Timeless Figures, #1: Albert Einstein

So much has been written about Albert Einstein over the ages that it is sometimes easy to take for granted and forget what made him special. Most of us know the earth-shattering impact his special and general theories of relativity had on physics, but it is easier to forget the very special man whose character traits undoubtedly made these soaring works of the human intellect possible.

Einstein’s parents, Hermann and Pauline, were intelligent and diligent. Hermann had an affinity for mathematics but had to become an apprentice and a professional to make ends meet. Pauline had an affinity for music and German literature. Their son inherited both talents, although later in life – perhaps repulsed by the Nazis’ obsessions with heredity – he attributed his success simply to heightened curiosity rather than inheritance. But given the respectable but by no means outstanding degree of his parents’ intellect, it is hard to deny that Einstein was the product of a very lucky genetic lottery.

In later popular accounts, Einstein was typically portrayed as a lazy student lost in his world, with a lackluster performance in school. But like other Einstein myths, this was false; he consistently received the highest grades grades, especially in mathematics and the sciences. His bent for science was clear at an early age and was illustrated especially by two episodes whose vivid impressions on him he could recall even decades later. One was the gift of a compass when he was five years old and sick: Albert was enthralled by the fact that the needle always pointed North, and this alerted him to “something deeply hidden” in the laws of Nature. The second was when his uncle Jakob introduced him to algebra: “We go hunting for an animal whose name we don’t know, so we call it x. When we bag our game, we pounce on it and give it its right name.”

It was early on that Einstein demonstrated his two most important traits, more important even than the glittering intellect that had been bestowed upon him. One was an open disdain for conformity and authoritarianism, whether it was in renouncing his German citizenship at the startling age of sixteen to avoid military conscription, impertinently questioning his professors or marrying his girlfriend Mileva Marić against his parents’ approval. Later these same traits would lead him to discover a revolutionary theory of physics (assuming that the speed of light was constant took an enormous amount of courage), snub his nose at German militarism and antisemitism, leave the country of his birth for good and carry on political activism in his adopted country. An accompanying trait was fearlessness; fearlessness at being mocked for his scientific and political beliefs. Both traits were enveloped in a self-effacing humor that let him see the absurd in life and the world. Undoubtedly these traits, and especially the humor, kept him sane at the brink of scientific discovery and in a world gone half-mad.

The story of Einstein’s lackluster educational performance is well-known. He lived a Bohemian existence and preferred to hang out with his friends in coffee shops, discussing philosophy and science and playing music on his violin. His admission to the famed ETH in Zurich failed because he did not do well enough in the general examination and had to take remedial courses. After he got in on his second attempt, he met the twenty-year-old Mileva – the only woman in his class – and was instantly smitten. His letters to her are full of passionate pronouncements, dirty limericks and poetry.

Graduating from the ETH, Einstein had trouble finding a teaching and research position. There is a letter from around his time from an anguished Hermann to the distinguished physical chemist Wilhelm Ostwald, later the winner of a Nobel Prize, asking for the good professor to give his son a job as an assistant. There is no reply from Ostwald on record. It was thanks to his friend Marcel Grossman’s father that Einstein found a job as a patent clerk, “third-class”, at the Swiss patent office in Bern. Grossmann was to later play a major role in Einstein’s mathematical enlightenment.

Einstein’s time at the patent office from 190 to 1909 and his ‘annus mirabilis’ of 1905, in which he produced five revolutionary papers that forever changed our understanding of physics, is well documented; these included the paper in which he introduced his famous equation relating mass to energy. In all of his science, Einstein’s two most important qualities were summed up by his biographer Abraham Pais: they were an appreciation for invariants (quantities that are independent of the frame of reference) and for statistical fluctuations. The former would enable him to explain relativity, the latter phenomena like Brownian motion and Bose-Einstein condensation.

What is perhaps less appreciated is the contribution of his humdrum daily job to the theory of relativity. Relativity sprang not from abstract manipulation of algebraic symbols but from imaginative thought experiments concerning everyday objects - clocks, rulers, trains, elevators. It was his time at the patent office that immersed Einstein in the details of mechanical implements. His daily job involved sharpening the often fuzzy, vague, partially thought-out ideas of inventors to make them legally defensible and workable in practice. He was quite good at this analysis and received praise from his supervisor as one of the most competent young men in the office. It is impossible to overestimate the impact of this immersion in the details of technical contrivances on Einstein’s future work on the frontiers of physics. Crucially, the job at the patent office left him free to focus on his physics and family in the evenings.

