The Year That Was Season 1 Episode 23 Relativity - Part 2 Through Cloud, Hopeful: Eddington, Einstein, and the Eclipse of 1919 Attitudes toward conscientious objectors have changed dramatically the last century, thanks a great deal to widespread opposition to the Vietnam War. It is difficult for us to grasp how much hate and revulsion was felt toward those claiming this status in Britain during World War I. Conscientious objectors, or COs, were despised, spat upon, viewed as unpatriotic cowards. Most of the men who sought CO exemption were denied. If they continued to refuse to fight, they were subjected to military punishment on the grounds they were disobeying orders. Here is an account by one CO, named Fenner Brockway, part of an oral history in the collection of the Imperial War Museums: We found the prison system was absolutely inhuman and denying human rights. As I've said, we were not even allowed to speak to each other. Of course we did, but we always had the sense of doing something which was prohibited and which, if we were found doing it, would lead to punishment – bread and water, solitary confinement. Here is another account, by man named Harold Bing: I was in a cell by myself the whole time. . . . The cell was about six feet by thirteen feet with one small window above one's head so that you couldn't see out of it except by standing on your stool for which of course you might be punished if you were found doing it. Prison was far preferable to what was called field punishment. Here's an account by one Howard Marten of what happened to him after he and a group of other COs were taken to France: Then we were given 28 days’ field punishment. Now field punishment can be a very nasty thing. In its most extreme form a man can be tied up to a gun carriage, which isn't at all a pleasant thing, but normally he's sent to what is known as a field punishment barracks, and there the prisoners are tied up for three nights out of four. They’re tied up maybe to a fence, or to ropes, with their arms extended, and their feet tied together, or they may be tied back to back – it varies in form – and that's done for two hours. Well, it’s not exactly a pleasant experience… His account continues: After a few more days, we were taken out to the parade ground. There was a big concourse of men, mostly of the Non-Combatant Corps and the labour battalions, lined up in an immense square. . . . I was the first of them and until my verdict was known nobody knew exactly what was going to happen. . . . And then, one of the – an officer in charge of the 2 proceedings read out the various crimes and misdemeanours: refusing to obey a lawful command, disobedience at Boulogne and so on and so forth. And then: ‘The sentence of the court is to suffer death by being shot’. Then there was a suitable pause, and one thought, ‘Well, that's that’. And then, but, now the second thing: ‘Confirmed by the Commander in Chief’. That's double-sealed it now. Then another long pause, ‘But subsequently commuted to penal servitude for ten years’. And that was that. This is the Year That Was. I'm Elizabeth Lunday. Thank you so much for listening and coming back for the second half of our look at Arthur Eddington, Albert Einstein and the Theory of Relativity. I'm going to pick up right where I left off in the previous episode, so please make sure you've listened to part I--it won't make much sense otherwise. We left off in the spring of 1918. Germany was pouring everything it had into the Spring Offensive, its last attempt at breaking through the Allied line before the Americans were at full strength. Britain was desperate for more soldiers, and so all previous exemptions for service were revoked. Arthur Eddington would have to again go before a tribunal to keep himself from being sent to the front. This time he was determined to argue his conscience whether Cambridge University liked it or not. In 1916, the university had intervened on his behalf, arguing his work was of national importance. He had let it go, but it had stung. Eddington believed it was wrong to hide behind the university when what really kept him from fighting was his deep opposition to violence. Now, I'm not saying Eddington was right and everyone who fought in the war, or anyone who has fought in any war, was wrong. I suspect I'm like a lot of Americans today--I respect those courageous enough to serve their country, but I also respect those willing to take a stand against war. I'm fortunate to live in an era in which I am able to hold both of these views. Eddington had no such luck. He knew very well it would be extraordinarily difficult for him to secure CO status. Many tribunals took it upon themselves to question if the individual applying was genuinely a pacifist- -or just a coward. Eddington could expect questions like, "What would you do if a German attacked your mother?" There was no answer to this question. Reply that you would defend your mother, and clearly you weren't really a pacifist because you were be willing to use violence under certain circumstances. Reply that you would stand by peacefully, and you were a monster--or lying. Attacks on applicants by tribunal members were commonplace--one was told, quote, "You're nothing but a shivering mass of unwholesome fat." Furthermore, even if Eddington was granted conscientious objector status, he would likely not be able to continue his work and make his observation of the 1919 total solar eclipse. CO designation would only exempt him from combat. He would probably be put to working digging ditches in Flanders or assembling shells in a munitions factory. If he refused these duties, as many Quakers did, he could be arrested for refusing a direct order. We've heard what that was