Roger Jones

Pre-analytically, we are all scientific realists. But both philosophers and scientists become uncomfortable when forced into analysis. In the case of scientists, this discomfort often arises from quite practical difficulties in setting out a carefully described set of objects and their properties which adequately account at least for the phenomena with which they and those in their research specialty are concerned. I offer a set of representative examples of these difficulties for contemporary physicists. These examples challenge the traditional realist vision of mature scientific activity as struggling toward a clear and ontologically well-defined world picture.

Among the principles that are generally taken to underlie the general theory of relativity is a general principle of relativity. Such a principle is supposed to extend the special principle of relativity, which holds observers in uniform motion to be indistinguishable by appeal to the laws of physics, to a requirement on observers in arbitrary states of motion. Starting with physical intuitions described graphically by Galileo, proceeding through a series of formal requirements on reference frames defined on models of space-time theories, and considering other "observations" commonly associated with relativity principles, this paper argues that the general principle of relativity is neither justified by "fact", nor exemplified by the general theory of relativity.