------SPRING744 BOOKS------NATllRF VOL ..1.12 21 APRIL 1988 major factors leading Kramers to turn of its author in several ways. Dresden is a Inside a physicist away from active participation in work of distinguished physicist from Holland, who John Stachel the quartet just when it was about to studied with Kramers before going to the culminate in the definitive formulation of United States in 1939, and who met him the new mechanics. again several times after the war. He is H.A. Kramers: Between Tradition and K,ramers left Copenhagen in 1926 to clearly very involved, both intellectually Revolution. By M. Dresden. Springer­ accept the chair of physics in Utrecht, and emotionally. with the subject and his Verlag:1987. Pp.563. DM 120, $74.95, £45. becoming the dean of the Dutch physics milieu (he spent 11 years working on this ccmmunity after the deaths of Lorentz book), and is well acquainted with many THE Dutch theoretical physicist Hendrik and Ehrenfest. His life and scientific others who figure in the story. The book is Antonie Kramers is probably known to activity after the move are treated sketchily based on a close reading of Kramers's more physicists as an initial than as a in Part Three, except for a chapter of over writings. both technical and popular, and name. How many realize what lies hidden 100 pages devoted to his work on quantum of a host of other sources in physics behind the modest 'K' of the WKBJ electrodynamics. Like Pauli. Kramers was and the history of physics. As might be approximation method in quantum very critical of Dirac's approach. He felt expected from a physicist of Dresden's mechanics? A smaller number will be that the answer to the problems of the eminence, the explanations of Kramers's familiar with one or another of such quantum theory lay in a careful re­ work are masterly and will be indispen­ phrases as Kramers theorem or the examination of the classical theory of the sable for those interested in the early Kramers-Kronig relations, but his name interaction of electrons and radiation. history of quantum mechanics and of is hardly a household word among the Dresden shows that his faithfulness to the quantum electrodynamics. But Dresden current generation of physicists. Yet, as classical legacy of Lorentz's electron attempts much more than exposition. He )> :;; ! 0:, :;0 C: cr" ]

Kramers and contemporaries - the famous line-up at the Fifth Solvay Conference in 1927. Kramers is fourth from the left in the second row. Max Dresden sets out to demonstrate, he theory was a source of both strengths and tries to explain the intra-psychic reasons has a claim to be remembered along with weaknesses in Kramers's work. After the for the succession of 'near misses' in that distinguished trio consisting of his Second World War, Kramers's approach, Kramers's career- cases in which he just friends, Wolfgang Pauli and Werner with its emphasis on the need for mass failed to make some major discovery. He Heisenberg, and his mentor, Niels Bohr, renormalization, started to receive wide­ also speculates on why Kramers never who contributed so decisively in the early spread recogmt1on among physicists worked on certain problems that he was 1920s to shaping the emerging quantum searching for a way to understand the eminently qualified to tackle. mechanics, and through it the course of newly discovered Lamb shift. But Kramers These portions of the book lean very physics over the past 60 years. again turned away from active participa­ heavily on a number of personal inter­ The depiction of the interrelationships tion in the further development of views with members of Kramers's family, between Kramers and the other members the theory that led to the now classic dose friends and fellow scientists, who of this quartet, and a masterly discussion Feynman-Schwinger- Dyson relativistic would presumably not have spoken so of some of its consequences for Kramers's version of quantum electrodynamics. freely to someone in whom they did not research, form the central core of the In the final part of the book, Dresden have full confidence. Kramers's children book. After some introductory scientific attempts to assess Kramers's personality made available his diaries, date books and background in the first four chapters, the and scientific style, his social and religious private poems. This material enables remainder of Part 1 gives a quick intro­ commitments (or lack of them), and his Dresden to provide a number of remark­ duction to the quartet and a summary of self-image. A lot of additional biograph­ able insights into his subject's inner life. their accomplishments during the decade ical material is presented here, so that The picture that he presents is a gloomy {1916-1926) that Kramers was in Copen­ a reader trying to form a connected one. Dresden sees an essential continuity hagen as Bohr's assistant. The second part picture of Kramers's life