Linking 'The Book of Nature' and 'The Book of Science': Using Circular Motion as an "Exemplar" beyond the Textbook.

Abstract

Bacon exhorted the natural philosophers of his day to read and interpret the 'book of nature' by clever and cunning experimentation. The increasing scientific activity after Bacon and Galileo, however, quickly produced a second book. This was a book of interpretations of nature, namely the 'the book of science'. Newton went beyond Bacon and Galileo and developed an ongoing dialogue between these two books, a repeated give and take between mathematical construct and physical reality. Unfortunately, the physics textbook, the 'book of science' the students read, does not acquaint them with this style of reasoning. As an example of high-grade scientific thinking this paper discusses Newton's long struggle with the concepts of inertia and especially of 'centrifugal force'. In his quest to understand the dynamics of circular motion Newton clearly progressed through four levels of conceptualizations, leading to progressively less severe discrepancies, in his ascent to a full understanding of centripetal acceleration. While it is not possible or desirable to expect teachers or students to recapitulate high-grade scientific thinking, partial retelling of the intellectual struggle that was involved in establishing important scientific concepts must be seen as important. This kind of pedagogy, however, requires that physics teachers have a good understanding of the history of scientific ideas as well as the findings of cognitive science. 1. The 'Book of Nature' and 'The Book of Science' On the eve of the Scientific Revolution, Sir Francis Bacon condemned the uncritical acceptance of Aristotelian physics and of scientific dogma in general. The failure of Aristotle's methods, he claimed, was due to the misreading of Aristotle. Rather than observe nature as Aristotle advocated, Bacon charged that Aristotelians studied only the deductive consequences of his first principles. This dogmatic theorizing, he argued, cut off the interrogation of nature (science) from its empirical base. In his influential book Novum Organum, Bacon exhorted scientists (natural philosophers) to read and interpret the 'book of nature'. Bacon insisted that we must "put Nature to the rack" by clever and cunning experimenting. He believed that the secrets written in the 'book of nature' are accessible to us and that the phenomena we observe can be described and catalogued through imaginative clas- sification. Moreover, he argued that regularity in nature can be captured by careful