Leonhard Euler's ‘anti-Newtonian’ theory of light

Leonhard Euler was the leading eighteenth-century critic of Isaac Newton's projectile theory of light. Euler's main criticisms of Newton's views are surveyed, and also his alternative account according to which light is a wave motion propagated through the aether. Important changes are identified as having occurred between 1744 and 1746 in Euler's thinking about the way in which a wave such as he supposed light to be is propagated through a medium. Paradoxically, in view of Euler's overtly anti-Newtonian stand, these amount to Euler abandoning his early, Malebranchian notions about the physical basis of wave propagation, in favour of the ideas set out by Newton in Book II of his Principia.     

Émilie Du Châtelet's interpretation of the laws of motion in the light of 18th century mechanics

Émilie Du Châtelet is well known for her French translation of Newton's Philosophiae Naturalis Principia Mathematica. It is the first and only French translation of Newton's magnum opus. The complete work appeared in 1759 under the title Principes mathématiques de la philosophie naturelle, par feue Madame la Marquise Du Chastellet. Before translating Newton's Principia, Du Châtelet worked on her Institutions de physique. In this book she defended the Leibnizian concept of living forces – vis viva. This paper argues that both of these works were part of a critical transformation and consolidation of post-Newtonian mechanics in the early 18th century, beyond Newton and Leibniz. This will be shown by comparing Du Châtelet's translation of Newton's axioms with her own formulations of the laws of motion in light of Thomas Le Seur's and François Jacquier's Geneva edition which holds a special place among the several editions of the Principia that appeared in the early 18th century.     

A Dispute Over Superposition: John Wallis,Honoré Fabri,and Giovanni Alfonso Borelli

This paper aims first and foremost to unravel and clarify an interesting 17^th century controversy around superposition in projectiles, which allegedly existed between the French Jesuit Honoré Fabri and the Italian physicist and astronomer Giovanni Alfonso Borelli. This conflict – initially described by the English mathematician John Wallis in a letter from 1670 to the secretary of the Royal Society – has been erroneously identified with Fabri's Dialogi physici (1669), a work written in response to Borelli's De vi percussionis (1669). In fact, this “conflict” was nothing but Wallis's account of a contradiction between Borelli's above mentioned work and Fabri's Tractatus physicus de motu locali from 1646, while Fabri's 1669 work expressed views very different from those contained in his Tractatus physicus. I will try here to reconstruct Fabri's change of heart between 1646 and 1669 concerning projectiles and superposition, while tracing the real bone of contention between (the later) Fabri and Borelli – superimposing contrary motions – to its Aristotelian origins. My analysis will lead me to problematize the way modern historians usually interpret the relation between Aristotle's physical thinking and projectile theories of early modern theoreticians (e.g. Nicollò Tartaglia's).     

Science,self improvement and the first industrial revolution

This study considers Newton's views on space and time with respect to some important ontologies of substance in his period. Specifically, it deals in a philosophico-historical manner with his conception of substance, attribute, existence, to actuality and necessity. I show how Newton links these “features” of things to his conception of God's existence with respect of infinite space and time. Moreover, I argue that his ontology of space and time cannot be understood without fully appreciating how it relates to the nature of Divine existence. In order to establish this, the ontology embodied in Newton's theory of predication is analysed, and shown to be different from the presuppositions of the ontological argument. From the historical point of view Gassendi's influence is stressed, via the mediation of Walter Charleton. Furthermore, Newton's thought on these matters is contrasted with Descartes's and Spinoza's. In point of fact, in his earliest notebook Newton recorded observations on Descartes's version of the ontological argument. Soon, however, he was to oppose the Cartesian conception of the actuality of Divine existence by means of arguments similar to those of Gassendi. Lastly, I suggest that the nature and extent of Henry More's influence on Newton's conception of how God relates to absolute space and time bears further examination.     

Theories that narrate the world: Ronald A. Fisher's mass selection and Sewall Wright's shifting balance

Theories are composed of multiple interacting components. I argue that some theories have narratives as essential components, and that narratives function as integrative devices of the mathematical components of theories. Narratives represent complex processes unfolding in time as a sequence of stages, and hold the mathematical elements together as pieces in the investigation of a given process. I present two case studies from population genetics: R. A. Fisher's “mas selection” theory, and Sewall Wright's shifting balance theory. I apply my analysis to an early episode of the “R. A. Fisher – Sewall Wright controversy.”     