has to do a good between certain basic traits manifested in is a detailed survey of Kramers's work deal of skipping around. The author Kramers's closest interpersonal relations, during this period, which culminate in explains that he was forced to cut down a in his relations with his fellow scientists two rewarding but technically demanding manuscript of some 1,400 printed pages, and even in his relationship to science chapters on the Bohr-Kramers-Slater which may account for certain imbalances itself. An inability to commit himself (BKS) theory and the Kramers- Heisen­ and gaps in the treatment of various completely to anyone, friend or wife, or to berg dispersion theory. The author estab­ periods in Kramers's life, as well as the any cause, religious or political, showed lishes the importance of Kramers in the scattering of information on some topics itself early in his life and deepened as he events that led Heisenberg to formulate throughout the book. {The circumstances grew older. He feared any major decision, matrix mechanics. He suggests that of Kramers's marriage, for example, are because it foreclosed all alternative paths. Kramers's depression after the collapse of discussed at several widely separated His strong attraction to and talent for such the BKS theory, in which he had placed places.) The index is very weak and does varied fields as music, literature and such exaggerated hopes, as well as fear of not make it any easier to gather together science made the choice of a career par­ competition with Heisenberg, to whom such information. ticularly difficult for the young man. His Kramers felt intellectually inferior, were This biography bears the distinct stamp first mentor, Paul Ehrenfest, felt that this

© 1988 Nature Publishing Group _NA_T_U_R_E_V_0_L_.• _1.1 _2 _21_A_P_R_IL_l_98_8 ______SPRING BOOKS ______745 trait would prevent him from succeeding published. It is dedicated to Erwin in physics. Kramers also had a horror of Jump in quantum Schrodinger, and appears at a time when interpersonal conflicts, and would go to the centenary of his birth has just been extraordinary lengths to avoid them. He history celebrated. Schrodinger was undoubtedly person. regarded this as a family characteristic, Nicholas Kemmer a great physicist and a remarkable telling a young relative "A Kramers has to Why, however, was he not covered fight to fight". He was well aware that his together with the 'greats' of the previous Development of Quantum inability to fight for his convictions The Historical volumes? That would have been appro­ 5 Erwin Schrodinger and hindered him scientifically. Theory. Vol. priate chronologically - and indeed his Wave Mechanics. Part 1 Perhaps the most remarkable example the Rise of name is not absent from those earlier in Vienna and Zurich 1887- is Kramers's unpublished anticipation of Schrodinger pages. Schrodinger receives special 2 The Creation of Wave the Compton effect. The idea occurred to 1925; Part treatment because, within the history of Mechanics: Early Response and Applica­ him in 1921, but he allowed Bohr, who at quantum theory, he holds a quite unusual By Jagdish Mehra and the time was a vigorous opponent of the tions 1925-1926. position. He was a most distinguished Rechenberg. Springer-Verlag: photon concept, to talk him out of pub­ Helmut scientist who worked on many aspects of 1987. Pp.980. Part 1 DM98, £36, $54. Part lishing his work. Indeed, Bohr was so theoretical physics, but until 1926 his con­ £55, $79.95. effective in converting Kramers to his 2 DM148, tributions to quantum theory were quite point of view that Kramers became an modest. In that year he published a series even more intemperate opponent of the OuANTUM theory was born with this of papers that immediately transformed photon than Bohr himself. Compton later century and needed a quarter of it to reach ideas and methods in quantum theory received a Nobel prize for his work, a maturity as quantum mechanics. That quite profoundly. In due course this work prize which it is reasonable to suppose theory soon gained almost universal gained him a Nobel prize. However, Kramers would have shared had he pre­ acceptance as the key to a much-deepened because the interpretation of his 'wave dicted the effect two years before the understanding of inanimate nature. mechanics' by the great majority of his experiment. It is sad to learn that As Jagdish Mehra told us at the start of colleagues differed drastically from his Kramers's life, like that of many other this multi-volume work, he began prepar­ own, he soon parted company with them. outstanding scientists, was embittered by ing it just about another quarter-century Only his wave equation flourished within his failure ever to receive a coveted Nobel. later. For him, the time was then most quantum mechanics. One is left with the impression of a bril­ auspicious; nearly all those who, from This