_NA~r~u~RE~v_o_L~~~~-~~RI_L_I~------SPRINGBOQKS,------~7" magnetic waves, whether transverse or First World War, put a temporary stop to longitudinal, pulse-like or periodic. He most experimental studies of the particu­ Putting the heavens stresses the key role that the pulse inter­ late aspects of radiation (with the notable pretation played in the transition between exception of Millikan's work on the photo­ to order classical and quantum viewpoints. Once electric effect). The great successes of the Owen Gingerich the wave view predominated, studies of the Bohr theory from 1913 on in understand­ ionizing properties of the new radiation ing atomic structure and identifying atomic Ptolemy's Almagest. confronted physicists with what Wheaton energy levels posed most acutely the ques­ Translated and annotated calls the paradoxes of quantity and quality: tion of the photoelectric effect and its byG.J. Toomer. how could any wave-like disturbance, X-ray andy-ray analogues. Post-war work Duckworth, London/Springer-Verlag, whose energy spreads out spherically from on these problems made it more and more New York: 1984. Pp.693. £55, $64. a central target, ionize only a few of the difficult to avoid facing up to the wave­ atoms in the surrounding region; and how particle paradoxes, first glimpsed over a could secondary electrons so produced decade earlier. Maurice de Broglie's group CLAUDIUS Ptolemy's geocentric system has each have about as much energy as the in Paris, which included his younger long since been dumped into the dustbin of primary electrons whose deceleration at the brother Louis, played a prominent role in discarded theories. Why, then, is anyone target produced the rays in the first place? this research. Wheaton shows how this still concerned with his hoary treatise? It is Physicists here faced the fundamental work formed a natural background out of because Ptolemy's Almagest, more than paradox which was to remain unresolved which Louis's brilliant idea of transferring any other book, convinced people that the for two decades: a wave-like disturbance the wave-particle paradox from radiation seemingly complex phenomena of the manifested properties most readily ex­ to matter could emerge. With a brief indi­ heavens could be represented by a simple plained by the assumption that the distur­ cation of the stimulating effect of de bance consisted of particles! Attempts to Broglie's work on the ideas of Einstein and dodge this paradox are considered by Schrodinger and the experiments of Wheaton, notably the triggering hypo­ Davisson and Germer the book ends. thesis (X-rays only trigger the release of Readers may want to consult Vol. 1 of energy stored within the atom) and Bragg's Mehra and Rechenberg's recent Historical attempt to suppress the wave aspect of the Development ofQuantum Theory (Spring­ paradox by asserting that X-rays were er-Verlag, 1983) for additional details on nothing but a particle beam. Such attempts and somewhat different interpretations of were definitively ruled out by the discovery de Broglie's work and various other topics in 1912 of X-ray diffraction by crystals. treated by Wheaton. Similarly paradoxical features of visible Wheaton tries to weave into the book a light had been elucidated since 1905 by Ein­ running contrast between •'the mechanistic stein who, by 1909, was publicly calling for bias of British physicists" leading to the a theory of light which somehow united "British proclivity to seek mechanical wave and corpuscular aspects. Wheaton models" (pp.5-6) and "German mathe­ suggests that "our story developed quite matical physicists" who "were not deter­ independently" of Einstein's "imaginative red by an inability to represent physical and prescient statistical treatment of light" concepts mechanically" (p. 7). He himself (p.xvii). But recently discovered letters notes that "Larmor in Britain held views from Einstein to Sommerfeld (Physikal­ similar to those of many Germans" (p. 7) ische Bliitter 40, 29; 1984) show that Ein­ and we can at once add the names of Poyn­ stein was involved in the discussion, during ting, Campbell, Pearson and Eddington to Star gazer - Ptolemy depicted on the Campa­ 1909 and 1910, between Stark and Som­ the list of British crusaders against mechan­ nile del Duomo, Florence. merfeld over the interpretation of the ism. On the other hand, prominent Ger­ underlying mathematical description, one observed angular asymmetry in X-ray in­ man theoretical physicists such as Voigt, that afforded the possibility of continuing tensity. Einstein stressed the paradoxical Boltzmann and Helmholtz (and the adole­ prediction of celestial events. Certainly this features, insisting (at a time when this was scent Einstein in his first scientific essay!) was a milestone in the development of not clear to everyone) that light and X-rays expended considerable effort to construct science. differ "only quantitatively". mechanical models of the electromagnetic G.J. Toomer's new English edition of The little Wheaton has to say about Ein­ aether. Given that we are talking about a Ptolemy's classic treatise is more than just stein's role in the quantum story includes small number of physicists in each country, a fresh translation. It is a most intelligently one major