Putting the Heavens to Order

_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.

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