Einstein's Masterwork Read online

  Rescue

  In any case, Einstein’s anger was a little assuaged by news he received while Kleiner was still considering the dissertation. On 11 December he heard from Grossmann that the vacancy in the patent office was about to be advertised. Uniquely in the history of the patent office up to that time, the ad specified that applicants should have a university education with a ‘specifically physical direction’; before 1902, there were no physicists in the Swiss Patent Office. Impulsively, as well as applying for the post, Einstein gave up his job and moved to Bern in January 1902, blissfully unconcerned that even if he got the job he would not be starting immediately. At about the same time, he became a father; after a difficult (indeed, life-threatening) labour Mileva gave birth to a little girl, Lieserl.

  Although their correspondence clearly shows that the couple initially intended to keep their daughter, there was no prospect of Mileva bringing her to Switzerland. A respectable Swiss civil servant could not possibly be seen to be flouting conventional morality – and conventional morality in Bern at the time was so strict that women were legally forbidden to smoke in the street. There was no prospect of marriage until he had the patent office job – and there would be no prospect of the job if the authorities knew about his relationship with Mileva. So, in the short term at least, Einstein would be living as an impoverished but independent bachelor in Bern. It was almost an echo of his early days as a student in Zurich.

  The Swiss bureaucracy only moved slowly towards the process of carrying out interviews and appointing new patent officers to fill the two vacancies that were becoming available, and meanwhile Einstein had to live. He decided to make a little money by private teaching, helping students at the University of Bern, and advertised his services in the local paper, picking up a couple of students willing to pay the modest fee he requested. One if these men, Louis Chavan, soon became a good friend. Einstein already had some contacts in Bern. An old schoolmate from Aarau, Hans Frösch, was now studying medicine at the University, and Paul Winteler, one of Marie’s brothers, was studying law. Another old friend, Max Talmey, was travelling in northern Italy in the spring of 1902; after visiting Einstein’s parents in Milan he called in to see Einstein himself in Bern. Talmey found Einstein living in a ‘small, poorly furnished room’ and struggling to make ends meet.10 But if things were so hard financially that Einstein wasn’t even getting enough to eat, socially and intellectually he was having the time of his life.

  During the Easter vacation, Einstein ran the ad offering his services as a tutor again. This time, one of the responses came from Maurice Solovine, a 26-year-old Romanian student from a wealthy family who was fascinated by the big ideas in physics and philosophy, but had no clear sense of what direction to follow. In him, Einstein found a kindred spirit, and the idea of Solovine paying for his education was soon forgotten as they became firm friends and met frequently to discuss the big issues of the day. Early in the summer, they were joined by Conrad Habicht, a mathematics student, and took to calling themselves the ‘Olympia Academy’, meeting regularly in the evenings and working their way steadily through books on the big ideas in philosophy and physics. Among the most influential of these works on Einstein himself were those by David Hume, Ernst Mach and Henri Poincaré. It was Poincaré who introduced Einstein to the concept of non-Euclidean geometries, mathematically self-consistent and logical versions of geometry in which, for example, the angles of a triangle do not add up to 180° and parallel lines can either meet or diverge from one another.f Poincaré’s book Science and Hypothesis, which the ‘Academy’ studied and discussed in detail, poses an interesting question about the relationship between these geometries and the world we live in. Poincaré asked his readers what would happen if astronomers discovered that a pair of parallel light rays travelling through space eventually converged on one another. Would they conclude that space obeyed non-Euclidian geometry? Or would they conclude that some unknown force was bending the light rays? Poincaré had no doubt that the answer would be in favour of the unknown force.

  While Albert enjoyed himself in poverty in Bern, Mileva had returned to Zurich, without her baby, who was left with her relatives or a friend back home. Einstein’s visits were rare, even when she moved to a small town closer to Bern, and in spite of the warmth of his letters to her it seems likely that the relationship might have ended in the way his relationship with Marie Winteler had ended, if it had not been for the child and the sense of duty that he felt towards the woman that he had, in what was still the language of the day, ‘ruined’.

  Mileva’s prospects brightened in May 1902, when Einstein was at last called for an interview at the patent office and duly offered the post of ‘Technical Expert III Class’. The other person appointed at the same time was an engineer, Heinrich Schenk. The patent office had recognised the need for a physicist because so much of their work now concerned inventions based on the application of electromagnetism, but Einstein’s lack of experience in technical matters meant that he was initially appointed on probation, at a salary of 3,500 francs a year (roughly twice what he would have got in a university assistantship). Although he took up the post in June 1902, it wasn’t until September 1904 that his appointment was confirmed as permanent and his salary increased to 3,900 francs. But even the initial salary was a fortune to Einstein, who happily wrote to Mileva that now he could abandon the ‘annoying business of starving’.11

  There was now no financial impediment to the marriage. But there was still strong opposition from Einstein’s parents, who knew about the baby. Einstein’s mother Pauline, in particular, regarded Mileva as a scheming foreign hussy who was trying to trap her son. The situation wasn’t helped by the fact that even though the Einsteins were secular Jews, nobody in the family had married a Gentile before. In spite of his independent nature and rebellious streak, Einstein couldn’t bring himself to defy them on this occasion. His reluctance may have been partly due to a desire not to cause them more grief at a time when the family was already under stress. The latest business hadn’t actually gone bust, but it was clear that it would never be profitable enough to repay the huge debts that the Einsteins owed to their relatives, who had begun pressing for the money. In addition, Einstein’s father, Hermann, was ill with heart trouble, undoubtedly exacerbated because of the stress caused by his years as an unsuccessful businessman. On October 1902, his heart finally gave up the struggle; Hermann was just 55.

