It was a nerve-racking five minutes, and when it was over, the group was in a somber mood. As Eddington recalled, “We had to carry out our programme of photographs in faith.” Since he had to keep on changing plates, he scarcely looked up to see the eclipse. Halfway through he did take a quick glimpse to estimate the cloud cover. By the end they had taken sixteen photographs, but since there had been so much cloud they didn’t know if any of their pictures would be usable. Everyone was disappointed. Then, to make it worse, only minutes after the peak moments of the eclipse the sky cleared entirely.
From that point on the researchers were consumed with decoding the photographs. They were able to develop two each night, and they did that for six nights, while during the daytime they started trying to measure the distant star displacements they were looking for. But the spotty results they had due to all the clouds meant that Eddington couldn’t yet be sure if what they’d recorded confirmed Einstein’s predictions or not.
The best Eddington could conclude was what he wrote in a telegram he left on Principe to be sent to Dyson: THROUGH CLOUDS STOP HOPEFUL STOP EDDINGTON. Before he could complete the careful measurement of the displacements—effects that would appear as movements of bare fractions of a millimeter on his plates, scarcely more than the width of a human hair—they had to get off the island. One of the planters had told them of rumors that there was going to be a steamship strike, and Eddington decided that he had better take the first boat back, since otherwise his team might be stuck on the island for months. The sea journey could damage the developed plates, but they had been away from Cambridge long enough.
If Eddington was chagrined about the outcome of his study after he returned to England, he could at least comfort himself that his team wasn’t the only one that had struggled with their measurements. The Brazil expedition staggered back later, and they’d suffered an even greater disappointment with their big telescope. The sky had been clear enough, and conditions had been much better than on the rugged island of Principe. They’d had use of what was apparently the first car ever seen in that region of Brazil to haul their equipment, which they neatly set up on the conveniently flat racecourse of Sobral’s Jockey Club. There was cool, if not quite cold, water available to develop their test plates. In the days before the twenty-ninth, interested locals even lined up to buy tickets to look through the telescope.
But the very fact that the sky was so clear proved to be a problem. The Brazilian team was barely four degrees away from the equator, and the direct heat distorted their primary apparatus. The team’s notes, scribbled down as they were developing the plates the night after the exposure, record their foreboding that their observations might have been a failure: “3 am . . . There has been a serious change of focus, so that, while the stars are shown, the definition is spoilt.” They realized this was because the intense daylight heat had made their telescope’s mirror expand unevenly.
The main telescope had failed the Brazilian team—but Father Cortie had known what he was doing when he’d insisted on sending the extra four-inch telescope along. From a sense of obligation as much as anything else, the Brazil team had inserted a handful of extra plates at the ideal focal point of that small device—and from that had ended up with the best plates of the entire expedition: better than those from the heavy telescope at the Jockey Club; better than Eddington’s equally large telescope arduously transported so high above the Atlantic on the raw cliffs of Principe.
When Eddington and his assistants in Cambridge analyzed the plates from Principe, they worked separately to be sure their individual handling didn’t affect the readings. Two of the plates weren’t quite as bad as they’d feared, and Eddington could incorporate their results as well. As they worked, they knew that Einstein in his final calculations in 1915 had come up with an estimate for light streaming from a distant star, and it would be bent only a very small amount. Hold your little finger at arm’s length, and its width is about 1 degree of arc. Astronomers divide that degree into 60 minutes, and each of those minutes into 60 seconds. Einstein’s prediction was that incoming starlight would be diverted a scant 1.7 seconds of arc (symbolized as 1.70") as it passed near the sun, compared to where it would be if the sun wasn’t there and the space it traveled through was flat. That’s smaller than the slightest scratch you can see on your finger. Such measurements are hard to detect. Would they conform to Einstein’s predictions, or would they sink his brave new theory once and for all?
DYSON AND EDDINGTON had a great sense of the dramatic and planned to hold off announcing the results until they could assemble a large, distinguished audience. This delay also meant that scientists who’d heard rumors of what was going on became anxious to learn what had really happened. From Berlin, Einstein—who later pretended to have known all along that he would be proved right—ever so casually wrote to a physicist friend in the Netherlands, asking, “Have you by any chance heard anything over there about the English solar eclipse observation?”
In November 1919, six months after the eclipse, Eddington was ready. The findings would be presented at a grand joint session of the Royal Society and the Royal Astronomical Society, in the august setting of Burlington House, the mansion where both were headquartered, on Piccadilly in London. Depending on their findings, the world would learn whether Newton’s theories—which had dominated all scientific thought for more than two centuries—were to be overthrown, or if the bizarre predictions of the Swiss/German theorist Einstein were worth no further attention. The fact that Newton had once served as president of the Royal Society and that his presence was still very much felt within its ranks only raised the stakes.
Tea was served at 4 p.m., as always, and in proper English style the guests had to pretend they had no special interest in what was going to happen next. Finally, at around 4:30, it was time to begin. Frank Dyson strode to the podium. The philosopher Alfred North Whitehead was in attendance and later recalled, “The whole atmosphere of tense interest was exactly like that of the Greek drama . . . There was a 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 modification. Nor was the personal interest wanting: a great adventure in thought had at length come safe to shore.”