like. Eddington knew exactly what could happen. He recorded many of these cases himself for the archives of the Cambridge Friends Meeting House. Eddington appeared before the local tribunal on June 14, 1918. It was immediately clear that Cambridge had applied pressure behind the scenes to avoid scandal. Again and again, Eddington tried to declare himself a conscientious objector, but the tribunal wouldn't listen. They only considered if his work was of national importance, and they decided that it was not. They ordered Eddington to report for service, but then, clearly under pressure from above, suspended their decision for a month. In July, a second hearing was held, and this time, in contrast, matters went much more smoothly. Eddington presented to the tribunal a letter from the Astronomer Royal, Frank Dyson. This letter described Eddington's work as critical to the nation and then declared that in May of 1919, Eddington would be leading a major scientific expedition to observe a solar eclipse. Dyson hoped that the tribunal would allow Eddington to continue this incredibly important work. At this point, the tribunal allowed Eddington to make a statement about his pacifist beliefs. The tribunal probably nodded and looked stern, but what they found interesting was the eclipse. They asked Eddington several questions about when and where it would happen and what Eddington planned to do. Finally, and without withdrawing to discuss their decision, the tribunal issued its ruling. First, they declared that Eddington's work was definitely of national importance. Then they stated that they were convinced that he was a genuine conscientious objector. However, the official grounds of his exemption was his work, which specifically included the observation of the eclipse. Eddington left the hearing a free man. None of the paperwork associated with the case said anything about conscientious objection, sparing Cambridge University the stigma of keeping a Conchie on staff. All of this was extraordinary. Most of the records of tribunals were destroyed after the war, so we can't say for a fact that Eddington's case was unique. It was at least unusual. Clearly, strings were pulled, and clearly Eddington must have agreed to the pulling. Before, he had always refused to cooperate with schemes to obtain him an exemption. So why did he go along with this one? Two points seem critical. First, Eddington was allowed to make a statement of his beliefs, and those beliefs were acknowledged by the tribunal. Second, the eclipse observation had become incredibly important to Eddington, and not only as a scientific experiment. It was a way for him to demonstrate--to live out--his belief in the value of scientific internationalism. Eddington wanted to prove not only that space is curved. He also wanted to prove that the pursuit of truth transcended human differences. The expedition had become for him a matter of conscience. Eddington was as dedicated to this work as--well, as Fritz Haber was to his chemical weapons. They both wanted to save something they believed bigger than themselves. So, what exactly did Eddington want to prove? What was he hoping to find in his photographs of the 1919 eclipse? Let us go then, you and I, and discuss the General Theory of Relativity. We can do this, with a little effort and imagination. The General Theory is fundamentally a theory of gravity. Now, Isaac Newton had presented his Law of Universal Gravitation all the way back in 1687, and Newton's math still worked in 1915-- it still works today, under most circumstances. But it breaks down sometimes, such as when trying to describe the behavior of very massive objects. It also broke down when trying to describe the orbit of the planet Mercury, which has a sort of wobble in its path around the sun that that scientists couldn't explain. Furthermore, while Newton's theory was very good at predicting the effects of gravity, it couldn't explain the why of gravity--what was the mechanism behind it? What made objects move in the ways they did? This was deeply unsatisfying to scientists. Einstein's work explained the mechanism, and that explanation relied on a totally new way of understanding space, time, and all of the stuff that exists within space and time. Newton had understood space as most of us intuitively understand it. He thought of space as simply a stage or a field on which the universe plays itself out. Nothing can alter space--it is what it is. Think of an American football field. It is 100 yards end to end, always. The space between one endzone and another isn't going to compress, or expand, or twist, or be different depending on who is doing the measuring or when--a fact that must be somewhat reassuring to quarterbacks. Objects can move within space, but space itself is just . . . a fact. Nope, said Einstein. Quarterbacks needs to buckle up, because space isn't fixed and can be stretched and distorted in myriad ways--by mass. The usual image called upon at this point is a rubber sheet, which I've always though as odd. Who regularly encounters rubber sheets? I suggest instead you think of a trampoline. Not a modern trampoline, with railings and nets and safety warnings and strict adult supervision. Imagine a 1980s trampoline--big, no net, slapped down the backyard of every third 1980s family, never supervised because we were all latchkey kids, and if you fell off and got a concussion you walked it off. Now, imagine one small child standing on the trampoline--a young sibling, perhaps. The surface of the trampoline is going to curve downward slightly in response to the weight of the child. Right? Now imagine a whole crew of teenagers on the trampoline standing very close together. The surface will curve much more