Different shades of Newton: Herman Boerhaave on Newton mathematicus,philosophus, and optico-chemicus

In this paper I will probe into Herman Boerhaave's (1668–1738) appropriation of Isaac Newton's natural philosophy. It will be shown that Newton's work served multiple purposes in Boerhaave's oeuvre, for he appropriated Newton's work differently in different contexts and in different episodes in his career. Three important episodes in, and contexts of, Boerhaave's appropriation of Newton's natural philosophical ideas and methods will be considered: 1710–11, the time of his often neglected lectures on the place of physics in medicine; 1715, when he delivered his most famous rectorial address; and, finally, 1731/2, in publishing his Elementa chemiae. Along the way, I will spell out the implications of Boerhaave's case for our understanding of the reception, or use, of Newton's ideas more generally.     

Visiting Newton's atelier before the Principia, 1679–1684

The worksheets that presumably contained Newton's early development of the fundamental concepts in his Principia have been lost. A plausible reconstruction of this development is presented based on Newton's exchange of letters with Robert Hooke in 1679, with Edmund Halley in 1686, and on some clues in the diagram associated with Proposition 1 in Book 1 of the Principia that have been ignored in the past. A graphical construction associated with this proposition leads to a rapidly convergent method to obtain orbits for central forces, which elucidates how Newton may have have been led to formulate some of his most fundamental propositions in the Principia.     

The Reception of Miller's Ether-Drift Experiments in the USA: The History of a Controversy in Relativity Revolution

This paper analyses documents from several US archives in order to examine the controversy that raged within the US scientific community over Dayton C. Miller's ether-drift experiments. In 1925, Miller announced that his repetitions of the famous Michelson-Morley experiment had shown a slight but positive result: an ether-drift of about 10 kilometres per second. Miller's discovery triggered a long debate in the US scientific community about the validity of Einstein's relativity theories. Between 1926 and 1930 some researchers repeated the Michelson-Morley experiment, but no one found the same effect as Miller had. The inability to confirm Miller's result, paired with the fact that no other ether theory existed that could compete with special relativity theory, made his result an enigmatic one. It thus remained of little interest to the scientific community until 1954, when Robert S. Shankland and three colleagues reanalysed the data and proposed that Miller's periodic fringe shift could be attributed to temperature effects. Whereas most of the scientific community readily accepted this explanation as the conclusion of the matter, some contemporary anti-relativists have contested Shankland's methodology up to now. The historical accounts of Miller's experiments provide contradictory reports of the reaction of the US scientific community and do not analyse the mechanisms of the controversy. I will address this shortcoming with an examination of private correspondence of several actors involved in these experiments between 1921 and 1955. A complex interconnection of epistemic elements, sociological factors, and personal interests played a fundamental role in the closure of this experimental controversy in the early 1930s, as well as in the reception of Shankland's reanalysis in the 1950s.     

Spacetime Models for the World

In this paper I take a sceptical view of the standard cosmological model and its variants, mainly on the following grounds: (i) The method of mathematical modelling that characterises modern natural philosophy—as opposed to Aristotle's—goes well with the analytic, piecemeal approach to physical phenomena adopted by Galileo, Newton and their followers, but it is hardly suited for application to the whole world. (ii) Einstein's first cosmological model (1917) was not prompted by the intimations of experience but by a desire to satisfy Mach's Principle. (iii) The standard cosmological model—a Friedmann–Lemaı̂tre–Robertson–Walker spacetime expanding with or without end from an initial singularity—is supported by the phenomena of redshifted light from distant sources and very nearly isotropic thermal background radiation provided that two mutually inconsistent physical theories are jointly brought to bear on these phenomena, viz the quantum theory of elementary particles and Einstein's theory of gravity. (iv) While the former is certainly corroborated by high-energy experiments conducted under conditions allegedly similar to those prevailing in the early world, precise tests of the latter involve applications of the Schwarzschild solution or the PPN formalism for which there is no room in a Friedmann–Lemaı̂tre–Robertson–Walker spacetime.     

