Einstein's War

by Matthew Stanley

  On the other side of the Channel, some London academics were congratulating themselves on their tolerance. King’s College and University College London allowed their foreign students to stay. The British government had other plans, though. Immediately after the war began, Parliament passed the Aliens Registration Act. Elaborate rules were set for citizens of Germany or Austria-Hungary in the country, controlling their residences, work, and movements. They had to register at the nearest police station and could not go more than five miles from it. They could not live near areas of military importance, which included the entire east coast. German newspapers were banned and communication devices were forbidden. Immigrants were no longer allowed to change their names—it would be too easy for them to hide. Postal censorship was introduced to catch German spies but was quickly used to build a list of anyone with antiwar views.

  Internment of suspicious persons began as well. The German physicist Peter Pringsheim had been at the BA meeting in Australia and heard Oliver Lodge’s declarations in support of international science. He spent the length of the war held in a British camp. Albrecht Penck, a geologist who had also been at the meeting, narrowly escaped internment in England but was then arrested as a spy.

  * * *

  ISOLATION WAS A double-edged sword. Einstein had hoped isolation would let him ignore the madhouse and focus on his work. Instead, as his colleagues rallied around the flag he realized that solitude could be a curse. How could he talk to Haber and Planck about scientific matters when they proclaimed that science was united with the Reich? The militaristic trappings of the Prussian Academy had unexpectedly become more real.

  Eddington, too, was shocked to find his friends declaring that British science was, indeed, British and not international. Dyson had decided to embrace the “Royal” part of his title, and astronomy was now supposed to be explicitly in service of the Crown. Eddington was sharply reminded that as a Quaker he was an outsider. His professional success in moving into the inner circles of the scientific establishment had suddenly been compromised. As a pacifist in a newly militaristic nation, he was increasingly lonely.

  The destruction of Louvain had set in motion a chain of events that cut both Einstein and Eddington off from their intellectual communities. This separation would only grow as the war increased its terrifying scale. Both had begun searching for new routes forward. Einstein’s first attempt with Nicolai had failed, but perhaps the BNV showed some promise. Eddington’s Society of Friends had begun mobilizing for peace, though it was not yet clear how they could best work for their cause. Pacifists in Britain and Germany had begun organizing, but would they be strong enough to resist the militarism that had enveloped Europe? And would science place itself on the side of war or peace?

  CHAPTER 5

  The Collapse of International Science

  “No Compromise with a Race of Savages.”

  ON AUGUST 10, 1915, a twenty-seven-year-old signals officer was shot through the head by a Turkish sniper. He was in the Dardanelles as part of Winston Churchill’s daring, perhaps foolhardy, plan to open a new front in the war. The Ottoman Empire had joined Germany and Austria-Hungary months before, widening the conflict even further. What became known as the Battle of Gallipoli was a disaster, failing to achieve any of its strategic goals. It claimed hundreds of thousands of lives, including that of the young English signals officer—Henry Moseley, who had just been nominated for the Nobel Prize for physics.

  Moseley had published only eight papers in his short life, but he was on the verge of revolutionizing physics and chemistry. He had developed a method to use X-rays to probe the inner structure of the atom in ways that seemed almost fantastical. He had been about to receive a prestigious professorship during the summer of 1914 when the war broke out. In Australia with Eddington, he cut the trip short to return to England and volunteer for the army.

  Scientists around the world reacted with shock at the news of his death. The physicist Robert Millikan in America lamented, “Had the European War had no other result than the snuffing out of this young life, that alone would make it one of the most hideous and most irreparable crimes in history.” Even the Germans called it “a heavy loss for science.”

  Moseley’s mentor, the famous experimenter Ernest Rutherford, wrote an obituary for the flagship journal Nature. It was a tribute to genius cut short far too soon. He described the mixture of emotions that he and his colleagues felt about the enlistment of talents like Moseley: “pride for their ready and ungrudging response to their country’s call, and with apprehension of irreplaceable losses to science.” Rutherford, himself one of the greatest experimenters of all time, saw in Moseley all the future of physics. His frustration came through clearly. He called it a national tragedy that the government regarded that young man only as a combatant: “we cannot but recognise that his services would have been far more useful to his country in one of the numerous fields of scientific inquiry rendered necessary by the war than by exposure to the chances of a Turkish bullet.”

  Other British scientists were lost at Gallipoli: Charles Martin, a Glasgow zoologist; Keith Lucas, a Cambridge physiologist. A single lab in Oxford lost five men. It seemed that the next generation of scientists were being scythed down by the war. An article in the Times complained about this “waste of brains.” Imagine, it said, if the war had taken place eighty years before. There might be a burial plaque that read “Killed in Flanders, Charles Darwin.”

  These mournful warnings showed one of the fundamental tensions of science during the Great War. Even as most scientists on all sides supported the war, it was not at all clear what that meant. Should they support it with their intellect and their scientific skills? Or should they support it with their body and their skill at arms?

