The Year That Was Season 1 Episode 23 Relativity - Part 1 The Pursuit of Truth: Eddington, Einstein, and the Eclipse of 1919 It was May 29, 1919. At the Peace Conference in Paris, the last touches were put on the Treaty of Versailles. African- American activist William Monroe Trotter, who had recently arrived in France disguised as a ship cook's assistant, tried to get the attention of delegates. In Russia, the Bolshevik Red Army advanced on the Czecho-Slovak Legion and drove them eastward along the Trans-Siberian Railway. At the northern port of Archangel, American troops in the Polar Bear Regiment boarded ships for home. In India, word spread about the massacre at Amritsar. Unrest simmered in Korea, China and Egypt, and Afghan troops launched an attack on the British across the Khyber Pass. In the United States, J. Edgar Hoover investigated several dozen mail bombs discovered earlier in the month. W.E.B. DuBois received responses to his essay "Returning Soldiers," published on May 1st. In Charleston, black residents mourned five men killed by rampaging whites on May 10th. Woman suffrage activists celebrated the House passage of the 19th Amendment on May 21st. And the Chicago White Sox played a double-header against the Cleveland Indians, winning both games. Meanwhile, events continued elsewhere, on a totally different scale. On May 29th, 1919, the earth rolled, as ever, around the sun, and sunlight raced over the globe. At the same time, the moon slipped into alignment between the sun and the earth. It began to pass between the two bodies. An enormous shadow fell across the planet. A blob of darkness, intensely black in the middle but fuzzy around the edges, raced from west to east. It began in southwest Peru, crossed the Andes, darkened the rainforests of Brazil, then shadowed the ocean all the way across the Atlantic. It touched Africa at what is now Equatorial Guinea and Gabon and swept over today's Democratic Republic of Congo, throwing forest elephants and lowland gorillas into sudden darkness. After crossing Zambia and Malawi, the shadow faded near sunset in today's Mozambique. Meanwhile, light from a cluster of stars known as the Hyades had been traveling toward the earth for about 153 years. It had begun its journey the same year Britain repealed the Stamp Act that had so inflamed the American colonies. The light, the photons, had been minding their own business, zipping along at 300 thousand kilometers per second through the Milky Way. As the light neared our sun, it encountered . . . A jog. A swerve. Imagine a slight curve on an otherwise straight road. The light took the curve without slowing down and continued on its way. Eight minutes later, those photons plummeted down the tube of a telescope on the island of Principe off the west coast of Africa. An image of this light, these stars, was captured in a photograph by an Englishman so intent on his work that he barely noticed the total darkness of the eclipse surrounding him. This light, and the man who recorded it, would change our understanding of the universe. This is The Year That Was. I'm your host, Elizabeth Lunday. Thank you so much for listening. I really appreciate your response to my return to podcasting. I love doing this work, and I'm thrilled to find an audience. This episode is our second in a row that deals with science and society in 1919. The story is very closely linked to last week's episode on Fritz Haber--in fact, I originally planned to combine the two topics in one episode, but that would have required cutting a huge amount of the story. I hope you consider the two of them part of a pair--and I think you'll very quickly see why. I also decided mid-way through writing this episode to divide it into two parts. I could have found a way to cut it down, but I found this material so interesting that I didn't want to do that. So this episode will end on a bit of cliffhanger. I intend to release part 2 a day or two after part 1, so you won't have long to wait to wrap it all up. Let's begin with the Englishman I mentioned just a moment ago, the one who captured the photo of the total eclipse on May 29, 1919. That man was Arthur Eddington. Eddington was born on December 28, 1882. His parents were both Quakers, and they raised their son in the Quaker community. Let's talk about this for a few minutes, because Eddington's identity as a Quaker plays a significant role in what follows. The Religious Society of Friends, nicknamed the Quakers, arose in the mid-17th Century in England. Members of the community believe that all people have within them the spark of the Divine Spirit, giving each human being unique worth. This led to an emphasis on equality and human dignity--for example, Quakers opposed slavery, since it placed some human beings under the control of other human beings. It also led to opposition to war, since Quakers felt-- and still feel--called to protect the Divine Spark within others. Quakers do not merely refuse to fight in war; they actively oppose violence and work for peace. Quakers were therefore among the first modern conscientous objectors. Some people have presumably refused to fight in wars since wars began, but we're focusing on recent history. In America, many Quakers refused to fight