Newton,Gases, and Daltonian chemistry: The foundations of combination in definite proportion

This study deals with the relationship between Newton's gas model in the Principia (Book II, Proposition xxiii) and Dalton's theorizing. Dalton's first theory of mixed gases is an elegant extension of the Newtonian gas model which, in turn, led Dalton to a general model of chemical combination. The views on combination are contrasted with those of Arnold Thackray. Interestingly, the model of combination was knowingly based on a falsified theory.     

Editing Newton in Geneva and Rome: The Annotated Edition of the Principia by Calandrini,Le Seur and Jacquier

This contribution examines the circumstances of composition of the annotated edition of Newton's Principia that was printed in Geneva in 1739–1742, which ran to several editions and was still in print in Britain in the mid-nineteenth century. This edition was the work of the Genevan Professor of Mathematics, Jean Louis Calandrini, and of two Minim friars based in Rome, Thomas Le Seur and François Jacquier. The study of the context in which this edition was conceived sheds light on the early reception of Newtonianism in Geneva and Rome. By taking into consideration the careers of Calandrini, Le Seur and Jacquier, as authors, lecturers and leading characters of Genevan and Roman cultural life, I will show that their involvement in the enterprise of annotating Newton's Principia answered specific needs of Genevan and Roman culture. The publication and reception of the Genevan annotated edition has also a broader European dimension. Both Calandrini and Jacquier were in touch with the French république des lettres, most notably with Clairaut and Du Châtelet, and with the Bernoulli family in Basel. Therefore, this study is also relevant for the understanding of the dissemination of Newton's ideas in Europe.     

The Transformation of Aristotle's Mechanical Questions: A Bridge Between the Italian Renaissance Architects and Galileo's First New Science

The reception process of Aristotle's Mechanical Questions during the early modern period began with the publication of the corpus aristotelicum between 1495 and 1498. Between 1581 and 1627, two of the thirty-five arguments discussed in the text, namely Question XIV concerning the resistance to fracture and Question XVI concerning the deformation of objects such as timbers, became central to the work of the commentators. The commentaries of Bernardino Baldi (1581–1582), Giovanni de Benedetti (1585), Giuseppe Biancani (1615) and Giovanni di Guevara (1627) gradually approached the doctrine of proportions of the Renaissance architects, some aspects of which deal with the strength of materials according to the Vitruvian conception of scalar building. These aspects of the doctrine of proportions were integrated into the Aristotelian arguments so that a theory of linear proportionality concerned with the strength of materials could be formulated. This very first theory of strength of materials is the theory to which Galileo critically referred in his Discorsi where he published his own theory of strength of materials. Economic and military constraints are determined as the fundamental reasons for the commentators’ commitment to developing a theory of strength of materials that later linked Galileo's work to the practical knowledge of the architects and machine-builders of his time.     

Epistemology of a believing historian: Making sense of Duhem's anti-atomism

Pierre Duhem's (1861–1916) lifelong opposition to 19th century atomic theories of matter has been traditionally attributed to his conventionalist and/or positivist philosophy of science. Relatively recently, this traditional view position has been challenged by the claim that Duhem's opposition to atomism was due to the precarious state of atomic theories during the beginning of the 20th century. In this paper I present some of the difficulties with both the traditional and the new interpretation of Duhem's opposition to atomism and provide a new framework in which to understand his rejection of atomic hypotheses. I argue that although not positivist, instrumentalist, or conventionalist, Duhem's philosophy of physics was not compatible with belief in unobservable atoms and molecules. The key for understanding Duhem's resistance to atomism during the final phase of his career is the historicist arguments he presented in support of his ideal of physics.     

Re-conceiving quantum theories in terms of information-theoretic constraints

This paper examines Bub's interpretation of the foundational significance of the theorem of Clifton, Bub, and Halvorson (CBH) which characterizes quantum theories in terms of information-theoretic constraints. Bub argues that quantum theory must be re-conceived of as a principle theory of information where information is a new physical primitive, to the exclusion of hidden variable theories. I will argue, contrary to Bub, that the CBH theorem cannot be used to exclude hidden variables theories. Drawing inspiration from Bub, I sketch an alternative conception of quantum mechanics as a theory of information, but one which embraces all empirically equivalent quantum theories.     

