“An Expedition to Heal the Wounds of War” The 1919 Eclipse and Eddington as Quaker Adventurer

“An Expedition to Heal the Wounds of War” The 1919 Eclipse and Eddington as QuakerAdventurerAuthor(s): Matthew StanleySource: Isis, Vol. 94, No. 1 (March 2003), pp. 57-89Published by: The University of Chicago Press on behalf of The History of Science SocietyStable URL: http://www.jstor.org/stable/10.1086/376099 .

Accessed: 19/05/2013 08:16

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

The University of Chicago Press and The History of Science Society are collaborating with JSTOR to digitize,preserve and extend access to Isis.

http://www.jstor.org

This content downloaded from 138.73.1.36 on Sun, 19 May 2013 08:16:28 AMAll use subject to JSTOR Terms and Conditions

http://www.jstor.org/action/showPublisher?publisherCode=ucpress

http://www.jstor.org/action/showPublisher?publisherCode=hss

http://www.jstor.org/stable/10.1086/376099?origin=JSTOR-pdf

http://www.jstor.org/page/info/about/policies/terms.jsp


Isis, 2003, 94:57–89� 2003 by The History of Science Society. All rights reserved.0021-1753/03/9401-0003$10.00

57

“An Expedition to Heal the Woundsof War”

The 1919 Eclipse and Eddingtonas Quaker Adventurer

By Matthew Stanley*

ABSTRACT

The 1919 eclipse expedition’s confirmation of general relativity is often celebrated as atriumph of scientific internationalism. However, British scientific opinion during WorldWar I leaned toward the permanent severance of intellectual ties with Germany. That theexpedition came to be remembered as a progressive moment of internationalism waslargely the result of the efforts of A. S. Eddington. A devout Quaker, Eddington importedinto the scientific community the strategies being used by his coreligionists in the nationaldialogue: humanize the enemy through personal contact and dramatic projects that high-light the value of peace and cooperation. The essay also addresses the common miscon-ception that Eddington’s sympathy for Einstein led him intentionally to misinterpret theexpedition’s results. The evidence gives no reason to think that Eddington or his coworkerswere anything but rigorous. Eddington’s pacifism is reflected not in manipulated data butin the meaning of the expedition and the way it entered the collective memory as a cele-bration of international cooperation in the wake of war.

Science is above all politics.

—Sir Oliver Lodge (1914)

Is it not an actual fact that babies have been killed in ways almost inconceivably brutal,and not as a mere individual excess, but as a part of the deliberate and declared policyof the German army? . . . Is it not a fact that German men of science have gone out of

their way to declare their adhesion to these things?

—“From an Oxford Note-Book,” Observatory (1916)

* Department of the History of Science, Harvard University, Science Center 235, Cambridge, Massachusetts02138.

I would like to thank the staff of the Department of the History of Science at Harvard University and the MaxPlanck Institute for the History of Science, where some of this research was carried out. I would also like toextend special thanks to Peter Galison, David Kaiser, Michael Gordin, and Janelle Stanley. This essay receivedthe 2002 Henry and Ida Schuman Prize of the History of Science Society.



58 “AN EXPEDITION TO HEAL THE WOUNDS OF WAR”

W HEN ONCE ASKED WHY EINSTEIN enjoyed such a tremendous public reputationcompared to the founders of atomic and quantum physics, Ernest Rutherford replied

that it was due to the timing of the 1919 eclipse expedition that provided a confirmationof general relativity: “The war had just ended, and the complacency of the Victorian andEdwardian times had been shattered. The people felt that all their values and all their idealshad lost their bearings. Now, suddenly, they learnt that an astronomical prediction by aGerman scientist had been confirmed by expeditions . . . by British astronomers. . . . Anastronomical discovery, transcending worldly strife, struck a responsive chord.” Ruther-ford’s description of the setting was exactly right: coming out of the Great War, Britishsociety was devastated from years of trench warfare, rationing, and hatred of the enemy.However, the note of international harmony is rather misleading. Rutherford’s view is stillwidespread, and the expedition is often portrayed as a great victory for scientific interna-tionalism over jingoistic militarism. For example, many years later the astrophysicist Wil-liam McCrea wrote a patriotic, congratulatory article on how much of his success Einsteinowed to the good auspices of the Royal Astronomical Society (RAS).1 Unfortunately, theclaim that the RAS’s support of Einstein was a straightforward scientific step ignoresthe tremendous anti-German forces that were present in British science during and afterthe war, as well as the difficult and unpopular struggle waged in support of Einstein andGerman science in general. I will argue that the expedition’s significance as a dramaticand pivotal event in both science and society was far from inevitable and that it was onlybecause of its wartime context and the value-driven actions of particular individuals thatit achieved its canonical status in the history of modern science.

The key figure in the formation of the expedition’s significance as a historical event wasA. S. Eddington, the Plumian Professor at Cambridge. Eddington was then a rising star inthe astronomical community: by the start of the war his work in statistical cosmology hadestablished his reputation as a creative and talented scientist, and his later work in stellarstructure was a crucial element in the development of theoretical astrophysics as a field.He was one of the leading public spokesmen for science between the world wars and wasoften the source of controversy owing to his writings on science and religion, as well ashis attempts at unifying quantum physics and relativity.

But his name is most widely associated with relativity, both for his role in the 1919expedition to measure Einstein’s predicted light deflection and for his aggressive popular-ization and promulgation of the theory in the anglophone world. Eddington’s passion forEinstein’s theory is often pointed to as a weakness, and there is a widespread assumptionthat his sympathy for relativity led to inappropriate, or even fraudulent, interpretation ofthe 1919 data in favor of Einstein. Because of this, the eclipse expedition is often seen asan intrinsically great event in both scientific and social history (for bringing Einstein tothe fore and soothing wartime anger) but one based on contextually contaminated science(Eddington’s biased observations). I would like to invert this dichotomy: the evidenceshows that Eddington’s work on the eclipse was well within the scientific standards of theday and that the larger significance of the expedition, both contemporaneously and in thepresent, was largely the result of Eddington’s contextual concerns.

Eddington became a pivotal figure in these events owing to his religious antipathy to

1 S. Chandresekhar, Truth and Beauty (Chicago: Univ. Chicago Press, 1987), p. 115 (quoting Rutherford); andW. H. McCrea, “Einstein: Relations with the RAS,” Quarterly Journal of the Royal Astronomical Society, 1979,20:251–260.



MATTHEW STANLEY 59

the war. He was a member of the Religious Society of Friends (better known as theQuakers), a small but historically influential Christian sect whose beliefs center on thedivine Inner Light found in all people and the consequent values of pacifism, nondog-matism, and tolerance.2 His campaigns for an astronomy free of nationalism emerged fromthe roots of his religious belief. His Quaker values meant that he saw international scienceas a site for a moral contestation of war and prejudice. His actions, particularly in regardto the 1919 expedition, shared the motivation of the Friends who organized the refugeecamps and ran the blockade to feed German children. These Quakers who braved the chaosof wartime and postwar Europe became known as “adventurers”: men and women led byreligious conviction to leave the safety and comfort of home to work for peace. I willargue that the expedition to “weigh light” was as much a religious calling as the foodprograms and that Eddington saw himself as one of these Quaker adventurers. The eclipseexpedition, then, becomes an event steeped in political, moral, and religious meaning.Einstein and relativity became a focal point through which Eddington could advance bothscience and international understanding. In practice, these two goals blurred together, ashe truly felt that astronomy could not progress in a world wracked by hatred and war.

The conflicts within the RAS emerged from the wider culture of anti-German sentimentand wartime hatred, and Eddington refused to deal with them as though they were uniqueto astronomy. Rather, he sought to combat jingoism in science by importing the techniquesused by Quaker pacifists in British society as a whole. An understanding of this origin forEddington’s efforts and arguments will show that the expedition and its place in the historyof science have a meaning that can be understood only with reference to the Great Warand its impact on British astronomy. To investigate the context and significance of theexpedition, this essay will follow the historical actors, and specifically Eddington, throughthe experience of being a scientist in a country at war. I will first establish the socio-cultural context of the actors: What values and beliefs were in play? How did it becomepossible for the expedition to be relevant to the war? Next, the expedition’s execution andinterpretation will be examined in detail. Questions of technical diligence and scientificresponsibility will be paramount here. Finally, we will look at the expedition’s presentationto the world community and the influence it had on the first shaky steps of astronomy afterthe Great War.

ASTRONOMY IN THE GRIP OF WAR

The crisis of the summer of 1914 happened to coincide with the annual meeting of theBritish Association for the Advancement of Science (BAAS), held that year in Australia.Many of the greatest figures in British science, including Eddington, were thousands ofmiles away from the stormy fields of Europe, considering issues of experiment and or-ganization rather than sovereignty and strategy. After Archduke Ferdinand’s assassinationon 28 June, events in Europe were followed closely by the members of the association, inattitudes varying from excitement to dread. Eddington wrote to his mother on 3 August:“We heard definitely of the war between Germany and Russia. Everyone here seems totake it for granted that England will join in. It all seems incredible. We are anxiouslyawaiting news.” Confirmation of Britain’s entry into the war arrived in Australia slightlybefore an important dinner, at which several foreign members of the BAAS were in atten-dance. Seeking to reassure the Germans present, Oliver Lodge rose and gave a short speech,

2 In this essay “Quaker” or “Friend” will refer to a member of the Religious Society of Friends.




declaring that science was beyond all politics. This mood of camaraderie was maintainedby the Australian hosts, who went out of their way to make the Germans feel welcome.The war was taken lightheartedly enough that some clever soul rewrote the patriotic anthem“The British Grenadiers” with lyrics praising the valor of physics and astronomy.3

Unfortunately, this isolation from the war faded during the journey home. The shipmade a detour to Singapore to pick up 140 British soldiers, soon to be assigned to theBritish Expeditionary Force. Eddington noted sourly that the ship would now make a fineprize for the Emden, the feared German commerce raider. Indeed, at one point a falsereport circulated in London that the BAAS ship had been sunk, with everyone capturedand their papers lost.4

Upon the scientists’ return to Britain, the impact of the war on astronomy was imme-diately evident. The commencement of hostilities had led to the severing of telegraphconnections to the Central Powers, a move that had disproportionate effects on astronomersby interrupting their “Science Observer” scheme of rapid dissemination of observationsand discoveries. The central hub of the network was in Kiel, Germany, and astronomerswere anxious about the disruption of their well-oiled system. Stopgaps such as those ar-ranged by Frank Dyson, Edward Pickering, and S. E. Stromgren faltered because manyEntente astronomers were distrustful about dealing with institutions in neutral countries.Dyson also ran into official difficulties: the Defence of the Realm Act’s censors wereunwilling to let coded telegrams pass back and forth unfettered.5

Hostility against the enemy was rampant across Great Britain. Even before the decla-ration of war widespread anti-German rioting had broken out across the country. TheBritish public had been anticipating conflict with Germany for years, its agitation fannedby invasion scare stories and books such as Erskine Childers’s The Riddle of the Sands.One historian remarked, “Of the mood of the inarticulate public it is difficult to say morethan that its most obvious features were an intense hatred of the German Kaiser andpeople.” Concerns grew beyond suspicion of German citizens to encompass anyone oranything of German origin: the Royal Society even received an angry letter asking whyGerman continued to be taught at Gresham College.6

3 A. Vilbert Douglas, The Life of Arthur Stanley Eddington (London: Nelson, 1957), pp. 90, 91 (quotation);Observatory, Oct. 1914, 479:397 (Lodge’s speech); and ibid., Nov. 1914, 480:430 (“British Grenadiers”). Manyof the items in the Observatory do not have titles or attributed authors. When such are present they will be cited.

4 Douglas, Life of Eddington, p. 92; and Observatory, Mar. 1915, 485:155.5 E.g., on 6 Mar. 1916 the astronomer royal received a curt telegraph from the Chief Censor’s Office: “With

reference to a telegram in code, addressed by you to Stromgren, Copenhagen, will you kindly let me know theexact meaning of the telegram, and whether you have authority to use private code to Copenhagen. The telegramwas transmitted.” Individual uses of the code had been summarily rejected on “censorship grounds” since thebeginning of the war. Post Office to Frank Dyson, 27 Nov. 1914, F. W. Dyson Papers, MS.RGO.8 (hereafterDyson Papers), 104, Cambridge University Library, Royal Greenwich Observatory Archives. On the attemptsto set up a wartime system see Dyson to Edward Pickering, 20 Oct. 1914; and S. E. Stromgren to Dyson, 6 Nov.,9 Nov. 1914, Dyson Papers 104. For reluctance to route communication through neutral countries see, e.g.,R. T. A. Innes to Dyson, 10 Dec. 1914, Dyson Papers 104. Innes confessed that “he would prefer to send suchmessages to a British Institution.” The French expressed similar reservations—Bureau de Longitudes to Dyson,18 May 1917, Dyson Papers 104—and eventually all schemes hoping to reach across military alliances collapsed.