because the mass of a horde of teenagers is much greater than that a single child. So far so good? Now let's say you invent a game in which you roll a tennis ball across the surface of trampoline. Doesn't sound like much of a game, but we didn't have cable and had to make our own fun. If you roll a tennis ball across the trampoline with no one on it, the ball will roll straight across the apparently flat surface. But if the young sibling gets back on the trampoline, you will see the surface is curved slightly by their weight. The tennis ball will follow that curve as it rolls across the trampoline. The ball will make a jog or swerve as it passes close by the sibling, because the mass of the child will deform the surface. Now put the teenagers back on the trampoline. The curve of the trampoline surface will be much greater, and the path of the tennis ball will be much more distorted--the ball may even go completely off course and swing around the teenagers, responding to the increased curvature of the stretched and deformed surface. This, in a very, very general way, is analogous to Einstein's explanation of general relativity. Space is not fixed; it curves and deforms around objects with mass. The greater the mass, the greater the deformation. The Earth, like the young sibling, deforms space much less than the sun, the group of teenagers. So: as objects move in space, their paths are determined by the deformations in space created by objects of varying mass. The earth isn't "attracted" to the sun by a mysterious force. It is simply stuck in a dip, a well, in space-time caused by the mass of the sun. And that's gravity. Now, there are problems with this analogy. The first is that trampolines are really dangerous and concussions should be taken seriously. The second is that this comparison implies that space is a flat surface on which everything sits. That's not true--space is three-dimensional, and the warping of space is also three dimensional. Space deforms into itself, or within itself?, and objects within space deform with it. This is not a concept that our brains evolved to visualize so we struggle with it. For example, Einstein proposed a phenomenon called gravitational waves--waves in space caused by the actions of incredibly massive objects. You might imagine if a gravitational wave swept by you right now, you would ride on top of it like a surfer atop a wave in the ocean. But you are in space, not on top of it. You would wave right along with everything else--your house, your car, your sidewalk, your dog, everything around you compressing and expanding in a deeply weird cosmic ripple. If this happens to you, consult a medical professional immediately. So. This is--sort of, more or less, specifically with more math and fewer trampolines--what Einstein presented in November 1915 in his paper on General Relativity. There's a lot, a lot more to it, especially concerning time, which is tied up with space in a combined phenomenon called space-time, but we don't have time for that. Einstein presented his theory along with a series of equations that scientists could use to calculate orbits that became known as the Einstein Field Equations--these were the equations that Karl Schwarzschild worked under fire on the Russian Front. Einstein also shared one finding and several predictions. The finding is that when he used his equations to calculate the orbit of Mercury, the equations exactly matched observations. Newton's math had never worked for Mercury, so this was a real achievement. The predictions were more complicated, because science had no way of measuring most of the phenomena he described. I mentioned gravitational waves a moment ago--scientists couldn't begin to imagine how to detect them. It would take a century--2015, in fact--for gravitational waves to be directly observed. However, the technology of 1919 could just barely test one aspect of the theory. This was the prediction that the sun would bend the light of distant stars, and that this deflection would be visible and measurable during a total solar eclipse. Let's break this down. Remember the Hyades, the star cluster I talked about in part 1? They are a group of stars off doing their thing emitting light that travels 153 light years and then runs smack dab into the earth. That light goes in a straight path from the star system to us, beebopping along at 300 thousand kilometers per second. Sometimes the Sun moves between the Earth and the Hyades. Space curves around the mass of the sun, and the light from the Hyades follows that curve. To be clear, the light itself doesn't actually curve at all, because all light rays travel in straight lines, but the space in which the light is moving curves, and the light can't help but curve with it. From our perspective, thet light makes a small jog or swerve as it passes through the part of space deformed by the sun. And the Hyades appear to be in a slightly different location than usual. Most of the time, this effect will be invisible. If the sun is between us and the Hyades, the sun's light will prevent us from observing the Hyades. However, on rare, rare occasions during an eclipse when the moon blocks the sun's light, the stars on the very edge of the blackened disc of the sun will be observable. And they will appear to have shifted location when compared to previous observations. Now, we talked in part 1 about how Einstein first published papers about general relativity back in in 1913. These papers included the prediction that massive objects would deflect starlight and specified that that deflection would measure 0.83 arc seconds. However, we also talked about how Einstein had a major breakthrough in November 1915 that allowed him to complete his theory and fix