The American Philosophical Society and the rise of astronomy in the United States in the middle of the nineteenth century

Early geological investigations in the St David's area (Pembrokeshire) are described, particularly the work of Murchison. In a reconnaissance survey in 1835, he regarded a ridge of rocks at St David's as intrusive in unfossiliferous Cambrian; and the early Survey mapping (chiefly the work of Aveline and Ramsay) was conducted on that assumption, leading to the publication of maps in 1845 and 1857. The latter represented the margins of the St David's ridge as ‘Altered Cambrian’. So the supposedly intrusive ‘syenite’ was regarded as younger, and there was no Precambrian. These views were challenged by a local doctor, Henry Hicks, who developed an idea of the ex-Survey palaeontologist John Salter that the rocks of the ridge were stratified and had formed a Precambrian island, round which Cambrian sediments (now confirmed by fossil discoveries) had been deposited. Hicks subsequently proposed subdivision of his Precambrian into ‘Dimetian’, ‘Pebidian’, and (later) ‘Arvonian’, and he attempted correlations with rocks in Shropshire, North Wales, and even North America, seeking to develop the neo-Neptunist ideas of Sterry Hunt. The challenge to the Survey's work was countered in the 1880s by the Director General, Geikie, who showed that Hicks's idea of stratification in the Dimetian was mistaken. A heated controversy developed, several amateur geologists, supported by a group of Cambridge Sedgwickians, forming a coalition of ‘Archaeans’ against the Survey. Geikie was supported by Lloyd Morgan. Attention focused particularly on Ogof Lle-sugn Cave and St Non's Arch, with theory/controversy-ladenness of observations evident on both sides. Evidence from an eyewitness student record of a Geological Society meeting reveals the ‘sanit`ized’ nature of the official summary of the debate in QJGS. Field mapping early in the twentieth century by J. F. N. Green allowed a compromise consensus to be achieved, but Green's evidence for unconformity between the Cambrian and the Dimetian, obtained by excavation, can no longer be verified, and his consensual history of the area may need revision. Unconformity between the Cambrian and the Pebidian tuffs is not in doubt, however, and Precambrian at St David's is accepted. The study exhibits features of geological controversy and the British geological community in the nineteenth century. It also furnishes a further instance of the great influence of Murchison in nineteenth-century British geology and the side-effects of his controversy with Sedgwick.     

Kepler and the Telescope

There is an uncanny unanimity about the founding role of Kepler's Dioptrice in the theory of optical instruments and for classical geometric optics generally. It has been argued, however, that for more than fifty years optical theory in general, and Dioptrice in particular, was irrelevant for the purposes of telescope making. This article explores the nature of Kepler's achievement in his Dioptrice . It aims to understand the Keplerian 'theory' of the telescope in its own terms, and particularly its links to Kepler's theory of vision. It deals first with Kepler's way to circumvent his ignorance of the law of refraction, before turning to Kepler's explanations of why lenses magnify and invert vision. Next, it analyses Kepler's account of the properties of telescopes and his suggestions to improve their designs. The uses of experiments in Dioptrice , as well as the explicit and implicit references to della Porta's work that it contains, are also elucidated. Finally, it clarifies the status of Kepler's Dioptrice vis-à-vis , classical geometrical optics and presents evidence about its influence in treatises about the practice of telescope making during roughly the first two-thirds of the seventeenth century.     

The Lunar Theories of Tycho Brahe and Christian Longomontanus in the Progymnasmata and Astronomia Danica

Tycho Brahe's lunar theory, mostly the work of his assistant Christian Longomontanus, published in the Progymnasmata (1602), was the most advanced and accurate lunar theory yet developed. Its principal innovations are: the introduction of equant motion for the first inequality in order to separate the determination of direction and distance; a more accurate limit for the second inequality although requiring a more complex calculation; additional inequalities of the variation and, in place of the annual inequality in Tycho's earlier theory, a reduction in the equation of time; in the latitude theory a variation of the inclination of the orbital plane and an inequality of the motion of the nodes; a reduction in the range of variation of distance, parallax, and apparent diameter. Some of these were already present in Tycho's earlier lunar theory (1599), but all were changed in notable ways. Twenty years later Longomontanus published a modified version of the lunar theory in Astronomia Danica (1622), for the purpose of facilitating the calculation through new correction tables, and also explained his reasons for parts of the theory in the Progymnasmata. This paper is a technical study of both lunar theories.