  According to Einstein’s sister Maja, on his deathbed Hermann relented and gave Einstein formal permission to marry Mileva.12 Ironically, though, his death left Einstein rather less able to support a wife, since he began sending part of his salary to Pauline each month, to help her to pay off the debts her husband had left her with. Nevertheless, towards the end of the year Mileva moved to Bern, and on 6 January 1903 the couple were married at the register office. The only witnesses were the other two ‘Olympians’, Habicht and Solovine. Much later, to his biographer Carl Seelig, Einstein would admit that he had married from a ‘sense of duty’ in spite of his feelings of ‘internal resistance’. For her part, Mileva still seems to have regarded it as a love match, and to have happily taken on the domestic role, cooking and looking after her new husband, while tolerating his friends. The only problem, from her point of view, was what to do about Lieserl.

  The couple settled into a comfortable existence in their apartment in Bern. Albert wrote to his old friend Besso that: ‘[I] am living a very pleasant, cosy life with my wife. She takes excellent care of everything, cooks well, and is always cheerful.’13 While Mileva wrote to her friend Helene Savic: ‘[Albert] is my only companion and society and I am happiest when he is beside me.’14

  But she was not his ‘only companion and society’. He still had his work at the patent office, which he enjoyed, and his friends, including the ‘Olympians’. And he had his research, which was now developing along extremely promising lines, which he carried out in his own time and also when things were quiet in the patent office. Betw
een 1902 and 1904 Einstein produced a series of three papers, all published in the Annalen der Physik, which came close to making him a name as an important member of the scientific community. Working completely on his own, he found how to interpret the laws of thermodynamics mathematically entirely in terms of the statistical behaviour of a myriad of tiny particles, laying the foundations of statistical mechanics. The only snag was, entirely unknown to Einstein, the American Josiah Willard Gibbs had beaten him to it and published what became the standard work on statistical mechanics in 1902. Their two approaches were almost the same, but Einstein only came across Gibbs’s book in 1905, after it had been translated into German. The fact that two people independently came up with the foundations of statistical mechanics at about the same time is not surprising, since this step was (for anyone clever enough to take it) a logical progression from the work of the pioneers such as Maxwell and Boltzmann. It was just Einstein’s bad luck that on this occasion he came second, but anyone who read and understood those papers in the Annalen der Physik can have been left in little doubt that the author was a scientist of note.

  We don’t know what discussions took place between Albert and Mileva in the first months of their marriage concerning Lieserl, but in August Mileva set off back to her homeland to sort the situation out. She was away for a month, during which she found out that she was pregnant again, and returned without the little girl. Historians have scoured the fragmentary correspondence that survives from the period, and the official records, in an effort to find out what happened to Lieserl, but in effect she just disappeared from sight in September 1903. The consensus is that she was adopted, most probably given up formally to strangers or possibly informally taken into the family of Mileva’s friend Helene Savic and given another name. A reference to scarlet fever in one of Albert’s letters to Mileva also raises the possibility that she died in infancy, as so many children did at the time. Whatever Lieserl’s fate, when Mileva returned to Bern in the autumn of 1903 it was essentially a fresh start, crowned by the arrival of Einstein’s first son, Hans Albert, on 14 May 1904.

  By then, there were major changes in Einstein’s circle of friends. Habicht and Solovine had finished their studies and moved on, but by that time Einstein had a more than adequate scientific sounding board to replace them. His friend Michele Besso had been finding it hard to make a living as a freelance engineer, and when a vacancy for ‘Technical Expert II Class’ came up at the patent office, Einstein drew Besso’s attention to it. Besso applied and got the job, starting in the summer of 1904. He was a grade above Einstein and earned an annual salary of 4,800 francs (Einstein’s raise to 3,900 francs would not come through until September), but this was entirely appropriate to his age and experience.

  Now Einstein had a companion he could talk to about science during breaks at work, while walking to and from the patent office, and during his so-called leisure time. But there was very little real leisure time. Contemporary accounts describe how even when Einstein was pushing Hans Albert about in his baby carriage on a Sunday afternoon stroll, he would have his pipe in his mouth and a notepad resting on the carriage, ready to write down his thoughts when inspiration struck. Thanks to Mileva, he had no domestic worries at all and never had to concern himself with routine details like cooking and cleaning. It was in this sense that she would make a major contribution to his miraculous year, and although she might have dreamed of sharing a scientific partnership with Albert like that of Marie and Pierre Curie (who won the Nobel Prize together in 1903), it was not to be.

