes visible results.
Oddly, Bohr’s persuasiveness might have rested in part on his mathematical limitations. Although he cited equations throughout his lectures, there was very little mathematical reasoning of the kind in, say, Einstein’s original paper on light quanta. There, if you cannot follow the math you cannot follow the argument. Instead of undercutting Bohr, this mathematical thinness made him seem more profoundly connected to physical reality. Of course, his admiring listeners did have an instinct for mathematics. Thus, even though he found Bohr’s lectures exciting, Heisenberg rose to challenge one of the calculations Bohr had reported, and Bohr had no good reply.
Bohr was frank about the many mysteries that atomic structure still posed. The fundamental challenge lay in tracing what happened when two or more electrons move through subatomic space. It was proving impossible to distinguish even the theoretical motions of one electron from another. New refinements seemed constantly required as experimentalists discovered new subtleties in light intensity and frequency. For Einstein, these problems meant that the basic theory of quantum radiation was, at best, incomplete. For Bohr, the fundamentals were sound; physics just needed more tools. Bohr was out there proselytizing, winning interest while Einstein stayed invisible, working in his study or skreek-skreek-skreeking on his violin.