6 The rioting is reported in Times [London], 4 Aug. 1914; and [London] Daily News, 5 Aug. 1914. ForChilders’s book see Erskine Childers, The Riddle of the Sands (1903; London: Grafton, 1986). For the historian’sremark see Arthur Marwick, The Deluge: British Society and the First World War (London: Bodley Head, 1965),p. 49. The Royal Society responded to the letter: “It is contrary to the practice of the Society to express anopinion in its Corporate capacity upon questions involving political considerations.” Royal Society CouncilMinutes, 1 Nov. 1917, Royal Society, London, Vol. 10, p. 258.



MATTHEW STANLEY 61

QUAKERS AND THE WAR

Eddington’s reaction to these and subsequent events was largely shaped by his membershipin British society’s traditional bastion of pacifism: the Society of Friends. Since theirorigins in the turbulent seventeenth century, the Quakers had resolutely opposed violencein what is often called the Testimony against War, originally a protest against the King ofEngland: “It springs from our belief of the potentiality of the divine in all men—the InnerLight, as we call it, which is in every man, no matter how hidden or darkened it may be.. . . Hatred and violence only feed the flame of evil. . . . If this be true of personal relations,we believe it to be true equally of civic and international ones.” Surrounded by the anti-German violence at home and the organized violence across the Channel, they felt clearcalls to duty and they mobilized to testify for peace. The Quakers in Britain held a con-ference at the opening of the war to discuss their options, out of which came a messageto everyone in the British Empire. It read, in part: “We find ourselves today in the midstof what may prove to be the fiercest conflict in the history of the human race. [We reaffirmthat] the method of force is no solution of any question [and] that the fundamental unityof men in the family of God is the one enduring reality. Our duty is clear: to be courageousin the cause of love and in the hate of hate.” Their pacifism was based on the idea that thewar was epiphenomenal to the dangers of nationalism. A Friend spoke in this spirit: “what-ever may be the guilt of the individual countries concerned, it is the system which is muchmore at fault.”7 Despite its militarism, Germany was not the enemy; the true opponent forthe Society of Friends was the human misery that came out of any war. As we shall see,it was exactly this attitude that mobilized Eddington in the struggles around internationalscience.

THE BATTLEFIELD OF SCIENCE

Hatred toward the Germans was not limited to mobs in the street, and it was the anger ofthe British intelligentsia that would eventually lead Eddington to place the eclipse expe-dition on the world stage. Literati and scientists alike had been alienated by an incident inAugust, as the Germans pushed deeper into Belgium. While trying to take the town ofLouvain, the German army destroyed many buildings suspected of harboring snipers, in-cluding the magnificent library. The destruction of the fourteenth-century structure and itsliterary riches was a severe blow to Germany’s reputation.8 Academics, artists, and intel-lectuals around the world were outraged at what was seen as an assault on culture itself.The German self-identification with the Hun suddenly came to seem shockingly appro-priate, and many argued that the war had become one for the preservation of civilization.

The German intellectual community was deeply offended by their country’s portrayalin the world press as barbaric. In response, ninety-three leading members of that com-munity drafted and signed “The Manifesto to the Civilized World,” in which they indig-nantly defended their nation and its Kultur: “As representatives of German science and artwe protest before the whole civilized world against the calumnies and lies with which ourenemies are striving to besmirch Germany’s undefiled cause in the severe struggle forexistence which has been forced upon her.” The document was signed by twenty-two

7 A. Ruth Fry, A Quaker Adventure (London: Nisbet, 1926), p. xvii; and Rufus Jones, A Service of Love inWartime (New York: Macmillan, 1920), pp. 3–4, 65–66.

8 The firsthand reports of the destruction of the library can be found in Martin Gilbert, A History of theTwentieth Century, Vol. 1: 1900–1933 (New York: Morrow, 1997), p. 345.




natural scientists and doctors, including (as one observer noted) almost all those “of realcelebrity.”9

Of course, some in Germany disagreed with this sentiment, and G. F. Nicolai, AlbertEinstein, and Willem Forster drafted their own manifesto, which was sent out privately:“Never has any previous war caused so complete an interruption of that cooperation thatexists between civilized nations . . . educated men in all countries not only should, butabsolutely must, exert all their influence to prevent the conditions of peace being the sourceof future wars.” Unsurprisingly, this statement received virtually no attention in Germanyand was completely unknown outside the country. The Manifesto of Ninety-three came tobe seen as representative of German intellectuals; the Provost of Trinity College, Dublin,wrote: “[The] declaration from 93 German men of science and letters . . . was issued byway of influencing neutral opinion. . . . Most of them required no coercion, for they signedit not as independent men but as courtiers . . . and so they have adopted all the vices ofthe most servile courtiers, with one curious exception. They still maintain their boorishmanners.”10 Louvain had exposed German science, art, and literature to the full spectrumof contempt and hatred and to accusations ranging from barbarism to simple rudeness.

This hatred was inflamed by the arrival of refugees from the Continent, particularlyBelgium. These refugees, mostly women and children, brought tales of murder and arsonat the hands of invading German troops. Among the refugees was Robert Jonckheere, ofthe Lille Observatory. He made an appearance at the Royal Astronomical Society, wherehe described his flight from German shelling on 3 October.11 Stories such as his helpedpaint the Germans as savage occupiers ignoring all conventions of war and encouragedagitation in England.

The reaction of the British astronomical community is recorded in the Observatory, amonthly publication that recorded the transcripts of the meetings of several groups, in-cluding the Royal Astronomical Society and the British Astronomical Association. It alsoincluded official announcements, notes from individual researchers, and an anonymouscolumn titled “From an Oxford Note-book” that contained quips, stories, and miscella-neous observations about life in science. It was written by H. H. Turner, Savilian Professorof Astronomy at Oxford. However, the column’s anonymity presented it as something likean unofficial voice of the astronomical community, without the author’s byline that wouldhave marked it as individual opinion. It was in the Observatory that many of the battlesover the course of British astronomy were fought.

At the beginning of the war, the journal was happy to quote Oliver Lodge’s optimisticclaim about apolitical science, although it did note later that many of the celebrations inAustralia became “a symbol that the Empire was united and determined in the face of thecommon enemy, and not to be dismayed by his aggression.” By mid 1915 the war was aregular feature, especially reports of astronomers killed or taken prisoner at the front. Thenephew of a Canadian astronomer was recorded as having died fighting with Entente troopsat Ypres on 23 April. The same page reported the wounding of two English astronomers.12

9 G. F. Nicolai, The Biology of War (New York: Century, 1919), pp. ix, xiv.10 Ibid., pp. xvii–xix; and Observatory, May 1916, 500:241. For the German perspective on the manifesto see

J. L. Heilbron, The Dilemmas of an Upright Man: Max Planck as Spokesman for German Science (Berkeley:Univ. California Press, 1986).

11 A. J. P. Taylor, English History, 1914–1945 (Oxford: Oxford Univ. Press, 1965), p. 19 (refugees); andObservatory, Jan. 1915, 483:47. A more detailed account of Jonckheere’s escape is given ibid., Mar. 1915,485:143–145.

12 Observatory, Oct. 1915, 492:409; and ibid., July 1915, 489:306.



MATTHEW STANLEY 63

The June issue included a meditation on the centenary of Waterloo and a sad commentthat England’s former ally now aimed at “brute control” of Europe. The 1915 BAASmeeting had none of the optimism of the previous year’s. Zeppelin warnings broke up themeeting on several occasions. The May 1916 issue brought an unprecedented burst ofanger from the “Oxford Note-book,” in which the possibility of returning to a normalinternational world of science was abandoned. In a discussion of the need for new astro-nomical journals appeared this unexpected comment: “But shall we be able to resume theuse of German organizations in the near future? Have the Germans themselves not madeit practically impossible?” Following this was a more extended protest:

At the declaration of War . . . the general attitude of scientific men was voiced by the President,Sir Oliver Lodge, who declared that “Science was above all politics,” and took the opportunityof proposing the health of the foreign guests of the Association. It would not be possible toadopt this attitude now. We have seen how engagements and relationships, which we all thoughtwere “above all politics,” and safe to be respected even in time of war itself, have, nevertheless,been broken and tossed aside in a moment if Germany took the fancy that it could therebybenefit itself. Many of us do not see how, after such an exhibition, we can face the mockery ofnew understandings and undertakings with such a nation. There is much to be said for awaitinga less heated moment for decision; but meantime there are matters, both great and small, whichcall for action—and are we not too sanguine in hoping that decision will be easier in the nearfuture? Is not the die really cast already?13

The anger toward Germany was as unmistakable as the resignation of any hope of resumingnormal relations. The piece was even more shocking given its author: before the war, H. H.Turner was one of the astronomical community’s most dedicated internationalists. He wasthe principal coordinator of one of the first organized international astronomical efforts in1887. In 1914 he was recommended by Eddington for the post of foreign secretary of theRAS on the basis of his experience working with foreign scientists. Turner had workedclosely with Germans on all of his projects, but now he was willing to abandon them; thetrauma of the war, even on the home front, was such that he could no longer accept themas colleagues. He quoted the official investigation into German atrocities, which read: “Thedilemma is inexorable: we can readmit Germany to international society and lower ourstandard of international law to her level, or we can exclude her and raise it. There is nothird course.”14 By its prosecution of the war, Germany had forfeited its position in thecivilized world. Science, no matter how ideally apolitical, was not exempt. There is noquestion which “course” Turner espoused.

A single lonely response appeared a month after the “Oxford Note-book” called for theexclusion of Germany from the international scientific community. In a letter to the Ob-servatory entitled “The Future of International Science,” Arthur Eddington called for afuture not embittered by the war. He began by pleading that astronomy in particular de-pended on international cooperation, a plea that became a call for science as a brotherhood:

13 “From an Oxford Note-Book,” Observatory, June 1915, 488:265 (“brute control”); Observatory, Oct. 1915,492:413 (1915 BAAS meeting); and “From an Oxford Note-Book,” Observatory, May 1916, 500:240.

14 J. H. Morgan, “German Atrocities: An Official Investigation,” quoted in “From an Oxford Note-Book,”Observatory, May 1916, 500:241–242. Regarding Turner’s recommendation for the post of foreign secretarysee A. S. Eddington to Hills, 27 Jan. 1914, RAS MSS Grove Hills 2/1 14, Royal Astronomical Society, London.Eddington wrote: “I have been considering the problem of the next Foreign Secretary. . . . The conclusion I havecome to is that it ought to be Turner. [He] is so intimately in touch with international organisations and foreignastronomers generally that he has an exceptional claim. Moreover he is tremendously loyal to the Society.” Allletters from Eddington are used with the kind permission of the Eddington Trustees.




I think that astronomers in this country realize the disaster to progress which would result fromdissolution of partnership, and there is no disposition to belittle the contributions of Germany.Some of the problems of our science can only be attacked by world-wide cooperation . . . thelines of latitude and longitude pay no regard to national boundaries. But, above all, there is theconviction that the pursuit of truth, whether in the minute structure of the atom or in the vastsystem of the stars, is a bond transcending human differences—to use it as a barrier fortifyingnational feuds is a degradation of the fair name of science.

Eddington argued that using science to extend the fronts of the war was a complete mis-understanding of both the practical needs and the higher aims of science. Progress couldbe made only if astronomers realized that the pursuit of truth must cut across all divisions:unity was to be found in the scientific quest for knowledge, not a shallow and selfishpatriotism. Eddington’s Quaker roots are clear; the ideas and vocabulary could just aseasily have been applied to mysticism or the interpretation of Scripture.15

His letter continued, trying to show the essential humanity of the enemy, by quotingGerman scientists who expressed regret over the Manifesto of Ninety-three and praisingWillem Forster, an associate of the RAS, who was undertaking the dangerous work ofassisting citizens of the Entente interned in Germany. Eddington pointed out that the BerlinAcademy of Science had twice refused to eject its foreign members and that the Astro-nomische Gesellschaft had honored its commitments to send its publications to Englishmembers.16

His strategy, like that of Quakers around the world, was to humanize the enemy andthus weaken the hatred that fueled the war:

It is not any personal attitude of the German scientists that presents a difficulty, but the feelingthat we are involved in a general condemnation of their nation. But the indictment of a nationtakes an entirely different aspect when applied to the individuals composing it. Fortunately,most of us know fairly intimately some of the men with whom, it is suggested, we can nolonger associate. Think, not of a symbolic German, but of your former friend Prof. X, forinstance—call him Hun, pirate, baby-killer, and try to work up a little fury. The attempt breaksdown ludicrously. . . . The worship of force, love of empire, a narrow patriotism, and theperversion of science have brought the world to disaster.17

In this letter Eddington strove to inject into the scientific dialogue the same humanitari-anism that the Society of Friends was pushing into the national dialogue. Both, however,faced tremendous inertia and anger from those who were convinced of German barbarityin and responsibility for the war.

