The anti-relativists were partly parasites grabbing some free fame like barnacles stealing a free ocean voyage, but they were also fuel that kept the fame machine turning. Industrialized fame is wind powered; its blades turn only when something blows. The overthrow of the Newtonian universe had swept the hats off many unsuspecting heads, but eventually the word spread and that breeze began to fade. Then the anti-relativists appeared and the fame engines had something further to turn them, but Einstein’s effectiveness at facing down his challengers made anti-relativism look like a losing cause. Weyland’s secret financiers appear to have halted his funding, and new backers did not step forward. Once again the fame mills seemed to be winding down for Einstein. Then in 1921 he began to travel widely and the fame machinery resumed its steady whir.

In March 1922, a year into their goings and comings, Einstein and Elsa hosted a dinner party in their Berlin apartment. The guests included some of the city’s most fashionable and wealthiest people. Members of the Warburg banking family attended. Among the fashionable guests was Count Harry Kessler, a diplomat who knew everybody, went everywhere, and wrote it all down in his diary. He had spent the afternoon with the foreign minister, Walther Rathenau, trying to find a way for Germany to again figure in international affairs.

Then, in the evening, he was at Einstein’s where the topic of the hour was the amazing ease with which Einstein had penetrated every foreign heart. Einstein described for his guests his triumphal receptions in America and Britain, but he admitted that he could not grasp why people were so enthusiastic.

Einstein, of course, understood what was new in his theory of relativity. Previously, people had thought that matter, space, and time were separate, fundamental things. He showed that they are like the corners of a triangle. Each has meaning only in the presence of the other two. But why, Einstein wondered, did people become so excited about that? What change did relativity make in the way people looked at their own lives? In Britain the Archbishop of Canterbury told Einstein that he had heard relativity “ought to make a great difference to our morals.” “Do not believe a word of it,” Einstein reassured him. “It makes no difference. It is purely abstract science.”

Elsa told Kessler that her husband felt like a conman who arrived to great applause and then failed to deliver on his promise. Pre-science had been filled with figures who, if not full confidence men, enjoyed and gained authority from their impenetrability. Paracelsus, the Swissborn alchemist, is remembered both for his insistence on experiment and his obscure language. He coined pseudoscientific words like “alkahest,” choosing them for their Arabic sounds to enhance his authority and learned appearance. Two generations later Giordano Bruno managed to get himself excommunicated by the Lutherans and burned as a heretic by the Catholics. One thing seems clear: nobody understood exactly what Bruno taught in his treatises on magic and occult astronomy. Yet his obscurity provoked great emotion and excitement among the baffled. Einstein, who spent his whole life struggling to understand, was dismayed to find himself cheered for ideas that the hurray-sayers could not grasp.

Kessler confessed to sensing the significance of Einstein’s thought more than to understanding it. It was exactly the response sixteenth century readers had had to Paracelsus and to Bruno. Einstein was a champion for all those who hoped the world made sense but could not make sense of it themselves. By being smarter than them, Einstein had seen the way the universe does indeed make sense. With his suc-

cessful stride toward understanding he had assured the halt and the lame that the fault is in themselves and not in the stars.

Berlin’s distinguished visitors commonly included Einstein on their list of must-sees. The Indian poet Rabindranath Tagore came to Berlin in 1921 and sought out Einstein. Although such an East-West, art-science, religion-secularism meeting strikes some tastes as absurd, both men saw themselves as separate points in a shared, human civilization and they got along. Tagore’s friends called him Rabi. Einstein jokingly added another “b” and called him Rabbi.

Whenever he traveled outside Berlin, Einstein was cheered as the good man who knew what was what. He went first to Prague, a city where he had taught before the war, and then to Vienna. Next he sailed to the United States. On the way home from America he stopped in Britain to become the toast of London. Everywhere he went, the local machinery rolled out more applause and more fame. There were banquets, lectures, and crackpots. People snapped photographs and shouted questions. Elsa came along and learned how to play the role of simple goodheart married to the great man. In New York she laughed off American reporters who wanted to know if she understood her husband’s theory. In London, when the Archbishop of Canterbury’s wife said that a friend had been explaining the mystical aspects of Einstein’s theory, Elsa burst into laughter, “Mystical! Mystical!” She was having a roaring good time.“My husband mystical!” and she kept laughing.

