Quantum_ Einstein, Bohr and the Great Debate About the Nature of Reality - Manjit Kumar [63]
It was inevitable that sooner rather than later Einstein would become a prime target for the men in Berlin. In July 1913 Max Planck and Walther Nernst boarded the train to Zurich. They knew that it would not be easy to persuade Einstein to return to a country he had left almost twenty years ago, but they were prepared to make him an offer he simply could not refuse.
As Einstein met them off the train, he knew why Planck and Nernst had come, but not the details of the proposal they were about to make. Having just been elected a member of the prestigious Prussian Academy of Sciences, he was being offered one of its two salaried positions. This alone was a great honour, but the two emissaries of German science also offered a unique research professorship without any teaching duties and the directorship of the Kaiser Wilhelm Institute of Theoretical Physics once it was established.
He needed time to mull over the unprecedented package of three jobs. Planck and Nernst went on a short sightseeing train ride as he considered whether or not to accept. Einstein told them they would have his answer when they returned by the colour of the rose he carried. If red, he would go to Berlin; if white, he would stay in Zurich. As they got off the train, Planck and Nernst knew they had got their man when they saw Einstein clutching a red rose.
Part of the lure of Berlin for Einstein was the freedom to 'give myself over completely to rumination' with no obligations to teach.7 But with it came the pressure of having to deliver the sort of physics that made him the hottest property in science. 'The Berliners are speculating with me as with a prize-winning laying hen,' he told a colleague after his farewell dinner, 'but I don't know if I can still lay eggs.'8 After celebrating his 35th birthday in Zurich, Einstein moved to Berlin at the end of March 1914. Whatever reservations he might have had about returning to Germany, he was soon enthusing: 'Intellectual stimulation abounds here, there is just too much of it.'9 The likes of Planck, Nernst and Rubens were all within easy reach, but there was another reason why he found 'odious' Berlin exciting – his cousin Elsa Löwenthal.10
Two years earlier, in March 1912, Einstein had begun an affair with the 36-year-old divorcee with two young daughters – Ilse, aged thirteen, and Margot, eleven. 'I treat my wife like an employee whom I cannot fire', he told Elsa.11 Once in Berlin, Einstein would often disappear for days without a word of explanation. Soon he moved out of the family home altogether and drew up a remarkable list of conditions under which he was willing to return. If Mileva accepted his terms she would indeed become an employee, and one her husband was determined to fire.
Einstein demanded: '1. that my clothes and laundry are kept in good order and repair; 2. that I receive my three meals regularly in my room; 3. that my bedroom and my office are always kept neat, in particular, that the desk is available to me alone.' Further, she was to 'renounce all personal relations' and refrain from criticising him 'either in word or deed in front of my children'. Finally he insisted that Mileva adhere to 'the following points: 1. You are neither to expect intimacy from me nor reproach me in any way. 2. You must desist immediately from addressing me if I request it. 3. You must leave my bedroom or office immediately without protest if I so request.'12
Mileva agreed to his demands and Einstein returned. But it could not last. At the end of July, after just three months in Berlin, Mileva and the boys went back to Zurich. As he stood on the platform waving goodbye, Einstein wept, if not for Mileva and the memories of what had been, then for his two departing sons. But within a matter of weeks he was happily enjoying living alone 'in my large apartment in undiminished tranquillity'.13 It was a tranquillity that few would enjoy as Europe descended into war.
'One day the great European war will come out of some damned foolish thing in the Balkans', Bismarck