in the Revolutionary War. This did not go over well. Some were imprisoned and others had their goods and property seized. However, the Quakers stood firm through all of the wars that followed, and the American government eventually legally exempted members of historic peace churches, including Quakers, from military service. The situation was different in Britain, because Britain maintained an all-volunteer army through the 19th and into the early 20th century. As a result, Britain had no mechanism for dealing with conscientious objection. This will be important later. Back to Eddington. He received his undergraduate degree from the University of Manchester and then was awarded a scholarship to Trinity College, Cambridge in 1902 to study astronomy. He was a brilliant student, with a thorough grasp of physics, a solid grounding in mathematics, and a knack for the painstaking observations and measurements that made up the bulk of astronomical research. In 1906, after receiving his Ph.D., he was appointed chief assistant to the Astronomer Royal at the Royal Greenwich Observatory. Eddington was a modest and reserved man, with few close friends. I talked in my previous episode about how Fritz Haber was a delight at dinner parties. Eddington didn't attend many dinner parties, and if he did he was the type to be standing awkwardly in the corner with a glass of water. Eddington had been raised to avoid temptations such as alcohol, tobacco and gambling, and he retained most of his abstemious habits as an adult, although he did take up smoking. When he wasn't working, he was most likely exercising. He loved to walk, hike, and, best of all, bicycle. He kept obsessive records of his journeys--in 1905 he noted he had ridden a total of 2669 miles. One of his few close friends was C.J.A. Trimble, a mathematician he met at Cambridge. Trimble and Eddington were inseparable. Historians have speculated the two had a sexual relationship, but honestly we don't know. Eddington certainly never married and never showed any romantic interest in women. His letters were destroyed at the end of his life, so it's likely we'll never know the true nature of their relationship. It doesn't matter except that the thought of him having to hide his identity makes me very sad. But he would have had little choice--if he had been exposed as homosexual, Eddington's career would have been ruined and he could have been imprisoned for gross indecency. Conscientious objection was barely tolerated, but homosexuality was unacceptable. One of the tasks of the Royal Observatory was to observe solar eclipses. A total solar eclipse was an opportunity for astronomers to study phenomena only visible when the blinding disc of the sun is blocked by the moon. Today we have all sorts of equipment that lets us monitor the sun all of the time. In the early 20th century, phenomena such as the sun's corona were observable during an eclipse. We think of solar eclipses as being incredibly rare. In fact, one occurs about every 18 months somewhere on Earth. But the Earth is really big, people only live on a small part of it, and the area of complete shadow during an eclipse is, at maximum, 166 miles wide. Many eclipses fall over open ocean with only sea-life to experience them. So when an eclipse is predicted over land, astronomers flock to see it. This is still true today, but it was even more important to scientists one hundred years ago. Astronomers knew an eclipse would cross over South America on October 10, 1912. Eddington would be sent to observe it as a representative of the Royal Observatory. Planning began years in advance. Astronomers had to find a location within the path of totality where they were likely to have good weather--rain and clouds ruined many eclipse observations--and where they could ship their equipment without too much difficulty. Astronomical equipment including telescopes, spectrographs, and cameras was expensive and incredibly delicate. Imagine trying to haul precious, hand-ground glass lenses, precision motors, and costly cameras halfway across the world in the days before packing peanuts. Eddington's team selected Passa Quatro, Brazil as the site from which to study the 1912 eclipse. This was a village located about halfway between Rio de Janeiro and Sao Paulo and roughly fifty miles from the coast. Eddington was in charge of the equipment, and he took his responsibility seriously; on one leg of the trip, he slept with the luggage on the train station platform to ensure that wherever he went, the crates went also. Setting up all of that equipment required days of unpacking and careful adjustments to mirrors and motors. Eddington's team wasn't alone in Brazil. Multiple expeditions had been launched by astronomers around the globe, and naturally these scientists met, exchanged news and discussed their research. Science was an international pursuit, and knowledge knew no borders. Among the astronomers in Brazil that October was Charles Dillon Perrine, an American astronomer who had recently been appointed director of the Argentine National Observatory. Like Eddington, Perrine hoped to photograph the sun's corona, but he planned another experiment as well. He hoped to photograph some stars that would be visible