E=mc2

by David Bodanis

  Arthur Eddington

  AIP EMILIO SEGRE VISUAL ARCHIVES

  This is the point at which the Astronomer Royal, Frank Dyson, called attention to the remarkable eclipse opportunity. If Dyson could get Eddington to arrange the expedition, could Eddington still be deferred, despite that postscript? Dyson's work was relevant to navigation, and so he was close to the admiralty. The admiralty had a word with the Home Office. Eddington was free . . . so long as he led that expedition. They had two years to prepare.

  It rained during the expedition, of course, but this is only what you'd expect on an island off the African coast, just north of the Congo, where Eddington ended up. But remember, Freundlich wasn't with Eddington. The rain cleared, and Eddington got two good plates. Most of the developing would have to be done in Britain, however, and no one would know the result for several months.

  Afterward, Einstein tried to pretend that he hadn't been bothered by the delay. But by mid-September, still having no word, he wrote to his friend Ehrenfest, asking, with overelaborate casualness, if perhaps he'd heard anything about the expedition? Ehrenfest had good connections with the British. But no, he knew nothing. He wasn't even sure if Eddington had made it back.

  In fact, Eddington had been back at Cambridge for several weeks now, but his photographic plates were a mess. They'd been carried by ship to West Africa, then kept in tents on a humid island, then carried into the rainstorm at the start of the eclipse, handled in and out of the camera, then brought back to the tents, and finally shipped by ocean steamer once more. The physical separations Eddington was looking for, in the movement of the distant stars, were going to be measured in tenths of a second of arc. On the small photographic plates, that came to barely a millimeter. (A thick pencil line is about one millimeter. If you have very good vision, you can just make out dust motes 1/20 of a millimeter across.) Eddington had micrometers to help, but Einstein would only be right if these tiny displacements were exactly as predicted, and so far, Eddington couldn't see them clearly enough to be sure if they were. The emulsion from the West Africa plates had become so jellylike in all the heat and transportation that if Eddington was honest he might never make out the necessary detail.

  No one at Cambridge wanted to give up, though, for Einstein's was such a sweet theory. It was tremendous to think that the great tumbling ball of the sun was crashing down on the very fabric of space and time, sagging it so much that distant starlight started veering sideways as it got caught in the bend. Nor was it just the "traditional" mass of the sun that would be doing this. The 1905 equation entered in also. All the heat and radiation blasting out of the sun—all that "energy"—was acting as an additional form of "mass." It added to the bulk of the sun as well. (This was at the heart of what Chandra would build on, in his later sea voyage of 1930.)

  Luckily, the British Empire had its traditions, and one of the prime ones was that something always went wrong. Explorers, conquerors, younger sons and even metal-eyeglassed Quaker astronomers had learned that lesson: picking it up from a lifetime of hearing about one imperial expedition after another.

  And that's why Eddington had sent out a second team—an entire duplicate crew—to be sure he proved Einstein's prediction.

  This second crew had a different telescope, and had been sent to a different continent (they'd been in northern Brazil), and they even had a different mechanical drive for the telescope. It was all in the finest tradition of spreading the odds, and it worked. Once the Brazil team's plates came back, and a special oversized micrometer had been built to fit around their larger plates, and Eddington and the others had measured and remeasured, the congratulatory telegrams started bursting out. Bertrand Russell, who had recently been a Fellow at Trinity, now received a message from his old friend Littlewood: "Dear Russell: Einstein's theory is completely confirmed. The predicted displacement was 1 ".72 and the observed .1"75 +/- .06."

  The celebration was in style. The Royal Astronomical Society was invited to a joint session with the Royal Society on November 6, 1919, in the great room at Burlington House, on Piccadilly. Scientists came in from Cambridge and elsewhere to the stations at King's Cross and Liverpool Street; cabs were taken; nonscientists who'd heard something momentous was to be announced arrived as well. A visitor described the evening: "There was dramatic quality in the very staging:—the traditional ceremonial, and in the background the picture of Newton to remind us that the greatest of scientific generalizations was now, after more than two centuries, to receive its first modifications."

