by Manjit Kumar
Planck acknowledged his debt to Boltzmann. Having named k after the Austrian, a constant that he had discovered in his research leading up to the blackbody formula, Planck also nominated Boltzmann for the Nobel Prize in 1905 and 1906. By then it was too late. Boltzmann had long been plagued by ill health – asthma, migraines, poor eyesight and angina. Yet none of these were as debilitating as the bouts of severe manic depression he suffered. In September 1906, while on holiday in Duino near Trieste, he hanged himself. He was 62, and though some of his friends had long feared the worst, news of his death came as a terrible shock. Boltzmann had felt increasingly isolated and unappreciated. It was untrue. He was among the most widely honoured and admired physicists of the age. But continuing disputes over the existence of atoms had left him vulnerable during periods of despair to believing that his life’s work was being undermined. Boltzmann had returned to Vienna University for the third and last time in 1902. Planck was asked to succeed him. Describing Boltzmann’s work as ‘one of the most beautiful triumphs of theoretical research’, Planck was tempted by the Viennese offer but declined.63 h was the axe that chopped up energy into quanta, and Planck had been the first to wield it. But what he quantised was the way his imaginary oscillators could receive and emit energy. Planck did not quantise, chop into h-sized chunks, energy itself. There is a difference between making a discovery and fully understanding it, especially in a time of transition. There was much that Planck did that was only implicit in his derivation, and not even clear to him. He never explicitly quantised individual oscillators, as he should have done, but only groups of them.
Part of the problem was that Planck thought he could get rid of the quantum. He only realised the far-reaching consequences of what he had done much later. His deep conservative instincts compelled him to try for the best part of a decade to incorporate the quantum into the existing framework of physics. He knew that some of his colleagues saw this as bordering on a tragedy. ‘But I feel differently about it’, Planck wrote.64 ‘I now know for a fact that the elementary quantum of action [h] played a far more significant part in physics that I had originally been inclined to suspect.’
Years after Planck’s death in 1947, at the age of 89, his former student and colleague James Franck recalled watching his hopeless struggle ‘to avoid quantum theory, [to see] whether he could not at least make the influence of quantum theory as little as it could possibly be’.65 It was clear to Franck that Planck ‘was a revolutionary against his own will’ who ‘finally came to the conclusion, “It doesn’t help. We have to live with quantum theory. And believe me, it will expand.”’66 It was a fitting epitaph for a reluctant revolutionary.
Physicists did have to learn to ‘live with’ the quantum. The first to do so was not one of Planck’s distinguished peers, but a young man living in Bern, Switzerland. He alone realised the radical nature of the quantum. He was not a professional physicist, but a junior civil servant whom Planck credited with the discovery that energy itself is quantised. His name was Albert Einstein.
Chapter 2
THE PATENT SLAVE
Bern, Switzerland, Friday, 17 March 1905. It was nearly eight o’clock in the morning as the young man dressed in the unusual plaid suit hurried to work clutching an envelope. To a passer-by, Albert Einstein appeared to have forgotten that he was wearing a pair of worn-out green slippers with embroidered flowers.1 At the same time six days a week, he left his wife and baby son, Hans Albert, behind in their small two-room apartment in the middle of Bern’s picturesque Old Town quarter, and walked to the rather grand sandstone building ten minutes away. With its famous clock tower, the Zytloggeturm, and arcades lining both sides of the cobbled street, Kramgasse was one of the most beautiful streets in the Swiss capital. Lost in thought, Einstein hardly noticed his surroundings as he made his way to the administrative headquarters of the Federal Post and Telephone Service. Once inside he headed straight for the stairs and the third floor that housed the Federal Office of Intellectual Property, better known as the Swiss Patent Office. Here he and the dozen other technical experts, men in more sober dark suits, laboured at their desks for eight hours a day sorting out the barely viable from the fatally flawed.
Three days earlier, Einstein had celebrated his 26th birthday. He had been a ‘patent slave’, as he called it, for nearly three years.2 For him the job brought to an end ‘the annoying business of starving’.3 The work itself he enjoyed for its variety, the ‘many-sided thinking’ it encouraged and the relaxed atmosphere of the office. It was an environment Einstein later referred to as his ‘worldly monastery’. Although the post of technical expert, third class, was a humble one, it was well-paid and allowed him time enough to pursue his own research. Despite the watchful eye of his boss, the formidable Herr Haller, Einstein spent so much time between examining patents secretly doing his own calculations that his desk had become his ‘office for theoretical physics’.4
‘It was as if the ground had been pulled out from under one, with no firm foundation to be seen anywhere, upon which one could have built’, was how Einstein recalled feeling after reading Planck’s solution of the blackbody problem soon after it was published.5 What he sent in the envelope to the editor of Annalen der Physik, the world’s leading physics journal, on 17 March 1905 was even more radical than Planck’s original introduction of the quantum. Einstein knew that his proposal of a quantum theory of light was nothing short of heresy.