on the very edge of the sun when viewed during the eclipse. Perrine was interested in measuring the position of these stars to see if they appeared in a slightly different place than when observed under normal conditions. He had gotten the idea from a colleague from Germany, the astronomer Erwin Freundlich. Freundlich had described to Perrine the recent work of an obscure German physicist. This physicist predicted that the light of the stars would be bent by the gravity of the sun, and the stars would appear in a slightly different place during the eclipse. Perrine wanted to see if the physicist, a man named Albert Einstein, was right. We don't know for a fact that Perrine told Eddington about Einstein, but it seems likely. If so, it would have been the first time Eddington had ever heard about the new theory of relativity. In any case, he didn't do anything with the information. He had his own job to do. The morning of the eclipse, Eddington's team was ready. The equipment was in place, and everyone was prepared. But they woke to heavy rain. It poured for hours, and the cloud cover was so heavy it was barely possible to tell when the eclipse passed by. The October 1912 eclipse was a bust. These things happen. Eddington packed up his equipment and headed back to England, where at least he could get a decent cup of tea. The failure of the expedition did no lasting damage to Eddington's career. The next April, he was named Plumian Professor of Astronomy and Experimental Philosophy at the University of Cambridge. Let's now move over to Central Europe and learn more about this obscure physicist and his new theory. Albert Einstein was born in Ulm, Germany on March 14, 1879 into a family of secular Jews. Despite stories to the contrary, Einstein was a good student, although he lacked focus. He was fascinated with science and mathematics and started teaching himself advanced math at age 12. At 17, he moved to Switzerland to begin college, in part to avoid mandatory military service in Germany. From a young age, Einstein was as much of a pacifist as Eddington. He became a Swiss citizen in 1896, which removed him from the grasp of the German military permanently. In 1903, Einstein married Mileva Maric and they had two sons, Hans and Eduard. He had hoped to get a teaching job, but his college professors hesitated to write the necessary recommendation letters. They didn't think this bright but easily distracted young man would make a good teacher. Einstein was the sort of person who could never remember where he left his keys, forgot the times of important exams, and lost the books he had borrowed without asking. He avoided wearing socks. He was soft-spoken but had a notoriously loud laugh--like a seal barking, one friend said. Finally, and famously, in 1903 Einstein accepted a job at the Swiss Patent Office--not a glamorous job, but it allowed him to continue his work. Einstein was a theoretical physicist. Unlike Eddington, an experimental astronomer, or Fritz Haber, an experimental chemist, he didn't need a lab. His work involved lots of math and his brain. He soon achieved remarkable breakthroughs with just these two instruments. In 1905, he published four groundbreaking papers, including two that introduced the theory of special relativity. Now, I am not going to try to explain the theory of special relativity. Why not? First, relativity theory is a vast and sweeping thing, and if I try to explain more than one little corner of it, we would have no time to talk about anything else. Second, I am not qualified to explain it on more than a surface level. Third, many people who are qualified have explained relativity. Those explanations are widely available. In part 2 of this episode, I will do my best to explain some elements of general relativity. For now, please take it as read that Einstein discovered remarkable things in 1905. These papers opened doors for Einstein, and he was able to leave the Patent Office in 1908 for a university professorship. In 1913, he was invited to take a position at the University of Berlin and become the founding director of the Kaiser Wilhelm Institute for Physics. You'll remember that Fritz Haber's career breakthrough was his appointment as the director of the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry. Haber and Einstein had met a few years earlier, and despite their totally different personalities, became close friends. Haber was instrumental in persuading Einstein to come to Berlin. Haber was also instrumental in getting Einstein through his divorce, as we touched on in the last episode. The details of the breakdown of the Einstein marriage are ugly and include the fact the scientist had began an affair with his cousin, Elsa. Elsa lived in Berlin and was part of the appeal of the city. Soon Mileva and the two boys moved back to Switzerland. Einstein had continued working on his theories through all of his divorce drama, and between 1907 and 1913 he published papers that began to lay out the principles of general relativity. In these papers he predicted several phenomena that could be observed to test his theory. One of these was that the light from stars would be bent or deflected by the sun when viewed during a total solar eclipse. One of