  Dyson spoke, and Eddington spoke—there's no record if any narrow-eyed parole officer from the Home Office was in the room—and then the elderly chairman stood up to speak:

  This is the most important result obtained in connection with the theory of gravitation since Newton's day, and it is fitting that it should be announced at a meeting of the Society so closely connected with him. . . .

  If it is sustained that Einstein's reasoning holds good . . . then it is the result of one of the highest achievements of human thought.

  With World War I just over, these findings were wondrous. God may have seemed lost after the trenches, but now order had been divined in the cosmos. Even better, a German and an Englishman working in harmony had found it. Royalty and generals and political leaders and even artistic figures who'd made their reputation under the old regime—the regime that had led to the slaughters of World War I—were discredited. The category of "people to respect" was nearly empty. Einstein, instantly, was the greatest media celebrity on the planet. Headlines in the New York Times for November 10, 1919, announced:

  "Light All Askew in the Heavens: Men of Science More or Less Agog Over Results of Eclipse Observations."

  and

  "Einstein Theory Triumphs: Stars Not Where They Seemed or Were Calculated to Be, but Nobody Need Worry."

  This meeting was also when the rumors began that only a dozen people could understand what it all meant. The New York Times did have a few knowledgeable science writers, but they were in New York. The London bureau was handed the story, and Henry Crouch was asked to cover Burlington House. In the history of inappropriate assignments this is at the Lyman Briggs level. Crouch was a good journalist in the sense that he knew you had to make a story interesting. He was somewhat less good, however, in having the slightest clue what was going on here—Crouch was the paper's golfing specialist.

  But he was also a Times man through and through, and nothing like a simple lack of knowledge was going to hold him back. He kept on filing, and the headline writers pulled out the key parts of his story:

  "A Book for 12 Wise Men: No More in All the World Could Comprehend It, Said Einstein When His Daring Publishers Accepted It."

  He made that up. Einstein wasn't writing a book, there were no publishers involved—daring or not—and most of the physicists and astronomers attending understood easily enough what the meeting was about. Crouch had started the theory off on its track record of poor public comprehension, from which it never entirely recovered.

  That only added to its fame. In almost all religions, there's a powerful difference between a priest and a prophet. A priest merely stands below an open hole in the sky, and lets the truth that's normally kept hidden up there come pouring down. (Press secretaries and nuclear technicians are examples.) A prophet, however, is someone who manages to journey up through that opening. They are individuals who can venture to that Other Side, before returning back to ordinary life, here with us on Earth. As a result, we'll try to glimpse, in the expression on their face, or in the potent equations they've plucked and brought back down, what things are like up there, in that higher realm, which so many of us believe in, but know we'll never get to visit directly,

  Martin Luther King Jr. and Nelson Mandela have been considered such prophets, carrying down a vision of racial harmony, their words spreading afterward with a power that came from the feeling that they had originated from that higher source. In post-World War I Europe, Einstein's findings
were received with the veneration King's or Mandela's words would be granted later. And since very few people understood Einstein's work at first, all the feeling it suggested—all the desire for transcendence and for knowledge from Einstein's divine library—would soon be shifted onto images of Einstein himself. Perhaps that's why people were attracted to photos of him that had a distinctive, sadly bemused look. They matched the later, most powerful photos of Martin Luther King, where he too seemed to be sadly seeing something greater than ordinary mortals could.

  Einstein tried to push back some of the fame. He called the exaggerating newspaper accounts an amusing feat of imagination. Two weeks after the public announcement, he wrote in the London Times that although the Germans were proudly calling him a German, and the English were proclaiming him a Swiss Jew, if his prediction ever came to be shown false, the Germans would call him a Swiss Jew, and the English would call him a German. In fact, he got it wrong: his astronomical prediction and the 1905 equation both stayed true, but English anti-Semites such as Keynes still scorned him ("a naughty Jew-boy, covered with ink"), and with the rise of Hitler the German government not only called him a Jew but supported the calls to have him killed. After leaving the Continent, and trying England, he ended up in America for the rest of his life: in 1939 signing the letter to President Roosevelt, which, albeit indirectly, helped lead to the atomic bomb; otherwise just living a quiet professorial life at 112 Mercer Street, in Princeton, New Jersey.

