Who are the three most significant people alive? A Japanese publisher asked Britain’s already well-known philosopher Bertrand Russell that question in 1921.
Einstein and Lenin, Russell answered. Perhaps a sudden fit of modesty led him to omit a third name. The mills of the worldwide fame machine, Japanese branch, began to turn and Einstein signed contracts calling for a dozen lectures during a six-week tour of Japan. After the Rathenau murder, Einstein canceled all his scheduled lectures and public appearances, except for the Japanese plans.
In September, while Einstein still hid from public view, he received word that he should not do anything that would prevent a trip to Stockholm in December. It seemed that the Nobel Prize was coming. However, Einstein refused to postpone the journey to Japan, partly because he had signed a contract, partly because prizes, even Nobels, did not mean much to him, perhaps also because the prize money was already promised to his first wife, Mileva. Einstein’s action carried some risk. The Nobel committee was easily offended and might not vote an award to someone who did not appreciate its grand importance, but by autumn 1922 the shame of Einstein never having received a Nobel fell much more on the prize givers than it did on the supposed honoree.
Einstein and Elsa made their way discreetly from Berlin to Switzerland, and then to the French port of Marseilles where a Japanese passenger steamer awaited them. It was an excellent time to be leaving Germany because the mark had begun to collapse into worthlessness. The life savings of millions were being consumed as though by fire.
It took six lazy weeks at sea to reach Japan, giving the passengers ample time to get used to having so renowned a traveling companion. Toward the journey’s end, as the ship traveled from Hong Kong to Shanghai, Einstein received the news that the previous year’s Nobel Prize in physics had at last gone to him. At the same time the Swedish Academy announced that the 1922 prize was awarded to Niels Bohr. There was some confusion as to just what Einstein won the prize for. The award statement seemed to indicate that his theory of relativity still held uncertain status, then it mentioned Einstein’s general “services to the theory of physics, and especially for his law of the photoelectric effect.”
Mondo bizarro indeed! By 1922, only envy-maddened physicists were still questioning Einstein’s 1905 theory of relativity. Those who knew enough to have an opinion also accepted his view of gravity. Most physicists, however, continued to reject light quanta as an explanation for the photoelectric effect. Of course, the committee did not award the prize for the light quanta, only for the photoelectric “law.” That law states that the energy of an electron sent flying by electromagnetic radiation equals hυ minus a fixed amount of work needed for the electron to escape its atom. In Einstein’s theory, hυ is a light quantum. The committee seemed to be ignoring the equation’s meaning and mentioning only that the equation succeeded.
It was not even Einstein who had established his equation’s accuracy. That achievement went to an American, Robert A. Millikan, at the University of Chicago. He began his experimental study of the photoelectric effect in 1905, the same year Einstein published his light-quanta hypothesis. The distance between Chicago and Berlin was very great in those days, and Millikan was not immediately aware of Einstein’s theory. If he had been, he would not have been impressed, because Einstein’s law has only one variable, the electromagnetic frequency. Millikan expected to find that temperature is most important
in determining photoelectric action. As an American, who no doubt had enjoyed his share of popcorn, it is easy to picture what Millikan had in mind. Roasting popcorn’s bursting rate and ferocity increases along with the rising temperature. He expected to find that the thermometer went up as electron energy increased. His experiments, however, determined decisively that temperature has nothing to do with the case.
Millikan’s first experimental efforts paid two rewards. They removed temperature from any further consideration of the issue and they taught Millikan powerful techniques for producing and measuring the photoelectric effect. He learned how to test the effect with different materials and different wavelengths under many different conditions. There seems no question that he passed Lenard in his experimental knowledge of photoelectricity and its effects. The puzzle was that none of Millikan’s experiments challenged Einstein’s law.
In 1912 Millikan visited Europe and its leading physicists, including Planck in Berlin and Lorentz in the Netherlands. Neither had any sympathy for the light-quantum hypothesis. Following his return to America, Millikan published an article on the nature of radiation. After surveying four other theories, he reported, “The facts … are obviously most completely interpreted in terms of … [Einstein’s] theory, however radical it may be. Why not adopt it? Simply because no one has thus far seen any way of reconciling such a theory with the facts of diffraction and interference so completely in harmony in every particular with the old theory of ether waves.” [Millikan’s italics]
Millikan went back to work, testing Einstein’s equation and by 1915 had proved that it was right on the money. The frequency of the electromagnetic radiation is the only property that determines an electron’s energy when it is knocked free. Millikan drew a graph showing Einstein’s prediction and another showing what he found experimentally. The match was so precise that it might have seemed suspicious if people had not known that Millikan was hoping to disprove Einstein. Millikan’s experiments destroyed all rival photoelectric theories but did not establish Einstein’s idea. Millikan insisted that accepting Einstein would be a mistaken response to his work. “The semi-corpuscular theory by which Einstein arrived at his equation
seems at present to be wholly untenable,” he wrote, adding that Einstein’s “bold, not to say reckless, [hypothesis] seems a violation of the very conception of an electromagnetic disturbance.”