the German scientists intrigued by this theory was astronomer Erwin Freundlich. Freundlich was so excited he told his old friend Charles Dillon Perrine about relativity and convinced Perrine to try to measure the effect in Brazil during the 1912 eclipse. And that brings the two strands of our story back together. In 1913, Eddington took up his position at Cambridge. As well as teaching astronomy, he was in charge of the Cambridge Observatory. His job included a very nice house, and Eddington invited his sister Winifred to live with him. Eddington and his sister became regulars at the Quaker Meeting House, where Eddington served on various committees and put his training in advanced mathematics to use handling the books for the community. Meanwhile, in Germany, Erwin Freundlich was determined to prove Einstein's theory by observing the deflection of starlight during the eclipse--and don't worry, I will eventually explain this. The next opportunity the heavens presented was a total solar eclipse on August 21, 1914 that would pass over Norway and Sweden, sweep into Russia at today's Baltic states, cross all the way down to the Ottoman Empire and Persia and conclude at the western tip of India. The best viewing was predicted for the Crimean Peninsula and Ukraine, and teams from around the world headed to Russia in the summer of 1914. Freundlich set up in Crimea and shared their viewing station with researchers from Britain and Charles Perrine's team from Argentina. An American team went to a small town near Kiev, and another British team was stationed near Minsk. Eddington, however, did not go to Russia as he was booked to attend a meeting of the British Association for the Advancement of Science in Australia in September. When the eclipse passed over Crimea, Eddington would be in Perth giving a free public lecture on "The Stars and Their Movements." I hope all of you are noting these dates--August 1914, September 1914. I have it on good authority that some of you listen to the podcast while walking your dogs, and I can only hope that you are now gripping the lease with some anxiety. Because on June 28, shortly after everyone arrived in Russia and Eddington set out for Australia, Archduke Franz Ferdinand was assassinated in Sarajevo. On July 30, Russia ordered general mobilization. The scientists watched as the roads filled with men heading toward their local military depots, often accompanied by their families and priests carrying icons. Anxiety was highest among the German teams. Government officials warned them that Russia would not be responsible for their safety if war was declared. The astronomers may have believed that science knew no borders. They were about to learn otherwise. Sure enough, on August 1, Russia declared war. The German astronomers were ordered to report to Russian government offices. The Germans said goodbye to their colleagues and headed to an unknown fate. They hoped they would be sent home; they feared they would be taken prisoners of war. The remaining teams went ahead with their preparations. But the weather didn't cooperate, and most observations were ruined by either complete or partial cloud cover during the eclipse. The August 1914 eclipse was another bust. The disappointed astronomers now had to figure out how to get home. The Russian train system had been handed over to military control, and getting a civilian ticket was next to impossible. Shipping freight was totally impossible. Russian authorities made it clear that the crates of valuable, fragile scientific instruments weren't going anywhere. The scientists reluctantly left their gear behind--I won't have opportunity to mention it again, so I'll tell you now that it took four whole years for the Americans to get their telescopes back. Then they began the tedious, frustrating, costly process of getting out of Russia. It took weeks. The fate of the German scientists remained unknown to their international colleagues for some time. But Freundlich and his team were fortunate that the local governor was a sensible man. He confiscated their equipment, and he sent four of the men, all younger members of the team who were Army reservists, to a POW camp, where they were interned for a year. The rest, including Freundlich, were repatriated and made it home weeks before their British colleagues. They were safe, but Freundlich was now stuck in Germany for the rest of the war. Since the next total eclipse to cross the country wasn't predicted until 1999, he had to resign himself to the likelihood he would not prove Einstein's theory any time soon. Meanwhile, Eddington and a whole host of other scientists assembled in Australia for the British Association for the Advancement of Science meeting. As news of the war hit, the attendees realized that their German and Austrian colleagues were now enemy aliens. Well, surely that had nothing to do with science. The association president toasted the health of the Germans and Austrians at the plenary dinner and the German geographer Albrecht Penck received an honorary degree. The Australian government was less gracious. Penck's belonging were searched and he was questioned sharply because he had map of Australia in his belongings. He explained that he was a geographer, and