Dyson spoke, and then the head of the Brazil expedition spoke, and finally it was Eddington’s turn to announce the expeditions’ results. Over a year’s work had been building up to this moment, and much of Einstein’s efforts hinged on it as well.
Had he been in the room, Einstein would not have been disappointed. The predicted deflection, Eddington announced, was 1.70". The most trustworthy results from the two expeditions came out at 1.60", with a margin of error of 0.15". Dyson said it simply: “After a careful study of the plates I am prepared to say that there can be no doubt that they confirm Einstein’s prediction”—his prediction, that is, that light would curve when it got close to the sun. Based on the latest scientific evidence, Einstein’s new, geometric picture of sufficiently massive things curving space enough for us to detect had been shown to be true.
One unconvinced member of the audience pointed to the portrait of Newton and said, “We owe it to that great man to proceed very carefully in modifying or retouching his Law of Gravitation.” No one was listening. In fact, the official chair of the meeting—the elderly Nobel laureate J. J. Thomson, discoverer of the electron—stood up to finish and put his respected word on Einstein’s side. “This is the most important result obtained in connection with the theory of gravitation since Newton’s day,” he told the crowd. “It is . . . the result of one of the highest achievements in human thought.”
The thinker behind this “highest achievement” was still unknown to the general public, but the scientific establishment had given his theory the ultimate official support. It wouldn’t be long now before the world knew the name Albert Einstein.
IN
TERLUDE 2
The Future, and the Past
Back at Cambridge, over a decade after his fateful expedition to Principe, Arthur Eddington found himself sitting before the fire in the Senior Combination Room at Trinity College, along with Ernest Rutherford, the director of Cambridge’s greatest physics lab, and a handful of other guests. The topic of fame came up, of public celebrity, and one young guest asked why in the previous few years Einstein had had so much public acclaim, while hardly anyone among the general public knew who Rutherford was, despite his Nobel Prize. After all, it was Rutherford, more than anyone, who’d uncovered the inner structure of the atom.
“Well, it’s your fault, Eddington,” Rutherford teased. Not everyone immediately grasped his meaning. All present—including the bright young Indian researcher who would later relate the story—knew that Eddington’s dramatic presentation at the Royal Society in November 1919 had had some effect on Einstein’s reputation, but why had it been so overwhelming?
The men settled into their deep chairs, and Rutherford spoke, more reflectively this time. The war had just ended when Eddington announced the results of his study, Rutherford recalled. Astronomy had always appealed to the public imagination. Now people learned that an astronomical prediction by a German scientist had been confirmed by British expeditions—prepared while the two countries were at war—to Brazil and West Africa. Harmony was possible. True peace was possible. The discovery “struck a responsive chord,” Rutherford concluded, “and then the typhoon of publicity crossed the Atlantic.”
And a “typhoon” it was, for what had happened to Einstein after that Royal Society meeting was unprecedented—unimaginable, even, at least at the time.
It began, as many things do nowadays, in the media. The London Times had been moderately restrained in its coverage of the meeting, but the same could not be said for its many counterparts across the pond. Although the New York Times had some excellent reporters, the best one it could get to London for the Burlington House meeting on short notice was Henry Crouch, the paper’s main golf correspondent, who’d thought he was going to be spending his time in Britain at St. Andrews and similar beguiling links. He would have been the first to admit that he was very much not an authority on the mathematics of four-dimensional space-time. Crouch did, however, work out that something extraordinary had occurred, and his enthusiasm was transmitted to the New York Times’ headline writers. Hence, just six days after the big meeting, the newspaper reported:
LIGHTS ALL ASKEW IN THE HEAVENS
Men of Science More or Less Agog Over Results of Eclipse Observations.
EINSTEIN THEORY TRIUMPHS
Stars Not Where They Seemed or Were Calculated to be, but Nobody Need Worry.
A BOOK FOR 12 WISE MEN
No More in All the World Could Comprehend It, Said Einstein When His Daring Publishers Accepted It.
The headline was appropriately breathless but impressively incorrect. The stars were exactly where Einstein had predicted: that was, indeed, the whole point of the expedition. Crouch had never spoken to Einstein and had made up the quote about only a dozen men being able to understand the theory.
None of that mattered. Rutherford was right about people liking the international harmony that Eddington’s expedition had demonstrated. There had been some other examples of coorperation after the war—in exploration and medicine—yet Einstein alone was given an open-top-car parade before tens of thousands in the United States, saw massive lecture halls filled hours before he appeared in Prague and Vienna, and was mobbed at movie premieres. When he was home in Berlin, letters constantly arrived, hundreds of them, and then thousands. They were delivered in such volumes that Einstein once had a dream in which he couldn’t breathe, for “the postman was roaring at me, hurling bundles of letters.”