Einstein was completing his work on general relativity when Millikan finished that photoelectric paper. Only after he settled relativity did he turn again to light quanta. Defiant as ever, he wrote a classic paper that is best remembered these days as laying the foundation of laser technology. Meanwhile, Millikan was still perplexed. In 1917 he wrote that Einstein’s photoelectric law “stands complete and apparently well tested, but without any visible means of support. These supports must obviously exist, and the most fascinating problem of modern physics is to find them. Experiment has outrun theory, or better, guided by erroneous theory it has discovered relationships which seem to be of the greatest interest and importance, but the reasons for them are as yet not at all understood.”
Seeing such universal doubt among capable physicists, it seems natural to ask why Einstein remained so confident of his light quanta. It was not that he had gone chasing after a windmill. He had done the math and found that Maxwell’s theory did not work when applied to the facts of the emission and absorption of radiation. Using Maxwell’s theory, Einstein proposed an equation—we can call it equation Ē—that had to be correct if Maxwell’s wave theory was true. He then examined the experimental data and found that equation Ē did not accurately describe what happened. Thus, for Einstein, every rebuttal based on an appeal to Maxwell served as a reminder that Maxwell’s waves did not work in this case.
Well then, if Maxwell was wrong, why did other physicists stick by him so fervently? Probably because Maxwell did work brilliantly everywhere else. Einstein had conceded that “the wave theory of light … has proved itself superbly in describing purely optical phenomena and will probably never be replaced by another theory.” It was also true that Einstein’s mathematical argument was novel and many physicists probably could not follow it in all its richness. But Lorentz, Planck, and Max Born could follow the math, yet they did not move on to light quanta.
Something beyond evidence and mathematics shaped this dispute.
Einstein was uniquely able to work in situations where language was ambiguous and theory offered no guidance. Most scientists, Thomas Kuhn reported, when forced to choose between a false theory or no theory will cling to the false one: “Though they may begin to lose faith and then to consider alternatives, they do not renounce the paradigm that has led them into crisis.” Einstein was different. He rejected theories he knew to be false and went on working. While other people clung to Maxwell, Einstein pressed on like Columbus into the unknown ocean. Yes, he was a scientist and did not share the imagination of a poet who seeks language that will embrace reality’s contradictions. He accepted the scientist’s position that things are one way or another, but he was also like a star trapeze artist who leaps from one perch and flies beyond the net, confident that somewhere ahead is another swing.
To be blunt, Einstein had more courage than his colleagues, and his courage came from faith, although no honest preachers will claim Einstein’s faith as their own. For Einstein did not believe in the Hebrew God, an immortal person who intervened in the affairs of nations. His faith was in the abstract proposition that the universe makes sense and runs on meaningful, physical law. If something is wrong with our current understanding we should immediately abandon that error in the sure and certain hope that a better understanding can be found. That great bravery mixed with grand ability is rare in every field. Shakespeare had it. Copernicus had it too, for he, like Einstein, first rejected the established picture of the cosmos and then cast about for a better explanation. Meanwhile their contemporaries could see the problems and recognize the need for something new but could not find the will to jump from their perches. However bumblingly and nervously they had come to it, the Nobel committee had finally honored Einstein for the fruits of his unusual mind and even more unusual courage.
Bohr immediately sent Einstein a congratulatory message, “The external recognition cannot mean anything to you…. For me it was the greatest honor and joy … that I should be considered for the award at the same time as you. I know how little I have deserved it, but I should like to say that I considered it a good fortune that your
fundamental contribution in the special area in which I work [that is, the quantum theory of radiation] as well as contributions by Rutherford and Planck should be recognized before I was considered for such an honor.”
Einstein replied, “I can say without exaggeration that [your letter] pleased me as much as the Nobel Prize. I find especially charming your fear that you might have received the award before me—that is typically Bohr-like. Your new investigations on the atom have accompanied me on the trip, and they have made my fondness for your mind even greater.”
