This is the editors' introduction to a new anthology of commissioned articles covering the various branches of philosophy of physics. We introduce the articles in terms of the three pillars of modern physics: relativity theory, quantum theory and thermal physics. We end by discussing the present state, and future prospects, of fundamental physics.

[Abstract and PDF at the Pittsburgh PhilSci Archive] A slightly shorter version of this paper is to appear in a volume edited by Jonathan Barrett, Adrian Kent, David Wallace and Simon Saunders, containing papers presented at the Everett@50 conference in Oxford in July 2007, and the Many Worlds@50 meeting at the Perimeter Institute in September 2007. The paper is based on my talk at the latter meeting (audio, video and slides of which are accessible here).

Highlighting main issues and controversies, this book brings together current philosophical discussions of symmetry in physics to provide an introduction to the subject for physicists and philosophers. The contributors cover all the fundamental symmetries of modern physics, such as CPT and permutation symmetry, as well as discussing symmetry-breaking and general interpretational issues. Classic texts are followed by new review articles and shorter commentaries for each topic. Suitable for courses on the foundations of physics, philosophy of physics and philosophy of science, (...) the volume is a valuable reference for students and researchers. (shrink)

This is the review paper for the section III ("Symmetry breaking") of the volume "Symmetries in physics: philosophical reflections", Cambridge University Press, 2003, edited by Katherine A. Brading and Elena Castellani. The paper's sections are: 1. Preliminaries (I); 2. Symmetry breaking and Curie's analysis; 3. Preliminaries (II); 4. Symmetry breaking of physical laws (4.1. Explicit symmetry breaking; 4.2. Spontaneous symmetry breaking); 5. Symmetry breaking and philosophical questions.

In a famous paper in Noûs in 1979, John Perry points out that action depends on indexical beliefs. In addition to “third-person” information about her environment, an agent need “first-person” information about where, when and who she is. This conclusion is widely interpreted as a reason for thinking that tensed claims cannot be translated without loss into untensed language; but not as a reason for realism about tensed facts. In another famous paper in the same volume of Noûs, Nancy (...) Cartwright argues that action requires that agents represent their world in causal terms, rather than merely probabilistic terms: for, Cartwright argues, there’s a distinction between effective and ineffective strategies, that otherwise goes missing. This is widely taken as a reason for thinking that causal claims cannot be translated without loss into merely probabilistic claims; and also – in contrast to Perry’s case – widely regarded as a reason for realism about causation. In this paper I ask whether the latter conclusion is compulsory, or whether, as in Perry’s case, the need for causal beliefs might merely reflect some “situated” aspect of a decision-maker’s perspective. (shrink)