maps were kind of his thing. He was allowed to go back to Germany. Austrian anthropologist Bronislaw Malinowski was less fortunate. He wasn't allowed to go home, but the Australians permitted him to continue his research in Melanesia. The treatment of Penck and Malinowski was an early sign that scientific internationalism would be severely tested by the war. In fact, Penck and Freundlich had barely made it home when the first fissure split the international community of scientists. You may remember that Germany began the war by invading neutral Belgium on August 4th. This was a violation of international law, since Germany, like all European powers, had sworn to uphold Belgian neutrality. But that was just the start. As the Army swept through the small nation, German authorities were furious at the resistance they encountered. The Germans retaliated by taking civilian hostages and, more often than not, executing them. First houses, then neighborhoods, then entire cities were burned to the ground. Most imfamous was the attack on the ancient city of Louvain. Its historic library of 300,000 medieval books and manuscripts was torched. Allied and neutral newspapers were full of horror stories about German actions in Belgium and recounted tales of sexual assault, mutilation and child murder. Many of these stories were exaggerated or invented--but they were built on a foundation of real atrocities. The official German policy in Belgium was known by a word that translates to "frightfulness." Back home in Germany, the populace was appalled--not by the actions of their Army but at the reactions of the world. The Germans of 1914 took great pride in their civilization. To be attacked as barbarians was . . . Well, mean. A group of German intellectuals were so offended they decided to defend Germany's actions. They wrote up a document and titled it "A Manifesto to the Civilized World." The document begins, quote, As representatives of German Science and Art, we hereby protest to the civilized world against the lies and calumnies with which our enemies are endeavoring to stain the honor of Germany in her hard struggle for existence—in a struggle that has been forced on her. unquote. It continues by defending the actions of the Germany Army and then concludes, quote: Have faith in us! Believe, that we shall carry on this war to the end as a civilized nation, to whom the legacy of a Goethe, a Beethoven, and a Kant is just as sacred as its own hearths and homes. unquote It was signed by 93 artists, poets, architects, physicists, chemists, and philosophers, including 14 previous or future Nobel Laureates. Among them was chemist Fritz Haber. The Manifesto did not win over the civilized world. In fact, it convinced the civilized world that Germans had lost their minds. It was a slap in the face to those who promoted international scientific cooperation. German scientists asserted that they were German first and scientists second and that they fully backed the actions of their military. Quote, "The German Army and the German people are one." Einstein was also horrified by the Manifesto, which he refused to sign. He felt like his closest friends had been brainwashed--that term didn't yet exist, but that was the idea. He wrote about the quote, "collective insanity" of his friends, the quote "mass psychosis" of the populace, and said the whole world had turned into, quote, "a madhouse." One of the few of Einstein's friends who agreed with him decided to draft a counter-manifesto called "An Appeal to Europeans." This document bewailed the breakdown of cross-border scientific communication and cooperation and urged intellectuals the world over to work for peace. Einstein enthusiastically signed the manifesto. He was one of only three Germans to do so. Communication and cooperation had definitely broken down, and the rift was growing wider by the day. For decades, English libraries had subscribed to German scientific journals, and vice versa. The war made such interchange impossible. Further, before the war, astronomers had developed an efficient system for communicating observations and discoveries around the world via telegram. This system relied on a code to compress information and was headquartered in Germany. It came to a screeching halt when the war began. Neutral nations tried to devise a workaround, but British censors strongly objected to scientists sending coded telegrams into enemy nations. As the war dragged on and the casualty numbers mounted, attitudes toward the enemy hardened. Then in April 1915, Fritz Haber's pet project unleashed lethal chlorine gas on the Allied line. British scientists recoiled in horror and fury that science had been used for such a purpose. And then many British chemists went to work developing chemical weapons for their side. Hate spread into labs and lecture halls. A German physicist urged his colleagues to avoid referring to English scientists whenever possible and to "uncover" the German origins of discoveries the English claimed. Similarly, English scientists suggested that most German discoveries had actually been stolen from the English. Esteemed British professors began to question if Germans could even do science and asked if findings reported by German