Einstein (42 page)

Despite being back with such friends and diversions, Mari
’s depression continued to deepen, and her health to decline. She developed
rheumatism, which made it hard for her to go out, especially when the streets became icy in winter. She attended the Hurwitz recitals less frequently, and when she did show up her gloom was increasingly evident. In February 1913, to entice her out, the Hurwitz family planned an all-Schumann recital. She came, but seemed paralyzed by pain, both mental and physical.
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Thus the atmosphere was ripe for a catalyst that would disrupt this unstable family situation. It came in the form of a letter. After almost a year of silence, Elsa Einstein wrote to her cousin.

The previous May, when he had declared that he was writing her “for the last time,” Einstein had nonetheless given her the address of what would be his new office in Zurich. Now Elsa decided to send him a greeting for his thirty-fourth birthday, and she added a request for a picture of him and a recommendation of a good book she could read on relativity. She knew how to flatter.
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“There is no book on relativity that is comprehensible to the layman,” he replied. “But what do you have a relativity cousin for? If you ever happen to be in Zurich, then we (without my wife, who is unfortunately very jealous) will take a nice walk, and I will tell you about all of those curious things that I discovered.” Then he went a bit further. Instead of sending a picture, wouldn’t it be better to see each other in person? “If you wish to make me truly happy, then arrange to spend a few days here sometime.”
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A few days later, he wrote again, with word that he had instructed a photographer to send her a picture. He had been working on generalizing his theory of relativity, he reported, and it was exhausting. As he had a year earlier, he complained about being married to Mari
: “What I wouldn’t give to be able to spend a few days with you, but without my cross!” He asked Elsa if she would be in Berlin later that summer. “I would like to come for a short visit.”
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It was therefore not surprising that Einstein was very receptive, a few months later, when the two towers of Berlin’s scientific establishment—Max Planck and Walther Nernst—came to Zurich with an enticing proposal. Having been impressed by Einstein at the Solvay Conference of 1911, they had already been sounding out colleagues about getting him to Berlin.

The offer they brought with them, when they arrived with their wives on the night train from Berlin on July 11, 1913, had three impressive components: Einstein would be elected to a coveted vacancy in the Prussian Academy of Sciences, which would come with a hefty stipend; he would become the director of a new physics institute; and he would be made a professor at the University of Berlin. The package included a lot of money, and it was not nearly as much work as it may have seemed on the surface. Planck and Nernst made it clear that Einstein would have no required teaching duties at the university and no real administrative tasks at the institute. And though he would be required to accept German citizenship once again, he could keep his Swiss citizenship as well.

The visitors made their case during a long visit to Einstein’s sunny office at the Polytechnic. He said he needed a few hours to think it over, though it is likely he knew he would accept. So Planck and Nernst took their wives on an excursion by funicular railway up one of the nearby mountains. With puckish amusement, Einstein told them he would be awaiting their return to the station with a signal. If he had decided to decline, he would be carrying a white rose, and if he was going to accept, a red rose (some accounts have the signal being a white handkerchief). When they stepped off the train, they happily discovered that he had accepted.
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That meant that Einstein would become, at 34, the youngest member of the Prussian Academy. But first Planck had to get him elected. The letter he wrote, which was also signed by Nernst and others, had the memorable but incorrect concession, quoted earlier, that “he might sometimes have overshot the target in his speculations, as for example in his light quantum hypothesis.” But the rest of the letter was suffused with extravagant praise for each of his many scientific contributions. “Among the great problems abundant in modern physics, there is hardly one to which Einstein has not made a remarkable contribution.”
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The Berliners were taking a risk, Einstein realized. He was being recruited not for his teaching skills (as he would not be teaching), nor for his administrative ones. And even though he had been publishing outlines and papers describing his ongoing efforts to generalize relativity,
it was unclear whether he would succeed in that quest. “The Germans are gambling on me as they would on a prize-winning hen,” he told a friend as they were leaving a party, “but I don’t know if I can still lay eggs.”
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Einstein, likewise, was taking a risk. He had a secure and lucrative post in a city and society that he, his wife, and his family loved. The Swiss personality agreed with him. His wife had a Slav’s revulsion for all things Teutonic, and he had a similar distaste that had been in-grained in childhood. As a boy he had run away from Prussian-accented parades and Germanic rigidity. Only the opportunity to be gloriously coddled in the world capital of science could have compelled him to make such a move.