Two months later, in the middle of May, Einstein wrote to his friend Conrad Habicht promising to send four papers he hoped to see published before the year’s end. The first was the quantum paper. The second was his PhD dissertation in which he set out a new way to determine the sizes of atoms. The third offered an explanation of Brownian motion, the erratic dance of tiny particles, like grains of pollen, suspended in liquid. ‘The fourth paper,’ Einstein admitted, ‘is only a rough draft at this point and is an electrodynamics of moving bodies which employs a modification of the theory of space and time.’6 It is an extraordinary list. In the annals of science only one other scientist and one other year bears comparison with Einstein and his achievements in 1905: Isaac Newton in 1666, when the 23-year-old Englishman laid the foundations of calculus and the theory of gravity, and outlined his theory of light.
Einstein would become synonymous with the theory first sketched out in his fourth paper: relativity. Although it would change humanity’s very understanding of the nature of space and time, it was the extension of Planck’s quantum concept to light and radiation that he described as ‘very revolutionary’, not relativity.7 Einstein regarded relativity as simply a ‘modification’ of ideas already developed and established by Newton and others, whereas his concept of light-quanta was something totally new, entirely his own, and represented the greatest break with the physics of the past. Even for an amateur physicist it was sacrilegious.
For more than half a century it had been universally accepted that light was a wave phenomenon. In ‘On a Heuristic Point of View Concerning the Production and Transformation of Light’, Einstein put forward the idea that light was not made up of waves, but particle-like quanta. In his resolution of the blackbody problem Planck had reluctantly introduced the idea that energy was absorbed or emitted as quanta, in discrete lumps. However, he, like everyone else, believed that electromagnetic radiation itself was a continuous wave phenomenon, whatever the mechanism of how it exchanged energy when it interacted with matter. Einstein’s revolutionary ‘point of view’ was that light, indeed all electromagnetic radiation, was not wavelike at all but chopped up into little bits, light-quanta. For the next twenty years, virtually no one but he believed in his quantum of light.
From the beginning Einstein knew it would be an uphill struggle. He signalled as much by including ‘On a Heuristic Point of View’ in the title of his paper. ‘Heuristic’, as defined by The Shorter Oxford English Dictionary, means ‘serving to find out’. What he was offering physicists was a way to explain the unexplained when it came to l
ight, not a fully worked-out theory derived from first principles. His paper was a signpost towards such a theory, but even that proved too much for those unprepared to travel to a destination in the opposite direction to the long-established wave theory of light.
Received by the Annalen der Physik between 18 March and 30 June, Einstein’s four papers would transform physics in the years ahead. Remarkably, he also found the time and energy to write 21 book reviews for the journal during the course of the year. Almost as an afterthought, since he did not tell Habicht about it, he wrote a fifth paper. It contained the one equation that almost everyone would come to know, E=mc2. ‘A storm broke loose in my mind’, was how he described the surge of creativity that consumed him as he produced his breathtaking succession of papers during that glorious Bern spring and summer of 1905.8
Max Planck, the adviser on theoretical physics for the Annalen der Physik, was among the first to read ‘On the Electrodynamics of Moving Bodies’. Planck was immediately won over by what he, and not Einstein, later called the theory of relativity. As for the quantum of light, though he profoundly disagreed with it, Planck allowed Einstein’s paper to be published. As he did so he must have wondered about the identity of this physicist capable of the sublime and the ridiculous.
‘The people of Ulm are mathematicians’ was the unusual medieval motto of the city on the banks of the Danube in the south-western corner of Germany where Albert Einstein was born. It was an apt birthplace on 14 March 1879 for the man who would become the epitome of scientific genius. The back of his head was so large and distorted, his mother feared her newborn son was deformed. Later he took so long to speak that his parents worried he never would. Not long after the birth of his sister, and only sibling, Maja in November 1881, Einstein adopted the rather strange ritual of softly repeating every sentence he wanted to say until satisfied it was word-perfect before uttering it aloud. At seven, to the relief of his parents, Hermann and Pauline, he began to speak normally. By then the family had lived in Munich for six years, having moved so Hermann could open an electrical business in partnership with his younger brother Jakob.
In October 1885, with the last of the private Jewish schools in Munich closed for more than a decade, the six-year-old Einstein was sent to the nearest school. Not surprisingly in the heartland of German Catholicism, religious education formed an integral part of the curriculum, but the teachers, he recalled many years later, ‘were liberal and did not make any denominational distinctions’.9 However liberal and accommodating his teachers may have been, the anti-Semitism that permeated German society was never buried too far beneath the surface, even in the schoolroom. Einstein never forgot the lesson in which his religious studies teacher told the class how the Jews had nailed Christ to the cross. ‘Among the children,’ Einstein recalled years later, ‘anti-Semitism was alive especially in elementary school.’10 Not surprisingly, he had few, if any, school friends. ‘I am truly a lone traveller and have never belonged to my country, my home, my friends, or even my immediate family, with my whole heart’, he wrote in 1930. He called himself an Einspänner, a one-horse cart.
