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] and models , 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 . 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)

A new method was devised to test object permanence in young infants. Fivemonth-old infants were habituated to a screen that moved back and forth through a 180-degree arc, in the manner of a drawbridge. After infants reached habituation, a box was centered behind the screen. Infants were shown two test events: a possible event and an impossible event. In the possible event, the screen stopped when it reached the occluded box; in the impossible event, the screen moved through the space (...) occupied by the box. The results indicated that infants looked reliably longer at the impossible than at the possible event. This hnding suggested that infants (1) understood that the box continued to exist, in its same location, after it was occluded by the screen, and (2) expected the screen to stop against the occluded box and were surprised, or puzzled, when it failed to do so. A control experiment in which the box was placed next to the screen provided support for this interpretation of the results. Together, the results of these experiments indicate that, contrary to Piaget’s (1954) claims, infants as young as 5 months of age understand that objects continue to exist when occluded. The results, also indicate that 5-month-old infants realize that solid objects do not move through the space occupied by other solid objects. (shrink)

Prior to the twentieth century, theories of knowledge were inherently perceptual. Since then, developments in logic, statis- tics, and programming languages have inspired amodal theories that rest on principles fundamentally different from those underlying perception. In addition, perceptual approaches have become widely viewed as untenable because they are assumed to implement record- ing systems, not conceptual systems. A perceptual theory of knowledge is developed here in the context of current cognitive science and neuroscience. During perceptual experience, association areas in the (...) brain capture bottom-up patterns of activation in sensory-motor areas. Later, in a top-down manner, association areas partially reactivate sensory-motor areas to implement perceptual symbols. The stor- age and reactivation of perceptual symbols operates at the level of perceptual components – not at the level of holistic perceptual expe- riences. Through the use of selective attention, schematic representations of perceptual components are extracted from experience and stored in memory (e.g., individual memories of green, purr, hot). As memories of the same component become organized around a com- mon frame, they implement a simulator that produces limitless simulations of the component (e.g., simulations of purr). Not only do such simulators develop for aspects of sensory experience, they also develop for aspects of proprioception (e.g., lift, run) and introspec- tion (e.g., compare, memory, happy, hungry). Once established, these simulators implement a basic conceptual system that represents types, supports categorization, and produces categorical inferences. These simulators further support productivity, propositions, and ab- stract concepts, thereby implementing a fully functional conceptual system. Productivity results from integrating simulators combinato- rially and recursively to produce complex simulations. Propositions result from binding simulators to perceived individuals to represent type-token relations. Abstract concepts are grounded in complex simulations of combined physical and introspective events. Thus, a per- ceptual theory of knowledge can implement a fully functional conceptual system while avoiding problems associated with amodal sym- bol systems. Implications for cognition, neuroscience, evolution, development, and artificial intelligence are explored. (shrink)

We will examine Kepler's use of a relation between velocity and distance from a centre of circular motion. This relation plays an essential role, through a derivation in chapter 40 of the Astronomia Nova, in the presentation of the Area Law of planetary motion. Kepler transcends ancient and contemporary applications of the distance-velocity relation by connecting it with his metaphysical commitment to the causal role of the Sun. His second main innovation is to replace the astronomical models of his predecessors (...) with an account that derives trajectories from physical principles. In this paper we restrict our attention primarily to the first 40 chapters of Kepler's Astronomia Nova. Hence, we do not discuss Kepler's discovery of elliptical planetary orbits. (shrink)

I propose a new perspective on the study of scientific revolutions. This is a transformation from an object-only perspective to an ontological perspective that properly treats objects and processes as distinct kinds. I begin my analysis by identifying an object bias in the study of scientific revolutions, where it takes the form of representing scientific revolutions as changes in classification of physical objects. I further explore the origins of this object bias. Findings from developmental psychology indicate that children cannot distinguish (...) processes from objects until the age of 7, but they have already developed a core system of object knowledge as early as 4 months of age. The persistence of this core system is responsible for the object bias among mature adults, i.e., the tendency to apply knowledge of physical objects to temporal processes. In light of the distinction between physical objects and temporal processes, I redraw the picture of the Copernican revolution. Rather than seeing it as a taxonomic shift from a geocentric to a heliocentric cosmology, we should understand it as a transformation from a conceptual system that was built around an object concept to one that was built around a process concept. (shrink)

