In separate reviews of The Copernican Question published in the Summer 2012 issue of this journal, Noel Swerdlow and John Heilbron find little that meets their approval while failing to provide readers with a full and accurate summary of the book’s major claims and arguments.* The reviewers engage in an exercise in deconstructive surgery, essentially breaking down and reconstituting the work into separate studies. Swerdlow, who devotes most of his twenty-five page treatment to chapter 3 (with brief side-glances at the (...) introduction, chapters 1, 8, and 11), leaves the impression that my book is almost entirely about Copernicus. Heilbron, who confines himself mostly to what I have to say about Galileo, identifies a .. (shrink)

General discussions of the appropriate relations between history and philosophy of science must be complemented by examinations of particular studies involving both fields. Martin Curd's attempt to illuminate the rationality of theory change through analysis of the Copernican Revolution is such a study; his work is undercut by serious flaws and actually displays an ahistorical approach. The result misleads both about the Copernican Revolution and the general problem of theory change in science. The study does illustrate several types of failing (...) that can vitiate efforts to bring historical considerations into philosophical discussion, namely, pitfalls in the characterization of theories, arguments, range of choices, and criteria. (shrink)

Attempts to find perennial elements in Aristotle’s cosmology are doomed to failure because his distinction of sub- and supra-lunary realms no longer holds. More fruitful approaches to the contemporary importance of Aristotelian cosmology must focus on parities of reasoning rather than content. This paper highlights the striking parallels between Aristotle’s use of symmetry arguments in cosmology and instances of Noether’s First Theorem in contemporary physics. Both observe simple motion, find symmetries in that motion, argue from those symmetries to notions of (...) conservation, and then conclude to cosmological structure. These parallels reveal an enduring relevance for Aristotelian cosmology that does not depend on positing an enduring content to his cosmological claims. (shrink)

Distortion of Scientific Terms by Supposed Modernizing Translations: The Example ‘orbis’ (sphere)/‘orbita’ (orbit). The use of modern terminology and thinking hinders to understand historic astronomical and physical texts and often misleads the reader, because between celestial physics from Aristotle and Ptolemy to Copernic on the one side and since Kepler and Newton on the other side a fundamental change of paradigm had taken place. The former started from the assumption that planets are indirectly moved by large equally rotating etherical spheres (...) combined with each other to form every kind of unequally apparent planetary motion as a resultant, whereas the later started from Kepler's idea that every motion of a planet is directly caused by two forces moulding his (naturally unequal) ‘orbit’. ‘orbita’ was Kepler's new specific term for the way of the planet coined in late 1604; in contrast, the Latin term of the elder paradigm has been ‘orbis’ (‘sphere’), on the one hand as concentric ‘orbis totalis’ of a planet (or the fixed stars), on the other hand as non‐concentric ‘orbes particulares’ (of the eccenters and epicycles) within the space of an ‘orbis totalis’. These terms were interpreted and translated in accordance with modern dynamic (as the supposed ‘true’) thinking as if they were ‘orbits’ (German: ‘Bahn’). But you cannot bring the two paradigms into line. As a result, the texts of seemingly ‘modern’ translations become incomprehensible, absurd and wrong. The study shows this on thinking (1st) about Aristotelian physics of former times using terms and ideas of modern dynamics, and on thinking (2nd) about the former explanation of apparent motions of heavenly bodies using these dynamics and ignoring the different special Aristotelian and Ptolemaic physics of ‘orbes’ (spheres). (shrink)

: This study of the concept of orbit is intended to throw light on the nature of revolutionary concepts in science. We observe that Kepler transformed theoretical astronomy that was understood in terms of orbs [Latin: orbes] (spherical shells to which the planets were attached) and models (called hypotheses at the time), by introducing a single term, orbit [Latin: orbita], that is, the path of a planet in space resulting from the action of physical causes expressed in laws of nature. (...) To demonstrate the claim that orbit is a revolutionary concept we pursue three lines of argument. First we trace the origin of the term; second, we document its development and specify the meaning of the novel term as it was introduced into astronomy by Kepler in his Astronomia nova (1609). Finally, in order to establish in what sense the concept is revolutionary, we pay attention to the enduring impact that the concept has had on the relevant sciences, in this case astronomy and indeed physics. We claim that orbit is an instance of a revolutionary concept whose provenance and use can provide the insights we are seeking. (shrink)