Democratic Germany was delighted to find that it had a popular goodwill ambassador, and its diplomatic pouches carried home the good news of Einstein’s friendly receptions. Even back in Germany Einstein was turned into a make-believe traveler and fêted at a grand party, just as though he were a foreign dignitary honoring Berlin with a visit. The republic’s cabinet ministers, dressed in their bourgeois best, turned out with their wives. President Ebert also came to meet Einstein, giving each man the chance to see how the other had changed since the afternoon when Ebert had given Einstein a chit to procure the freedom of the university’s rector and faculty.

Einstein seemed to love travel. Between his journey to Vienna and the United States, he made a brief, diplomatic trip to Amsterdam and

enjoyed his first ride in a sleeping car. The diarist Count Kessler traveled with him and was astonished to see a middle-aged man become as wide-eyed and curious about everything as a child on his first train. Sea voyages fascinated him still more, and passengers noticed his curiosity about the machinery used to keep tables steady on a rolling sea.

Wherever he went, lunatics and well-meaning naïfs were eager to talk to him. The cranks whom Einstein especially regretted were the mad warriors who wanted to turn relativity into a bomb. After Einstein showed that, like ice and steam, matter and energy are different forms of the same thing, people began to wonder what would happen if, on cue, matter melted into energy. In 1914, H.G. Wells published a story about a bomb that converted atomic matter into explosive energy. Amateur scientists often wrote to Einstein about such ideas, seeming not to realize that the pacifist Einstein was revolted by their ambition. In Prague a would-be bomb maker managed to corner him briefly. As Einstein made his escape he told the young man, “You haven’t lost anything if I don’t discuss your work with you in detail. Its foolishness is evident at first glance.”

All this travel and hectoring was a great distraction from his scientific work. Light, quanta, and the link between gravity and electromagnetism were always bubbling in the corners of his mind, but it was hard to practice science while living in the public view. He had been looking forward to the renewed Solvay conference and the chance to put science first. The original Solvay conference, 10 years earlier, had been one of the outstanding scientific gatherings of the twentieth century. Lorentz had presided, as he did at succeeding Solvay conferences. Einstein had presented a paper. Marie Curie had been there. Planck had come. The conference had been organized to alert the scientific world to the way Planck’s quantum was revolutionizing everything. The conference made its point. After it was over, Henri Poincaré went into a creative frenzy and proved mathematically that the quantum hypothesis was the only possible explanation for the observed facts.

That first Solvay conference had been inspired by German physicists and chemists who wanted to publicize a German idea—the quantum of energy. They had persuaded a Belgian millionaire, Ernst Solvay,

to give his money and name to create the conference. A second had been held in 1914, just as war was breaking out. The 1921 conference marked their resumption, but Einstein was now the only German invited. His colleagues in Berlin were angry and insisted that Einstein should not attend. All of Einstein’s internationalist leanings supported going. Also, it was absurd that he could travel around the world in his role as famous man, but not as a working scientist. Yet, he knew German science was still great science and that serious international science could not do without it. So, as a gesture to German science, he did not go to Solvay 1921, politely explaining that he would be touring America instead.

As it turned out, the third Solvay conference was not as important as its predecessors. Without the Germans, how could it be? Bohr did not attend either. Quantum physics was stuck. The successes that followed the first Solvay had faded during the war. It was clear that physics needed a new idea, but physicists were reluctant to embrace anything really radical. Einstein’s light quantum, with its inherent particle and wave properties, was the most successful radical idea on hand, and yet few physicists, apart from Einstein himself, dared be that revolutionary. Accepting light quanta would mean reconsidering nineteenth century physics’ greatest achievement, establishing that light was an electromagnetic wave. Newton had taught that light was a substance composed of particles, but early in the nineteenth century a physician named Thomas Young, one of the Rosetta Stone’s translators, had performed a series of experiments that could only be explained if light were a wave. The French mathematician (and yet another Egyptologist), Baron Fourier, developed a technique for analyzing wave motions. Physicists could suddenly make very precise calculations to test the wave theory of light. James Clerk Maxwell had finally clinched the argument when, by simply assuming that light is a wave, he introduced a wonderfully accurate series of equations that unified light, electricity, and magnetism. Like nervous dukes on the eve of reckoning, physicists could see that something drastic had to be done if they were to stave off revelation, but they were unwilling to defy past achievements. So Solvay 1921 came and went without clarifying quanta, atoms, electrons, or the photoelectric effect.