The first direct response to Eddington’s letter was from his Cambridge colleague JosephLarmor, who also sent to the Observatory an open letter titled “The Future of InternationalScience.” Larmor thanked Eddington for bringing the opposing viewpoint to the table butdefended the shutdown of relations with enemy scientists as a conservative measure, atolerant and prudent way to keep scientific relations “frozen” at the status quo. He took

15 A. S. Eddington, “The Future of International Science,” Observatory, June 1916, 501:271. For explicitdiscussions of mysticism and the interpretation of Scripture see Eddington, Science and the Unseen World (NewYork: Macmillan, 1930).

16 By this point in the war, it appears that Eddington was the only British member still active in the Astro-nomische Gesellschaft. He received their notices through Copenhagen, and he was apparently the source of thereports of the work of German astronomers that occasionally appeared in the Observatory.

17 Eddington, “Future of International Science” (cit. n. 15), p. 271. An example of Eddington’s strategy forinvoking the essential humanity of German colleagues was his moving obituary of Karl Scharzschild, publishedin the Observatory: A. S. Eddington, “Karl Schwarzschild,” Observatory, Aug. 1916, 503:337–339.



MATTHEW STANLEY 65

exception to Eddington’s suggestion that a measure of identification with the enemy hadbeen actively discouraged, pointing out that the government had given many groups—including the Quakers—full rights to oppose the war on conscientious grounds. Edding-ton’s own conscientious objector hearing was coming up in just two weeks, and one sensesthat Larmor was suggesting that he should be content with his personal right to opposethe war. Eddington was given space for a short response: he asserted that he was notcritical of the government on this issue but meant, rather, to point out that a warm-heartedpartisan could not also be a neutral judge. This was not only a warning of conscience tohis British colleagues but also a reminder that the same problem “must confront Germanscientists also.” Eddington expressed his personal difficulties in this situation in a privateletter to Larmor: “I did not wish to strike a discordant note. I am sorry if I have failed. Itis very difficult.”18

The “Oxford Note-book” wasted no time in responding to Eddington’s initial letter, inparticular to his query “What stands in the way of a continuance of that co-operation whichis for the welfare of astronomy?” The brutal response:

My reply is that the facts stand in the way—hard, horrible facts, such as we should not havebelieved possible before the war. He proposes to shut his eyes to these facts, and to test thesituation by the play of our imaginations in connection with some individual. . . . Surely Prof.Eddington is here using his preconceptions formed before the war, and his own shrinking fromhorrors, to help him in ignoring actual hard facts? Is it not an actual fact that babies have beenkilled in ways almost inconceivably brutal, and not as a mere individual excess, but as a partof the deliberate and declared policy of the German army? Is it not a fact that the Lusitaniawas sunk with a national rejoicing that puts the cold-bloodedness of former pirates to shame?Is it not a fact that German men of science have gone out of their way to declare their adhesionto these things, and that one of them who ventures some excuse still boasts of a “quiet con-science”? If we cast our memories back before the war, it is easy to recall that we should havevowed these things incredible; but that does not alter facts.19

The writer’s disgust for Eddington’s pacifism is obvious, and the remark about his “shrink-ing from horrors” was likely an attack on his conscientious objection to conscription.Overall, it is interesting to note that Eddington’s insistence on trying to understand theopponent’s point of view has been missed entirely; this is illustrative of what happenedthroughout Great Britain during the war. The magnitude of atrocities, real and imagined,was such that it became impossible to see beyond them to ask who was responsible andto remember old friends before they became villains.

While he was navigating the rough waters of scientific politics in wartime, Eddingtonwas also beginning his investigations into stellar structure. This work would cement hisscientific reputation at the RAS, but discussion continually returned to the war. With theslaughter at the Battle of the Somme, the banner of patriotic science was taken up onceagain, this time by R. A. Sampson. He insisted that his desire to exclude the Germans didnot stem, as Eddington had suggested, from an attitude of moral superiority. Rather, itcame from “resentment . . . that the base and bloody experiences of this war have destroyedthe ground in which unguarded trust and friendship must grow.” Sampson’s personal, evenpained, approach to the problem strikes a reader as more balanced than the usual tone of

18 Joseph Larmor, “The Future of International Science,” Observatory, July 1916, 502:313–314; A. S. Ed-dington, ibid., p. 314; and A. S. Eddington to Joseph Larmor, 7 June 1916, Joseph Larmor MSS 603-9 403,Royal Society.

19 “From an Oxford Note-Book,” Observatory, July 1916, 502:23–24.




the “Oxford Note-book,” but in practical details he was no different. “Speaking in generaland of the immediate future, anything except merely formal relations, even in the scientificfield, would strike me as forced, if not impossible.”20

An American correspondent soon entered the debate. Edwin Frost, writing from YerkesObservatory, quoted a letter he had received from an anonymous German colleague: “Andyet not one of us scholars was consulted in advance [of the war]. Each one is innocent,and each one should believe the same of his colleagues, in the hostile country, that he, too,is innocent of the frightful calamity. . . . We must prepare [after the war] to make ourrelations closer than before. We must attempt to attain the solidarity of the scholars of allnations.” The “Oxford Note-book” was quick to respond, again focusing on the notion ofindividual responsibility. As in his rejoinder to Eddington, Turner refused to acknowledgethe possibility that a citizen could disavow the policies and actions of his or her nation.“As for the question of individual responsibility . . . it may be worth remarking that thoughEnglish astronomers were certainly not consulted about the war in advance, from themoment of the brutal attack on Belgium there are few indeed of us who wish to disavowthe responsibility for the action of England.”21 This passage crystallizes the points ofdisagreement between the anti-German faction, chiefly represented by Turner through the“Oxford Note-book,” and the pro-German group, chiefly represented by Eddington.Turner—and most of the British population—refused to believe that German individuals,scientists or no, could truthfully claim to have no part in their government’s atrocities.This view was strengthened by documents such as the Manifesto of Ninety-three. Edding-ton, however, was motivated chiefly by his Quaker perspective on human nature, whichsaw individual understanding and responsibility as the salient factors in relationships. Fromhis point of view, the German scientists were as much victims of the war as were theirBelgian counterparts.

The Society of Friends organized its war relief efforts around that very assumption: thatthe victims of war were not just those on the defensive side of the fighting. Friends madeit a point not to limit their services because of national boundaries: refugee camps wereestablished in France and Holland, but also in the Russian district of Buzuluk, where theycared for displaced Prussians and German prisoners of war. In Britain, the Quakers set upthe Emergency Committee for the Assistance of Germans, Austrians, and Hungarians inDistress, a group led by close friends of Eddington’s and organized to aid enemy citizensdetained when the war broke out. There was some question of whether this activity violatedthe five-hundred-year-old Treason Act, and the Emergency Committee received manydeath threats. Three members of the committee were imprisoned for conscientious objec-tion to conscription, including Eddington’s friend and fellow Cambridge scientist ErnestB. Ludlam.22

The root of the anger against the Quakers was the impression that, since they wereopposed to the war, they were supporting the aggression and atrocities of the CentralPowers. An American observer sought to correct this notion: “The Friends who thus keptalive their human sympathies and humanitarian instincts were not ‘pro-German.’ They didnot approve at all of German military aims, policies or methods.”23 The Society of Friends

20 R. A. Sampson, Observatory, Aug. 1916, 503:344–345.21 Edwin Frost, Observatory, Oct. 1916, 505:435–436; and “From an Oxford Note-Book,” ibid., Nov. 1916,

506:476–477.22 Report of the War Victims Relief Committee of the Society of Friends (London: Spottiswoode, 1914–1919),

Vol. 1, pp. 5, 13, 15; Vol. 3, p. 44.23 Jones, Service of Love in Wartime (cit. n. 7), p. 252.



MATTHEW STANLEY 67

argued that pacifism, not violence, was the key to confronting German militarism andending the war. Compassion for individuals and their suffering would lead to a new andmore robust internationalism that would prevent future wars.

THE ADVENTURERS AND THE AFTERMATH OF WAR

The end of the war did not end the calling of these Quakers, but instead brought newopportunities. The Cambridge Friends Meeting, of which Eddington was a prominentmember, expressed this statement of purpose on hearing of the armistice:

Suffering and unrest are by no means over, nor is the conflict, tho’ it may be removed to anotherplane of action. And while we could take no part in the late warfare we feel that the inevitablestruggle now before the world, social political or economic, is one to which we may rightlyhave some thing to give, indeed we feel that it is precisely here that our place may lie. Thevalue and power of this contribution depends on one thing, the ability in which our Church andeach one of us as individual members of it can lay hold of the power of the Spirit. Nothingelse can avail in this great moment.

British Quakers headed to Germany immediately to help ease suffering in the wake ofthe fighting. Hopes that the blockade would be lifted and material conditions in Germanyimproved were dashed as the public began calling for reparations and revenge. During thewar, many in Britain had expressed high hopes for a just peace—H. G. Wells wrote that,in victory, Britain would “save the liberated Germans from vindictive treatment”—but bythe armistice such ideals had been lost in the horrors of the trenches. Public opinion quicklygathered behind leaders such as Sir Eric Geddes, who called for “squeezing Germany untilthe pips squeak.”24

Part of this “squeezing” was the maintenance of the wartime blockade of Germanybetween the armistice and the signing of the Treaty of Versailles. One postwar commentatorexplained the reasoning: “The Germans are . . . suffering as they deserve to suffer fromacute humiliation as well as from all kinds of impoverishment.” Starvation was rampantin Germany; Foch and Churchill hoped to use it as a lever to force German acceptance ofthe Paris peace terms. Quakers, led by the Emergency Committee, purchased food andhumanitarian supplies in England and then shipped them to Germany, in contravention ofgovernment orders. Much damage had already been done, however; in midsummer 1919—as Eddington was returning from the eclipse expedition—American and British Friendsestimated that the post-armistice blockade had led to seven hundred thousand deaths, inaddition to endemic starvation and disease among children. As evidence of the appallingconditions inside Germany mounted, Clemenceau and Lloyd George were persuaded toloosen the blockade.25

Those Friends who ventured to Europe to relieve this suffering, both during and afterthe war, worked in difficult and sometimes dangerous conditions. These relief workerscame to be known as “adventurers,” and they hold a special place in Quaker history asmen and women who journeyed into far and foreign lands as a duty of conscience. The

24 Cambridge Friends Meeting Minutes, Nov. 1918, Cambridgeshire County Records, Cambridge; Marwick,Deluge (cit. n. 6), pp. 48–49 (quoting Wells); and Times, 24 Nov. 1918 (quoting Geddes).

25 Frank Dilnot, England after the War (New York: Doubleday, 1920), p. 184 (quotation); and John Forbes,The Quaker Star under Seven Flags, 1917–27 (Philadelphia: Univ. Pennsylvania Press, 1962), pp. 93, 95–98,91. Margaret Macmillan, Peacemakers: The Paris Conference of 1919 and Its Attempt to End War (London:Murray, 2001), is an excellent resource for understanding the conference.




strategies used by these adventurers became the models for Eddington’s efforts to use theeclipse expedition as a tool in repairing international relationships. Their personal presencein the devastated areas was seen as being as important as the material relief they brought:social and intellectual relationships needed to be stimulated as well. The problem was this:“The entire population was shut up within the frontiers of the country, unable to get anyrelief from the monotony of suffering, unable, too, to exchange ideas.” The Friends’ goalwas to demonstrate “the brotherhood of man overstepping all artificial barriers of race,politics or creed, which we believe to be the only true foundation upon which the familyof nations can rest.” Many Quakers were called to these adventures when the plight of theGerman educational system was discovered. Convinced that resurrecting the German in-tellectual system was crucial—even in times of famine—Quakers undertook to feed hun-dreds of students in Berlin. Among the German faculty involved was Albert Einstein, whowas reported as being “closely connected” with this work. The program grew eventuallyto feed nearly sixteen thousand students.26

Quakers saw one of the most important benefits of this work to be the connection forgedwith a young generation of students, which they hoped would repair or replace thoseconnections severed by the war. In a sense, this was the Quaker war: “While chemists aretesting out the deadliest types of poison gas for future wars . . . it is well that there shouldalso be some notable attempts made to conquer the hearts of men by kindness and todemonstrate that one person who heads an expedition to heal the wounds and desolationof war is stronger than a battalion of men under arms.”27

RELATIVITY AND GERMAN SCIENCE

Like the Emergency Committee, Eddington had begun his own efforts to repair the intel-lectual connections of the scientific community. He was one of the few British scientiststo maintain contact with scientists working in enemy or neutral countries. Among hiscontacts was Willem de Sitter of the Netherlands, who alerted Eddington (then the secretaryof the RAS) to a new theory of gravity being developed in Germany.28

De Sitter submitted a pair of papers on general relativity for the Monthly Notices of theRoyal Astronomical Society in 1916, and Eddington was immediately fascinated by Ein-stein’s work. He had been vaguely familiar with the principle of relativity as it was for-mulated by Einstein in 1911 and had mentioned its gravitational implications a full yearbefore receiving de Sitter’s letters. A significant point of interest was the ability of relativityto link the forces of nature: “a positive result [of relativity’s prediction] would mean thatgravitation has been pulled down from its pedestal, and ceases to stand aloof from theother forces of nature.”29

Einstein’s full theory of 1915, however, was a very different beast. General relativity’ssuccessful explanation of the advance of the perihelion of Mercury was significant, but itwas that explanation’s origin in a coherent and revolutionary understanding of space and

26 Edward Thomas, Quaker Adventures (London: Revell, 1935), pp. 1–30; and Fry, Quaker Adventure (cit.n. 7), pp. 312 (no relief ), 315 (“true foundation”), 330–331.