It helped that Einstein had an informality that contrasted with the snobbery of the upper classes who had led the world during the Great War. Reporters loved the fact that once, when he was arriving to give a grand address at the University of Vienna, officials at the train station waited, and waited, for the great man to emerge from the first-class compartment. Then—shades of Max von Laue’s visit to the Patent Office in 1907—they saw a familiar shape, far down the platform, walking contentedly along on his own from the third-class car he had taken: violin case in one hand, briar pipe and suitcase in the other.
But there were further reasons for the fame. Looking upward to the stars can be felt to be the same as looking upward to the divine. Mankind had always wanted to understand the ways of God—to know why chaos occurs and how the meanings we want to believe lie behind it could be found. And this, the world was convinced, was what one quiet, thoughtful Swiss/German physicist had discovered.
Most of all, however, Einstein’s fame was a result of the trauma the world had just endured. Millions of men had died in the Great War, and innumerable families had lost a father, a son, a husband. There was a need to find some way back. Séances became popular, even though they were repeatedly shown to be run by charlatans. It was too painful to think that the dead were so completely gone that no contact—not even a whisper—could be maintained. An alternative seemed more plausible than it might have in earlier times, for homeowners were beginning to install large electrically operated machines—the first radios—in kitchens and living rooms, and through these devices, one could hear voices that had traveled invisibly over long distances. Who knew what else might be invisibly traveling, waiting, somewhere beyond?
This is what Einstein’s work also seemed to promise, for he showed that at least some forms of time travel are definitely possible. Before Einstein, it was taken for granted that we live in three dimensions and that, quite separately—at right angles to that, one might say—there is a fourth dimension, of time, which we move through at a steady, unchanging forward rate. Einstein transformed all this. The reasoning that led to his prediction of starlight bending as it neared the sun also leads to this prediction that time “bends” depending on how strong gravity is around it. Usually we don’t notice this, because the effects are very slight in the fairly weak and uniform gravity around us on earth and at the speeds—so much less than the speed of light—with which we move about. But Einstein had unveiled this unsuspected truth about time, and with the success of Eddington’s expedition, everyone now learned that he was right. In particular circumstances, some of us can travel forward through time—can be sped into the future—at greater rates than others.
Strange implications follow from the facts of nature that Einstein discovered. Think what might happen when our explorer who was kidnapped by space pirates and dragged at high speeds through the galaxy is finally rescued. The explorer has been living within time that from his perspective is moving more slowly than that of his rescuers; the rescuers have been living within time that from their perspective is moving more quickly than his. Of course, if they manage to free him from the space pirates without much delay, there will be little chance for that difference to build up. But if the pirates haul him around on a huge roundabout journey before the rescuers finally reach him, they might be decades older, while he—undergoing sufficient acceleration—will have aged only a few days. If his journey has seen truly tremendous acceleration, he might be just a week older when he’s found, but the original rescuers will have long since died, and it will be their distant descendants who greet him.
This mind-bending stuff isn’t merely imagined, postulated, unproven. Einstein showed that the effect is not just on our measuring machinery, but in reality itself. A traveler to the stars could return after what to him was genuinely no more than two or three years, but while he would still be a young man, millennia would have passed on earth, and everyone he knew—possibly even the civilization he’d left—would have long since vanished.
Were these effects to be magnified so that they were noticeable even at the ordinary speeds and in the usual gravitational fields we’re accustomed to on earth, someone driving fast enough to an exercise cla
ss would be in the car for only one minute by his measurement, while his friends waiting for him there would be watching him drive for half an hour of their time. Parents who could afford to rent apartments on the very top floors of tall skyscrapers—where gravity is weaker—would age much more slowly than children they’d left in boarding schools on the ground. They could pass a single week up there while their children trundled through all the years from primary school to graduation.
These were the sorts of results that prompted such baffled comments as that from the distinguished scientist and Zionist leader Chaim Weizmann: “Einstein explained his theory of relativity to me for weeks, and by the end I was convinced that he understood it.” But Eddington’s findings showed that somehow, extraordinarily, relativity was true. Distant starlight didn’t veer around the sun only because space itself was sagging. Rather, time was operating at different rates as well. (This is hard to envisage, but imagine incoming starlight being made up of a row of light beams all rushing forward in parallel, like a row of sprinters. The ones on the outside get a longer time to advance a given distance, and so, like the runners taking a banked curve, that’s why the entire row begins to swerve.)
How much further could Einstein’s insights go? The fact that with the right technology, we could accelerate into the future was impressive. But after the Great War, many people would have given anything to be able to travel in the other direction, to the past—if not to bring back lost life, then to get more time, even if just one final hour, with those they loved before a bullet or a shell brought them down.
Although some recent developments of Einstein’s work have suggested that it may in fact be possible to travel backward in time, in the immediate aftermath of Eddington’s expedition, no physicists, not even Einstein, saw how to do that. But they did, even at that time, appreciate another solace-giving implication of his theory: not quite the ability to travel into the past, but not quite an acceptance that those we love are entirely lost either.
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