There was a moment in that summer of 1921 when something new might have been tried in quantum physics. In Copenhagen, Bohr’s chief assistant, Hendrik Kramers, thought he had found a way to test Einstein’s light quanta idea and resolve the dispute for good and all. He noticed that if a quantum loses some energy it must change to a lower frequency. The math behind Kramers’ idea was extremely simple. The energy of a quantum equals Planck’s constant (h) times its frequency (υ). Since h never changes, any change in energy must reflect a change in υ. Thus, if a quantum of blue light loses energy, the light will move down the spectrum to some other color, perhaps red. Red light, when it loses energy, might even become invisible as its frequency drops down to the infrared band, which the eye cannot detect. But how could a quantum lose energy? One way, if you take Einstein’s quantum seriously, would be for it to collide with something and transfer some energy just as one billiard ball loses energy when it collides with another.

Kramers was intensely excited to realize that he could establish or abolish Einstein’s idea, but Bohr pointed out that the idea assumed that energy conservation holds on the quantum level. Could Kramers really be sure that energy changes for quanta would really work the way billiard balls worked? Quantum energy conservation had not yet been proved and, personally, Bohr did not believe in it. Kramers disagreed. His idea was beautiful and should be tested. Bohr argued with the tenacity of an interrogator for the secret police. He reasoned, he threatened, he cajoled and insisted. Kramers stood his ground, then wavered, then grew sick. Bohr nursed him and kept up his interrogation. Finally Kramers saw reason and abandoned his hope for a decisive experiment.

It sometimes happens that interrogators do more than wheedle a confession from somebody. They break them and their humanity just as a determined rider can break a wild horse to the saddle. Something like this seems to have happened to Kramers, because after this duel with Bohr he changed. Visitors to Copenhagen after that summer were often surprised by what a tame and compliant assistant Bohr had in his Kramers.

The fame machine never pressed Einstein on this light-quanta

business. Everywhere he went he was asked to explain relativity, but never to discuss his other ideas. Industrialized fame was clouding Einstein’s successes, reducing his whole achievement to that one incomprehensible word—relativity. Often, reporters said that he had revolutionized science, and usually he denied the claim, insisting that relativity was merely an extension of established physical ideas. Apparently no reporter thought to ask, “Well, have any of your other ideas been revolutionary?” Perhaps they did not know he had had other ideas.

At least not other scientific ideas. Einstein did make one big unscientific pronouncement that caught the public’s ear. He deepened German nationalist contempt and he horrified intellectual German Jews by announcing that he was a Zionist. Einstein’s trip to America, although it included many scientific lectures, was billed as a fund raiser for the proposed Hebrew University in Jerusalem. He told a Jewish colleague in Berlin, “Naturally I am needed [in America] not for my abilities, but solely for my name, from whose publicity value a substantial effect is expected among the rich tribal companions in Dollaria.” Inevitably, Einstein’s proposed travel to wartime enemy countries drew yelps from German nationalists. Many assimilationist Jews were troubled as well. Adolf Hitler, at that time an unknown, would-be rabble-rouser, wrote an editorial in his party newspaper at the year’s end warning that “science, once our greatest pride, is today being taught by Hebrews … [as a means of] triggering the inner collapse of our nation.” At the time it seemed only more noise in the fame machine’s persistent hum.

If Einstein had won the Nobel Prize that year he would have spent December in Stockholm, but no prize in physics was announced for 1921 and Einstein passed the year’s end in Berlin doing science. Despite fame’s distractions, he continued to think about physics. He was not required to teach, but when he was in Berlin he liked to participate in a weekly colloquium at the university. The students appreciated these sessions because of Einstein’s immediate ability to find the central issue of any idea. Perhaps his Swiss heritage was coming to the fore. Like William Tell, his arrows seemed always to strike their targets. Tourists sometimes came to these sessions as well and listened

as Einstein spoke in a language they did not know, about questions they could not imagine.