some problems with the work. When he reran his calculations in late 1915, he realized he had been wrong. His new prediction for the deflection was 1.7 arc seconds. Now, arc seconds and an arc minutes are a measurement system used to describe small astronomical angles. The full moon's apparent size from the surface of the earth is about 31 arc minutes. One arc second is approximately the apparent size of a U.S. dime viewed from a distance of about 2.5 miles or 4 kilometers. The difference between 0.83 and 1.7 arc seconds is incredibly, incredibly small, only apparent in photographs under magnification. However, astronomers of this era, despite studying the largest objects in the universe, were accustomed to making incredibly small measurements on photographs of heavenly bodies. Technically, in 1919, it was just possible for Einstein's prediction to be verified during an eclipse. Eddington was determined to get the job done. God willing. After his exemption came through, Eddington dove into preparations for the expedition. He and Dyson decided they would send out two groups of scientists to double their chances of getting good weather. The path of totality would travel from Peru to Brazil and across the Atlantic to Africa. One group, headed up by astronomer Charles Davidson, would travel to Sobral, a town about 700 miles east of the mouth of the Amazon river along the northern coast of Brazil. The second group, headed by Eddington, would go to Principe, a small island then belonging to Portugal and located just north of the Equator in the Gulf of Guinea. As Eddington assembled telescopes, cameras, and photographic plates, the war began to turn. America entered the fighting, the Allies began to push the enemy back. Finally, in November, Germany sued for peace. You'll recall Haber collapsed when realized his side had lost. Eddington's reaction was relief, for the world and for himself. The threat of conscription was over and he could concentrate on his work. Einstein, meanwhile, greeted with joy the end of the war and the unrest sweeping Berlin. As a socialist, he hoped for at least a little revolution, enough to shift power to the proletariat. But the winter of 1919 was hungry, cold and miserable, and a new socialist dawn did not break in Berlin. Instead all revolutionary movements were stamped out, and a weak and feckless republic took power. At least Einstein could travel again, which allowed him to take care of some personal business. In February, he went to in Switzerland to divorce his first wife; he would marry his second wife Elsa in June. And in March Einstein received word from colleagues in neutral nations that Eddington had set out on his expedition. Einstein could only wait for the results. The two British teams sailed from England on March 8 and traveled together to Madeira. Then they split up. Davidson and his partner caught a steamer for Brazil. Eddington and his partner set off for Principe. It was a two week journey of nearly 5000 miles, and Eddington passed the time trying to learn a little Portugese and playing musical chairs with the other passengers. Both teams were greeted with open arms when they reached their destinations. Local officials in both Brazil and Principe were eager to demonstrate to their guests that civilization had reached these far-flung outposts. Afternoon tea was served, a gesture the Englishmen appreciated, although they recorded privately that the quality was sup-par. They arrived in parts of the world struggling through their own crises. Principe had an ideal climate for growing cocoa for chocolate and in the late 19th century had become the number one supplier for the British company Cadbury's. Then a 1905 expose in Harper's Monthly Magazine revealed that Principe's plantations were actually worked by enslaved laborers kidnapped from Angola. Conditions were horrific--I mean, really, really bad, so bad I won't describe them--and deeply shocking to the British, who thought slavery was a thing of the past. This was bad enough, but Cadbury was owned by a prominent Quaker family. The company had prided itself on its corporate ethics back before corporate ethics were really a thing; it had worked hard over decades to provide quality living and working conditions for its British employees. The incident was deeply embarrassing to Cadbury. Eddington must have been familiar with the scandal--it was followed closely by the Quaker community. Measures were put into place to improve working conditions on the island, but these were complicated by political upheaval in Portugal, including the 1908 assassination of the king and the heir to the throne and a 1910 revolution that installed a deeply unstable republic. When Eddington arrived in 1919, it's unclear if the workers he saw tending the cocoa fields were free or enslaved. Meanwhile, northern Brazil was in the grip of a devastating drought that had take the lives of almost 300 thousand people. Many locals had fled from the countryside to urban areas, but the Brazilian government feared instability. So they set up what can only be called a concentration camp to house them. Eventually about 8000 people were detained in this camp. The drought had begun to lessen by 1919, but Sobral remained a shadow of itself, its fields parched and its streets empty. The Brazilian writer and journalist Paulino de Almeida Brito read about the eclipse expedition and wrote, quote, "What is the use of knowing the weight of the planet Mars and the distance that separates it from Saturn, if we do not know enough of our terrestial habitation to remedy or even prevent the bewilderments that endanger our existence?" unquote. It's a fair question. Working conditions in Principe and drought in Sobral might seem to have