  * * *

  IN LONDON, THESE questions were bound up with the expanding sense of the home front. German zeppelins dropped bombs in January. While these early air raids did little damage, the psychological impact of the war literally landing on one’s doorstep was immeasurable. Soon after this, the Germans aimed another new weapon at the civilian population. In retaliation for the British blockade of their ports, their submarines began attacking any ship headed to the British Isles. These new craft could evade the Royal Navy almost at will, striking and vanishing before overwhelming power could be brought against them. Like Germany, Britain’s industrial might relied on a worldwide network of raw materials and foodstuffs to support it. They were just as vulnerable. Between fifty and a hundred merchant ships were sunk each month by U-boats. Sugar started disappearing from market shelves in Cambridge and York. Two imperial giants, unable to advance on the battlefield, began slowly strangling each other.

  A decisive moment came in May, when the British liner Lusitania was finishing its 202nd transatlantic crossing, and passed in front of the lurking submarine U-20. It sunk after a single torpedo, taking 1,201 passengers and its cargo of ammunition to the depths. The huge casualty list sparked international outrage. Of those killed, 128 were Americans, which nearly brought the sleeping colossus into the war. Skillful German diplomacy kept that at bay for the time being. King George V finally removed the banner of the kaiser—his cousin—from St. George’s Chapel at Windsor Castle. He had resisted public pressure to do so since the declaration of war. No longer.

  The sinking triggered anti-German riots across the UK. Shops were ransacked and people dragged from their homes. A piano belonging to a German immigrant family was hauled into the street, where it was used to play patriotic songs. Germans who had not yet been interned were quickly arrested. Some 32,000 were placed in camps by that fall. Mob actions continued to be spurred by the press. The hugely popular magazine John Bull ran an editorial calling for a “vendetta” against all Germans. Headlines such as “No Compromise with a Race of Savages” were common.

  * * *

  A MEMBER OF that race of savages was having some trouble with his calculations. Einstein was German by b
irth and residence, but he was quick to correct anyone who described him that way. He clung to his Swiss citizenship like a talisman. It not only prevented the kaiser from trying to conscript him, it provided some mental solace—a way of keeping himself apart from the patriotic madness around him. Even so, his scientific correspondence often seemed to bring him face-to-face with his isolation:

  I love science twice as much in these times when I feel so painfully for almost all of my fellows about their emotional misjudgments and the sad consequences. . . . We scientists in particular, must foster international relations all the more and must distance ourselves from the coarse emotions of the mob; unfortunately we have had to suffer serious disappointments even among scientists in this regard.

  He found himself relying more and more on those few colleagues with whom he could speak freely. The war had made it obvious, he wrote, that “the only thing really worth striving for in this world is the friendship of exceptional and independent persons.”

  Paramount among those remained Lorentz. No one had his perfect balance of scientific expertise and diplomatic presentation. Einstein could sometimes be prickly when criticized, but he always welcomed Lorentz’s amendments. After one such correction he wrote back: “The theoretician is led astray in two sorts of ways: 1) the devil leads him up the garden path with a false assumption. (For this he deserves pity.) 2) He argues inaccurately and sloppily. (For this he deserves a thrashing.).” He humbly accepted his Dutch mentor’s thrashing.

  Lorentz was one of Einstein’s main confidants about the great weakness of the Entwurf theory—the lack of general covariance. Einstein wavered about whether this was a real problem. Had his hole argument put covariance to rest? Or was covariance still hiding somewhere within the equations? Lorentz thought it wasn’t necessary. He was still confident in the ether, whose absolute reference frame would make covariance impossible. He gently suggested to Einstein that, perhaps, his attachment to the principle of relativity was merely a “personal view” and not “self-evident” as the younger man had hoped. Generations of scientists had worked with the ether—perchance it could be brought back into Einstein’s gravitational theory?

  Einstein wasn’t willing to go that far. The lack of covariance was a flaw, but he could live with imperfection. And it did not shut down further work. He had two avenues of research into general relativity—the physical and the mathematical, what Einstein called a “kaleidoscopic mixture.” Covariance was a physical problem, so he decided to focus on the mathematical approach for a time. He began corresponding with Tullio Levi-Civita in Italy, a mathematician who had helped establish the absolute differential calculus Einstein had built his theory with. Their conversations were fruitful—only to be cut off by Italy joining the Allied powers.

  He checked in regularly with Freundlich about possible ways to test his theory. Einstein was still trying to get him time off to work on relativity. Freundlich’s supervisor, Otto Struve, continued to say no—this time because the young astronomer was already notoriously unreliable about getting his assigned tasks done.

  Without a handy eclipse, that left the wobble of Mercury’s orbit as Einstein’s best bet. This wobble (technically a “precession of the perihelion”) had been known since the 1850s and had resisted all attempts to explain it with Newtonian gravity. If the sun was a little fat around the waistline, that would explain it (but it wasn’t). A planet inside Mercury’s orbit, code-named Vulcan, could explain it (but neither it nor its effects had been seen, and astronomers had been looking hard). Ad hoc adjustments to Newton’s equations would fix it (but who was willing to alter those sacred texts?). The standing solution was to assume diffuse bands of gas and dust floating near Mercury—conveniently just thick enough to cause the precession but not thick enough to be seen. Einstein had gambled that the Entwurf would provide a clear mathematical prediction of the precession and thus convert disbelievers to his side. It didn’t—the calculation it offered was way off.