Einstein found the prospect thrilling and a bit amusing. “I am going to Berlin as an Academy-man without any obligations, rather like a living mummy,” he wrote fellow physicist Jakob Laub. “I’m already looking forward to this difficult career!”
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To Ehrenfest he admitted, “I accepted this odd sinecure because giving lectures gets on my nerves.”
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However, to the venerable Hendrik Lorentz in Holland Einstein displayed more gravitas: “I could not resist the temptation to accept a position in which I am relieved of all responsibilities so that I can give myself over completely to rumination.”
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There was, of course, another factor that made the new job enticing: the chance to be with his cousin and new love, Elsa. As he would later admit to his friend Zangger, “She was the main reason for my going to Berlin, you know.”
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The same evening that Planck and Nernst left Zurich, Einstein wrote Elsa an excited letter describing the “colossal honor” they had offered. “Next spring at the latest, I’ll come to Berlin for good,” he exulted. “I already rejoice at the wonderful times we will spend together!”

During the ensuing week, he sent two more such notes. “I rejoice at the thought that I will soon be coming to you,” he wrote in the first. And a few days later: “Now we will be together and rejoice in each other!” It is impossible to know for sure what relative weight to assign to each of the factors enticing him to Berlin: the unsurpassed scientific community there, the glories and perks of the post he was offered, or the chance to be with Elsa. But at least to her he claimed it was primarily
the latter. “I look forward keenly to Berlin, mainly because I look forward to
you.
”
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Elsa had actually tried to help him get the offer. Earlier in the year, on her own initiative, she had dropped in on Fritz Haber, who ran the Kaiser Wilhelm Institute of Chemistry in Berlin, and let him know that her cousin might be open to a position that would bring him to Berlin. When he learned of Elsa’s intervention, Einstein was amused. “Haber knows who he is dealing with. He knows how to appreciate the influence of a friendly female cousin . . . The nonchalance with which you dropped in on Haber is pure Elsa. Did you tell anyone about it, or did you consult only with your wicked heart? If only I could have looked on!”
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Even before Einstein moved to Berlin, he and Elsa began to correspond as if they were a couple. She worried about his exhaustion and sent him a long letter prescribing more exercise, rest, and a healthier diet. He responded by saying that he planned to “smoke like a chimney, work like a horse, eat without thinking, go for a walk
only
in really pleasant company.”

He made clear, however, that she should not expect him to abandon his wife: “You and I can very well be happy with each other without her having to be hurt.”
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Indeed, even amid his flurry of love letters with Elsa, Einstein was still trying to be a suitable family man. For his August 1913 vacation, he decided to take his wife and two sons hiking with Marie Curie and her two daughters. The plan was to go through the mountains of southeastern Switzerland down to Lake Como, where he and Mari
had spent their most passionate and romantic moments twelve years earlier.

As it turned out, the sickly Eduard was unable to make the trip, and Mari
stayed behind for a few days to get him settled with friends. Then she joined them as they neared Lake Como. During the hikes, Curie challenged Einstein to name all the peaks. They also talked science, especially when the children ran ahead. At one point Einstein stopped suddenly and grabbed Curie’s arm. “You understand, what I need to know is exactly what happens to the passengers in an elevator when it falls into emptiness,” he said, referring to his ideas about the
equivalence of gravity and acceleration. As Curie’s daughter noted later, “Such a touching preoccupation made the younger generation roar with laughter.”
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Einstein then accompanied Mari
and their children to visit her family in Novi Sad and at their summer house in Ka
. On their final Sunday in Serbia, Mari
took the children, without her husband, to be baptized. Hans Albert remembered later the beautiful singing; his brother, Eduard, only 3, was disruptive. As for their father, he seemed sanguine and bemused afterward. “Do you know what the result is?” he told Hurwitz.“They’ve turned Catholic. Well, it’s all the same to me.”
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