As a schoolboy he preferred solitary pursuits and enjoyed nothing more than constructing ever-taller houses of cards. He had the patience and tenacity, even as a ten-year-old, to build them as high as fourteen storeys. These traits, already such a fundamental part of his make-up, would allow him to pursue his own scientific ideas when others might have given up. ‘God gave me the stubbornness of a mule,’ he said later, ‘and a fairly keen scent.’11 Though others disagreed, Einstein maintained he possessed no special talents, only a passionate curiosity. This quality that others had, however, coupled with his stubbornness, meant that he continued to seek the answer to almost childlike questions long after his peers were taught to stop even asking them. What would it be like to ride on a beam of light? It was trying to answer this question that set him on his decade-long path to the theory of relativity.
In 1888, aged nine, Einstein started at the Luitpold Gymnasium, and he later spoke bitterly of his days there. Whereas young Max Planck enjoyed and thrived under a strict, militaristic discipline focused on rote learning, Einstein did not. Despite resenting his teachers and their autocratic methods, he excelled academically even though the curriculum was orientated towards the humanities. He scored top marks in Latin and did well in Greek, even after being told by his teacher ‘that nothing would ever become of him’.12
The stifling emphasis on mechanical learning at school, and during music lessons with tutors at home, was in stark contrast to the nurturing influence of a penniless Polish medical student. Max Talmud was 21, and Albert ten, when every Thursday he began dining with the Einsteins as they adopted their own version of an old Jewish tradition of inviting a poor religious scholar to lunch on the Sabbath. Talmud quickly recognised the inquisitive young boy as a kindred spirit. Before long the two would spend hours discussing the books that Talmud had given him to read or had recommended. They began with books on popular science that brought to an end what Einstein called his ‘religious paradise of youth’.13
The years at a Catholic school and instruction at home by a relative on Judaism had left their mark. Einstein, to the surprise of his secular parents, had developed what he described as ‘a deep religiosity’. He stopped eating pork, sang religious songs on the way to school, and accepted the biblical story of creation as an established fact. Then, as he devoured one book after another on science, came the realisation that much of the Bible could not be true. It unleashed what he called ‘a fanatic freethinking coupled with the impression that youth is intentionally being deceived by the State through lies; it was a crushing impression’.14 It sowed the seeds of a lifelong suspicion of every kind of authority. He came to view the loss of his ‘religious paradise’ as the first attempt to free himself from ‘the chains of the “merely personal”, from an existence which is dominated by wishes, hopes and primitive feelings’.15
As he lost faith in the teachings of one sacred book, he began to experience the wonder of his sacred little geometry book. He was still at primary school when his Uncle Jakob introduced him to the rudiments of algebra and began posing problems for him to solve. By the time Talmud gave him a book on Euclid’s geometry, Einstein was already well versed in mathematics not normally expected of a boy of twelve. Talmud was surprised at the speed with which Einstein worked through the book, proving the theorems and completing the exercises. Such was his zeal that during the summer vacation he mastered the mathematics to be taught the following year at school.
With a father and an uncle in the electrical industry, Einstein not only learnt about science through reading but was surrounded by the technology that its application could produce. It was his father who unwittingly introduced Einstein to the wonder and mystery of science. One day, as his son lay ill in bed with a fever, Hermann showed him a compass. The movement of the needle appeared so miraculous that the five-year-old trembled and grew cold at the thought that ‘Something deeply hidden had to be behind things.’16
The Einstein brothers’ electrical business initially prospered. They went from manufacturing electric devices to installing power and lighting networks. The future seemed bright as the Einsteins notched up one success after another, including the contract to provide the first electric lighting for Munich’s famous Oktoberfest.17 But in the end the brothers were simply outgunned by the likes of Siemens and AEG. There were many small electrical firms that prospered and survived in the shadow of these giants, but Jakob was over-ambitious and Hermann too indecisive for their company to be one of them. Beaten but not bowed, the brothers decided that Italy, where electrification was just beginning, was the place to start afresh. So in June 1894 the Einsteins relocated to Milan. All except fifteen-year-old Albert who was left behind in the care of distant relatives to complete the three remaining years to graduation from the school he detested.
For the sake of his parents he pretended that everything was fine in Munich. However, he
was increasingly troubled by the thought of compulsory military service. Under German law, if he remained in the country until his seventeenth birthday, Einstein would have no choice but to report for duty when the time came or be declared a deserter. Alone and depressed, he had to think of a way out, when suddenly the perfect opportunity arose.
Dr Degenhart, the teacher of Greek who thought Einstein would never amount to anything, was now also his form tutor. During a heated argument, Degenhart told Einstein he should leave the school. Requiring no further encouragement, he did just that after obtaining a medical certificate stating that he was suffering from exhaustion and required complete rest to recover. At the same time, Einstein secured a testimonial from his mathematics teacher that he had mastered the subject to a level required to graduate. It had taken him just six months to follow in the footsteps of his family and cross the Alps into Italy.
His parents tried to reason with him, but Einstein refused to go back to Munich. He had an alternative plan. He would stay in Milan and prepare for the entrance exams, the following October, of the Federal Polytechnikum in Zurich. Established in 1854, and renamed Eidgenossische Technische Hochschule (ETH) in 1911, the ‘Poly’ was not as prestigious as Germany’s leading universities. However, it did not require graduation from a gymnasium as a precondition for entry. To be accepted, he explained to his parents, he just needed to pass its entrance exams.