little to do with proving the theory of relativity. But this entire podcast is based on the idea that context is everything. African workers helped set up Eddington's telescopes. Could they have told him, no, we'd rather not? We cannot escape the time and the place in which we live. On arriving at their destinations, the teams sought locations to make their observations. Eddington set up at a cocoa plantation in the northwest corner of the Principe. Davidson found a spot at an unused racecourse. The following weeks were devoted to the tedious, painstaking job of setting up the equipment and practicing the observations. Both teams would spend the eclipse sliding glass photographic plates under the telescope, briefly exposing them, sliding them out and replacing them with another. Each member of the team had a job, and they had to work in perfect harmony no matter what happened around them. These were all experienced eclipse observers, and they knew that in the dramatic moment when the sun goes totally dark, the temperature plummets, the birds stop singing and the stars appear, it is easy to become distracted. The day of the eclipse dawned, and the photons that had been traveling for 153 years neared their destination. They began their journey when they were emitted by stars from the Hyades star cluster, which is part of the constellation Taurus. About a dozen stars can be seen in the cluster with the naked eye in a dark country sky, but even a pair of binoculars brings several dozen stars into view. In fact, the Hyades contains hundreds of stars in a rough sphere about ten light years across. Scientists have found three planets orbiting one of the stars of the Hyades, a dwarf star known by the deeply memorable name LP 358-348. One is what is called a mini-Neptune, so similar in composition to our Neptune but smaller. Another is a super-Earth, a class of planet much larger than Earth but made of rock or ice. They also found a planet in some way very much like our Earth--about the same size and rocky. It's fun to imagine intelligent life on one of these planets looking back at us. It's also profoundly unlikely. All three planets orbit their star in less than thirty days; one year on the earth-size planet is equivalent to 7.9 days. This means they are incredibly close to their star and mind- bogglingly hot. Temperatures on their surfaces range from 212 to 536 degrees Fahrenheit. Their star is also much younger than ours--800 million years compared to our 4.6 billion years. So any life there would have had very little time to evolve and would exist under extreme, extreme conditions. Anything is possible, but after studying 1919, I kind of hope no one was looking at us very closely that year. I would say we were not at our best. In rained in Sobral in the days leading up to the eclipse, good news to the locals but worrying to the astronomers. The morning of May 29 dawned cloudy, and the team assembled, uncertain if they would capture anything. They had two telescopes to photograph the eclipse, one with a sixteen-inch wide lens and one with an eight-inch lens. The eight-inch had been a last minute addition, a back-up in case something went wrong with the larger instrument. They worried both would be useless if the weather refused to cooperate. Just as totality approached, the clouds parted and the sky cleared around the sun. Then the world went dark, and Davidson and his team began their work. When it was over, they had nineteen photos with the large telescope and eight with the smaller. They sent a telegram back to England: "Eclipse splendid." Meanwhile, in Principe, Eddington watched a tremendous thunderstorm dump rain on the island. Water poured down the hillsides and drenched the cacoa trees. At breakfast, the situation seemed hopeless. Eddington munched on the red bananas that grew all over the island--he consumed about a dozen a day--and contemplated the complete failure of his expedition. The rain finally stopped in the afternoon, but the sky remained cloudy. The astronomers could do nothing but go ahead with their preparations. As the moon moved closer and closer to the sun, the clouds began to break up. At 2:13 p.m., the moon crossed before the sun, and all Eddington could do was slide in a photographic plate, count, slide it out, slide in another. Five minutes and nineteen seconds later, it was all over. When Eddington could finally take a breath and look up, the sun was clear and bright in a perfectly clear blue sky. Eddington sent his own telegraph: "Through cloud. Hopeful." The next step in both Brazil and Principe was for the scientists to develop the photographic plates. This was a another painstaking process, and in Sobral, the results were immediately disappointing. The images from the sixteen-inch telescope were slighly distorted, likely the result of the mirror expanding in the heat. However, the images from the backup eight-inch telescope were clear and sharp. All was not lost. In Principe, Eddington found the first photographs were useless. Clouds had totally blocked the stars. But six of the images were free of cloud cover and clearly showed the Hyades. He had no intention of waiting until he got back to England to look for results. Working in the basement of the plantation, usually a storage space, he took out his micrometer and began making measurements and running calculations. Within a week, he was sure in his own mind, if not to a degree suitable for announcement, that Einstein's theory had stood the test. Eddington called this the greatest moment of his life. Eddington's team returned home on July 14, Davidson's on August 25. Eddington poured over the photos from both teams, measuring, calculating, assessing. He and Dyson met and debated how to