researchers could be trusted. Some individual scientists paid the price for this mood of rage and distrust. Arthur Schuster was a kind and generous 68-year-old astronomer who taught physics at Manchester University. He had been born in Germany but moved to England as a teenager. Fellow scientists hounded him mercilessly and tried to force him out of his job and his position as president of the British Association for the Advancement of Science. Meanwhile, his son, a British soldier, was wounded in the Dardanelles. Even more harrowing was the experience of James Chadwick, a young British physicist. He was studying under scientist Hans Geiger in Berlin when the war broke out. Chadwick was arrested and interned in a camp located at a converted racecourse. He lived in a horse stall with five other men and barely survived on the scant rations provided the internees. When Geiger was asked how he felt about his former student living under such conditions, Geiger replied that Chadwick was atoning for the sins of the English. Chadwick remained in the camp until the Armistice. In 1935 he won the Nobel Prize for the discovery of the neutron. Eddington and Einstein were among the few scientists who still believed in and argued for scientific internationalism. Eddington, for example, wrote essays and articles arguing that German scientists shouldn't be held responsible for the actions of the German military. He tried to humanize German researchers for his English readers, writing, quote, "Think, not of a symbolic German, but of your former friend Professor X, for instance. Call him Hun, pirate, baby-killer, and try to work up a little fury. The attempt breaks down ludicrously." unquote. His claims convinced no one. Both Einstein and Eddington went on with their work under increasingly difficult circumstances. Most of Eddington's students and all of his assistants went away to war. Government funding for research was slashed and rationing imposed. His physical conditions were nevertheless much better than Einstein's, since shortages of food and fuel were much worse in Germany. Einstein developed chronic digestive problems, likely the result of a poor diet. Unlike many of his friends, including Haber, who devoted themselves to war work, Einstein continued to work on his general theory of relativity. He had published several papers outlining the foundations of the theory, but they weren't quite right. Some elements of the theory didn't exactly work, and Einstein wrestled with his ideas, trying to find the solution. Einstein's breakthrough came in late autumn 1915. I am not going to attempt to describe that breakthrough, because honestly, I don't understand it myself. But a breakthrough it was, and it allowed Einstein to complete his Theory of General Relativity. On November 25, as Americans celebrated Thanksgiving, Einstein made a formal presentation to the Prussian Academy of Sciences. Here's the thing. I am not going to try to explain the Theory of Relativity to you right now. I want to save that until part 2 because that's where it makes the most sense. For now, I want you to accept that Einstein unveiled a radical new theory that provided a totally different way to understanding space and time and the movement of objects such as planets and stars. He showed that things like space and time that everyone had assumed were fixed and unchanging were actually distorting and stretching all around us. It was a big deal. You might think the German scientific community would be electrified by Einstein's new vision of the universe. Instead the reaction was a profound "meh." The war took up too much of their attention. One exception was Karl Schwarzschild, an astronomer. Schwarzschild, like most Germans who weren't Einstein, had volunteered for military service. He had been sent to the Russian front to calculate artillery trajectories and risen to the rank of lieutenant. To distract himself from the horrors, Schwarzschild kept up with scientific papers, and in December 1915 he received a copy of Einstein's paper. The heart of this paper was a set of ten equations, now known as the Einstein Field Equations. These were differential equations, a complicated bit of mathematics usually reserved for the third-semester university calculus students. Even Einstein, who had written the equations, hadn't actually solved them but only approximated the solutions. Schwarzschild worked through the equations, applying them to the example situation of a round object sitting by itself in space. He was able to work out the shape that space-time would take around this imaginary object, which let him find exact trajectories for anything moving in that area. Please note that he did this at the front line under Russian artillery fire with nothing but a pencil and paper. And I have trouble figuring the tip. Anyway, Schwarzschild wrote Einstein a letter containing his work and concluding, quote "As you see, the war treated me kindly enough, in spite of the heavy gunfire, to allow me to get away from it all and take this walk in the land of your ideas." Einstein was thrilled. Schwarzschild's work was still theoretical, but the math worked beautifully to make verifiable predictions. The two men began an enthusiastic correspondence, and