27 Fry, Quaker Adventure, pp. 331–332, 355 (quotation).28 De Sitter’s motivations for and strategies in communicating the relativity papers to Eddington were complex

and interesting. For an insightful analysis see Andrew Warwick’s forthcoming Masters of Theory: The Rise ofMathematical Physics in Cambridge.

29 A. S. Eddington, “Some Problems of Astronomy (XIX: Gravitation),” Observatory, Feb. 1915, 484:93–98,on p. 98.



MATTHEW STANLEY 69

time (not to mention the impressive mathematics) that held Eddington’s attention. Beyondthe scientific import of the paper, he saw an opportunity to repair some of the damagecaused by the war. Writing to de Sitter, he reported that he was “interested to hear that sofine a thinker as Einstein is anti-Prussian.” Finding a fellow pacifist (and a brilliant one atthat) in the German physics community was just what was needed to restore internation-alism to science. Einstein was equally excited at the opportunity, and he praised de Sitterfor his work to “throw a bridge over the abyss of misunderstanding.”30

The debate over the merits of general relativity developed quickly, with Eddingtonvirtually the only defender of the theory against vigorous attacks from many high-profilefigures, not the least of whom was Oliver Lodge.31 The theory was heavily constrained bythe lack of experimental evidence and its general technical difficulty. Few scientists couldmanipulate the mathematics, and there was widespread suspicion about a theory that wasboth highly abstract and made sweeping claims that gravity was merely a property ofspace. Astronomers were probably better placed than physicists to grapple with a newtheory of gravity, though; the motion of Mercury had inspired several attempts to modifyNewtonian gravitation. Some members of the RAS felt that Einstein’s theory should betested, if only because of its possible impact.

But much of this tentative interest was derailed by the general unease at dealing withwork from an enemy country. The “Oxford Note-book,” in discussing an astrophysicalhypothesis of German origin that had recently been shown to be false, speculated on thepossibility of any German producing good science: “We have tried to think that the ex-aggerated and false claims made by Germans today were due to some purely temporarydisease of quite recent growth. But an instance like this makes one wonder whether thesad truth may not lie deeper.” The implicit suggestion was that German scientific claimswere tainted not only by wartime propaganda but also by the barbarity and corruptionhidden in the German character. How could they ever be trusted? The apparent success ofGerman science in many fields was attributed by one observer to “plagiarism and piracy”of more civilized nations.32

This lack of trust formed the cornerstone of the continuing argument for German ex-pulsion from international science. Scientific associations, Turner claimed, rested on cer-tain intangibles: “The basis of such organizations is the good faith of the contractingparties: can we accept in scientific matters assurances which are, by some of the parties,not considered binding in other connections?”33 Just as the German violation of Belgiumhad made the claims of their politicians unreliable, their scientists’ reports were likewiseworthless. No experiment, no mathematical analysis, could be beyond suspicion.

This attitude led to the closing of the official channels of scientific communication. TheRAS aggressively kept its journals out of neutral and enemy hands, even after the war.There were some concerns about leaking technical secrets, but in general the reluctanceto make journals available was a result of exactly the position Turner represented: the

30 A. S. Eddington to Willem de Sitter, 13 Oct. 1916, quoted in Pierre Kersberg, The Invented Universe (Oxford:Oxford Univ. Press, 1989), p. 99; and Albert Einstein to de Sitter, 23 Jan. 1917, Albert Einstein Archives(hereafter Einstein Archives), 20-540 (permission granted by the Albert Einstein Archives, Jewish National andUniversity Library, Hebrew University of Jerusalem, Israel). Eddington saw religious implications in relativityas well. For an overview see Loren Graham, Between Science and Values (New York: Columbia Univ. Press,1981).

31 For an overview of the development and reception of general relativity see Don Howard and John Stachel,eds., Einstein and the History of General Relativity (Boston: Birkhauser, 1989).

32 “From an Oxford Note-Book,” Observatory, Mar. 1918, 524:128; and Nature, 6 Feb. 1919, 102:446–447.33 “From an Oxford Note-Book,” Observatory, Mar. 1918, 524:147.




belief that the Germans had forfeited their right to participate in the scientific community.After the war the RAS happily provided back issues of its publications to Belgium andSerbia while refusing to send any to “enemy countries.” Eddington pushed his colleaguesto renew communications with former colleagues and institutions, often pointing to thesocioeconomic devastation of the former Central Powers. Scientists in the former Germanand Austrian empires tried to beg, borrow, or trade for British publications, and they oftendirected their requests through Eddington, knowing his sympathies to internationalism.Eddington did his best to help them and was quite pleased when bureaucratic confusionallowed otherwise unavailable materials to slip through.34

As the war raged on, scientists, both individually and through their professional orga-nizations, began seeking to sever any remaining ties with German colleagues, no matterhow indirect or informal. After the collapse of the ersatz astronomical telegraph network,the Royal Society moved to expel its German members:

In view of the war having continued nearly 4 years without any indication that the scientificmen of Germany are unsympathetic toward the abominable malpractices of their governmentand their fellow countrymen, and having regard to the representative character of the RoyalSociety among British scientific bodies as recognized by the patronage of His Majesty the King,this Council forthwith take the steps necessary for removing all enemy aliens from the foreignmembership of the Society.

The virulent anti-German sentiment found throughout Britain, France, and America hadbegun to have concrete consequences for the possibility of resurrecting scientific relationsafter the war.35

THE EXPEDITION: EDDINGTON AS ADVENTURER

Help for Eddington’s efforts against this mentality came from his friend and former col-league at the Royal Greenwich Observatory, Astronomer Royal Frank Dyson, who wasseeking permission and resources to mount an expedition to test Einstein’s theory at the1919 eclipse. Einstein’s theory predicted that a ray of light traveling near a massive object,such as the sun, would undergo a small but measurable deflection of its path. This was oneof the three “classic” relativistic effects predicted by Einstein: the advance of the perihelionof Mercury was already established, and the measurement of the redshift of the solar spec-trum was proving difficult. This left observing the gravitational deflection as the onlyrealistic hope of confirming general relativity. Earlier attempts to observe the deflectionhad been made by the German astronomer Erwin Freundlich, with no success. Accordingto Eddington, Dyson “was at that time very skeptical about the theory though deeplyinterested in it.”36 Dyson felt that while the theory was speculative, its implications

34 Stromgren to W. H. Wesley, 22 July 1917, RAS Letters 1917; RAS Council Minutes, Vol. 11, 9 Nov. 1917(keeping materials from the enemy); RAS Council Minutes, 14 Feb. 1919, 9 Apr., 14 May 1920, 11 Feb. 1921(back issues); A. S. Eddington to A. C. Crommelin, 28 Dec. 1919, RAS Letters 1919; and A. S. Eddington toWesley, 30 Jan. 1921, RAS Letters 1921. The RAS archives have large numbers of such requests from formerCentral Powers countries.

35 Royal Society Council Minutes, 20 June 1918. For a useful overview of issues of nationalism in sciencesee Elisabeth Crawford, Nationalism and Internationalism in Science, 1880–1939: Four Studies of the NobelPopulation (Cambridge: Cambridge Univ. Press, 1992).

36 A. S. Eddington to Hermann Weyl, 18 Aug. 1920, ETH-Bibliothek Zurich, Hs 91:523 (used by permissionof Dr. Michael Weyl and the ETH-Bibliothek Zurich). Dyson’s initial efforts are recorded in Monthly Notices ofthe Royal Astronomical Society, Mar. 1917, 77:445. For more details on the expedition and its scientific back-



MATTHEW STANLEY 71

were so important that it needed to be investigated. He had examined older eclipse pho-tographs in search of this effect but found nothing. The upcoming eclipse of 29 May 1919would find the sun in the center of a bright field of stars, the Hyades, perfect for measuringthe deflection. The path of the eclipse was in an inconvenient location, however, and alarge expedition would need to be mounted to make the observations. This expedition wasjust the sort of work that required the international cooperation that Eddington had arguedwas fundamental to the spirit of science. Further, it offered an opportunity to bring a peace-loving, insightful German to prominence in both science and society. In this sense, theexpedition was as much a “Quaker adventure” as a journey to war-torn Europe would havebeen. Unlike many adventurer Friends, Eddington was never in physical danger, but hisexperiences on the eclipse expedition were fraught with excitement and the exotic flavorof West Africa. Further, his later account of the journey strongly reflected the literaturereporting the adventures of Quakers working in the aftermath of the war.

The eclipse’s scientific significance had gradually become clear over the course of thewar years. The first mention of relativity’s prediction of the bending of light in the Ob-servatory was an anonymous 1913 note entitled “Gravitation and Light.” This note referredto the deflection Einstein predicted in 1911 (which was only half the value he would laterpredict), long before he had developed the general theory or even adopted the Minkowskianformulation of space-time.37

Einstein’s full theory, along with the new value for the deflection, arrived in 1916 viade Sitter, and Eddington wasted no time in arguing for its importance. At the same timeas he was embroiled in controversy at Cambridge over the treatment of pacifists such asBertrand Russell, Eddington set himself up as the chief exponent of relativity. He re-sponded to concerns about de Sitter’s papers, defended the theory at the RAS, and eluci-dated confusion caused by the new mathematics. He had become Einstein’s “bulldog.”Through the next year he worked on his Report on the Relativity Theory of Gravitation, asmall volume that would be the first complete treatment of general relativity in English.Soon, enough interest in the theory had been generated to begin investigation into thelogistics of an expedition to test it. Geographic considerations dominated the discussion,since the eclipse path did not go near any observatories or even any easily accessible areas.It seemed likely that those who carried out the expedition would have to make their wayto Africa or South America.38

ground see John Earman and Clark Glymour, “Relativity and Eclipses: The British Expeditions of 1919 andTheir Predecessors,” Historical Studies in the Physical Sciences, 1980, 11:49–85 (see the conclusion of thisessay and note 77, below, for commentary on Earman and Glymour’s analysis of Eddington’s work on theexpedition). Their article also discusses observations of the deflection before and after 1919. Eric B. Forbes,“Erwin Finlay Freundlich,” in Dictionary of Scientific Biography, ed. Charles Coulston Gillispie, 18 vols. (NewYork: Scribner’s, 1970–1986), Vol. 5, pp. 181–184, has details on Freundlich’s many observations to test rela-tivity’s predictions.

37 “Gravitation and Light,” Observatory, May 1913, 461:231. Einstein’s first calculation was based solely onthe equivalence principle and yielded a value equal to an explicitly ballistic calculation, as would be expectedfrom Newtonian theory. This is also the origin of the first “half ” of the general relativistic deflection; the second“half ” comes from the curvature of space near the sun relative to distant space. The possibility of Newtoniangravity affecting light had been investigated a handful of times (notably by Henry Cavendish) over the previoustwo centuries, but the idea was never taken particularly seriously. For more see Clifford Will, “General Relativityat Seventy-five: How Right Was Einstein?” Science, 1990, 250:770–776.

38 A. S. Eddington, Report on the Relativity Theory of Gravitation (London: Fleetway, 1919). The Report wasread surprisingly widely, and Nature’s reviewer called it “the most remarkable publication during the war”:Nature, 6 Mar. 1919, 103:2. Eddington was heavily involved in the efforts to reinstate Russell after his dismissalfor authoring a peace pamphlet and also in protesting the treatment of conscientious objectors such as himself.For more on Russell and the war see G. H. Hardy, Bertrand Russell and Trinity (Cambridge: Cambridge Univ.