present their results. Finally, in November, they were ready. On November 6, 1919, Dyson and Eddington called a meeting of the Royal Astronomical Soceity and the Royal Society. The auditorium was packed, standing room only, and the mood was tense but excited. Most people noted the large portrait of Isaac Newton looming in the background as if in judgment. Dyson took the stage. He declared, quote, "After a careful study of the plates I am prepared to say that there can be no doubt that they confirm Einstein's prediction. A very definite result has been obtained that light is deflected in accordance with Einstein's law of gravitation." unquote It was actually a little more complicated than that, as Eddington, who spoke next, explained. They had results from three telescopes, two from Sobral and one from Principe. All three showed light deflecting around the sun, so yay for that. But how big was the deflection? Principe showed a deflection of 1.61 arc seconds. The small telescope at Sobral showed 1.98 arc seconds. The poor quality images from the large Sobral telescope showed 0.93 arc seconds of deflection. Now, you'll remember, because you were paying very careful attention, that Einstein predicted a deflection of 1.7 arc seconds. That is not, in fact, what any of the three telescopes found. And yet, Eddington and Dyson believed the 0.93 results from the wonky mirror were unreliable and should be thrown out. That left two results, 1.61 and 1.98. Even an English major like me can see if that if you average the two together, you get an answer that is pretty darn close to 1.7. Everyone at the meeting accepted these findings. Some were not entirely confident that they proved what Eddington said they proved, but they didn't doubt what Eddington told them. Despite the previous years of doubt and antagonism, despite the fact some of his colleagues had stopped speaking to him at the height of the war, none of them doubted his work. If Eddington said there was a deflection of 1.61 arc seconds, there was a deflection of 1.61 arc seconds. That says something about Eddington's integrity and reputation as a scientist. Einstein learned of Eddington's results a few weeks before the Royal Society meeting. It's not clear who leaked the news, but leak it did. Einstein was enormously, tremendously relieved. Some stories of this time have him acting blasé and saying he had always known he was right. But actual letters and telegrams reveal he was overjoyed and not afraid to show it. He wrote his friend Max Plank, quote, "I cannot postpone telling you how deeply and heartily pleased I was about the news. . . . Thus the intimate union between the beautiful, the true and the real has once again proved operative. You have already said many times that you personally never doubted the result; but it is beneficial, nonetheless, if now this fact is indubitably established for others as well." unquote. News broke to the wider world the day after the Royal Society meeting. The Times of London declared "Revolution in Science / New Theory of the Universe / Newtonian Ideas Overthrown." The paper made little attempt to actually explain the science but dwelt at length on how Einstein stood outside of the German mainstream. He was described as a Swiss Jew who had only taken a job in Berlin for the salary. The article noted he had not signed the infamous Manifesto to the Civilized World but had protested against it. This information went a long way in helping the British public accept the ideas of the a German scientist. On November 10th, the news reached America. The New York Times declared with more passion than accuracy or clarity, "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." I love that. "More or less agog"-- brilliant. It was not surprising that these early reports were unable to give any clear explanation of what the eclipse had actually demonstrated. It's unlikely than any American scientists were familiar enough with Einstein's work to help the Times reporters understand it, and it didn't help that the Times had asked their golf reporter to cover the Royal Society meeting. However, unfamiliarity with the theory was amplified to the point that it became generally accepted that relativity was next-to-impossible to understand. A wonderful, and likely fabricated, story was reported in one British paper. A journalit supposedly asked the Secretary of the Royal Society to explain the theory. Quote, "The Secretary rubbed a hand over a dome- like brow, and frankly admitted he was beaten." unquote. The reporter asked another scientist. He said, quote, "I don't understand it all. Don't mention my name." Then the reporter went to the library, read through the theory three times, and quote, "was led out sobbing." Another story told about Eddington goes like this. After the meeting of the Royal Society, a colleague came up to him and said, "Professor Eddington, you must be one of three persons in the world who understands relativity!" Eddington paused, and the scientist said, "Don't be modest, Eddington." Eddington replied, "On the contrary, I am trying to think who the third person is." This is nonsense, although entertaining. In the autumn of 1919, it's likely everyone who understood relativity could have sat down for dinner in smallish restaurant, but that was because the theory was so new. In very little time, and thanks in great part to Eddington, it became widely understood and was soon taught in physics courses around the world. The theory is certainly not easy to understand, as my foray into trampolines makes clear, and it relies on concepts that are not intuitive to the human mind. But it's not incomprehensible. Watch a few videos on Youtube and you can get the gist. Furthemore, I've been