Pendula, Models, Constructivism and Reality

Abstract

It is argued that Galileo made an important breakthrough in the methodology of science by considering idealized models of phenomena such as free fall, swinging pendula and the like, which can conflict with experience. The idealized models are constructs largely by our reasoning processes applied to the theoretical situation at hand. On this view, scientific knowledge is not a construction out of experience, as many constructivists claim about both the methods of science and about the learning of science. In fact Galileo’s models can, depending on their degree of idealization or concretization, be at variance with experience. This paper considers what is meant by idealization and concretization of both the objects and properties that make up theoretical models, and the ideal laws that govern them. It also provides brief illustrations of ideal laws and how they may be made more concrete, and briefly considers how theories and models might be tested against what we observe. Finally some difficulties are raised for a radical constructivist approach to both science and learning in the light of Galileo’s methodological approach. The upshot is that both the dialogue structure of Galileo’s writings and his method of model building provide a rich resource for science education that rivals that of the standard varieties of constructivism, and at the same time gives a much better picture of the actual procedures of science itself.