Einstein’s family life was not happy, to say the least, and he was not by any means the role model of the family man. Mileva, who herself had sacrificed a promising career, took care of the house and children and acted as an important sounding board for Einstein’s initial ideas, so much so that controversy later arose as to how much she might have contributed to them (there is no evidence that the key ideas came from anyone but Einstein). Einstein repaid her by omitting her name from the acknowledgments of his relativity paper, mentioning only his ETH friend Michele Besso who was another sounding board. The marriage was strained and often acrimonious. Einstein wrecked it by beginning an affair with his cousin, Elsa, in 1912; he would later have several affairs. When Mileva learned of his adultery, she moved to Zurich, taking their sons Eduard and Hans Albert. In 1919, after having her agree to a harsh set of conditions for remaining married to him, Einstein finally asked Mileva for a divorce; in return, he predicted that he would win the Nobel Prize and would give her the money from it. He did win it two years later, amusingly not for relativity, which even then was too abstract for the prize committee, but for his explanation of the photoelectric effect that grounded the nature of light in particles called photons.

After his annus mirabilis during which Einstein formulated the special theory of relativity, Einstein spent a hard ten years before coming up with the general theory of relativity. Both ideas were revolutionary, but Paul Dirac later remarked that while other scientists like Poincare and Lorentz might have stumbled upon the first one, it might have taken forever for anyone to discover the second one; its tenets were that original and novel. Einstein’s formulation of general relativity replaced gravity as a Newtonian force with gravity as a fundamental curvature of spacetime. He arrived at this startling, unexpected conclusion the same way that he had arrived at special relativity’s conclusions - by thinking of thought experiments. With special relativity, it was asking how the world would look like if he rode on a beam of light, a question he had first asked himself when he was sixteen. With general relativity it was realizing that a man in free fall would not feel his own weight - he called this thought the happiest thought of his life.

Unlike special relativity which could be explained with high school algebra - the physics was what was novel - general relativity needed mathematics that Einstein had never encountered. This is where his patent office friend Marcel Grossmann was crucial. After Einstein explained the requirements of general relativity, most notably the requirement of general covariance that would enable the laws of physics to look the same in all reference frames, Grossman told him that two branches of 19th-century mathematics would help him accomplish this. One was Riemannian geometry, developed by the German mathematical genius Bernhard Riemann, which extended plane geometry to curved surfaces. The other was the algebra of tensors, which are generalized extensions of vectors. 

That Einstein needed Grossmann’s insights to help him is a testament to his greatness as a physicist rather than a mathematician. It explains why there was no scientist like Einstein in the 20th century: while physicists like Paul Dirac, Wolfgang Pauli and Werner Heisenberg were more mathematically adept than Einstein, his feel for the physical picture and the thought experiment were unsurpassed. Among other physicists, probably only Richard Feynman and Enrico Fermi came close to this facility for visualizing the physical picture. In his later life, this facility left Einstein, and his failures would be explained by a peculiar over-reliance on mathematics which he had wisely avoided in his younger years.

1915, when war was engulfing the continent, saw Einstein putting the finishing touches on general relativity as a professor in Berlin; when he saw the equation explaining the longstanding problem of the anomalous precession of the orbit of Mercury, its deep truth made him feel like something had snapped inside him. Einstein was deeply shocked by Germany’s bombastic militarism and march toward war. His pacifism writ large, he refused to sign a letter supporting the war signed by ninety-three German scientific and artistic luminaries including Nobel laureates like Max Planck, Paul Ehrlich and Emil Fischer. Because of the war, experimental confirmation of general relativity had to wait until 1919, when an expedition to Africa led by the British astronomer Arthur Eddington confirmed a key prediction of the theory observable only during a total eclipse of the sun - the bending of starlight.

