Einstein's War

by Matthew Stanley

  Thomson opened the floor to questions and comments from the audience, and scientists leaped to their feet. Interestingly, everyone there seemed to accept the accuracy of the photographs and the reality of the deflection. No one was bothered by the discarding of the Sobral astrographic results, even though they seemed close to the Newtonian prediction. The astronomers and physicists gathered there trusted that the observers in the field had made the right call. No one knew better than they whether a measurement was reliable.

  Instead, the objections were about the nature of relativity itself, and whether the deflection should be considered evidence for it. F. A. Lindemann, who had tried to measure the deflection with daytime photography of stars, followed up on Thomson’s complaint about the mathematics. He was sure it was “elegant” in some sense, though he could not believe “that a profound physical truth cannot be clothed in simpler language.” He asked if Eddington could please translate the theory into such a form. H. F. Newall acknowledged that deflection had been seen but suggested that it was in fact due to refraction from the solar corona. Dyson replied that the location of the corona made that unlikely; Eddington provided detailed calculations refuting that interpretation too.

  Ludwik Silberstein, who saw himself as an expert on relativity, objected that the deflection should not be connected to the wider ideas of relativity, and that Einstein’s theory had not been confirmed. This was surely the objection Eddington had anticipated with his law/theory distinction (and, indeed, Silberstein would go on to propose alternatives to general relativity for decades to come). Silberstein insisted that it was “unscientific” to say that the deflection confirmed relativity without the gravitational redshift as well:

  The discovery made at the eclipse expedition, beautiful though it is, does not, in these circumstances, prove Einstein’s theory. We owe it to that great man [pointing to Newton’s portrait] to proceed very carefully in modifying or retouching his Law of Gravitation; this is by no means defending blind conservatism.

  It was noted that Oliver Lodge, the great defender of Newton, left the meeting halfway through without posing any questions. This departure was read as perhaps an insult or a de facto rejection of the results; Lodge reassured everyone that he simply had to catch a train.

  As the discussion settled and the meeting began to disperse, Silberstein came up to Eddington and reportedly quipped, “Professor Eddington, you must be one of three persons in the world [meaning Einstein, Eddington, and Silberstein himself] who understands general relativity.” As the story goes, Eddington demurred, whereupon Silberstein responded, “Don’t be so modest, Eddington,” and Eddington replied, “On the contrary, I am trying to think who the third person is.”

  * * *

  THE NEXT DAY, the Times of London presented the greatest scientific headline in history: REVOLUTION IN SCIENCE. Sharing the page was a reminder of the first Armistice Day observance (THE GLORIOUS DEAD). The proclamation of revolution headed a breathless article describing the joint meeting, reporting that “the greatest possible interest had been aroused in scientific circles.” The discovery was attributed to “the famous physician Einstein” (he was neither).

  The Times (London), November 7, 1919

  COURTESY OF THE AUTHOR

  This article was the culmination of nearly a year of Dyson and Eddington’s careful tending of the press, preparing the newspapers and their readers for this moment of scientific drama. It was written by Peter Chalmers Mitchell, a scientist turned journalist interested in physics and sympathetic to German science (he had studied in Leipzig and Berlin). We do not know if he and Eddington had met, though they were both Fellows of the Royal Society at the time. He could hardly have asked for a better spark to light public interest in relativity.

  On Saturday there was a follow-up article with the same title, with the addition “EINSTEIN V. NEWTON.” This was the general public’s first introduction to Einstein, and he appeared exactly as Eddington wanted to present him: a peaceful genius who repudiated all the wartime stereotypes of the militaristic German. He was described as a Swiss Jew who had only taken a position in Berlin due to the large salary. Further, “During the war, as a man of liberal tendencies, he was one of the signatories to the protest against the German manifesto of the men of science who declared themselves in favour of Germany’s part in the war.”

  The New York Times, November 10, 1919

  COURTESY OF THE AUTHOR

  The excitement jumped the Atlantic and on November 10, 1919, the New York Times blared, LIGHTS ALL ASKEW IN THE HEAVENS, along with “Men of science more or less agog over results of eclipse observations” (no word on how to determine one’s level of agogness). This article leaned heavily on the ones from London. The writer knew nothing about relativity and felt free to add embellishments such as “A book for 12 wise men—no more in all the world could comprehend it, said Einstein when his daring publishers accepted it.” Of course, Einstein said no such thing, although one still occasionally hears today that only twelve people “really” understand relativity. It is important to look back and remember that this was virtually the first mention of Einstein in the New York Times—he was a person of little consequence until this moment.

  In England, the story of Newton’s dethroning spread rapidly. Relativity was reported to be “a lively topic of conversation in the House of Commons.” Joseph Larmor said he had been “besieged by inquiries as to whether Newton had been cast down and Cambridge ‘done in.’” There was a genuine sense of wounded national pride that heightened attention. As usual, it was the satirists who were the real judges of what people were interested in. Punch gave this lovely quatrain:

  A patriot fiddler-composer of Luton

  Wrote a funeral march which he played with the mute on,

  To record, as he said, that a Jewish-Swiss-Teuton

  Had partially scrapped the Principia of NEWTON.