  He never especially liked the Ivy League snobbery of Princeton ("this village of puny demi-gods upon stilts," as he described it to a European friend). There were giggling bobby-soxers; the occasional gaping tourist; at the Institute for Advanced Study—a two-mile walk from his home, which he took regularly—younger scientists kept a surface politeness, but he knew that many disparaged him behind his back as someone too old to be useful.

  That alone didn't seem to bother Einstein. His goal, as always, was simply to see what had been intended for our universe by The Old One. What he had scribbled in his now-yellowing manuscripts decades before, as well as the new equations he was constantly working on now—trying to create a theory that would unify in a clear and predictable way all the known forces in the universe—still seemed, to him, the best possible track forward.

  What did hurt him were different reminders of how things had worked out. One, almost too horrible to think of vividly, was implicitly brought up each time he encountered Oppenheimer, his institute's head, who'd led the Manhattan Project that had demonstrated that E=mc2—despite Einstein's lack of involvement—could be turned into vast fields of death in Hiroshima and Nagasaki. "Had I known that the Germans would not succeed in producing an atomic bomb," Einstein once told his longtime secretary, "I would never have lifted a finger. Not a single finger!"

  Then, as the years went on, there was the increasing feeling of his own powers fading away. An unintentionally tactless young assistant once asked him about this. Einstein explained that it was more difficult now to judge which of his ideas were worth pursuing—a great contrast with his younger years, when he'd been superb at identifying the key issues in a field. "Discovery in the grand manner is for young people," he'd once told a friend, ". . . and hence for me a thing of the past."

  He settled into an old man's daily routine, in his simple clapboard suburban house on Mercer Street. His sister, Maja, was with him in America by now. She suffered a severe stroke in 1946, and virtually every evening after that, for the six years till her death, Einstein would drop whatever work he was doing and go to her room, where he would read aloud to her for hours. Before that, most days, there were the mock-chiding rituals with his housekeeper; the saddened disregarding of reminders of his mentally disturbed second son; sometimes visits from a friend with whom he'd enjoyed playing Bach's Double Concerto, as well as the violin parts in Purcell's or Handel's Baroque trios. But there were also the moments, settled comfortably in his upstairs study, when his steadily penciled pages of symbols lifted him back into his past, to the time when anything had seemed possible.

  Albert Einstein

  LIBRARY OF CONGRESS. EMILIO SEGRE VISUAL ARCHIVES

  And the works—of the divine library that he was convinced awaited—could once again be read.

  Appendix

  Follow-up of Other Key Participants

  When MICHAEL FARADAY took over Davy's position at the Royal Institution, he moved permanently into the Royal Institution with his wife. He continued to make major discoveries well into his fifties, but despite many requests, he never took on a personal student.

  After the execution of ANTOINE-LAURENT LAVOISIER, his remains were carted out of Paris, passing through one of his new tollgates that had survived the 1789 attacks. A few months after Lavoisier's death, the body of the man who'd ordered the executions, Marat's colleague Robespierre, was carted through the same gate, and placed in the same common grave. It was a converted wasteland called "Errands" ("maimed person"), which they now shared. Several fragments of the solid tollgates from the GENERAL FARM wall, which Lavoisier had ordered built, can be seen to this day, in the Pare Monceau, and near the metro exit at Denfert-Rochereau.

  A few months before Lavoisier's arrest, a young woman, Charlotte Corday, called at the apartment of JEAN-PAUL MARAT, asking to see him. His guards refused, but when she insisted she had news about dangerous political opponents, he overruled them, and had her let upstairs. Since Marat had skin complaints that forced him to spend much of the day in a bathtub, it was from that position that he greeted her, discovered that the political opponents were members of her family (whom he had ordered killed), and then saw her step forward, knife out. She stabbed him to death, in an assassination later immortalized by the society painter David.