Schwarzschild continued to work on the Einstein Field Equations. Later that winter, Schwarzschild noted a curious result when he ran the equations assuming an enormous quantity of mass in an extremely small space. He found that the space around a super-dense object would actually close off and become inaccessible to the rest of the universe. Schwarzschild reported this to Einstein as an oddity of the math, and Einstein accepted it as such. In fact, Schwarzschild had discovered the theoretical basis of black holes. It wasn't until the 1960s that scientists began to accept that black holes were a real thing that actually exist in space. Karl Schwarzschild remained at the Russian front until spring when he had to be evacuated due to illness. He died a few months later of a rare autoimmune disease. It has been conjectured, although not proven, the disease was triggered by contact with chemical weapons. His death devastated both Einstein and Eddington, who had met the German astronomer several times before the war. Few scientists outside of Germany had access to Einstein's work and so it was largely unknown beyond German borders. But a handful of researchers in the Netherlands, a neutral country, had remained in contact with both Einstein and the British. In late May or early June 1916, one of them wrote a summary of the new theory and mailed it to the one astronomer in Britain he thought would be open to receiving it, Arthur Eddington. Eddington had been having a difficult time. Britain had resisted imposing conscription as long as possible. It pushed volunteer enlistment through fair means and foul, even urging young women to hand men not in uniform white feathers to shame them for not serving. Finally in January 1916, the Military Service Act became law for England, Scotland and Wales. The law included exemptions for serious hardship (full-time care of an ill relative, for example), for work of national importance (say, making shells at an armaments factory), and for conscientious objectors. Cities and counties established tribunals to hear claims for exemptions. However, the government issued no guidance as to how these claims were to be assessed. Instead, the military pushed, pleaded, and begged for as many men as possible. Had Eddington been an ordinary person, his case would have been handled quickly. Most Quakers seeking conscientious objector status were mocked as "Conchies" and assumed to be slackers too cowardly to fight. Some agreed to take on alternate service. The Quakers had established an ambulance corps, and many tribunals allowed men to serve there. Others rejected even the ambulance service, since caring for men wounded in war was to give some tacit support to war. Men who refused all service could be sent to prison. Eddington worked with his chapter of Friends to support the families of these men. But whether he liked it or not, Arthur Eddington was no ordinary Quaker. He was the Plumian Professor of Astronomy at the University of Cambridge, and Cambridge had no desire for their their Plumian Professor to debate pacifist principles with the local tribunal. They were still smarting from the case of an even more famous academic, Bertrand Russell, who had recently made headlines for resisting conscription. So Cambridge submitted an exemption form on Eddington's behalf, claiming his work was of national importance. Eddington was appalled. He wanted to be treated the same as his fellow Quakers and was prepared to accept the same consequences. Of course he didn't want to go to prison, but to be singled out was against everything he believed in. He submitted his own exemption form requesting conscientious objector status. It appears the university intervened and Eddington's request was never processed. So the deed was done. It had consequences. Everyone knew Cambridge had kept Eddington from the front. Colleagues began avoiding the astronomer. After all, many of them had sons at the front, and everyone knew someone who had been killed. It seemed unfair, and some viewed Eddington with disdain, even disgust. Eddington's stance on scientific internationalism didn't help. Around this time, Eddington wrote an essay titled "The Future of International Science." He wrote, quote, "Above all, there is a conviction that the pursuit of truth, whether in the minute structure of the atom or in the vast system of the stars, is a bond transcending human differences--to use it as a barrier fortifying national feuds is a degradation of the fair name of science." unquote. His plea fell on deaf ears. So, in 1916, Eddington was one of the few scientists in Britain open to the ideas of a German scientist. It helped that one of the few things Eddington knew about Einstein was that he hadn't signed the 1914 "Manifesto to a Civilized World." Eddington's Dutch correspondents highlighted this fact and emphasized that Einstein was a pacifist. This made the theory even more interesting to Eddington. Here was an opportunity for a pacifist Englishman and a pacifist German to work together in the pursuit of truth. The summer and fall of 1916, Eddington wrestled with the theory and exchanged multiple letters with his Dutch colleagues. In turn, they let Einstein know he had a British ally. Einstein