volume is clearly meant both liant, upright and conscientious man, torn 1925 onwards had taken part in creating to continue the series and to tell Schro­ by incessant internal conflicts, constantly and developing quantum mechanics, were dinger's story. Given the authors' general tormented by feelings of personal and pro­ still active, not to mention some of their intent to provide maximum background fessional lack of fulfilment , who main­ teachers. Mehra established happy con­ material, it could hardly be the former tained external control over his feelings at tacts with, it would seem, nearly all these without the latter. There was thus a great a great cost to himself. people. A large part of the work that amount of further background material How accurate is this picture? It is hard Mehra then began is now in print. Since to collect beyond Mehra's earlier work for an outsider to know. Dresden freely 1970 he has had Helmut Rechenberg as (which had included interviews with admits that the book gives "my under­ partner. Schrodinger), explaining the time gap standing of Kramers' life". The wealth of Mehra displays a special ability to between the appearance of the previous intimate detail about Kramers that convert copious records of formal inter­ volumes and this one. Schrodinger left a Dresden provides relies so heavily on views and informal exchanges into lively huge amount of archival material behind personal interviews (Dresden himself accounts that ring very true. These are not which the authors not only use but also list notes the " 'soft' character" of this infor­ just incidental but rather quite central to in detail, and in addition much has been mation) that it is difficult for others to the structure of the first four volumes of assembled on his Viennese background assess the evidence until the interviews the work, which are not strictly chrono­ and some on Zurich, where his irruption (which I hope were taped), as well as logical in order. They split into parts into quantum theory took place. Kramers's personal papers, are made presenting the ideas that relate roughly Description of Vienna in the late nine­ available to others. Information that to the work of Planck, Bohr, Pauli, teenth century begins the work. We are would seem important to an assessment of Heisenberg and Dirac. Embedded into told some history of the multinational Kramers's psychological development is the very readable technical sections there Habsburg Empire and are introduced to not always provided. (His father turns up are biographies and pen pictures of these its many-sided culture, including a num­ remarried when Kramers is in his mid­ men and descriptions of their back­ ber of its great figures. Schrodinger enters twenties, for example, without any indica­ grounds. Naturally the work of many as an inheritor of great traditions - a tion of what happened to his mother.) other people is described, some of whom polymath growing up in a highly cultured We must be immensely grateful to receive similar, though shorter treatment. family. Every event, place or person Dresden for having broken with the Also, as an introduction, figures from the mentioned is the subject of detailed genteel tradition of scientific biography by prehistory of quantum theory appear in documentation. writing a fascinating book that leads us the setting of their achievements, with The reader learns of many men who into the forbidden territory of Kramers's very detailed documentation for each one. influenced Schrodinger in his youth. Per­ personal and psychic life . However, one The reader-interest of different sections haps the most relevant of them is Ludwig sometimes feels the need for a more of these volumes inevitably varies. For Boltzmann, because statistical mechanics expert guide through this territory, the me, the later technical chapters deal with became one of Schrodinger's main inter­ sort of superlative guide that Dresden topics and publications I remember from ests. (Boltzmann is first introduced along­ proves to be through the world of long ago, while earlier parts invite study side Ernst Mach, and we hear incidentally Kramers's physics. D for the twists and turns of how it was of their great debate on the acceptability before my time. As for the vast amount of of atoms as real.) In 1912 Schrodinger John Stachel, 745 Commonwealth A venue, background information and biographical began to be known to theoretical physi­ Boston, Massachusetts 02215. USA, is Profes­ one must be grateful that it exists. cists through his prolific publications on sor of Physics at Boston University and Editor detail, of the Collected Papers of Albert Einstein, the Now, after a five-year gap, a further many topics. Space forbids discussing first volume of which appeared in /987. two-part volume of this work has been them here, as Mehra and Rechenberg do

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