Unsurprisingly, many astronomers thought the expedition would be a waste of time.The refugee scientist Jonckheere warned that there were several different mechanisms thatmight duplicate the predicted deflection, making observations useless. The best-developedobjection was that refraction in the solar atmosphere could create an effect identical to thatof gravitational deflection. Other possibilities included optical effects from the particlesresponsible for zodiacal light and a condensation of ether around the sun, either of whichcould produce deflection effects. F. A. Lindemann, an Englishman of German descent,replied with pages of detailed calculations showing that the density of the stellar atmo-sphere necessary to cause appreciable refraction was unlikely: there were several goodobservations of comets passing close enough to the sun to rule out the possibility. Thezodiacal particles were too rarefied, and while an ether condensation would duplicate thequalitative effect, no one had a good enough ether model to make a quantitative prediction.Such a vague objection, Lindemann said, should carry little weight compared to Einstein’sdetailed and consistent theory.39

General relativity’s successful explanation of the advance of the perihelion of Mercurywas impressive to astronomers, and many thought the eclipse test should be carried outon those grounds alone. The third test, the gravitational redshift, was already being con-ducted. Charles St. John, an astronomer at Mt. Wilson, had produced preliminary results,and they were not favorable for Einstein. The supporters were persistent, however, and ananonymous note regarding St. John’s report reminded the scientific community that therewere “those who have welcomed Einstein’s relativity theory of gravitation, both on accountof its great beauty of conception and its remarkable success in explaining the discordanceof the perihelion of Mercury.”40

Discussions such as these were important in the scientific debate but had little impacton the actual planning of the expedition. This was chiefly in the hands of two astronomerswho were also interested in ramifications beyond the scientific test: Eddington and Dyson.Dyson had been making public statements in favor of the expedition since March 1917,and as astronomer royal he was perfectly placed to begin preparations even without thefull support of the astronomical community. Planning for the expedition was formally theduty of the Joint Permanent Eclipse Committee, a group set up by both the Royal Societyand the Royal Astronomical Society so as to pool the intellectual and logistical resourcesof the two groups.41 Eddington was not a member of the committee and attended itsmeetings only sporadically before 1916.

Preparations for the expedition began in earnest at the 10 November 1917 meeting.Eddington was present at the special invitation of Dyson. Relativity was the sole focus ofdiscussion. Dyson drew attention to the “specially favourable opportunity for testing thedisplacements of stars near the Sun, which are predicted by the Theory of Relativity. Itwas pointed out that such favourable opportunities are of rare occurrence, and there would

Press, 1970). On the likely necessity of journeying to Africa or South America see J. Evershed, “The EinsteinEffect and the Eclipse of 1919 May 29,” Monthly Notices Roy. Astron. Soc., 1917, 78:79.

39 “RAS Meeting,” Observatory, May 1918, 526:215, 323. Lindemann later became Lord Cherwell and wasChurchill’s science advisor. See R. V. Jones, “Frederick Alexander Lindemann,” in Dictionary of Scientific Bi-ography, ed. Gillispie (cit. n. 36), Vol. 8, pp. 368–369, for more detail.

40 Observatory, July 1917, 515:356 (favoring the eclipse test); Charles St. John, “The Principle of GeneralizedRelativity and the Displacement of Fraunhofer Lines toward the Red,” Astrophysical Journal, 1917, 96:249–265; and Observatory, Apr. 1918, 525:183.

41 For more on the culture of eclipse expeditions see Alex Soojung-Kim Pang, “The Social Event of the Season:Solar Eclipse Expeditions and Victorian Culture,” Isis, 1993, 84:252–277.



MATTHEW STANLEY 73

certainly be no equally suitable Eclipse for many years.”42 It was decided that there werethree possible stations for taking observations: northern Brazil, the island of Principe onthe west coast of Africa, and near the western shore of Lake Tanganyika. Hopes were thatexpeditions could be sent to two of these sites to guard against poor weather.

Money was an immediate problem, and Dyson planned on applying for a governmentgrant that would include £100 for modifying instruments and £1,000 contingent on thefeasibility of the expeditions. The war in Europe continued to rage (a massive Germanoffensive had just begun), and planning for this sort of scientific travel reflected an opti-mism that either peace would soon be at hand or the withered spirit of scientific interna-tionalism would suffice for its execution. Discussion settled on Brazil and the west coastof Africa as the best sites, and a subcommittee was set up to undertake serious preparations.

The subcommittee worked feverishly to account for all the logistical, scientific, andtechnical issues pertinent to accurate observation. The test would be nearly at the obser-vational limits of the techniques available in the field, and the expeditions needed excellentequipment. It was decided to use the astrographic telescope from Greenwich (which hadpreviously captured excellent star fields during eclipse exposures) and a similar lens fromOxford. As was standard practice in eclipse observations, the astrographs would be “fed”by 16-inch coelostats, mirrors rotated by clockwork to keep the image of the moving suncentered on the photographic plate. In this way, the telescopes could lie horizontal andunmoving (crucial considerations for mechanical stability) while the comparatively lightcoelostat mirrors could be pivoted steadily to compensate for the rotation of the earth. Theaging mechanisms of these coelostats were a worry, but improvements were dependent onobtaining a “priority certificate from the Ministry of Munitions” for the use of scarceresources. As a hedge against the unreliable coelostats, one of the expected observers,Father A. L. Cortie of the Stonyhurst College Observatory, suggested also bringing a 4-inch telescope fed by a different coelostat, which he had used to good effect on previousexpeditions.43 E. T. Cottingham, from Greenwich, would overhaul all the equipment to thebest of his ability in any case.

Actually getting the observers to their sites was proving a challenge. Although thefighting had ended in November 1918, the war had been hard on shipping, and theirdestinations were far from well-traveled routes. In order to be in the right places on 29May, the teams would have to leave England in February and be gone through June. Therewas some danger that Eddington himself would not be available: his conscientious objec-tion to conscription seemed likely to land him in prison. He had originally been exemptedas an astronomer (whose work was seen as having military value), but the British govern-ment desperately needed manpower in the spring of 1918 and revoked his exemption.Eddington refused to fight, on religious grounds, and even declined later opportunities forexemption where he needed to do nothing beyond simply not stating his religious objection.In an ironic reversal, Dyson (with his connections in the Admiralty) was able to gainEddington an exemption on the condition that he participate in the eclipse expedition.44

42 Minutes of the Joint Permanent Eclipse Committee Meetings (hereafter JPEC minutes), RAS Papers54/2, 10 Nov. 1917.

43 F. W. Dyson, “On the Opportunity Afforded by the Eclipse of 1919 May 29 of Verifying Einstein’s Theoryof Gravitation,” Monthly Notices Roy. Astron. Soc., Mar. 1917, 77:445 (astrographic telescope and Oxford lens);JPEC minutes, 14 June 1918 (worry about the coelostats); and Dyson, A. S. Eddington, and C. Davidson, “ADetermination of the Deflection of Light by the Sun’s Gravitational Field, from Observations Made at the TotalEclipse of May 29, 1919,” Philosophical Transactions of the Royal Society of London: Series A, 1920, 220:291–333, on p. 295 (Cortie’s suggestion).

44 JPEC minutes, 8 Nov. 1918 (travel time). See S. Chandrasekhar, “Verifying the Theory of Relativity,” Notes




From Eddington’s perspective, the agreement was that he would not be punished for hisobjection to the war so long as he took part in an activity that he was hoping to use as atool for peace.

Securing a leave of absence from Trinity was somewhat easier—even though Eddingtonwas the only member of the observatory staff not on war duty—but Cortie found that hecould not be spared. He was replaced at the last minute by C. R. Davidson, from Green-wich. The expeditions would leave from Liverpool on the Anselm, traveling via Madeira.As of their departure, no information on steamers to Principe (Eddington’s final destina-tion) was available. There was some discussion of trying to get a warship from the Ad-miralty, but that came to nothing.45 The travelers would simply have to hope for the best.

As the departure approached, Eddington became concerned with returning results toGreenwich as quickly as possible. He arranged for each party to take a micrometer (a toolfor making very fine measurements) in order that preliminary measures of check platesand eclipse plates might be made at the eclipse stations instead of waiting for the longjourney back. He also gathered information on the developing of photographic plates undertropical conditions, which would likely be quite different from those prevailing in anenclosed observatory in Europe. Plates were bought from different companies, and differ-ent lines within each, in case some particular chemistry proved unsuitable for the tropics.Eddington also arranged a telegraphic code for informing Dyson as to the weather con-ditions and the general character of the eclipse results.46 There was no particular need forhaste in returning the scientific results; certainly there was no danger of losing priority. Itseems, rather, that Eddington’s concern was to bring the results of the expedition home intime for them to have an impact on the fluid post-armistice situation.

Before leaving, Eddington wrote a review article (essentially a distilled version of hisReport on the Relativity Theory of Gravitation) on the expedition, detailing the theoreticaland logistical background of the planned observations. During the five minutes of totality,relativity would be the only topic of investigation. The expected displacement of stars atthe sun’s limb, as calculated by Einstein, was 1.75 seconds of arc, which would give adisplacement of approximately 1/60 mm on the plates. Not an easy matter to determine—but Eddington assured his readers that “this in itself calls for no extravagant precautionsof accuracy.”47 Plates taken in the field would be compared with photographs of the samestars already taken at Greenwich and Oxford. Check plates of other parts of the sky couldbe taken to determine scale, though this was not strictly necessary because the hoped-foreffect was distinct from the effect of change of scale.

According to Eddington, there were three possible results from the expedition obser-vations: no deflection, the predicted relativistic deflection, or a half-deflection calculatedfrom Newtonian mechanics. He pointed out that the results would have important impli-cations for the relationship between matter and energy, which would itself have importantconsequences for theories of stellar evolution (he made no mention of the important con-sequences for international science). “The problem of the coming eclipse may, therefore,be described as that of weighing light.” He addressed Jonckheere’s ether condensation

and Records of the Royal Society of London, 1976, 30:249–260, esp. p. 250. The proceedings of Eddington’sconscription hearings were recorded in the Cambridge press. Douglas, Life of Eddington (cit. n. 3), also has anaccount of these events.

45 JPEC minutes, 14 Feb. 1919.46 JPEC minutes, 14 Feb., 10 Jan. 1919.47 A. S. Eddington, “The Total Eclipse of 1919 May 29 and the Influence of Gravitation on Light,” Observatory,

Mar. 1919, 537:119–122.



MATTHEW STANLEY 75

hypothesis and assimilated the objection in a rather positivist fashion by arguing that sincethis would involve a deflection of light caused by the presence of a massive body it shouldreally not be regarded as a separate hypothesis. Carefully covering all possibilities, Ed-dington closed with the point that any result, even a null one, would be extremely impor-tant, and he held up the Michelson-Morley experiment as an example of an important nullresult.48 But there is no question that Eddington was hoping for a positive result, both inphysics and in the scientific community.

The expedition itself was far from smooth. The Principe team, Eddington and Cot-tingham, found themselves waiting for two weeks in Portugal for the next steamer toPrincipe. Eddington occupied himself with mountain climbing (his companion was unableto keep up) and a trip to the local casino (he assured his mother that he went there solelyfor the good tea). Their experiences were dominated by the oddity of traveling whileEurope was still technically at war. Eddington remarked on the strangeness of not eatingunder rationing and on the war damage in Portugal: “Three ships were torpedoed bysubmarine in Madeira during the war, and one sees the masts of two of them sticking upout of the water. The town was also bombarded and there are a few traces visible.” Dueto a held-over wartime regulation, passengers on a steamer were not allowed to knowwhere the boat was at any given time.49

The travelers arrived on Principe, an island off the west coast of Africa, on 29 April,with a month until the eclipse. The island was described as thickly wooded and “verycharming.” Unfortunately, they quickly discovered that Principe had terrible weather andthat they would be lucky to get a clear sky on the day of the eclipse. Rain, mosquitoes,and quinine became the daily regimen. Eddington and Cottingham built waterproof hutsfor the equipment, with the help of laborers from a local plantation. They were forced towork under mosquito netting and at least once helped hunt monkeys that had been inter-fering with their equipment. Thoughts of the war filled Eddington’s letters home. He wroteof how strange it was to see full sugar bowls and asked whether his family was stillrationed. Above all, he felt frustrated by being cut off from news of world affairs. “[Iwonder] whether peace has been signed.”50

Eddington and Cottingham began taking check plates on 16 May, with only a littledifficulty due to developing photographs in the high temperatures. Eddington spent hisdays measuring the plates. The weather worsened as May progressed, and the morning ofthe eclipse was not reassuring. It brought a tremendous rainstorm, which stopped abouttwo hours before totality but left significant cloud cover. The eclipse, for which they hadtraveled thousands of miles, was to reach totality at 2:15 in the afternoon. In Eddington’swords:

About 1:30 when the partial phase was well advanced, we began to get glimpses of the sun, at1:55 we could see the crescent (through cloud) almost continuously, and there were large patches

48 Ibid., p. 121. The origin of the “Newtonian” deflection in this troika of possibilities is unclear. In 1917Lodge presented a calculation of the deflection assuming that Newtonian gravitation held good, which yieldeda value half of Einstein’s. Earman and Glymour, “Relativity and Eclipses” (cit. n. 36), suggests that Eddingtoninvented the half deflection to give the expedition the flavor of a crucial experiment; it is not clear whether theywere aware of Lodge’s calculation.

49 A. S. Eddington to Sarah Ann Eddington, 11 Mar., 15 Mar. 1919, Uncatalogued Eddington Material, TrinityCollege, Cambridge. Although the fighting in Europe ended in November 1918, all the combatants were tech-nically still at war until the deliberations in Paris were finished and the treaties signed.