replied that it was a fine thing to throw, quote, "this bridge across the abyss of delusion." By early spring 1917, Eddington had become convinced Theory of Relativity was right. And he realized something. He was in a unique position to either prove or disprove the theory by measuring the deflection of stars during a total solar eclipse. Because, a total solar eclipse would take place on May 29, 1919 with the Hyades star cluster in an ideal position relative to the sun. The path of the eclipse would travel from South America across the Atlantic to Central Africa. Eddington had to assume the war would still be raging in 1919, so no German scientists would be able to observe the eclipse. But Britannia ruled the waves, and, with support from the right people, Eddington would be able to mount expeditions to the right locations. Eddington went to the Astronomer Royal, the astronomer Frank Dyson, who was his friend and former boss. Only Dyson could authorize and fund such an expedition in war time. Eddington asked to arrange an expedition, or better yet multiple expeditions to study the phenomenon. It took some convincing, but Dyson agreed in March 1917 to throw his support behind Eddington's plans. It was a strange time to be setting ambitious goals for the future. The war seemed neverending. Soon the Americans would join the fight, and perhaps that would make a difference, but in 1917 it seemed like the entire world was trapped in an endless cycle of death. Rationing made it hard for both Eddington and Einstein to get tobacco. Eddington regretfully gave up sugar in his tea. Einstein, meanwhile, lost nearly 50 pounds in two months and survived on food sent him from friends in Switzerland. He spent weeks at a time in bed. Perhaps it was warmer there anyway-- coal shortages made Berlin winters miserable. Einstein now lived with his cousin Elsa; he had little contact with his sons in Switzerland. His only non-scientific activities were participation in pacifist and socialist organizations. These efforts landed him on a police watchlist, and he was forbidden to leave the country. Eddington, meanwhile, now felt confident enough with the Theory of Relativity that he began spreading the word in a series of essays and speeches. He met heavy resistance--the theory seemed more like metaphysical philosophy than science, and anyway it was German. For most British scientists, the idea of traveling halfway around the world to prove a German theory was absurd and possibly traitorous. Only Eddington's reputation as a scientist of integrity kept him from being dismissed out of hand. Eddington forged ahead reviewing weather reports of potential observation sites and sourcing equipment. But this work came to screeching halt in the spring of 1918 when the government revoked all occupational exemptions for military service. Eddington was expected to report for duty. Right here, my friends, is where I'm going to leave you. Einstein was in bed, in pain and malnourished. He was confident his theory was right, but German scientists ignored him and Allied scientists dismissed him. Eddington knew he could prove Einstein right if he could only observe the 1919 eclipse. But the military wanted to throw him into the Flanders meat grinder. And the war went on. Germany began its Spring Offensive in March, throwing hundreds of thousands of men at the Allied lines. They employed new stormtrooper units who moved fast and light. For the first time in four years, Germany was able to break out of the trenches. On the other side, American troops were arriving en masse, but their commanders considered them not yet ready to fight. For a few weeks, it seemed possible Germany would break the French line and end the war before America fired a shot. Out in space, the light from the Hyades continued to stream toward Earth. They were unthinking particles barreling across unimaginable emptiness. One Einstein's thought experiments was to imagine himself riding on a beam of light. Had he hitched a ride on the light from the Hyades, he would have noticed a particular star was growing brighter and closer by the moment. The light was nearing the sun, our sun, and its cluster of planets, one brilliantly blue and white. From those millions of miles away, he couldn't have seen the bloody gash across France, and the wail of suffering rising from Earth would have been impossible to hear. Thank you so much for listening to The Year That Was. We will pick back up right here in Part 2 of this episode, which I will post in a few days. Please check out the website, www.theyearthatwaspodcast.com, for photos, links 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--both excellent books that I highly recommend. I want to thank my sponsors, Maggie S, Laura L. and Laura B, for their continued support. If you like what you're hearing, you can become sponsor yourself--just click on "Support" on the website. Please leave comments and questions on the Facebook page or on Twitter. I love the opportunity to chat. We're getting close to the end of 1919, so I hope you're thinking about what's next. Look for a survey soon on which year we're going to dive into next season. Thank you again for listening. I'm Elizabeth Lunday, and this is The Year That Was.