  The Daily Mail headline, LIGHT CAUGHT BENDING, placed a salacious spin on the results.

  Scientists were stunned at the broad public interest in Einstein and relativity. At least some of the credit for this goes to Eddington’s tireless efforts to promote exactly that interest. He held a public lecture in Cambridge where “hundreds were turned away unable to get near the room.” He gave interviews and wrote articles. And every time, it was a story of a scientific revolution made possible by scientific internationalism. From one piece: “The theoretical researches of Prof. Albert Einstein, of Berlin, now so strikingly confirmed by the British eclipse expeditions, involve a broadening of our views of external nature, comparable with, or perhaps, exceeding the advances associated with Copernicus, Newton and Darwin.”

  These were often adventure stories, too, with Eddington and his compatriots venturing to the edges of the Earth in the cause of science. Someone offered some new verses for “The Astronomer’s Drinking Song,” punning on the meaning of “Einstein” in German (“one stone”):

  We cheered the Eclipse Observers’ start.

  We welcomed them returned, Sir;

  Right gallantly they played their part,

  And much from them we’ve learned, Sir.

  No pains nor toil they thought too great,

  Nor left ein stein unturned, Sir,

  Right heartily we asseverate

  Their bottle a day they’ve earned, Sir.

  The Illustrated London News, November 22, 1919

  COURTESY OF THE AUTHOR

  There was a long tradition of newspapers reporting on eclipse expeditions with this sort of “astronomer-adventurer” frame. Now they could add wartime drama—science heals international rifts—to that as well.

  People in Britain flocked to Team Einstein, including those who had been rabidly anti-German during the war. Even H. H. Turner, who had called for the utter abandonment of German science, took the first Armistice Day anniversary
as an opportunity to meditate on the extraordinary victory of relativity: “Who could have anticipated, at the date of the actual Armistice, such a wonderful outcome? . . . Has there ever been so unexpectedly and completely successful an Eclipse Expedition? . . . A positive answer to a definite question is surely something new?” He hoped someone had placed a “modest wager” on the outcome. He did, however, call for many future tests of “The Great Result.”

  Turner also noticed an important theme of the press coverage and popular interest: the incomprehensibility of relativity. “The vain attempts of the reporters to apprehend exactly in what the revolution consists have been amusing, and would have been more so but for our own similar difficulties.” He recounted a story of uncertain origin and accuracy but of great entertainment value. A newspaper reporter allegedly went to the Royal Society and asked for an explanation of relativity: “The Secretary rubbed a hand over a dome-like brow, and frankly admitted he was beaten. The theory is down in black and white, with plenty of x=0, but compared with it the Rosetta stone in the British Museum is a child’s rag alphabet. . . . A distinguished scientist was next seen. ‘I don’t understand it at all,’ he said, wearily. ‘Don’t mention my name.’” The reporter then went to the library, read through the theory three times, “and was led out sobbing.”

  Fictitious stories like these helped cement the reputation of relativity as being beyond understanding. It wasn’t (and isn’t), but it looked scary, dealt with traditionally overwhelming philosophical ideas like time and space, and was distinctly foreign. We can see all of those in the tale of Turner’s reporter, who closed with this: “It is said that Professor Eddington, of Cambridge, claims to understand the theory, so, until he consents to put it in schoolroom prose—Gott strafe Einstein.” The final words were an inversion of the German wartime slogan “Gott strafe England” (May God punish England), a not-so-gentle reminder that Einstein was, until recently, the enemy.

  * * *

  THIS EXPLOSION OF interest around relativity finally made possible an important milestone. For the first time, Eddington and Einstein were able to write directly to each other. On December 1, Eddington sent his distant colleague a letter. He expressed all his hopes for what relativity and the expeditions might achieve:

  All England has been talking about your theory. . . . There is no mistaking the genuine enthusiasm in scientific circles and perhaps more particularly in this University. It is the best possible thing that could have happened for scientific relations between England and Germany. I do not anticipate rapid progress toward official reunion, but there is a big advance toward a more reasonable frame of mind among scientific men, and that is even more important than the renewal of formal associations.

  It was the personal relations among scientists that Eddington cared about. Changing organizations like the IRC would take a long time. His fellow Quakers doing relief work in Europe used the same strategy; they knew that nations would not be disarming anytime soon. Instead, Eddington and the Friends sought to build the personal relationships that humanized the enemy and laid the groundwork for peace. Eddington was particularly concerned to reassure Einstein that there was more than hatred in Britain:

  I have been kept very busy lecturing and writing on your theory. My Report on Relativity is sold out and is being reprinted. That shows the zeal for knowledge on the subject; because it is not an easy book to tackle. I had a huge audience at the Cambridge Philosophical Society a few days ago, and hundreds were turned away unable to get near the room. . . . One feels that things have turned out very fortunately in giving this object-lesson of the solidarity of German and British science even in time of war.