50 A. S. Eddington to S. A. Eddington, 29 Apr. 1919; and A. S. Eddington to Winifred Eddington, 5 May 1919,Uncatalogued Eddington Material.




Figure 1. The eclipse observation equipment at Sobral. The troublesome coelostats can be seen inthe foreground. Copyright Science Museum/Science and Society Picture Library. Inventory no. 1922-0277.

of clear sky appearing. We had to carry out our programme of photographs in faith. I did notsee the eclipse, being too busy changing plates, except for one glance to make sure it had begun,and another half-way through to see how much cloud there was. We took 16 photographs (ofwhich 4 are not yet developed). They are all good pictures of the sun, showing a very remarkableprominence; but the cloud has interfered very much with the star-images. The first 10 photo-graphs show practically no stars. The last 6 show a few images which I hope will give us whatwe need; but it is very disappointing. Everything shows that our arrangements were quitesatisfactory, and with a little clearer weather we should have had splendid results. Ten minutesafter the eclipse the sky was beautifully clear. . . . We developed the photographs 2 each nightfor 6 nights after the eclipse, and I spent the whole day measuring. The cloudy weather upsetmy plans, and I had to treat the measures in a different way from what I intended; consequentlyI have not been able to make any preliminary announcement of the result. But the one goodplate that I measured gave a result agreeing with Einstein and I think I have got a little confir-mation from a second plate.

He was more succinct in a telegraph to Dyson: “Through cloud. Hopeful.”51

The expedition to Sobral, in Brazil, was less harried (see Figure 1). C. R. Davidson andA. C. Crommelin were well taken care of by the local authorities and quickly found a goodobserving station. The team had the service of Brazil’s first automobile, as well as a supplyof ice (useful for developing photographs) produced by a nearby meatpacker. The coelostatmechanism functioned without difficulties, but the devices themselves displayed a newproblem during preparations. The team discovered that the coelostat mirror for the high-

51 A. S. Eddington to S. A. Eddington, 21 June 1919, Uncatalogued Eddington Material; and Observatory,June 1919, 540:256 (telegraph).



MATTHEW STANLEY 77

quality astrographic telescope had astigmatism, a serious optical defect. All was not lost,however, since the team could remain in Sobral until July to get check plates of the starfield and would still be able to measure the relative displacement of star images.52

In Brazil the eclipse became a public event, and an observatory near the edge of theeclipse path sold tickets to look through the telescope. The weather for the eclipse wasbeautiful, and the observers took nineteen plates with the astrographic telescope and eightwith the small 4-inch lens. They had every expectation of success and cabled home im-mediately: “Eclipse splendid.”53

The next day brought an unpleasant surprise. Four of the astrographic plates were de-veloped, and it was discovered that the image quality was far from adequate. A note madeat the time reads:

May 30, 3 am . . . It was found that there had been a serious change of focus, so that, whilethe stars, were shown, the definition was spoilt. This change of focus can only be attributed tothe unequal expansion of the mirror through the sun’s heat. The readings of the focusing scalewere checked next day, but were found unaltered at 11.0 mm. It seems doubtful whether muchcan be got from these plates.54

The displacements the astronomers were looking for were only a quarter of the diameterof the stellar images, so any distortion of the images made the measurement hopelesslyunreliable. The poor quality of the coelostat mirror had wrecked the finely tuned opticalsystem of the astrographic telescope; thus they would have to rely on whatever resultswere achieved with the small lens. In any case, Crommelin and Davidson had to stay inBrazil until July to take the check plates, and no measurements could be made before then.

RESULTS: FROM INTERPRETATION TO ACCEPTANCE

As negotiators in Paris arranged the final details of Germany’s reparations, Dyson waitedanxiously in Britain for news from the expeditions. The observers still had not returnedby early July, and he had no idea whether the photographs obtained were satisfactory.Measurements could not be completed at Principe owing to a steamboat strike that wouldhave stranded the observers had they stayed to finish their work. When the two teamsarrived home, the tedious task of measurement and analysis began. The photographs andtheir check plates were clipped into a micrometer, and two sets of screw readings weremade by two different people so as to minimize human error. The sixteen Principe pho-tographs taken through the cloud yielded only seven plates with star images, but all ofthese showed the crucial stars j1 and j2 Tauri, which had the highest predicted deflection.Only two of the plates had all five of the stars needed for a reliable analysis, however.These gave consistent results, with a calculated mean deflection of 1.61� �/� 0.30. Thesewere good results given the difficulty of the measurement, and Eddington was quitepleased, as the calculated deflection was rather close to the theoretical prediction of 1.75�.55

The astrographic photographs from the other expedition were less reassuring. The poorquality of the Sobral astrographic images was confirmed once they were compared with

52 Dyson et al., “Deflection of Light” (cit. n. 43), p. 298.53 Observatory, June 1919, 540:256. One of the tickets survives in the Royal Greenwich Observatory Archives:

Cambridge University Library, Royal Greenwich Observatory Archives, MS.RGO.8.150.54 Dyson et al., “Deflection of Light” (cit. n. 43), p. 309.55 Ibid., pp. 320–328.




the check plates. They were unambiguous about showing a deflection, however, and themean displacement was calculated to be 0.93�, far from Einstein’s predicted value. Theseresults were to be given little weight owing to the clear optical problems of the coelostat,but they were nonetheless worryingly close to the “Newtonian” half-deflection.56

The auxiliary lens, the 4-inch telescope recommended at the last minute by Father Cortie,ended up saving the day. Seven of the eight plates taken with it had excellent images ofthe seven hoped-for stars. The images were far better than those from Principe, with resultsof 1.98� �/� 0.12. Eddington wrote Dyson in relief: “I am glad the [4 inch] plates givethe full deflection not only because of theory, but because I had been worrying over thePrincipe plates and could not see any possible way of reconciling them with the half-deflection.”57 After a great deal of data reduction, Eddington presented a calculated meanof 1.64�. This mean included a particular weighting of the results according to how scaledeterminations made the Principe and Sobral 4-inch results much more important than theflawed Sobral astrographic.

Eddington and Dyson began writing the report, which would be given before a specialjoint meeting of the Royal Society and the Royal Astronomical Society in November.Eddington wrote the introduction, theoretical background, and much of the final analysis.He added a graph of the 4-inch telescope results from Sobral to show how well they fitthe predicted 1/r deflection dependence on distance from the sun (the Principe results didnot have enough stars). He felt that this was an excellent test to show the internal consis-tency of the data: “It seemed to me rather interesting and deals with a point that ought notto be overlooked and brings out the really remarkable agreement of individual stars atSobral.” At the last minute, Eddington changed his mind about the presentation of possiblythe single most important element in the paper: the final results. Initially, the results fromall three telescopes were averaged to give a very good mean deflection of 1.64�. He decidedthat this procedure was slightly disingenuous, given the obvious problems with one of thethree sets: “I do not like the combination of the astrographic with the other Sobral results—particularly because it makes the mean come so near the truth. I do not think it can bejustified; the probable errors of both are I think below 0.1� so they are manifestly discor-dant. . . . It seems arbitrary to combine a result which definitely disagrees with a resultwhich agrees and so obtain still better agreement.”58 It was agreed that the three sets ofdata would instead be presented separately, so as to clarify the case for and against each.Both Eddington and Dyson were quite confident in their results; now they had to convincetheir colleagues.

On 6 November 1919 J. J. Thomson presided over a special joint meeting of the RASand the RS assembled for the sole purpose of presenting the results from the eclipseexpeditions, which were unknown to nearly everyone. A. N. Whitehead, one of the manyobservers packed into the room, described the setting:

The whole atmosphere of tense interest was exactly like that of the Greek drama. . . . Therewas a dramatic quality in the very staging:—the traditional ceremonial, and in the background

56 Ibid., pp. 309–312.57 Ibid., pp. 299–309; and A. S. Eddington to Dyson, 3 Oct. 1919, Dyson Papers 150, no. 138.58 A. S. Eddington to Dyson, 21 Oct. 1919, Dyson Papers 150, no. 143. Letters such as this suggest that

Eddington’s analysis was very careful and sought to avoid even a suggestion of favoritism; they are the primaryevidence refuting the assumption that he manipulated the data in favor of Einstein. In any case, there were severalother people involved in the expedition and the data analysis, so a wide-scale conspiracy would have beennecessary (in addition to counterfeiting the photographic plates distributed to other astronomers). There are alsocriticisms that Eddington’s error analysis was poor; most of these claims are confused in assuming that heaveraged all three sets of results, which he explicitly did not do.



MATTHEW STANLEY 79

the picture of Newton to remind us that the greatest of scientific generalizations was now, aftermore than two centuries, to receive its first modification. Nor was the personal interest wanting:a great adventure in thought had at length come safe to shore.

Dyson, as astronomer royal, began the presentation. He reviewed the background of theexpedition and talked about why previous eclipse photographs were inadequate to measurethe Einstein effect. He described the techniques used to account for change of scale fromthe check plates and explained the disappointing problem with the coelostat. Finally, hecame to the results: “After a careful study of the plates I am prepared to say that there canbe no doubt that they confirm Einstein’s prediction. A very definite result has been obtainedthat light is deflected in accordance with Einstein’s law of gravitation.”59

Next, A. C. Crommelin, the leader of the Sobral expedition, rose to describe his half ofthe observations. He detailed the difficulties with the astrographic telescope and how theastronomers realized that there was a problem. The final speaker was Eddington, who notonly reported on the Principe expedition but dealt with the larger scientific issues impliedby the results and the impact they might have on physics. The observations from Africawere presented, and Eddington argued that the cloud cover was apparently a blessing indisguise, since it may have prevented the coelostat distortion under the sun’s heat thatruined the Sobral astrographic results. These plates also had the supplementary benefit ofhaving captured a tremendous solar prominence that would keep solar physicists busy forsome time. After presenting the data, Eddington moved on to the physical consequencesof the observations. He described the work as a crucial test between Newton’s and Ein-stein’s laws and noted that the results clearly favored the larger deflection. He did qualifyhis declaration that relativity had been confirmed in light of the so-far-unsuccessful at-tempts to measure the relativistic displacement of solar spectral lines. “This effect [thedeflection] may be taken as proving Einstein’s law rather than his theory. It is not affectedby the failure to detect the displacement of Fraunhofer lines on the Sun. If this latter failureis confirmed it will not affect Einstein’s law of gravitation, but it will affect the views onwhich the law was arrived at. The law is right, though the fundamental ideas underlyingit may yet be questioned.”60

Despite this fine line drawn between theory and law, many of those present were con-vinced that Newton had been overthrown. Thomson spoke for this viewpoint with re-markable vigor and also offered a common caveat:

This is the most important result obtained in connection with the theory of gravitation sinceNewton’s day, and it is fitting that it should be announced at a meeting of the Society so closelyconnected with him. . . . If it is sustained that Einstein’s reasoning holds good—and it hassurvived two very severe tests in connection with the perihelion of Mercury and the presenteclipse—then it is the result of one of the highest achievements in human thought. The weakpoint in the theory is the great difficulty in expressing it. It would seem that no one canunderstand the new law of gravitation with out a thorough knowledge of the theory of invariantsand of the calculus of variations.

Thomson then invited Ralph Fowler, the president of the RAS, to speak. Fowler thankedDyson for his tireless insistence on the importance of the expedition but concluded with

59 A. N. Whitehead, Science and the Modern World (New York: Macmillan, 1947), p. 15; and “Joint EclipseMeeting of the Royal Society and the Royal Astronomical Society,” Observatory, Nov. 1919, 545:391. Such ajoint meeting was the standard way to report results from expeditions performed under the auspices of the JointCommittee.

