9511796, Robert Rynasiewicz After the introduction of special relativity, physicists have come more and more to place a special emphasis on the role of relativity and symmetry principles in theory construction. Such was quite explicit in the considerations that led Einstein to the general theory of relativity, and the identification of appropriate symmetry groups has become a central concern in theoretical particle physics. There has, however, long been disagreement within the physics community as to what it means for a theory to embody or satisfy a relativity principle. One famous critique came form Erich Kretschmann in which he published a scathing review of Einstein's characterization in terms of the from invariance of the fundamental equations under coordinate transformation and suggested that Einstein's gravitational theory, despite its general covariance, is in fact an "absolute" theory in the sense that it satisfies no non-trivial principle of relativity. Since Kretschmann's critique, there is still no consensus as to (a) what relativity principles in fact are satisfied by what is traditionally called the general theory of relativity; (b) how to characterize in general the concept of a relativity principle; or (c) what the relationship is between relativity principles and other types of symmetry principles such as gauge symmetry and time-reversal invariance. The current project aims to do two things. The first is to identify the crucial historical factors responsible for the emergence among physicists of the general ideal of a relativity principle. The second is to make some systematic progress on how such a principle should be properly sketched out, relying in particular on ideas of Kretschmann and others and also the PI's own views as developed in previous grants. The resulting study should be of interest to physicists, historians and philosophers of science.