reliably informed that to anyone with a solid grasp of calculus and non-Euclidean geometry it's perfectly clear. This is a small proportion of the population, but not inconsiderable. I've also been reliably informed relativity is a walk in the park compared to quantum mechanics. In any case, the general public was fascinated by relativity, although a little worried about it. "Relativity" seemed like a questionable foundation for science--does it mean there is no such thing as truth anymore? Ministers and philosophers found this particularly worrying. Some cultural critics lumped relativity in with other forces of disruption and unrest sweeping the planet. Others objected to difficulty of the theory and that it could only be understood by those with a grasp of advanced mathematics; they protested that science should rely more on common sense. In Germany, some opposition focused on what was perceived as a "foreign spirit" in the work, a phrase that was code for "We don't like that Einstein is Jewish." It's bizarre and nonsensical, but fanatical nationalist antisemites denounced Einstein's work as anti-Aryan. As early as 1921, Einstein was receiving death threats from these circles. Eventually the Nazis attacked all so- called Jewish physics and banned their instruction. In 1919, this attitude was still a fringe position. Most people in and out of Germany came to revere Einstein. He became a favorite figure of the press around the world. Journalists delighted in interviewing the irreverant physicist who refused to wear socks and was happy to comment on any topic, from relativity to Prohibition. He became a global celebrity, the first scientist to reach this status, and the world generally treated him with goodwill despite his nationality. I mentioned in my last episode that the Allied scientific community was outraged with Fritz Haber was awarded the Nobel Prize in 1919, and that's absolutely true. Even so, the fury of British and Allied scientists toward their German and Austrian counterparts had begun to fade by the time Haber received his medal. The success of the Eddington experiment and the fact that an Englishman had proved a German theory had begun the process of healing. Within a few years, journals and papers were again passing across borders and students from one nation studied under scientists from the other. Einstein himself won the Nobel Prize in 1921, and not for his work on relativity. He was recognized for his discovery of the photoelectric effect, a completely different bit of physics that is also hugely significant. I'll put links on the website if you're interested. The New York Herald article announcing the prize continued the practice of emphasizing Einstein's Jewish origins, his Swiss citizenship, and his years spent working outside of Germany. Almost apologetically, the article mentioned his position at the University of Berlin. Tensions had lessened and certainly no one protested Einstein's award as they had Haber's. But no one was going to praise his German background either. Through all of the drama of the eclipse observations and the announcements to the Royal Society, Eddington and Einstein had never directly communicated. Finally, on December 1, 1919, Eddington wrote Einstein directly. And while he wrote about his delight in proving relativity, he was just as happy about improving international scientific relations. He wote, quote, "All England has been talking about your theory. . . . There is no mistaking the genuine enthusiasm in scientific circles. . . . It is the best possible thing that could have happened for scientific relations between England and Germany." unquote. Eddington had made the improvement of scientific relations a matter of conscience, and he had achieved the best possible results. It would be another year and a half before Einstein was able to meet Eddington in person, when the German physicist visited England in June 1921. He was greeted as the celebrity had become and followed everywhere by reporters as he attended dinners and laid a wreath at Newton's grave. In London, Eddington and Einstein men finally met at the Royal Astronomical Society. Einstein later told his wife that Eddington was, quote, "a splendid chap." They never became what you would call friends. They spent very little time together over the years. But they didn't need to be friends. They had saved one another. It was enough. Eddington continued to promote the Theory of Relativity and became one of its greatest English-speaking authorities. He also worked extensively on the formation and evolution of stars. He never married, continued to attend Quaker meetings and to bicycle for hours. When World War II broke out, he was too old to be conscripted, but once again his pacifist views were deplored and he became increasingly isolated. In 1944, he fell ill with stomach pains. Hospitals were overwhelmed with military patients and it was weeks before he could get an x-ray. It revealed he had stomach cancer and needed immediate surgery. He survived the surgery but died two weeks later, age 62. Einstein observed the rise of the Nazi Party in Germany with no delusions about where matters were headed. He was lecturing in America in 1933 when the government passed the law that barred Jews from holding public office. You'll recall it was this law that drove Fritz Haber out of Germany. Einstein never again set foot in Germany. In October 1933, he accepted a position at the Institute for Advanced Study at Princeton. He died in New Jersey in April 1955. Eddington's observations remained milestones in relativity science, but they were not without their critics. Observations were repeated during a total eclipse in September 1922 in Australia under excellent conditions. The