inaccuracy. He insists that Ein­ it is hard to see which names go to make up arranged presentation with a running, stein's special theory of relativity was "dia­ the rule and which constitute the excep­ critical commentary at the foot of nearly metrically opposed to the aether tions. It would seem wiser at this time to try every page, and it is based on a new reading ontology", and succeeded in "eliminating to trace out the growth and interrelation­ of both the Greek and Arabic manuscripts. the aether altogether" (p.I06). Einstein ship of smaller units, such as schools cen­ Included are a score of supplementary was at pains to stress (in one of the tred around leading figures or centres of diagrams that clarify (especially) Ptolemy's aforementioned letters to Sommerfeld, physics research, rather than attempt to instruments and his complex latitude among other places) that relativity theory make sweeping generalizations about nat­ theory, a brief introductory section that required no stand on such ontological ional styles of scientific research. For ex­ clues in the reader with respect to the tech­ issues. It forced relinquishment of a ample, how would Wheaton explain the nical background that Ptolemy assumes mechanically interpreted aether, but was fact that "Deutsche Physik", of which (such as ancient calendarial systems), and quite compatible with a non-mechanical Lenard and Stark were to boast a decade three appendices that give examples of aether. Indeed, Einstein's earliest attempt after Wheaton's story ends, prided itself on numerical problems and textual variants. to resolve the wave-particle paradox was a just those characteristics he attributes to What Toomer has produced is the best unified theory (of electrons and light quan­ British proclivities? D edition in any language, one that will ta) based on such a non-mechanical aether remain the standard preferred text for John Stachel is Professor of Physics at Boston field. University, and Editor ofthe collected papers of years to come. Ptolemy's Almagest is X-ray diffraction work, together with Albert Einstein, the first volume of which is clearly the most important volume for the the inhibiting effects on research of the scheduled to appear next year. history of ancient science since 0. © 1984 Nature Publishing Group -~------~NGBCX)KS------N_A_Tu_R_E_·v_o_t._.n__ ~ __ A_PR_n_._,~_ Neugebauer's A History of Ancient thereby bringing forth the charge in some leading up to the actual star list, he notes Mathematical Astronomy, published nine quarters that these tables were pilfered (p.330) that years ago by Springer-Verlag. from an earlier source. "Despite Ptolemy's all the evidence is in favour of the hypothesis In many respects, Ptolemy's work is to clear statement here of his motivation [for that Hipparchus did not record stellar positions applied mathematics as Euclid's Elements the arrangement], it has been the subject of in latitude and longitude (except for a few is to pure mathematics. The Almagest much fruitless debate", notes Toomer on special cases ...). Otherwise it is impossible to begins with instructions for computing the p.l40. "By the time he came to compose explain why Ptolemy went through the cumber­ trigonometric chord function, and the Handy Tables, he had realized the some process of comparing declinations, continues by applying these in a long series inconvenience of this arrangement, and instead of simply comparing latitudes observed of proofs, constructions and specific deri­ switched ... ". by Hipparchus and himself. vations of numerical parameters from his • For some centuries there has been Extensive though his notes are, Toomer observational material. Fortunately speculation that Ptolemy's extensive star does not speculate on the origins of the Toomer has not hesitated to use an catalogue, which occupies the better part Ptolemaic planetary models, nor on their anachronism, the equals sign (which did of two of the 13 books comprising the development in Ptolemy's later works. not come into common usage until the Almagest, was taken over wholesale from Nevertheless, this monumental volume sixteenth century), and he has carefully his predecessor Hipparchus. There exists now paves the way for further investi­ arranged his equations with the equality at no direct evidence, however, for any gations of what, precisely, was going on in a fixed position in the middle of the page. systematic set of numerical positions ancient applied mathematics, an analysis He has also adopted a double degree sign, compiled by the earlier astronomer. While that should bring a fuller understanding of o o, for the "demi-degrees" that Ptolemy Toomer does not argue for Ptolemy's the roots of our own modern science. 