books and arts The Einstein chronicles Two volumes of correspondence put Einstein’s work in a historical context. The Collected Papers of Albert Einstein, Volume 9. The Berlin Years: Correspondence, January AKG-IMAGES 1919–April 1920 edited by Diana Kormos Buchwald, Robert Schulmann, József Illy, Daniel J. Kennefick & Tilman Sauer Princeton University Press: 2004. 780 pp. $110, £72 The Born–Einstein Letters 1916–1955: Friendship, Politics and Physics in Uncertain Times by Albert Einstein & Max Born Macmillan Science: 2005. 256 pp. £19.99, $26.95 Gerald Holton On 22 September 1919, Albert Einstein, then aged 40, received at his Berlin home a brief telegram that signalled that his life would shortly change, suddenly and forever. The telegram contained the news that Arthur Eddington had shown during a solar eclipse that starlight is deflected by the Sun’s gravity — an effect predicted by Einstein’s general Man of letters: Einstein’s correspondence provides a wealth of personal and scientific information. theory of relativity. The scientific details, when published that November, made Ein- Other letters deal with epistemological For example,in a letter of November 1919 stein almost overnight the icon of charis- questions (such as exchanges with Moritz to Einstein,Lawson mentions in passing that matic scientific genius. The very stars had Schlick and Hans Vaihinger); with adminis- he understands that “the conditions of life in announced, to a public still in mourning trative,political and social problems,includ- Berlin are nearly unbearable”. The editorial after the barbaric First World War, that old ing Einstein’s intensifying interest in a Jewish note explains: “The Allied blockade of Ger- conceptions were being overturned. Einstein’s identity and in a form of Zionism. From many,which was extended past the end of the vast correspondence during the months that more personal letters, we learn about Ein- war to pressure Germany to accede to Allied followed reveal the reactions, ranging from stein’s own precarious health in those days, demands, together with economic disrup- adoration to vicious attacks. and his deep grief as his mother is dying tion from the war, caused a famine in central This tumultuous period is recorded in of cancer. Throughout there is evidence of Europe in the aftermath of the war.”There is volume 9 of The Collected Papers of Albert his often difficult relations with his wife then a discussion about the spread of disease. Einstein.The 399 letters and other docu- Mileva, who, soon after the family arrived in Similarly, to clarify an obscure sentence ments included, most of them previously Berlin in 1914, returned to Switzerland with in a letter by Fokker (dated 18 November unpublished, offer us an intimate view of their two sons, for whom Einstein’s letters 1919), the editorial note explains that, in the remarkable multidimensionality of Ein- show his great attachment. Also included testifying that month before the German stein’s life. Much of the correspondence is are the decree of divorce from Mileva (dated official committee exploring the responsibil- of course about the scientific findings and 14 February 1919) and the certificate of ities of the military during the war, General controversies of the time,chiefly on the light- his marriage to his cousin Elsa Löwenthal Hindenburg “used the occasion to launch bending and red-shift tests of his general (2 June 1919, both registering their religion the ‘stab-in-the-back’ legend which blamed theory of relativity, the attempt to find com- on the document as “Dissident”). civilian groups such as the communists, mon ground between quantum mechanics There is as much as a page of editorial Jews,and women for Germany’s defeat in the and relativity, and the programme to unify explanation and commentary on every war”. The ‘stab-in-the-back’ legend “served electromagnetism and gravitation. name, place and allusion recorded in the as a catalyst for those embittered by Ger- Even an incomplete list of Einstein’s corresponding letter — an astonishing com- many’s defeat, fueling the consolidation of scientific correspondents in this period will bination of scholarship and detective work rightist and militarist attitudes in Weimar draw historians of science and other scholars by the editorial team, now led by Diana Germany”. to this volume: Paul Ehrenfest, Theodor Kormos Buchwald and continuing the tradi- All this carefully researched editorial Kaluza, Felix Klein, David Hilbert, Gustav tion established by John Stachel, who edited commentary makes it easy to grasp the con- Mie,Adriaan Fokker,Max von Laue,Hendrik earlier volumes. These annotations establish text and conditions underlying the corre- Lorentz, Jean Perrin, Eddington, Willem not only the relationship between different spondence.Einstein usually seems somehow de Sitter, Hedwig Kohn — and not forget- parts of the whole correspondence (the first lifted above it all, being saved in those dark ting the English physicist Robert W.Lawson, volume was published in 1987), but also tell days largely by what Max