This paper offers a solution to a problem in Herschel studies by drawing on the dynamic frame model for concept representation offered by cognitive psychology. Applying the frame model to represent the conceptual frameworks of the particle and wave theories, this paper shows that discontinuity between the particle and wave frameworks consists mainly in the transition from a particle notion ‘side’ to a wave notion ‘phase difference’. By illustrating intraconceptual relations within concepts, the frame representations reveal the ontological differences between (...) these two concepts. ‘Side’ is an object concept built on spatial relations, but ‘phase difference’ is an event concept built on temporal relations. The conceptual analyses display a possible cognitive source of Herschel’s misconception of polarization. Limited by his experimental works and his philosophical beliefs, Herschel comprehended polarization solely in terms of spatial relations, which prevented him from replacing the object concept ‘side’ with the event concept ‘phase difference’, and eventually resulted in his failure to understand the wave account of polarization.Author Keywords: Herschel; Polarization; Object concept; Event concept; Frame; Cognitive psychology. (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)

: We question the claim, common since Duhem, that sixteenth century astronomy, and especially the Wittenberg interpretation of Copernicus, was instrumentalistic rather than realistic. We identify a previously unrecognized Wittenberg astronomer, Edo Hildericus (Hilderich von Varel), who presents a detailed exposition of Copernicus's cosmology that is incompatible with instrumentalism. Quotations from other sixteenth century astronomers show that knowledge of the real configuration of the heavens was unattainable practically, rather than in principle. Astronomy was limited to quia demonstrations, although demonstration propter (...) quid remained the ideal. We suggest that Osiander's notorious preface to Copernicus expresses these sixteenth century commonplaces rather than twentieth century instrumentalism, and that neither `realism', nor `instrumentalism', in their modern meanings, apply to sixteenth century astronomy. (shrink)

A highly condensed account of the author's present view of some philosophical problems unresolved in The Structure of Scientific Revolutions. The concept of incommensurability, now considerably developed, remains at center stage, but the evolutionary metaphor, introduced in the final pages of the book, now also plays a principal role.

A highly condensed account of the author's present view of some philosophical problems unresolved in The Structure of Scientific Revolutions. The concept of incommensurability, now considerably developed, remains at center stage, but the evolutionary metaphor, introduced in the final pages of the book, now also plays a principal role.

: This paper offers my current view of a joint research project, with Bernard R. Goldstein, that examines Kepler's unification of physics and astronomy. As an organizing theme, I describe the extent to which the work of Kepler led to the appearance of the form of Copernicanism that we accept today. In the half century before Kepler's career began, the understanding of Copernicus and his work was significantly different from the modern one. In successive sections I consider the modern conception (...) of Kepler's contribution to Copernicanism, the most influential sixteenth century view of Copernicus's work and its sequel, Kepler's work from the viewpoint of this tradition, and finally the historical origins of the modern view of Copernicanism. (shrink)

Thomas Kuhn's, book The Copernican Revolution deserves to be regarded as the best of that small group of longue duree histories that mark postwar historiography of science. In many respects, it is probably the single most influential one. Tightly written and brilliantly argued, it is responsible, together with The Structure of Scientific Revolutions, for the continued popularity of the metaphor of revolution in science among scholars and students alike. Yet, surprisingly, while aspects of the story conceived in Kuhn's original account (...) have been debated, researched, and considerably revised, his overall understanding of a scientific revolution initiated by Copernicus has received no detailed scrutiny. The same may be said of the deployment of Copernican episode in Structure. Finally, a critical appreciation is in order not least because Kuhn's story is so compact and his language at times metaphorical. (shrink)

I argue that Copernicus accepted the reality of celestial spheres on the grounds that the equant problem is unintelligible except as a problem about real spheres. The same considerations point to a number of generally unnoticed liabilities of Copernican astronomy, especially gaps between the spheres, and the failure of some spheres to obey the principle that their natural motion is to rotate. These difficulties may be additional reasons for Copernicus's reluctance to publish, and also stand in the way of strict (...) realism as applied to De Revolutionibus, although a realistic astronomy may be envisioned as a goal for Copernicus's research program. (shrink)