  Despite the problems, he felt pretty optimistic. The mathematical techniques of coordinate transformations were working fairly well, the equivalence principle was holding up against all challenges, and it was firmly grounded in conservation laws. The struggle had been painfully difficult, though. He complained to Ehrenfest that his “work on gravitation progresses, but at the cost of extraordinary efforts; gravitation is coy and unyielding! . . . What has been found is simple, but the search is hell!”

  In January 1915 he similarly wrote to a friend that general relativity was about to be “brought, in a sense, to a close.” In another letter he sounded satisfied: “I am working tranquilly in my booth in spite of the distressing, abhorrent war. The general theory of relativity has now been relieved of most of its obscurities.” He complained that it was “a pity” that the mathematics of the theory made it so difficult to study. He consoled himself with the memory that this was once true of Maxwell’s theory before it was simplified. The letter took a sudden turn once he had given the relativity news, though:

  Why do you write to me, “God chastise the English”? Neither to the former nor to the latter do I have any close relations. I just see with great dismay that God punishes so many of His children for their ample folly, for which obviously only He Himself can be held responsible; I think, His nonexistence alone can excuse Him.

  Even in nonpolitical communications, the war couldn’t be avoided.

  Support from other scientists for relativity waxed and waned. One week he felt that Planck, previously a determined opponent, was finally coming around. Another week he complained that interest in relativity was “exceedingly modest for the time being.” He had essentially run out of friends in Berlin. And with his letters and telegrams constrained by the Royal Navy’s vigilance, he did not know where he could find new recruits for his cause.

  * * *

  THE EFFECT OF the blockade was two-sided. As war was first breaking out in August 1914 and Eddington was still returning from Australia, British astronomers noted something odd. The most recent issue anyone had of the Astronomische Nachrichten—the main journal for German astronomy—was dated July 22. Surely there was a more recent volume? There was not. The trenches cut off scientific communication as efficiently as they stopped commerce. The British blockade kept out scientific journals along with Prussian propaganda and personal letters.

  Print was not the only medium the war disrupted. For years international astronomers like Eddington had relied on an elaborate telegraph network to spread the details of observations and discoveries. This “Science Observer” system used a special code to compress large amounts of astronomical data into an efficient form. This allowed for both speed and more reliable claims of scientific priority. The coded telegrams were sent to a hub in Kiel, Germany, and then disseminated to observatories around the world.

  Once the fighting began, though, the telegraph lines were cut. The astronomers’ well-oiled system had been decapitated. A Japanese observer wanting to get credit for discovering a new comet, or Eddington requesting confirmation of some unusual stellar motions, had no way to do so. Because the system ran through Germany, even communications between non-belligerent nations were disrupted. Edward Charles Pickering, the head of the Harvard Observatory in the neutral United States, complained to the Astronomer Royal, Frank Dyson, that the global project of astronomy had ground to a halt. “Owing to the cutting of the cables it is now impossible to communicate with the Centralstelle at Kiel. There is, therefore, no official means of intercommunication of astronomical discoveries.”

  The two scrambled to put a stopgap system in place. American astronomers would send telegrams to Pickering, who would send them to Dyson, who would then send them individually to Allied and neutral observatories in Europe. This situation was extremely confusing. Just as Dyson was setting up his procedures, Elis Strömgren, the leading astronomer in neutral Denmark, was trying to do the same thing. Strömgren thought it made more sense for his
institution to replace the cut-off German hub. The astronomers within the Central Powers knew and trusted him to act in a genuinely international fashion. Strömgren assured astronomers on both sides of the fighting that he would take care of the system for however long the war lasted.

  British censors, however, were not so sanguine. To the government it appeared simply that streams of coded telegrams were passing back and forth from enemy countries. The postmaster general objected and announced this would not be allowed. The Astronomer Royal appealed personally for an exception, providing the key to the technical code. It was refused again with no further explanation. Early in the war these matters were handled by the post office, which had little experience with censorship, and many of the astronomical messages made it to Copenhagen anyway. This changed abruptly when the Defence of the Realm Act was passed and the War Office took over censorship. Individual telegrams were examined and deciphered versions demanded.

  Even when the messages were decoded, scientific communication with the enemy was still seen as deeply suspicious. W. E. Plummer’s transmissions from the Liverpool Observatory marked him as possibly being in league with the enemy. The board of directors of the observatory grew suspicious and demanded that he cease all communications. He explained the telegrams’ purpose; nonetheless, they had “the appearance of assisting the enemy.” R.T.A. Innes did not think it was a good idea to allow neutral countries access to imperial data. He confessed that he “would prefer to send such messages to a British institution.”