  Since MARIE ANNE PAULZE had been only thirteen when she married Lavoisier, she was just thirty-five when her husband was killed. Although harassed by the Revolutionary government, and her wealthy apartment emptied, she outlived most of her persecutors, and enjoyed a peaceful old age.

  When he went back to Denmark, OLE ROEMER married the daughter of his ethics professor—the man who'd first brought him to the attention of Cassini's scout. Roemer ended up becoming a senior highway inspector, then mayor of Copenhagen, then prefect of police, and for several years was also the equivalent of a Supreme Court judge. In his spare time he worked on an improved device for the measurement of temperatures, which a visiting businessman named Daniel Fahrenheit thought had some merit. Roemer died in 1710, seventeen years before the British experiments that finally proved he'd been right about the speed of light.

  JEAN-DOMINIQUE CASSINI outlived Roemer, and continued to promote only those astronomers who—erroneously— agreed with him that light traveled at an unmeasurable speed. The dynasty he established ran for almost two centuries, up till the fourth generation, ending with the Cassini who was forced to close down his greatgrandfather's proud Observatory—the building Lavoisier had seen from his prison window.

  In 1997, a spacecraft with a European Space Agency (ESA) probe on board was launched on a seven year journey to Saturn. Along its way it flew past the planet Jupiter, which Roemer had used for his epochal prediction. The spacecraft was named Cassini. France is a major funder of the ESA.

  VOLTAIRE lived to extreme old age, writing and mocking all the way. His collected works run to over 10,000 printed pages, and did much to promote the Revolution, which began just a few years after his death. He never published significant commentaries on science after du Châtelet's death.

  The manuscript that EMILIE DU CHTELET finished in her final days—Principes Mathématiques de la Philosophic Naturelle—hecaxne a great success in the scientific circles of its time. A first edition can be viewed at the Bibliotheque Nationale in Paris. The????? Château de Cirey ended up shuttered and abandoned during the Revolution, but was later refurbished. Her first son never lived to see that, having become ambassador to Britain under Louis XVI, which led, after his return to France, to his arrest and subsequen
t death by the guillotine. "If I were King," du Châtelet once wrote, ". . . women would be worth more, and men would gain something new to emulate."

  HENRI POINCARÉ lived for seven years after Einstein's 1905 publications, still unreconciled to the fact that outside of France he wasn't recognized as a founder of relativity. In his final years he wrote eloquent, thoughtful essays on creativity. He also ensured that no one who wanted to work on Einstein's theories could be promoted in France.

  MILEVA MARIC-EINSTEIN continued looking up to her husband, even as he started an affair and their marriage broke apart. When he promised to give her any future Nobel Prize money as a divorce settlement, she saw nothing unusual in assuming that he would win it. (In 1922, when he did get the prize—though not for his theory of relativity, as the Swedish Academy was still not entirely convinced it would prove itself—he promptly transferred to her the substantial prize money as promised.)

  She never remarried after the divorce, and having missed her chance to retake her final university exams (her grades had been just slightly too low to get a teaching job), she never found a significant career. Although her first son ended up an engineering professor at Berkeley, she became exhausted caring for their second son, who was in and out of mental institutions his whole life. She died in Zurich in 1948, increasingly depressed and alone.

  MICHELE BESSO, Einstein's closest friend from his Bern years, with whom the ideas of special relativity were first talked over, had a rich home life, and a successful career as a mechanical engineer. Even in the 1950s, when he and the now twice-married Einstein were old, their correspondence continued and even became more frequent. After Besso's death, in early 1955, Einstein wrote Besso's family: "The gift of leading a harmonious life is rarely joined to such a keen intelligence, especially to the degree one found in him. . . . what I admired most about Michele was the fact that he was able to live so many years with one woman, not only in peace but also in constant unity, something I have lamentably failed at twice. . . ."