60 Ibid., p. 393.




a cautious reminder that further tests of relativity were necessary: “The conclusion is soimportant that no effort should be spared in seeking confirmation in other ways.” Severalother speakers voiced similar concerns about the incompleteness of the confirmation, andthere were several objections to the attribution of the results to gravitational deflection.Some verbal sparring ensued, and Eddington again insisted that it was Einstein’s law andnot necessarily his theory that had been confirmed, thus avoiding difficult questions ofmetaphysics.61

Eddington and Dyson spent the subsequent weeks defending the quality and meaningof the expedition results. Dyson was quick to refute “misconceptions which have arisenas to the magnitude of the observed quantity involved in the recent experiment.” Manyscientists objected that measuring a displacement that was only one-quarter the size of theentire image was dubious, but the astronomer royal reassured them that “those who arefamiliar with the measurement of astronomical photographs will know that it is quitepossible to measure quantities of this order of magnitude.” The displacements were muchlarger than those seen in measurements of stellar parallax, which were reliably and con-sistently measured, and Dyson argued that the results were quite reasonable to those con-versant with the methods.62

Lodge and others unhappy with the difficulty of duplicating the test asked repeatedlywhether the deflection from Jupiter could be observed, instead of waiting for the next solareclipse to confirm the results (it could not). Ludwik Silberstein argued that the platesshowed significant nonradial displacements not predicted by Einstein and that an objectiveanalysis unprejudiced by the theory would show that there was no radial effect. The JointCommittee had made copies of the eclipse plates available to anyone who wanted them(see Figure 2), and there was a frenzy of analysis across the astronomical community.63

Silberstein’s critique was refuted, and there was soon little doubt that there was a radialdeflection of the star images. Exactly what caused this displacement was still in contention.Refraction in the solar atmosphere remained the most popular alternative to Einstein’sexplanation, though there were others. Lindemann again provided detailed calculationsdismissing the possibility of refraction.64

Objections based on the aesthetic, conceptual, and mathematical unfamiliarity of rela-tivity were legion but had surprisingly little impact on the debate among astronomers.65

Careful analysis of the data had persuaded most of them that there was in fact a deflection.Charles St. John, himself still skeptical of the theory, wrote: “A deflection of light whilepassing through the near neighborhood of the Sun is now a fact of observation, destinedeither to influence profoundly our attitude toward the conceptions of space and time, asinvolved in the generalized theory of relativity, or to serve as a basis for the advancement

61 Ibid., pp. 394–395.62 Observatory, Jan. 1920, 547:37–38 (quotations); and Nature, 17 Feb. 1921, 106:786.63 Observatory, Jan. 1920, 547:41; and JPEC minutes, 14 Nov. 1919. The original plates have since been lost,

but many of the copies still exist.64 H. N. Russell, “Note on the Sobral Eclipse Photographs,” Monthly Notices Roy. Astron. Soc., 1920, 81:154–

164 (refuting Silberstein); and “RAS Meeting,” Observatory, Jan. 1920, 547:33–44, 56 (Lindemann). See alsoDyson Papers 123. For an interesting electromagnetic explanation see H. A. Wilson, Physical Review, 1921,17:54. For more competing explanations for the deflection see Donald Moyer, “Revolution in Science: The 1919Eclipse Test of General Relativity,” in On the Path of Albert Einstein, ed. Arnold Perlmutter and Linda Scott(London: Plenum, 1979), pp. 55–101.

65 These debates were more the province of physicists and philosophers and were of particular interest to thepublic. I will deal with these issues in a future publication.



MATTHEW STANLEY 81

Figure 2. One of the photographs taken by Eddington at Principe. No stars are visible here, but theimage does capture a spectacular solar prominence. Copyright Royal Astronomical Society PictureLibrary. RAS Photographs 2, No. A7/39. Special thanks to Peter Hingley.

of science in other directions.” Joseph Larmor took a similar position, calling the expe-dition a “very important astronomical determination that is to be regarded as a guide towardfuture theory rather than as the verification of the particular theory which suggested it.”Eddington’s assertion that Einstein’s law and not necessarily his theory had been provedwas an apt characterization of opinion among astronomers. This distinction was particu-larly useful for Eddington (he certainly did not think the distinction was valid) in that itallowed him to publicize a confirmation of Einstein even in the absence of the spectro-scopic results.66 Opponents of the theory used the distinction as well: Silberstein, acceding

66 Charles St. John, “Displacement of Solar Lines and the Einstein Effect,” Observatory, Jan. 1920, 547:158;and Joseph Larmor to Nature, 25 Dec. 1919, 104:412. Eddington had been worried about the lack of spectroscopicevidence for some time—see A. S. Eddington to W. S. Adams, 28 Jan. 1918, Huntington Library, San Marino,California—and this may have helped shape his “law not theory” strategy.




to the unlikelihood of refraction, maintained that the deflection was an “isolated fact” andhad no bearing on the truth of the theory. Others had similar thoughts:

The star images are certainly excellent and the photograph leaves little doubt that the deflectionis close to the double amount. You and your colleagues are to be heartily congratulated on theresults of the eclipse expeditions. I trust you are planning to observe the 1922 eclipse in thesame way, as I am sure you will be among the first to agree that results of such importanceshould be thoroughly confirmed before we accept them as establishing Einstein’s theory. I havea feeling that some explanation for the deflection will be found without resorting to non-Euclidean space.

The lack of spectroscopic evidence meant that many scientists had reservations aboutpronouncing relativity “proven,” but astronomers were comfortable announcing that Ein-stein’s quantitative prediction of the deflection of light had been confirmed. Many astron-omers, still much more comfortable with positional astronomy than with spectroscopy,found the combination of the deflection test and Mercury’s orbit convincing. Dyson, writ-ing a few years later, described the situation well:

But what appeals to me and the astronomers and physicists I know is that Einstein’s theorygives a formula—if not an explanation—of a number of very difficult and unexplained obser-vations and experiments. . . . Einstein’s predictions have been verified and his Law of Gravi-tation is correct, and as far as I can see, there is no alternative law. It is possible to accept thelaw and reject the theory which led to it, but it is not an unreasonable view to regard theverification of the law as confirmation of the theory.67

In short, the observations proved the law, and the law came from the theory. Many of thedifficulties of the theory were far outside the expertise of astronomers, and its utility ininvestigating astronomical phenomena made it worth using. What was clear to astronomerswas that there was a deflection, and it, coupled with Mercury’s orbit, effectively verifiedEinstein’s law of gravitation. The practical workings of gravity and celestial mechanicswere by far the dominant concerns; esoteric matters about clocks running slow and rulersshrinking were distinctly secondary. Even before the final spectroscopic results in favorof relativity were published, the “Oxford Note-book” could comment casually that debateamong astronomers had effectively ceased, with opinion firmly behind Einstein.68

The public response was, unsurprisingly, less measured. Among the audience at the jointmeeting on 6 November were several members of the press, and the excitement of thescene quickly found its way into public view. The Friday, 7 November 1919, edition ofthe Times proclaimed the headline “REVOLUTION IN SCIENCE” (see Figure 3), which sharedthe page with an announcement of the first Armistice Day observance (“THE GLORIOUS

DEAD”). The correspondent reported that “the greatest possible interest had been aroused

67 F. Schlesinger to Dyson, 16 Feb. 1920; and Dyson to unknown, 19 Apr. 1923, Dyson Papers 123. For aninteresting analysis of the relative importance of the eclipse results and the motion of Mercury see Stephen G.Brush, “Prediction and Theory Evaluation: The Case of Light Bending,” Science, 1989, 246:1124–1129.

68 “From an Oxford Note-Book,” Observatory, Jan. 1921, 560:234–235. Later expeditions by the Lick andother observatories returned values for the deflection very close to Einstein’s prediction, and the quality of thedata was significantly better than that obtained by the 1919 expedition. This was enough to convince most ofthe remaining skeptics of the reality of deflection. For more see Jeffrey Crelinsten, “William Wallace Campbelland the ‘Einstein Problem’: An Observational Astronomer Confronts the Theory of Relativity,” Hist. Stud. Phys.Sci., 1983, 14:1–91.



MATTHEW STANLEY 83

Figure 3. The headline in the Times reporting the meeting at which Eddington and Dyson presentedthe results of the expedition. Copyright Times, 6 November 1919.

in scientific circles.” On Saturday the paper ran a follow-up article under the same banner,this time subtitled “EINSTEIN V. NEWTON.” Two paragraphs at the end of the article intro-duced Einstein himself, who to this point had barely appeared in the accounts of his theory.He was described as a Swiss Jew who had taught at Zurich and Prague but took a positionin Berlin for a large salary. The paper noted that “during the war, as a man of liberaltendencies, he was one of the signatories to the protest against the German manifesto ofthe men of science who declared themselves in favour of Germany’s part in the war.”69

Clearly, the correspondent was concerned to demonstrate that the originator of this newtheory had nothing to do with the scientists who had aided and abetted the war. A yearafter the armistice, those British men of science who carried out the expedition and itsmeasurements still needed protection against accusations that they were consorting withthe enemy.

Einstein himself wrote an article for the Times three weeks later. He applauded theinternational character of the eclipse expedition: “After the lamentable breach in the formerinternational relations existing among men of science . . . it was in accordance with thehigh and proud tradition of English science that English scientific men should have giventheir time and labour . . . to test a theory that had been completed and published in thecountry of their enemies in the midst of war.” Einstein could hardly have expressed better

69 Times, 7 Nov. 1919; and ibid., 8 Nov. 1919. See also Nature, 22 Jan. 1920, 104:541, which points out thatEinstein was “called” to Berlin from his more pleasant posts in Zurich and Prague.




the hopes Eddington had for the eclipse observations. Primed with publicity from news-papers and magazines from across the United Kingdom, Eddington set out to spread themessage of international science. A representative passage from the opening paragraph ofone of his articles on relativity reads: “The theoretical researches of Prof. Albert Einstein,of Berlin, now so strikingly confirmed by the British eclipse expeditions, involve a broad-ening of our views of external nature, comparable with, or perhaps, exceeding the advancesassociated with Copernicus, Newton and Darwin.”70 Here was the crux of his strategy:explicitly linking the wartime enemies through an epochal scientific advance.

Eddington’s avalanche of lectures, public addresses, and articles on relativity reinforcedthe expedition’s quality of adventure as well (see Figure 4). For example, at an RAS dinnerhe presented the story of the expedition as a parody of the Rubaiyat, ejecting Kipling’sjingoism but retaining the excitement of pushing into the unknown. His best-selling Space,Time, and Gravitation also gave the expedition a privileged place. Thus Eddington did hispart to mend international relations, while bringing home as invigorating a tale as theFriends who had been chased by bandits while feeding Russian refugees. Needless to say,Quakers in Britain were delighted by the expedition and Eddington’s work to make itknown. This work brought him to prominence in the Society of Friends, and in later yearshe helped make the teaching of international relations part of science instruction in someQuaker schools.71

Eddington’s correspondence with Einstein revealed his high hopes for the political andsocial impact of the expedition. In December 1919 he wrote:

All England has been talking about your theory. . . . There is no mistaking the genuine enthu-siasm in scientific circles and particularly in this University. It is the best possible thing thatcould have happened for scientific relations between England and Germany. I do not anticipaterapid progress toward official reunion, but there is a big advance toward a more reasonableframe of mind among scientific men, and that is even more important than the renewal of formalassociations.

Like the Quakers working to rebuild Europe for a lasting peace, Eddington saw rapproche-ment as a slow process that began with personal relationships. His excited report of en-thusiasm in Britain shows that he was concerned not only to humanize the Germans to theBritish but also to show Einstein that there was more than ill will across the Channel. Hewent on to describe in some detail the interest the expedition aroused:

I have been kept very busy lecturing and writing on your theory. My Report on Relativity issold out and is being reprinted. That shows the zeal for knowledge on the subject; because itis not an easy book to tackle. I had a huge audience at the Cambridge Philosophical Society a

70 Times, 28 Nov. 1919; and A. S. Eddington, “Einstein’s Theory of Space and Time,” Contemporary Review,1919, 116:639–643, on p. 639. Eddington’s strategy for presenting relativity to the media and the public wascarefully planned and began well before the November joint meeting. This is dealt with in detail in AlistairSponsel, “Constructing a ‘Revolution in Science’: The Campaign to Promote a Favorable Reception for the 1919Solar Eclipse Experiments,” forthcoming in the British Journal for the History of Science. I thank Sponsel formany valuable conversations and helpful criticism.

71 A. S. Eddington, Space, Time, and Gravitation: An Outline of the General Relativity Theory (Cambridge:Cambridge Univ. Press, 1920); and “The Teaching of International Relations in Schools,” Friends Guild ofTeachers, 1928, Box 291, Friends House, London. E.g., a statement of the Friends Guild of Teachers (of whichEddington was a member and officer) reads: “The study of International Relationships should not be confinedto any one subject; possibly even more marked in Science or Mathematics, which deal with universal truths thanin other subjects” (ibid., p. 6).



MATTHEW STANLEY 85

Figure 4. The Illustrated London News presentation of the expedition and its results. Copyright Illus-trated London News Picture Library. Reference ILN 22 Nov. 1919, p. 815.

few days ago, and hundreds were turned away unable to get near the room . . . one feels thatthings have turned out very fortunately in giving this object-lesson of the solidarity of Germanand British science even in time of war.

Despite the interest in relativity, Eddington remained the principal advocate of a return tonormal scientific relations. When a group of German scientists organized a special




meeting of the Astronomiche Gesellschaft to discuss general relativity, the silence fromtheir British counterparts was deafening. Writing to Stromgren, the head of the Gesell-schaft, Eddington said: “I hope to show my interest in the Astronomische Gesellschaft byattending the next meeting—an individual step which no one has any right to object to.. . . International Science is bound to win and recent events—the verification of Einstein’stheory—has made a tremendous difference in the past month.” Despite the clear impli-cation that his British colleagues would in fact object to his attendance, Eddington madeplans for the trip to Germany. The meeting was held at Einstein’s house and came to beknown as the Potsdam Conference. Eddington was the sole British scientist present. Hecontinued to participate in German science as if there had been no disruption from the warand even published a paper in the Zeitschrift fur Physik, despite his near-total inability towrite or read German. It begins: “This paper is intended to give a full account on thetheory of the radiative equilibrium of the stars. It is written primarily because the originalpapers are not easily accessible in Central Europe in present circumstances.”72

Eddington’s hopes for a reconciliation between the enemy nations was no doubt boostedat the 14 November 1919 meeting of the Council of the Royal Astronomical Society, whenEinstein was nominated for the Gold Medal, the society’s highest honor. He was in com-petition with H. N. Russell for his theory of stellar evolution and Annie Jump Cannon forher catalogue of stellar spectra. In December Einstein was chosen to receive the medal.73

According to the society’s byzantine regulations, confirmation of the award would haveto wait until the January meeting, but an excited Eddington decided to send word toEinstein even before the end of the year. Eddington’s friend E. B. Ludlam was soon to goto Germany as part of the Quaker Emergency Committee’s war relief work in former enemycountries. Ludlam had done research under Philipp Lenard at Kiel and had a great deal ofexperience with German language and culture. He met with Einstein personally to conveythe news of his nomination.