ABSTRACT Throughout the early modern period, the most widely read astronomical textbooks were Johannes de Sacrobosco's De sphaera and the Theorica planetarum, ultimately in the new form introduced by Georg Peurbach. This essay argues that the images in these texts were intended to develop an “intelligent eye.” Students were trained to transform representations of specific heavenly phenomena into moving mental images of the structure of the cosmos. Only by learning the techniques of mental visualization and manipulation could the student “see” (...) in the mind's eye the structure and motions of the cosmos. While anyone could look up at the heavens, only those who had acquired the intelligent eye could comprehend the divinely created order of the universe. Further, the essay demonstrates that the visual program of the Sphaera and Theorica texts played a significant and hitherto unrecognized role in later scientific work. Copernicus, Galileo, and Kepler all utilized the same types of images in their own texts to explicate their ideas about the cosmos. (shrink)

ABSTRACT Throughout the early modern period, the most widely read astronomical textbooks were Johannes de Sacrobosco's De sphaera and the Theorica planetarum, ultimately in the new form introduced by Georg Peurbach. This essay argues that the images in these texts were intended to develop an “intelligent eye.” Students were trained to transform representations of specific heavenly phenomena into moving mental images of the structure of the cosmos. Only by learning the techniques of mental visualization and manipulation could the student “see” (...) in the mind's eye the structure and motions of the cosmos. While anyone could look up at the heavens, only those who had acquired the intelligent eye could comprehend the divinely created order of the universe. Further, the essay demonstrates that the visual program of the Sphaera and Theorica texts played a significant and hitherto unrecognized role in later scientific work. Copernicus, Galileo, and Kepler all utilized the same types of images in their own texts to explicate their ideas about the cosmos. (shrink)

This paper examines the correspondence and contacts between Galileo and a number of French intellectuals. It demonstrates that exchanges between Galileo and those Frenchmen did much to stimulate an interest in new scientific ideas in France, especially in astronomy; for example, Galileo provided a number of good telescopic lenses that did much to establish observational astronomy in France. The Frenchmen for their part provided Galileo with considerable useful information. Several were very active in his support after the condemnation of 1633 (...) and in publishing his later works. The paper further demonstrates the extent of the network of intellectuals who corresponded with Galileo and each other across Europe in the early seventeenth century. (shrink)

Discutindo acerca das centenas de detecções de planetas extrassolares, que supostamente aconteceram desde 1989 e que ele considera (incorretamente) como instâncias de observações, Peter Kosso disse, justamente, que segundo os parâmetros de Bas van Fraassen esses objetos celestes seriam observáveis. Ora, tais astros poderiam sem dúvida ser observados diretamente (sem a necessidade de instrumentos), nas condições apropriadas. Mas, acrescenta Kosso, “esse tipo de epistemologia externalista, que permite que a justificação se baseie em informação que não temos a disposição (nós não (...) estamos em condição de ver planetas extrassolares a olho nu [atualmente]), não ajuda a decidir quais particulares afirmações científicas garantem a crença” (Kosso 2006, 225, nota 1). Van Fraassen provavelmente incorre em uma petição de princípio não muito diferente daquelas que ele muitas vezes desmascarou em textos de autores realistas, quando apela para o fato de o objeto detectado ser observável, para atribuir o estatuto de ‘observação’ a uma certa detecção. O ponto é, mais uma vez, entender o que vale como observação, particularmente quando isso envolve o uso de algum instrumento. Endossar aquilo que Otávio Bueno chama de ‘padrão internalista’ parece garantir solidez à qualificação de determinadas ações como observações. Uma das principais consequências dessa adoção é que tal critério, não operando nenhuma distinção relevante entre detecções ‘diretas’ e detecções mediadas por instrumentos, permite que a linha que separa observáveis e inobserváveis seja traçada de maneira diferente de como van Fraassen acredita que deveria ser, abarcando, entre os observáveis, mais (tipos de) entidades do que esse parece estar disposto a admitir. (shrink)