The physics students were glad of these sessions, but others were not always so taken with them. The revolutionary students who had seized the university immediately after the war’s end had been a kind of mirage that soon disappeared from the postwar scene. Most of Germany’s youth was not socialist, not bohemian, not democratic, not even political. They were students with the general concerns of their mates around the world—classes and sex. The minority of students who considered larger issues leaned toward the political right, even the ultraright. As early as 1920 a national student convention meeting in Göttingen voted to limit their membership to “Aryans,” that is, no Jews allowed. This was more than a dozen years before the Nazis came to power. Generally, their teachers were not likely to challenge them. History, literature, and languages professors especially were heavily antidemocratic, anti-communist, anti-Jew.

Einstein did his own work off campus, mostly in the study room above his apartment. Then he would report the results at the next meeting of the Prussian Academy. Following this procedure late in 1921, Einstein finally hit on an experimentum crucis, to use the old Newtonian term for the decisive experiment that settles the argument between two ideas. Einstein had finally seen a way to distinguish between wave effects (which travel spherically) and quanta (which move in one direction). It was a way quite unlike the one dreamt up by Kramers. Einstein had designed a complicated device that focused beams of atoms and then refocused them to produce a second, parallel beam. Einstein calculated that if light travels in quanta there will be nothing extraordinary about the second beam, but if it travels in waves, the second beam’s wave length should change and the beam should fan out a bit.

Decisive experiments add the gambler’s reckless thrill to theoretical science. Years of thought ride behind one spin of the wheel. Einstein had worried that he might never find an experiment to test his theory of gravity against Newton’s; finally he realized that a total eclipse of the sun could be put to use. He had struggled even harder to find some test subtle enough and decisive enough to settle the light

quanta issue. Ehrenfest sent Einstein a note, “If your light experiment turns out anticlassically [that is, by disproving light waves] … then, you will have become really uncanny to me.” He added that proving light travels as quanta rather than waves would be “something completely colossal.”

Two experimentalists quickly built a working apparatus to create and measure Einstein’s beams. The wheel spun and up came the measurements. The wavelength did not change; the beam did not spread. Once again Einstein’s numbers were on the money. He wrote to Max Born, “This has been my most impressive scientific experience in years.” At last he had a chit proclaiming his light quanta’s authority.

The fame machine made not a peep, although perhaps that was just as well. Most classical theorists were out of their depth when it came to judging Einstein’s reasoning, but Einstein’s closest friends and colleagues understood what he was saying and they disagreed with him. Max von Laue energetically challenged Einstein in the Prussian Academy, and two days after his enthusiastic note, Ehrenfest sent Einstein a letter saying that he had seen a flaw in the calculations. Einstein, he said, had missed the point that in this experiment the wave behavior would match that of light quanta. Wave or quanta, the test would give the same results. Ehrenfest ended, “Of course you are such a devil of a fellow that naturally you will finally turn out to be right in the end,” and he begged, “Don’t be annoyed with me if I am wrong; and don’t be annoyed with me if I am right.”

Einstein was annoyed. He redid his calculations, this time with more rigor and told Ehrenfest that the recalculation still supported him. A week later, however, he wrote Ehrenfest, “You were absolutely right.” Further analysis had shown that in this experiment waves and quanta would behave in exactly the same way, so his “decisive” test could decide nothing. The chit was worthless.

Again the fame machine was quiet, at least about this matter. It had more amusing elements of the Einstein story to hum about. While Einstein was working on his experiment, the press erupted with a supposed quotation in which Einstein said that American men “are the toy dogs of the women, who spend money in a most unmeasurable, illimitable way and are themselves in a fog of extravagance.” Einstein

protested that he had been misquoted, but masses of articles, editorials, and letters to the editor held the public eye. “I suppose it’s a good thing I have so much to distract me,” Einstein wrote Ehrenfest, “else the quantum problem would have long got me into a lunatic asylum.” But distraction was taking its toll. It is hard to believe than an Einstein left fully to himself, working in his study with Elsa guarding the door, would have announced his misguided “decisive” experiment.

Einstein then went off to France where he was booed as a German and cheered as a genius. It looked as though 1922 was to be like 1921, a year of mad publicity, but on June 24 the foreign minister Walther Rathenau, a German patriot who had been instrumental in finding the money that kept the Kaiser’s army in the field, Einstein’s friend, and also a Jew, was assassinated by German nationalists. Einstein was rumored to also be on the list of Jews to be killed immediately and he disappeared from public view.