After their polite bowing, they made speeches that expressed mutually opposing views. One of Einstein’s Tokyo talks was about “The Present Crisis in Theoretical Physics,” in which he noted the battle over light waves versus light quanta and how both quanta and waves seemed absolutely necessary, although in different cases.
Six days later, in Stockholm, Bohr read his Nobel speech and in it he gave Einstein’s light-quanta theory no quarter. His talk summarized the six lectures given the previous June in Göttingen, but at the Festspiel he criticized Einstein only implicitly. At Stockholm he was more direct. He began praising Einstein, noting that it was Einstein who first commented on the revolutionary importance of Planck’s quantum discovery. Bohr then mentioned some important work Einstein did in 1907, while he was still a patent office clerk, in which Einstein had used the quantum hυ to calculate how much energy it takes to raise a substance’s temperature. Einstein solved an old conundrum with this quantum equation and founded the science now called solid-state physics. Oddly, Bohr said Einstein’s successful work on heat led to the formulation of the “so-called hypothesis of light-quanta,” but surely Bohr knew that Einstein’s light quanta had come two years earlier, in 1905. Or maybe he did not know. Bohr had been a university student in those years and had other things on his mind. Either way, Bohr’s account allowed him to tell Einstein’s story with a consistent flow—all the praise came up front and was followed by growing doubts about what Einstein had wrought. Bohr ended his summary of Einstein and quanta with the standard Millikan-style argument that although Einstein’s equation described the photoelectric effect per-
fectly it was an impossible explanation. Bohr was not yet ready to leave his old perch on the trapeze.
Unknown to both men, something new had happened. Two days before Einstein’s crisis lecture in Tokyo, an obscure American physicist named Arthur Compton read a paper in Chicago that would force the quantum experts in Europe to abandon their swings. But news did not fly in those years. Bohr gave his talk in Stockholm unaware of what had happened in Chicago. Einstein continued on in Japan. Compton’s discovery was like a bullet that had been fired but has not yet hit its target. That collision would come in 1923.
In Japan, Einstein enjoyed a triumphal tour that outdid even his huge successes in America and England. He conversed with Japan’s empress in French and was cheered by sold-out audiences who listened to him give scientific talks in German. His image filled newspapers. He played the violin, gazed on Mount Fuji, and attended kabuki theater.
There were also women. Folk wisdom reports: Your husband runs around with many other women? That’s not good. Your husband runs around with one other woman? That’s bad. Elsa had known from the start that her marriage to her cousin would not be so good. Her philandering husband would leave her at home to go off to an evening with somebody younger, prettier, and after he became world famous, what had been easy became even easier. The word groupie had yet to be coined, but young women who wanted to have sex with famous strangers were already common. Einstein was not as popular that way as, say, Babe Ruth, but neither was he ignored.
By the Japanese trip’s end, matters had gotten bad. Elsa’s oldest daughter, Ilse, had served as Einstein’s secretary, but after Ilse married, Einstein hired a young stranger named Bette Neumann. Trite though it is to fall for the secretary, Einstein fell. It was the old pattern. As quantum physics grew increasingly frustrating and baffling, the emotional appeal of a new woman grew stronger. By the end of the Japanese tour, Elsa had something serious to worry about.
Just before the new year Einstein boarded another steamer for the voyage home. He did stop off for a month in Palestine, where he got to know a variety of “tribal companions” who were present in every
form. The British governor was an intellectual, politically savvy Jew; Einstein also saw kibbutzim run by secular, socialist Jews after his own heart; he stood before the Wailing Wall, dismayed by “dull minded” Jews rocking in prayer: “A pitiful sight of men with a past but without a future.” He helped lay the cornerstone of Jerusalem’s Hebrew University, and then he was off to tour Spain.
By mid-March he and Elsa were back in Berlin. During their five-and-a-half month absence, the hyperinflation burning through Germany’s money had destroyed the middle class and began pressing it beyond ruination to a kind of überruin unknown to previous history. The bourgeoisie living on savings and fixed pensions were stripped bare. Elsa had had some money; now it was gone. Retired generals and diplomats who had spent their careers serving imperial Germany and who thought of themselves as distinguished people took to rooting through garbage cans for food. The only wealth that had survived was property and foreign currency, and even property became a loss the instant it was sold for cash. No matter how great a sum the property had brought, inflation at once set fire to the earnings and, within days, reduced them to ashes. Property was something to hold on to, if you could, or something to borrow money on, if you could find a lender, since the debt, whatever the size, would soon become meaningless. Einstein had no property, but his Japanese trip had provided him with a bushel of foreign currency so that neither he and Elsa, nor his two stepdaughters risked starving.