tests confirmed without a doubt that Einstein's prediction for the deflection of starlight was right on the money. Some questions remained, however, that Eddington had only seen what he wanted to see. He happened to be right, but did the photographs really demonstrate what he claimed? To resolve this question, later scientists have gone back more than once and reexamined the original photographic plates. Each time they have confirmed that Eddington and Dyson's observations. The men had not fudged the data to get their desired results. Eddington's reputation for integrity remains firm. There is now no question that the Theory of Relativity is valid. It has been proven time and time again. The entire Global Positioning System, which we tap into every time we look up directions to a new sushi place, is inadvertent proof of the theory. The system has to account for minute time shifts that are a consequence of earth's gravity. Every other prediction of Einstein's has been confirmed and reconfirmed. In the last ten years alone, scientists have photographed black holes and observed gravitational waves, Einstein's predicted ripples in space-time. The deflection of light by massive objects is now a well-understood phenomenon known as gravitational lensing. Astronomers routinely observe enormous galaxies millions of light years away causing the light of objects behind them to bend and distort. I've put some photos on the website and included some links--they are amazing images. Remote galaxies are stretched into thin bands or curved into rings by gravity. In fact, gravitational lensing has become a tool for measuring the amount of invisible dark matter in the universe--a concept that I am not going to attempt to explain but that I will provide links to. I said in my previous episode that the Haber-Bosch process may be the most important scientific discovery in history. I stand by that assertion--billions of people are live today because of Haber-Bosch. But relativity is a close contendor, because it changed how we understand the entire universe. It will remain critical as long as humans are around doing science. Relativity does have its limits--it does not play well with quantum mechanics under certain circumstances. Eventually it might be supplanted by a Theory of Everything that resolves these conflicts, but its truths will remain. Space curves. Light bends. Reality is far weirder than it seems. When I first set out my plans for this podcast season, I wanted to cover Fritz Haber and Arthur Eddington in the same episode. That proved impossible, but I want for a moment to consider the two men side by side. If you wrote a novel where these two characters acted as foils, your editor would argue you were too on the nose. A fanatical German nationalist who developed poison gas, for god's sake, against an English pacifist who fought only for conscientious objector status? Come on. Of the two, Haber is more believable. Fritz Habers aren't hard to find. They're fun at parties but absurdly vain, and they worship power. Arthur Eddingtons, on the other hand, are rare. To stand before a tribunal in 1918 and declare youself opposed to war--that took courage. Eddington faced contempt, ostracism, prison, the end of his career. The whole time he had an out--Cambridge was begging him, pleading with him to just accept an exemption on the grounds of work of national importance. But Eddington refused the easy path, only backing down on his own terms when he was allowed to make his values clear. Haber pranced around behind the lines on horseback and exposed himself--at a distance--to poison gas, and maybe that took some guts. But it took true courage for Eddington to stand again and again for what he believed. I have provided a link on the website to a beautiful poem that author Neil Gaiman wrote about Arthur Eddington. I would be violating copyright to play you the whole thing, and I can find no way to excerpt it without robbing it of its perfection. It captures all of Eddington's life and work in a way that I find extraordinary. If I haven't already made it clear, I admire Arthur Eddington like few other figures that I've learned about in this podcast. I will turn to a quote from 1919, when Einstein wrote Max Plank about Eddington's observations in Principe. Einstein said, "Thus the intimate union between the beautiful, the true and the real has once again proved operative." unquote. He was talking about his theory, but his words apply equally, I believe, to the man who proved it. Thank you so much for listening to The Year That Was. If you like what you hear, consider leaving a rating or review on Apple Podcasts--it's a great way to help new listeners find the show. Please visit the website at www.theyearthatwaspodcast.com for photos, images and sources. I want to specifically mention Einstein's War by Matthew Stanley and Proving Einstein Right by S. James Gates, Jr. and Cathie Pelletier as my two primary sources for these episodes. Thanks so much again to my husband Chris McAdams for his help understanding and explaining the Theory of Relativity. I couldn't do it with you--not any of it. Thanks also to my sponsors, Maggie S., Laura B., and new to the team Kate L. Hi, Kate, thanks so much. I really appreciate it. If you would like to support The Year That Was, click on the Support link on the website--you guys give me such a boost, I can't even tell you how much. In our next episode, we're going to take a trip to Mexico and learn about the remarkable revolutionary Emiliano Zapata. And that will be our penultimate episode of this season! Look for a survey soon about what year you want to take a deep dive into next. Thanks so much for listening. I'm Elizabeth Lunday, and this is The Year That Was.