0 uses in order to facilitate his clumsy trigo­ originality in compiling the catalogue, he makes it clear that he believes any attempt Owen Gingerich is Professor ofAstronomy and nometric manipulations. This attention to the History of Science at the Harvard­ detail has produced a new level of elegance to credit the positions to Hipparchus is Smithsonian Center for Astrophysics, Cam­ for the work, and, in combination with unfounded. In commenting on the text bridge, Massachusetts. highly specific running heads, makes Ptolemy accessible as never before. Ptolemy's attempt to be the Euclid of the Earth and then the other. applied mathematics was fraught with Picture astronomy The educational impact of the illus­ certain difficulties, because observational trations in The New Astronomy is typified data are not quite as tidy as the abstractions Stephen P. Maran by the colour-coded radial velocity maps of of pure points, lines and spaces. It is thus the Andromeda galaxy. From these it is not surprising that his pioneering effort The New Astronomy. clear which side of the galaxy is turning harbours certain ambiguities and outright By Nigel Henbest and Michael Marten. away from us and which side towards us; botches. Untamed nature is not so easily Cambridge University Press: 1983. shades of red (as in redshift) denote re­ brought into a mathematical harness. In his Pp.240. £12.50, $24.95. cession velocities and approach velocities preface, Toomer allows that Ptolemy has are represented by cooler green and blue, manipulated his material "in order to IN The New Astronomy, Nigel Henbest while off-colour patches signal velocity present an appearance of rigor in his and Michael Marten celebrate the recent pattern disturbances that may correspond theoretical treatment which he could never achievements made through digital image to density waves which maintain the spiral have found in his actual experience". processing and (for some spectral regions) arms. Indeed, Ptolemy, like astronomers today, through the use of two-dimensional A few points, if addressed, should lead undoubtedly built his edifice on a great detectors. In computer-generated astro­ to an even better second edition of the array of traditional techniques and data, physical images, colour may represent book. The presentation of visible, ultra­ rejecting, adjusting or incorporating them intensity or polarization of light, a physical violet and X-ray solar images would be as he saw fit. To examine how these parameter such as temperature or strength much improved if these were based on various elements blend together is both a of magnetic field, or the rate of change of photographs made on the same date and fascinating and a worthwhile research any such quantity with position in the sky. thus referring to the Sun in the same con­ endeavour. So not only are the pictures reproduced in dition. Consistency has gone too far in the Not everyone has been willing to investi­ this book of aesthetic appeal, they are captions for a set of ultraviolet, X-ray and gate Ptolemy with such scholarly calmness. pregnant with information. gamma-ray sky maps. In each, the wave­ In his The Crime of Claudius Ptolemy, Some of the most dramatic contrasts length is expressed in nanometers, but this, published in 1977, the Johns Hopkins between separate views of the same object together with deliberate avoidance of geophysicist R.R. Newton maintains that are provided by jovian imagery. Compared powers-of-ten notation, results in a des­ Ptolemy's work is riddled with deceit and with a highly-detailed Voyager photograph cription for one map ("0.000 000 2- 0.000 concludes that it would have been better of Jupiter, infrared scans show a seemingly 02 nm ") that neither novice nor expert can for astronomy if the Almagest had never more ordered planet, while radio and appreciate. Finally, some images need been written. Newton's conclusion is at X-ray images are so different from the marker lines at the borders, or some worst so extreme as to be silly, and at best a usual picture that an uninitiated judiciously applied arrows: few readers will debating point. The problems of the astronomer might well mistake the target. identify Eta Carinae in the photograph Almagest deserve critical and informed The X-ray Jupiter comprises two separate of complex nebulosity from the informa­ discussion, Toomer writes, but he adds sources, but 6-cm radio waves define a tri­ tion that the star is "at the lower-left end that Newton's book "provides nothing of partite Jupiter, a central oval flanked by of the small banana-shaped dark cloud". the kind, but rather tends to bring the two smaller patches, orientated at right For the non-specialist, this is a fine guide whole topic into disrepute". Although angles to the X-ray sources. Especially to the spectacle of modern astrophysics. Toomer chooses not to debate with striking are correlated sequences depicting Professional astronomers will find the Newton in the present forum (wisely, in my emission from the jovian magnetosphere: book, with its detailed list of picture opinion), he scores numerous points in his the pattern of 21-cm wavelength continuum sources, the right place to identify the best careful examination of the text. Here are sources wobbles up and down as Jupiter new illustrations for lectures and articles. 0 two examples. spins, while in the corresponding radio Stephen P. Maran is a Senior Staff Scientist in • Ptolemy's tables for the mean polarization maps the dominant mode of the Laboratory for Astronomy and Solar motions of the planets do not come up to circular polarization reverses as the planet Physics at the NASA-Goddard Space Flight his own epoch except by an extra addition, presents first one magnetic pole towards Center, Greenbelt, Maryland. © 1984 Nature Publishing Group