The prediction catapulted Einstein to the status of the world’s most famous scientist. Crowds thronged to hear him speak, and Eddington’s validation of his theory was also seen as the joining of nationalities that had been broken by a horrific war. In lecture tours of Asia and America, Einstein was welcomed as a celebrity; he met Charlie Chaplain and Upton Sinclair, and parents pushed their way through crowds to have their children meet him. But at home, where the “stab in the back” theory attributing Germany’s loss to communists and Jews was already being swallowed by many, including a young corporal named Adolf Hitler who had been blinded by poison gas, Einstein started finding a hostile reception. The Nobel laureates Johannes Stark and Philip Lenard had started agitating against him, and the general sullen mood of Germany because of the harsh terms imposed by the Treaty of Versailles made it easy for the population to search for easy scapegoats. Einstein’s friend Walther Rathenau, whose crucial actions as minister of production had made it possible for Germany to continue the war until 1919, was assassinated in 1922 by ultranationalists. Because of his internationalism and pacifism during the war, Einstein was a marked man and had good cause to fear for his own life.

His physics temporarily quelled conflict. The 1920s provided a fascinating contrast of sorts, between soaring and crippling economic deprivation on the one hand and unprecedented developments in physics on the other. The creation of quantum mechanics, beginning with Niels Bohr’s formulation of the structure of the atom in 1913 and continuing with work by Max Born, Werner Heisenberg, Paul Dirac and others, provided new fodder for Einstein. The same Einstein who had been a revolutionary in relativity became a conservative in quantum mechanics, although his positions were oversimplified later. He never rejected the success of quantum mechanics - through his explanation of the photoelectric effect, he was one of the originators of it, after all - but because of the intrinsic uncertainty and probabilistic interpretations it introduced, never thought it was a deep, final explanation of the world’s workings. His skepticism did not stop him from making two major contributions to it even in the 1920s; along with helping the Indian physicist Satyendranath Bose develop a novel form of quantum statistics, Einstein laid the foundations of what later became the laser.

But his philosophical problems with quantum mechanics continued for the rest of his life. They also led to a deep friendship with Niels Bohr. When Bohr had formulated his theory of atomic structure, Einstein had called it the “highest form of musicality in the sphere of thought”. Bohr was as deep a thinker in physics as Einstein; he and Einstein became intimate friends as well as spirited adversaries, forming a relationship which held fast and strong until the end of their lives. Each time Einstein would come up with what was purportedly a violation of a fundamental quantum principle like Heisenberg’s uncertainty principle, such as in the famous 1927 Solvay Conference, Bohr would reply with a rejoinder that sometimes embarrassingly relied on explanations based on Einstein’s own theories of relativity. Bohr’s “Discussions with Einstein on Epistemological Problems in Atomic Physics” is the most complete account of his disagreements.

In the 1930s, storm clouds gathered over Europe again as the Nazi party won increasingly larger shares of votes in the Reichstag elections. In January 1933, using perfectly legal means effected by a foolish and deluded Hindenburg and his associates, Adolf Hitler became chancellor of journey. A month later, Einstein, who had experienced increasing attacks and personal antisemitism since the 1920s and who was visiting the United States, announced that he would no longer return to Germany. That March, he renounced his German citizenship for the second time; he would not return to the country of his birth and high accomplishments for the rest of his life. By that time, knowing what direction the winds were blowing, Einstein had already discussed positions at Oxford, Caltech and the newly conceived Institute for Advanced Study. Future institute director Abraham Flexner was an ardent believer in what he called the “usefulness of useless knowledge.” With no teaching and administrative duties, Einstein accepted the IAS offer, becoming the baggy pant-wearing, shaggy-haired, affable sage of the small, provincial town of Princeton, NJ, for the next thirty years.

Einstein may have been a genius, but he was certainly not immune to mistakes. Two stand out, not so much because they demonstrate Einstein’s failures as his mode of thinking. In 1917, Einstein applied his general theory of relativity to the entire universe, essentially founding modern cosmology. Curiously, he found out that his toy universe would not remain static but would instead expand like a balloon. To keep it static, he introduced a “cosmological constant” that would retard its expansion. But in 1922, the Russian physicist Alexander Friedmann found that Einstein’s equations are valid in a non-static universe. Einstein often called the cosmological constant his “biggest mistake”, but by the 1930s, thanks to the pioneering experimental observations of the American astronomer Edwin Hubble, he had accepted the notion of an expanding universe. In the 1990s, a positive value for the cosmological constant acquired new meaning when independent teams found that the expansion of the universe is accelerating.