Abstract Galileo Then and Now (Draft of paper to be discussed at the Conference, HPD1, to be held at the Center for Philosophy of Science, University of Pittsburgh, 11-14 October 2007) William R. Shea, University of Padua The aim of this paper is to stimulate discussion on how shifts in philosophical fashion and societal moods tell us not only what to read but how to go about it, and how history and philosophy of science can jointly deepen our grasp of (...) the issues at stake. The first part highlights some of the things that have occurred in the field of Galileo studies between the monumental edition of Galileo Opere in twenty volumes, edited by Antonio Favaro between 1890 and 1909, and the new enlarged edition that will be published from 2009 onwards by a team of scholars working under Paolo Galluzzi. Part One. From Favaro to Galluzzi "Publish or perish" is an injunction that resonated as clearly in the ears of assistant professors at the end of the 19th century as it does in the first decade of the 21st. But publishing can also mean perishing when what is being edited is the work of an eminent scientist of the past. It simply does not do to offer material that is not what readers expect even if it was written by someone as famous as Galileo, and well authenticated sources were sometimes disregarded when they appeared to be of no interest. It is largely for this reason that a new national edition of Galileo's works is required. Of course, over the last hundred years, a number of letters from and to Galileo as well as a few laudatory or damning comments about his personality or his work have been uncovered, but this would not have been enough to drum up financial and scholarly support for a major editorial project. But the interesting material is Favaro had left out. Before mentioning what this material is, allow me a disclaimer. I'm not focusing on Favaro because he is a singularity, but because he illustrates how a conscientious historian can ride slipshod over evidence because of a philosophical commitment that he is only vaguely aware of, in this case naïve positivism. So what did Favaro to leave out? The answer is large chunks of three collections of manuscript notes that are bound in some of the 347 volumes of the Galilean material in the National Library in Florence. The first of these collections deals with logical treatises and related essays on Aristotelian philosophy, the second with Galileo's laboratory notes on the experiments that he carried out on the pendulum and inclined planes; and the third with astrological computations. Favaro rejected the first collection because they were "pre-Galilean" and hence could only have been trite scholastic exercises that "poor" young Galileo had to undergo in high school. He neglected the second because he had trouble making sense of them The third, astrological collection, he set aside with more trepidation since Galileo cast horoscopes for himself (at least twice), his children and his friends. But the fact that they were also, epistemologically speaking, "pre-Galilean", was enough to cast them into the outer darkness (in this case a dimly lit corridor of the National Library in Florence). The Aristotelian notes that Favaro had neglected were made available by William Wallace, who showed that Galileo culled long passages from professors at the Roman College. Galileo attacked several of Aristotle's ideas, but he never queried Aristotle's scientific realism–namely, the view that there is a uniquely true physical theory, discovered by human powers of reason and observation, and that alternative theories are consequently falls. Wallace made this the basis of his claim that Galileo created, in the heaven above and here on earth, a new science of motion by following the Aristotelian cannons laid down in the Posterior Analytics. On this view, Galileo used Aristotle's logic to subvert Aristotelian physics. It is interesting to contrast Wallace's thesis with that of philosophers of different allegiance, who offer a reconstruction of Galileo's methodology along lines that are much more modern and in which the epistemological core is no longer Aristotelian logic, but common sense instrumentalism. This is not to deny that experiments sometimes speak with a forked tongue, but to stress that methodological rules have also been known to be no more than clashing cymbals. Recent writers have also stressed that Galileo aimed his arguments at a specific audience, and that we must take cognizance of the values and whims of the society in which he operated. The sociology of science can help us understand the background against which Galileo's arguments were assessed and the reasons why he favored some rhetorical strategies over other ones. Mario Biagoli's Galileo Courtier sheds light on the Tuscan court and the Roman famiglia (as the popes styled their entourage), where Galileo found many of his readers and most of his critics. But Galileo was much more than a courtier, and I shall argue that we should use our enhanced knowledge of Galileo's education, his language, his style, and his emoluments to understand his science, not to supplant it. History and philosophy of science can combine their insights to achieve a more critical and balanced view of what actually occurred and why. (shrink)

This paper will serve as the editorial note on Einstein's 1916 review article on general relativity in a planned volume with all of Einstein's papers in Annalen der Physik. It summarizes much of my other work on history of general relativity and draws heavily on the annotation of Einstein's writings and correspondence on general relativity for Vols. 4, 7, and 8 of the Einstein edition.

Review of "The Collected Works of Eugene Paul Wigner", Volume I, III, and VI. Excerpt from the Conclusions: Many of Wigner’s papers on mathematical physics are great classics. Most famous is his work on group representations which is of lasting value for a proper mathematical foundation of quantum theory. The modern development of quantum theory (which is not reflected in Wigner’s work) is in an essential way a representation theory (e.g. representations of kinematical groups, or representations of C*-algebras). This (...) view owes very much to Wigner’s seminal papers on the unitary representations of compact and noncompact groups. Wigner showed much courage in relating the then unresolved questions of the measurement problem to the much deeper problem of consciousness. In view of this very unorthodox proposal it is astonishing that Wigner was very reactionary with respect of the dogmas of orthodox quantum mechanics. In contrast to von Neumann himself, he took the old von-Neumann codification of quantum mechanics as authoritative and not to be questioned. Much of the efforts to interpret the meaning of this codification and to prove no-go theorems, such as the insolubility of the measurement problem or the impossibility of a quantum theory of individual objects, are physically irrelevant since they are based on a codification of quantum mechanics that is valid only for strictly closed systems with finitely many degrees of freedom. However, in nature there are no such systems. Every material system is coupled to the gravitational and to the electromagnetic field – systems which require in a Hamiltonian description infinitely many degrees of freedom. A deeper insight into the conceptual problems of quantum theory is possible only if the modern development of a quantum theory of infinite systems is taken into account. (shrink)