  There was some fortune, surely—any project that succeeded despite weather and war needed some. More important, though, was deliberate action. The eclipse expedition became a symbol of German-British solidarity because Eddington chose to craft it that way. Einstein chose to fight against militarism in German science and made that symbolism possible. It is not an accident, not a fluke, that things turned out this way. This was a great moment for science across the gulf of war because certain scientists turned it into one.

  CHAPTER 12

  The Relativity Circus

  “Virtually nothing but Einstein is being talked about here.”

  ALL THE FUSS was about one number, or maybe two—1.61 or 1.98—and how close they were to Einstein’s prediction of 1.75. Years of work and planning, months in the field, weeks of measuring and calculating, all get reduced to those naked numbers. It takes an enormous amount of labor to produce a single scientific fact like “light is bent by gravity.” And all that labor tends to be erased afterward, to make it seem as though nature speaks clearly and easily.

  We can see how difficult it was to produce that fact by looking at another number: Eddington’s annual bicycle rides. His cycling dropped off precipitously in October 1918, just as preparations for the expeditions were picking up steam. In 1918 he rode 2,028 miles; in 1919 just 124 miles. Relativity had taken over his life. That is the kind of effort and commitment it takes to make a fact. Eddington was always a little frustrated by this. His areas of deep scientific interest were the composition and movements of stars, not space and time: “People seem to forget that I am an astronomer, and that relativity is only a side issue.” What made the investment in relativity worth it for him was not just the science but the political and social significance of the theory.

  It was that significance that consumed Eddington’s time even after the presentation of the results. He had to spend some effort defending his new fact’s scientific meaning, but he also had to ensure that people cared about relativity and Einstein, that they paid attention to the lessons for internationalism and the nature of scientific cooperation. It was those efforts that would change Einstein’s life forever. His transformation into an icon of genius was inextricably tied to his emergence as a scientific saint from the chaos of postwar Europe.

  * * *

  AT THE END of 1919 many scientific societies in Britain set up special meetings to discuss the new revolutionary science. In December the Royal Astronomical Society managed to get both Eddington and Dyson to speak at theirs. Eddington explained relativity and Dyson explained the measurements. Things were significantly different from the November 6 meeting. This time, most who wanted to had been able to inspect the eclipse photographs directly, not just trust the reports. Some people had contacted Dyson with concern about whether the changes in the star images had been too small to measure. He patiently explained that, yes, the changes were very small “but those who are familiar with the measurement of astronomical photographs will know that it is quite possible to measure quantities of this order of magnitude.” Translation: astronomers do this every day; trust us. The individual star images were about 4 arc-seconds across; the change was about 1 arc-second. Could they really measure a change smaller than the actual image? Certainly—if you were six feet tall, you would definitely notice if you moved eighteen inches.

  Oliver Lodge was there, attending his first-ever RAS meeting. He discussed his usual conceptual objections to relativity and then asked if the results could be rechecked with the gravity from Jupiter (no). Silberstein said the results could only be seen as supporting relativity if one was already biased toward Einstein (he got little agreement). Scientists sent letters so they would be part of the conversation even if they were not present. Alfred Fowler, running the meeting, provided a hint of how British scientists would come to change the way they remembered the war: “We may also find satisfaction in the knowledge that national prejudice was not allowed to interfere with any contribution that we could make to the progress of science.” Just months after barring the Germans from the IRC, they were already beginning to celebrate their support of internationalism. Everyone tends to rewrite history—intentionally or not—to make themselves look better; scientists’ history about themselves is no different.

  There was a frenzy in
the scientific community as those interested and able checked the eclipse plates for themselves. Even skeptics began grudgingly coming around. Charles St. John, while accepting the existence of the deflection, hinted that a future theory might explain the observation better than Einstein’s. A few people unhappy with relativity, such as Joseph Larmor, made similar suggestions. Most everyone wanted the test redone at the 1922 eclipse, just for thoroughness (and it was). Within a year or so, though, H. H. Turner concluded that the debate over relativity within the scientific community had essentially ceased, with opinion firmly behind Einstein.

  Having the evidence for the theory accepted by specialists was crucial but not sufficient for it to triumph. If it was to survive and become part of the scientific canon, it needed to be spread to the next generation of scientists as well—it needed to be taught in formal classes, so science students could make it their own and use it in their own work. Given the huge interest, professors around Britain tried to teach it, though it was often “the blind leading the blind.”

  The decisive moment was Eddington’s first course on relativity at Cambridge, originally planned to be offered in October 1919. The class actually began several weeks later, probably pushed back due to him being too busy with the eclipse data reductions. He lectured twice a week at the famous Cavendish Laboratory, scheduled late in the day so more people could attend. He gave another, more technical, course on relativity in the spring. His lecture notes from that became the basis of one of the first textbooks on relativity, which continued to be used for a generation. The historian Andrew Warwick points out that Cambridge became a center for research in relativity in a way that Leiden did not (even though there were plenty of experts there) because Eddington made deliberate efforts to pass it on to his students and colleagues.