Einstein’s second mistake is more interesting: he never accepted the existence of black holes and even wrote a paper arguing against their existence. Freeman Dyson’s explanation for Einstein’s refusal was that by the late 1930s when Robert Oppenheimer and his students had postulated black holes, Einstein had become the mathematical platonist he would turn into during his later years; black holes with their singularities were simply too ugly for him. Einstein’s abhorrence of black holes is a good example of how an excessive emphasis on preconceived beauty can blind even great minds to the logical consequences of their own theories.

Einstein’s time in Princeton was far from the most productive time of his life. He was a celebrity and his advice was sought by dignitaries and crackpots. He met FDR and formed a strong relationship with his Jewish Secretary of the Treasury, Henry Morgenthau. He regularly spoke against the Nazi regime even as the Nazis ransacked his house and burnt his books. But he was no longer at the frontier of physics, which was centered mostly around nuclear physics. In 1932 the neutron was discovered, and physicists had a new tool with which to probe the interior of the atom. Unknown to Einstein, scientists in Italy, Germany, Great Britain and other countries started investigating the effect of neutrons on different nuclei. At the end of 1938, German scientists Otto Hahn and Fritz Strassmann discovered nuclear fission, and physicists across Europe and America quickly realized the possibility of an atomic bomb. Foremost among these was the Hungarian-born American physicist Leo Szilard, who had conceived of a nuclear chain reaction while standing at a traffic light in London in 1933. Szilard and Einstein went back to their times in Berlin, when they had filed a joint patent for an intrinsically safe refrigerator. Szilard realized the urgency of the United States building a nuclear bomb before Germany and sought out Einstein as the only scientist with enough stature to convey the message to President Roosevelt. The famous Einstein-Szilard letter did convince FDR to start a nascent atomic bomb program, which kicked into high gear and became the Manhattan Project after Pearl Harbor. But ironically, Einstein because of his German and pacifist background was never granted a security clearance by the government and invited to join the project.

Later Einstein rued the violent uses to which his science had been put, quipping that he should have rather become a watchmaker or plumber; in an obituary, Oppenheimer puckishly suggested that Einstein had no idea how challenging an American plumber’s job was. However, his disdain for nuclear weapons led Einstein to become a powerful voice of peace and sanity in a world that was becoming increasingly paranoid because of the Cold War. He addressed radio audiences, supported civil rights and socialist dissidents, including former students like David Bohm who had been trapped in Joseph McCarthy’s red scare, and agitated against McCarthy’s thuggery. When Oppenheimer, who was technically Einstein's boss as the director of the Institute for Advanced Study, lost his security clearance because of a witch hunt, Einstein advised him to fling his security clearance at an ungrateful government. Most consequentially, Einstein who had embraced the cause of Zionism for decades, supported the creation of a home for Jewish people in Palestine. But Einstein would almost certainly have been horrified by some of Israel’s right-wing nationalism today; as his later letters indicate, he always wanted Palestine to be equally free to Jews and Arabs, with open entry for all.

Einstein’s scientific and political rebellion won him few friends, although as the world’s most famous scientist, he continued to be idolized. In physics, he had let the particle physics revolution sweep past him and kept on expressing his skepticism of quantum mechanics. The young revolutionary had become an old conservative, leading Oppenheimer to trenchantly remark that he was a “lighthouse, not a beacon.” With his trademark self-effacing humor, Einstein was well aware that he was being treated more like a sacred relic rather than a practicing scientist; in 1942, he described himself as having become “a lonely old man who is displayed now and then as a curiosity because he doesn't wear socks.” Lonely after Elsa had died in 1936, he kept on scribbling equations in quest of a grand unified theory combining gravity and electromagnetism, not realizing that he would critically need the strong and weak nuclear forces that were just being revealed.

On April 17, 1955, Einstein suffered internal bleeding because of a ruptured abdominal aneurysm. Surgery could have prolonged his life for a short period, but he refused, saying  "I want to go when I want. It is tasteless to prolong life artificially. I have done my share; it is time to go. I will do it elegantly.” He died in Princeton Hospital the next day.

Einstein’s life illustrates many lessons, but none more than the importance of curiosity and fearlessness and being true to himself. While the world changed momentously during his life, Einstein did not change in his essentials. His love of science and music and men, his commitment to pacifism and the international brotherhood of men and women, and his almost religious (although secularly so) feeling for the beauty and unity of nature’s laws stayed with him all his life. We are unlikely to see another like him for a long time, although he leaves us with lessons worth emulating for a lifetime.