Planck pointedly who persuaded Einstein to write an article us much about the scientific and social identified as “die freudige Sicherheit”— the for Nature in 1921 outlining his theory of milieu of the day,something only hinted at in joyful certainty. relativity. the letters themselves. A 24-page introduction serves as a guide NATURE | VOL 433 | 20 JANUARY 2005 | www.nature.com/nature 195 © 2005 Nature Publishing Group books and arts to the main events and ideas in the corre- themselves constitute one of the most vivid spondence;without it,it would be difficult to and valuable testimonies to the development keep in mind the main themes when reading of modern science. They also tell us much Relativity revisited the chronological series of letters. There is about the personal hardships that Einstein The Meaning of Relativity (5th edn) also an explanation of the editors’ triage of and Born overcame during two world wars, by Albert Einstein, with an introduction by the voluminous correspondence: some let- the vagaries of academic life, the daily grind Brian Greene ters are known but are inaccessible now, and of administrative work, the steadfastness Princeton University Press: 2004. 192 pp. the editors relegated other, less significant, and frailty of human relationships.” $14.95, £9.95 letters to reference in a calendar at the end Perhaps the most famous of these letters Special Relativity: A First of the volume. And although the corres- deal with the fundamental difference Encounter pondence is presented only in the original between these two good friends, with Born by Domenico Giulini language, mostly German, happily there upholding what came to be the Copenhagen Oxford University Press: 2005. 160 pp. exists a separately published English trans- interpretation of quantum mechanics, £14.99, $24.95 lation, provided by Ann and Klaus according to which the foundations Einstein 1905: The Standard Hentschel (Princeton Univer- of physics are laws of statistical of Greatness sity Press,2005). nature.Einstein responded in by John S. Rigden Many of the most inti- 1926: “Quantum mechan- Harvard University Press: 2005. 192 pp. mate letters in volume 9 ics is certainly imposing. $21.95, £14.95 are exchanges between But an inner voice tells Werner Israel Einstein and Max Born me that it is not yet the and his wife Hedwig. real thing. The theory What, another three books on Einstein? At Here,Einstein can says a lot. But it does the last count on www.amazon.com there truly relax and share not really bring us any were 498 currently in print, and the prolif- the good and the sad closer to the secrets eration of titles such as The Private Albert AIP EMILIO SEGRE VIS.AIP EMILIO SEGRE STEIN ARCH./MARIA in his life, his scien- of the ‘old one’. I, at Einstein, Einstein in Love and Einstein’s tific, social, musical any rate, am convinced Daughter should ensure that no corner of and personal thoughts. that He is not playing his life is left untouched. Max Born, whose Nobel at dice.” As a refreshing change, The Meaning of prize for his work in This judgement, Born Relativity,Special Relativityand Einstein 1905 quantum mechanics was records, was for him “a hard deal exclusively with science. All three are delayed until 1954, contri- blow”, separating Einstein valuable additions to the Einstein canon. buted to a wide spectrum of from the younger physicists The Meaning of Relativity, the master’s own fields, including relativity, In touch: Max Born and his wife of which Born, though only presentation based on lectures given at optics, crystal physics, epis- regularly wrote to Einstein. a few years younger than Princeton University in 1921, reappears in a temology, the theory of Einstein, considered him- reprinting of the final (1953) edition, which liquids and arms control. Max and Hedwig, self part. But the friendship survived, not included as an appendix his parting thoughts who was a delightful companion and corre- least by the intervention of Wolfgang Pauli, on his last abortive bid to unify the gravita- spondent, left Germany for Edinburgh after who cleared up a misunderstanding between tional and electromagnetic forces. This was Max was driven out from Göttingen in 1933. Born and Einstein. The exchange of letters in fact a revival, with modifications, of his His son,Gustav,tells that his father had taken continued, testifying to their constant inter- earliest attempt, begun in 1925 but soon seriously Einstein’s advice to leave immedi- ests in developments ranging from atomic abandoned because, as he admitted in 1927: ately,“thus helping to save the family”. physics to cosmic rays, from quantum “As a result of numerous failures,I have come The 117 surviving letters between the mechanics to stellar spectra, and of course to the conclusion that this road does not lead Borns and Einstein from 1916 to 1955 were relativity (the new ‘ether drift’ experiments, us closer to the truth.”It is curious that none published as a book in German in 1969,with gravitational red shift, gravitational light of his later works mentions this early attempt.