  With the breakup of the ‘Olympians’, the arrival of his son and Besso on the scene, and three solid scientific papers under his belt, Einstein now seems to have taken himself more seriously. Before, ideas had been tossed about in discussions over coffee and wine, but few of them had been followed through rigorously. Now, he buckled down to work through some of the ideas that had been floating around in his head for years. First, he would complete a new dissertation, making use of his growing understanding of statistical processes, and make a proper try for that elusive PhD. And then, there were three other ideas he had, concerning the reality of atoms, Planck’s light quanta and the old puzzle about what the world would look like if you could travel at the speed of light. By the end of 1904 the scene was set, although even Einstein cannot have sensed it, for the greatest outpouring of scientific creativity since the time of Isaac Newton.

  Footnotes

  a Maja’s reminiscences are preserved in the Einstein archive at Princeton University.

  b His name is sometimes translated as ‘Talmud’.

  c Shortly after Albert arrived, the family moved to the smaller town of Pavia, near Milan.

  d My Plans for the Future.

  e More precisely, 299,792.458 km/second. In a logical world, the second would be redefined to make the speed of light exactly 300,000 km/sec.

  f Coincidentally, Marcel Grossmann was studying non-Euclidean geometry for his PhD at around the same time.

  2

  The Annus Mirabilis

  The doctoral thesis; Jiggling atoms; Particles of light; The special one

  In March 1905, Albert Einstein celebrated his 26th birthday; two months later, his son Hans Albert celebrated his first birthday. That year, Einstein was living in a settled household with a steady job, his close friend Besso to talk to about scientific matters, and a settled routine for working on his own scientific projects in his own time. This didn’t leave much time for his family, and although he was a loving father he would hardly be regarded as a role model today. The ‘problem’ of Lieserl had been resolved, for good or bad, and once it was resolved his daughter seems to have been dismissed from his mind. Mileva, for all her one-time scientific aspirations, was essentially a conventional housewife, looking after her man so that he could concentrate on higher things. And as for being a father, rather than suffering the distractions most new fathers go through, Einstein just ignored them, the way he would ignore anything that threatened to disturb his scientific work throughout his life.a Several accounts recall how on those occasions when he was supposed to be looking after the baby he might be found with his pipe in his mouth, rocking the cradle with one hand, while writing out calculations on his ubiquitous notepad with the other. This ability to switch off from the distractions of the world around him and to concentrate on the problems he was interested in was a major reason why he was able to produce such an outpouring of papers in 1905, and to maintain a high standard of scientific achievement for many more years to come.

  The first hint of what Einstein had been up to in the early months of 1905 came in a letter he wrote at the end of May to his friend Conrad Habicht:

  I promise you four papers, the first … deals with radiation and the energetic properties of light and is very revolutionary, as you will see … The second paper is a determination of the true size of atoms by way of the diffusion and internal friction of diluted liquid solutions of neutral substances. The third proves that, on the assumption of the molecular theory of heat, particles of the order of magnitude of 1⁄1000 millimeters suspended in liquids must already perform an observable disordered movement, caused by thermal motion. Movements of small inanimate suspended bodies have in fact been observed by the physiologists and called by them ‘Brownian molecular movement’. The fourth paper is at the draft stage and is an electrodynamics of moving bodies, applying a modification of the theory of space and time; the purely kinematic part of this paper is certain to interest you.1

  That has to be one of the most remarkable letters in the history of science. The first paper Einstein mentions established the reality of light quanta (what we now call ‘photons’), and was so revolutionary that it earned him the Nobel Prize – although because it was so revolutionary it took sixteen years for the rest of the scientific community to catch up with him and make that award. The second paper formed the basis of his doctoral dissertation. The third proved the reality of atoms. And the fourth presented a bemused world with the
Special Theory of Relativity.

  The doctoral thesis

  I will describe these pieces of work in a slightly different order, starting with the doctoral thesis. One good reason for doing this is that this was the least revolutionary of the four papers, and Einstein knew it. When he decided to make a second attempt at obtaining a PhD from the University of Zurich, Einstein didn’t set out on a specific new project to achieve that goal, but simply seems to have looked at the various projects he had in hand and chosen the most straightforward one, based on solid, traditional methods, that wouldn’t tax the imaginations of the professors at the university too much. He was also careful to choose a piece of work based on experimental observations, although he didn’t carry out the experiments himself. There is a story, originating with Einstein’s sister Maja,2 that Einstein first offered his paper on the electrodynamics of moving bodies (the Special Theory of Relativity) and it was rejected because the examiners didn’t understand it; but this seems to be a myth. There is no evidence of such a rejected application, Einstein had more sense than to baffle the examiners in this way, and in any case the paper was the last of the four to be completed, as the letter to Habicht shows.