Unfortunately, the confirmation of the award was far from certain; many were uncom-fortable with the idea of giving an award to a citizen of a nation so recently at war withBritain. The minutes of the January meeting record only that “the award of the Gold Medalto Professor Einstein was not confirmed.” But the message was clear: rather than giveEinstein the award, the RAS elected to give no Gold Medal at all for the first time since1891. Eddington immediately sent an apology to Einstein:

I am sorry to say an unexpected thing has happened and at the meeting on Jan. 9 the Councilof the RAS rejected the award, which had been carried by quite a large majority at the previousmeeting. The facts (which are confidential) are that three names were proposed for the Medal.You were selected by an overwhelming majority in December. Meanwhile the “irreconcilables”took alarm, mustered up their full forces in January, and managed to defeat the confirmationof the award in January. . . . I confess I was very much surprised when the motion was proposedand carried originally (it was proposed by two men who during the war have been violently“patriotic”). . . . I am sure that your disappointment will not be in any way personal; and thatyou will share with me the regret that this promising opening of a better international spirit hashad a rebuff from reaction. Nevertheless I am sure the better spirit is making progress.

72 A. S. Eddington to Einstein, 1 Dec. 1919, Einstein Archives, ALS 9-260; and A. S. Eddington to Stromgren,Nov. 1919, quoted in Henrietta Hertzsprung-Kapteyn, “J. C. Kapteyn,” Space Science Reviews, 1993, 64:1–92,on p. 81. For the article see A. S. Eddington, “Das Strahlungsgleichgewicht der Sterne,” Zeitschrift fur Physik,1921, 7:531. It is not clear who translated the article. For the opening line see Eddington, “Radiative Equilibriumof the Stars,” MS, Aug. 1921, Uncatalogued Eddington Material.

73 RAS Council Minutes, 14 Nov., 12 Dec. 1919.



MATTHEW STANLEY 87

He closed the letter by expressing hope that Einstein would be able to visit England soonand even attend a meeting of the RAS, although he admitted there might be “some awk-wardness after what happened.” Eddington clearly placed the blame for the rejection ofthe award squarely on the shoulders of those who had joined in the wartime animosity.The facts of the case are unclear: the original nominations came from H. H. Turner andJames Jeans, both of whom during the war had been extremely vocal opponents of anycontact with German scientists. Whether they had a change of heart is unknown; they wereabsent for the final vote at the January meeting. In any case, the violence of anti-Germanrhetoric had not cooled in the months since the armistice, and it was likely that the attitudesvoiced so loudly during the conflict weighed against Einstein in the end. Ludlam, writingon Emergency Committee stationery, apologized for his countrymen:

I find it difficult to believe that English men of science can really be so narrow minded. I thinkone of the chief difficulties is that scientific men work so hard, and have so much to read, thatthey have not time to study the real facts in international affairs and accept too easily theopinions of the common press. Your visit to England may be postponed, but I hope not forvery long, and it is more evident than ever that there is need of every effort to overcome thesefoolish and narrow-minded prejudices . . . perhaps, when you consider the campaign of lieswhich has lasted for five years—in all countries—you will not judge these poor islanders tooharshly.74

For Ludlam and Eddington, the medal took on a political and religious dimension as atangible symbol of their work toward reconciliation and the prevention of future hostility.

Eddington nominated Einstein for the Gold Medal again in 1920, but this time he hadlittle support. Einstein was finally awarded the medal six years later. In a letter, Eddingtontold Einstein that “I had not much to do with this decision.” In a literal sense this was true,as Eddington was in Leiden when the vote was taken. However, in a wider and veryfundamental sense, Eddington was directly responsible for helping create the conditionsin which a former enemy could be welcomed in Britain. The expedition’s importance inthis regard was noted by many contemporaries. “The fact that a theory formulated by aGerman has been confirmed by observations on the part of Englishmen has brought thepossibility of cooperation between these two scientifically minded nations much closer.”The conduct of Einstein’s visit to England in 1921 showed both how much progress hadbeen made toward reconciliation and how much bitterness remained. He was welcomedby Lord Haldane, who had himself been a victim of Germanophobia, and was feted at awhirlwind series of dinner parties. There were serious misgivings, however, about his firstpublic appearance in a city where German science had even become an issue in the recentelection: one radical London M.P. noted that his patriotic colleagues wanted to “preventthe dumping of German science on these shores, and if [they win, they] will preserve intactan all-British Law of Gravity.” In the end, Einstein’s lecture was well received, despite itsbeing delivered in German.75

74 RAS Council Minutes, 9 Jan. 1920; A. S. Eddington to Einstein, 21 Jan. 1920, Einstein Archives, ALS 9-264; and E. B. Ludlam to Einstein, 23 Jan. 1920, Einstein Archives, ALS 9-266. See also R. J. Tayler, ed.,History of the RAS, Vol. 2 (London: Blackwell, 1987), p. 20.

75 A. S. Eddington to Einstein, 22 Jan. 1926, Einstein Archives, ALS 9-287; Ronald Clark, Einstein: The Lifeand Times (New York: World, 1965), pp. 238 (quotation), 272–277 (reception of the lecture); and W. Benn,“Alien Influence in England,” Contemp. Rev., 1919, 116:637.




CONCLUSION

Scientists and laymen alike marveled at the warm reception Einstein received despite thestill-manifest hostility toward all things German. His talk at the Royal Astronomical So-ciety was especially remarkable given the hatred and dehumanization directed towardGermans and German thought in the British scientific community, which had at timesappeared to overwhelm any hope for postwar cooperation. The fact that Einstein’s visittook place at all was due in large part to Eddington’s promotion of Quaker idealism in theface of patriotic anger. Eddington and the Friends both sought to alleviate the sufferingcaused by the war as well as to weaken the antagonism between nations that made the warpossible. Thus Eddington played the same role within the scientific community that hisfriends E. B. Ludlam and Anna Braithewaite Thomas played in British society at large: areminder that the enemy was human and was himself a victim of war. As a discrete anddramatic event that could be used to influence public opinion, the eclipse expedition pro-vided a focal point for these efforts. Eddington presented the expedition as a milestone inboth international relations and human thought, and it was this presentation that enteredboth the public imagination and the historical record. It now appears in innumerable text-books and popular histories, usually without a trace of Eddington’s Quaker values thatbrought it to prominence.

A crucial element of those values was the philosophy that responsibility for the warcould not be hurled as a blanket aspersion against anyone and everyone in the enemycountries. Rather, Quakers saw responsibility as an individual issue: this allowed them toseek both to defeat German militarism and to ease the suffering of the German people.That such a distinction could be drawn was flatly denied by the most patriotic supportersof the war, such as H. H. Turner, speaking through the mouthpiece of the “Oxford Note-book.” Such supporters argued that nationality alone was sufficient for incrimination andthat the acts of the German government and army directly reflected the character of itscitizens—and its scientists. Their views held sway long after the war and gained validationwith the establishment of the International Research Council and its subgroup the Inter-national Astronomical Union, which explicitly denied membership to scientists of theformer Central Powers.76 The struggle for the future of international science would con-tinue for nearly another decade, and its course would largely reflect the political attitudetoward Germany, as it had during the war.

The scientific merit of the eclipse expedition continues to be controversial today. Atypical accusation is that Eddington intentionally discarded or misinterpreted data so as toconfirm Einstein’s prediction.77 The basis of this is the claim that there was no justification

76 For more on the IRC, as well as on the American attitude toward German science during and after the war,see Daniel Kevles, “Into Hostile Political Camps,” Isis, 1971, 62:47–60. For more on the IAU in general andparticularly in this period see Adriaan Blaauw, History of the IAU: The Birth and First Half-Century of theInternational Astronomical Union (Boston: Kluwer, 1994). There is a great deal of correspondence in the RoyalGreenwich Observatory Archives regarding the exclusion and later admission of the Central Powers into theIAU, but a more in-depth analysis is outside the scope of this essay.

77 See Harry Collins and Trevor Pinch, The Golem: What Everyone Should Know about Science (Cambridge:Cambridge Univ. Press, 1993), pp. 27–56; and the conclusion of Earman and Glymour, “Relativity and Eclipses”(cit. n. 36) (their paper is the source for much of Collins and Pinch’s treatment of the expedition). Both pairsargue that Eddington had no justification for assigning little weight to the Sobral astrographic data, though theirviews of science are quite different. Both criticisms fail to deal with the observers’ stated reasons for treatingthe data as they did, nor do they acknowledge that Eddington et al., as trained professional astronomers, hadextensive experience in determining the accuracy and self-consistency of a measurement. Further, the astronom-ical community, with similar levels of experience and skill, had ample opportunity to check and evaluate their



MATTHEW STANLEY 89

for viewing some of the data as more reliable than the rest. But as I have argued, theevidence shows that the quality and the utility of the photographs were very carefullyconsidered by Eddington and Dyson; further, the determination of the unreliability of theSobral astrographic results was made in the field by the observers in Brazil, and Eddingtonwas not among them. Were these decisions difficult? Yes. Could they have been made onlyby trained and experienced observers? Yes. But the importance of this tacit knowledgedoes not mean that the results were untrustworthy: indeed, since the community the actorsneeded to persuade—most directly, astronomers—was also well versed in this knowledge,one cannot complain that it was used to obscure the basis of their choices.

This is not to say that the results were precise and unarguable. The error was fairlylarge—and indeed would not be greatly improved on until much later, with the develop-ment of techniques such as the Shapiro time delay. The bottom line, however, is thatcontemporary astronomers were persuaded that there was a deflection and that it was mostlikely associated with Einstein’s law of gravity. There was, of course, disagreement aboutthe results throughout the 1920s and 1930s, but I know of no serious accusations ofimpropriety on Eddington’s part. Why, then, has it now become common opinion that he“fudged” the results? Since this opinion exists largely as oral folklore, it lies beyond therealm of this essay to investigate it fully. However, I would like to suggest that it is theresult of the severe blow Eddington’s reputation sustained as a result of his writings onmysticism and religion, as well as the spectacular rejection of his attempts to unify rela-tivity and quantum mechanics. This later work of his, looked on with disfavor by manyof his colleagues, may have tarnished his reputation sufficiently to cast doubt on his earlierwork as well. It has been my personal experience that physicists are much more willingto impugn him than astronomers, and I speculate that this is because the former have hadmore exposure to his unified field theory while the latter remember his still-important workin astrophysics.

Despite frequent criticism of the results, astronomers and scientists still point to the1919 eclipse expedition as an example of how scientific internationalism could rise aboveany challenge. But the collective memory of this test of Einstein’s theory as a straightfor-ward and harmonious cooperation between scientists from nations embroiled in politicalconflict was not solidified until many years later. It was only through Eddington’s deliberatepresentation of the expedition as a milestone in international scientific relations that itcame to have that valence. To contemporaries, the expedition was a symbol of highlycontested visions of what it meant to do science in a world at war. Examining the expeditionin the context of wartime Britain shows that it was a pivotal moment not only in scientificinvestigation but also in the debate over the relationship between science, war, politics,and peace. For Eddington, Turner, and virtually every historical actor involved, sciencewas an enterprise necessarily tied to some aspect of civilization, patriotism, or religion.Eddington’s involvement with, and promotion of, Einstein and relativity therefore takeson the rich and important context of his role as the representative of Quaker pacifism in ascientific community grappling with the horrors of what was the greatest conflict yet totrouble human history.

work. For examples of similar criticisms outside science studies see C. W. F. Everitt, “Experimental Tests ofGeneral Relativity: Past, Present, and Future,” in Physics and Contemporary Needs, ed. Riazuddin, Vol. 4 (NewYork: Plenum, 1980), pp. 529–555; and Ian McCausland, “Anomalies in the History of Relativity,” Journal ofScientific Exploration, 1999, 13:271.



Date post:	09-Dec-2016
Category:	Documents
Upload:	matthew-stanley
View:	215 times
Download:	1 times

“An Expedition to Heal the Wounds of War” The 1919 Eclipse and Eddington as Quaker Adventurer

Documents