Director – Rotman Institute of Philosophy;
Professor; Department of Philosophy, Western University
I began my undergraduate years intending to study physics. I was drawn to physics partly because physicists had obviously been so successful in discovering a great deal about nature, but also because modern physics is so strikingly creative and counterintuitive. In my freshmen year of college, I studied philosophy for the first time as part of an intensive humanities program. The first term of that course (taught by Ruth Marcus) was responsible for kindling my interest in philosophy. I discovered that it was possible to pursue both physics and philosophy, as a combined major. Thinking about these topics was exciting and rewarding enough that I decided to go on to graduate study, at Pittsburgh’s Department of History and Philosophy of Science.
HPS at Pitt was an incredibly enriching experience. HPS departments tend to be more closely aligned with either history of science or philosophy of science. A colleague in graduate school once memorably described Pitt’s department as neither “big H” (emphasis on history) nor “big P” (emphasis on philosophy), but instead “big S” (emphasis on science). Like most of my peers in graduate school, I developed the skills to do “big S”-style work by continuing to study physics. My dissertation is a historical and philosophical study of the development of early universe cosmology. This has continued to be a major focus of my research, but I also have worked on topics ranging from Newton’s work to the nature of time in Einstein’s theory of gravity. The common thread tying together all of this work is an interest in both what specific physical theories say about the world, and how we should justify and evaluate these theories.
After finishing my dissertation, I held a postdoc at the Dibner Institute (affiliated with MIT) for one year. I was then an assistant professor of philosophy for four years at UCLA before accepting a position at Western in 2007.
My research focuses on scientific method and the structure of our knowledge in physics: what is the structure and content of physical theories, how are theories evaluated and justified, and how are they extended and refined? I have tackled these general issues through the detailed study of space-time physics, focusing primarily on episodes of significant theory change ranging from Newton’s Principia to contemporary cosmology. My work also addresses an important topic that has not received much attention from philosophers of science, namely the status of “hybrid theories” — theories combining aspects of two incompatible theories, used in lieu of an as yet undiscovered theory successfully combining them. In approaching these topics, I aim to clarify the conceptual and evidential problems that have shaped research, and to understand methodological successes and failures. I have found it fruitful to address these questions based on careful study of the historical development of physics, by looking for common epistemic strategies and patterns of argument, and considering several distinctive cases of conceptual change and theory development. My background provides me with the necessary technical tools to understand and elucidate these problems. My research on these theories has allowed me to contribute to debates in the foundations of physics regarding their interpretation and content.
Two reasons motivate my approach to issues of scientific method and the structure of theories via studies of scientific practice. First, my interest in method is broader than topics typically treated in confirmation theory or inductive logic. To use Reichenbach’s terminology, my focus is not limited to the context of justification; there are, I argue, a number of important epistemological issues in the context of discovery. For example, one of Einstein’s most productive insights was based on a careful reconsideration of the structure of Newton’s theory. Einstein’s path to general relativity was guided in part by his recognition that the equality of inertial and gravitational mass undercuts the ability to distinguish empirically between inertial motion and motion due solely to gravity. This entails that several distinctions crucial to Newton’s theory are not well-founded. Einstein’s recognition of this problem within existing theory was an important insight guiding his discovery of a new theory. The use of hybrid theories is an important part of research in the context of discovery. In both early universe cosmology and the proofs of no-go theorems related to time machines, one of the main goals is to isolate results that are expected to carry over to the undiscovered theory of quantum gravity. In both these examples, it would be a mistake to treat epistemological issues as arising only when a finished theory has been produced, and to view the task of philosophers of science as limited to analyzing the empirical support of such finished theories.
Second, the epistemic problems addressed by physicists are closely tied to the content of specific theories, whereas deracinated versions of the same problems lose much of their vitality. For example, a common claim in general discussions of method is that the use of idealizations to represent phenomena undermines claims of truth.
This is a generalized form of a problem faced routinely by physicists, namely whether they have appropriate control over the idealizations appearing in a particular theory. However, the generalized version of the argument misses the fact that physicists have developed a number of sophisticated, arguably successful responses to this problem.
This is not to deny that there is a general “problem of idealization,” but rather to insist that there are many problems of idealization — and many different, theory-specific ways of handling them. Nor do I deny the importance of stepping back from an understanding of specific cases to discuss idealization more generally, but it seems to me implausible that reversing the order of inquiry would be as fruitful. I have found careful study of the (implicit or explicit) methodology of scientists like Newton and Einstein to be rich and illuminating, much more so than attempts to tackle methodological issues at an entirely general level.
The Genesis of General Relativity, assistant editor, with J. Renn, M. Schemmel, and C. Martin. Vol. III, Theories of Gravitation in the Twilight of Classical Physics; Vol. IV, Alternative Approaches to General Relativity. Boston Studies in the Philosophy of Science, Vol. 250. Dordrecht: Springer, 2007. (2 volumes, 1,152 pages.)
“Do the Laws of Physics Forbid the Operation of Time Machines?” (with J. Earman and C. Wüthrich). Synthese 169 (2009): 91-124.
“Mie’s Theories of Matter and Gravitation,” with C. Martin. In The Genesis of General Relativity, (2007), pp. 623-632.
“The Elusive Higgs Mechanism.” Philosophy of Science 73 (2006): 487-499.
“False Vacuum: Early Universe Cosmology and the Development of Inflation,” in The Universe of General Relativity, edited by J. Eisenstaedt and A. J. Kox, Einstein Studies Vol. 11, Boston: Birkhauser (2005), pp. 223-257.
“Pendulums, Pedagogy, and Matter: Lessons from the editing of Newton’s Principia,” with Zvi Biener. Science and Education 13 (2004): 309-320. Reprinted in Matthews, M., Gauld, C., and Stinner A. (eds.), The Pendulum: Scientific, Historical, Philosophical, and Educational Perspectives (2005), Dordrecht: Springer.
“Philosophical Aspects of Black Holes.” Invited plenary talk at the Deutsche Physikalische Gesellschaft, Bonn. March 2010.
“The Limits of Evidential Reasoning in Newton’s Argument for Universal Gravitation,” with Zvi Biener. Invited speaker at Newton as/and Philosophy. Leiden, Netherlands, June 2007.
“From the H-Bomb to the Big Bang” (invited speaker). UCLA History of Science Colloquium Series, April 2007.
“Confirming Inflation?” Deutsche Physikalische Gesellschaft (invited speaker), Heidelberg, March 2007; Utrecht University Institute for the History and Foundations of Science (invited speaker), June 2007.
“Realism and Newton’s Invisible Realm.” Invited speaker at Second German-American Frontiers of the Humanities conference, sponsored by the American Philosophical Society and Humboldt Foundation. Hamburg, Oct. 2005.
“False Vacuum: Early Universe Cosmology and the Discovery of Inflation,” invited speaker at Sixth International Conference on the History of General Relativity, Amsterdam. June 2002.
“What is a Higgs Boson?,” paper given in symposium “The Higgs, Goldstone, and the LHC,’” at the European Philosophy of Science Association Conference. Vrije Universiteit, Amsterdam. October 2009. Also given at University of Wuppertal, to a seminar meeting of the research group, “Epistemology of the Large Hadronic Collider,” March 2010.
“Fine-Tuning Problems and Early Universe Cosmology,” UWO and Caltech. January 2007. “Gravitational Energy and Substantivalism.” Second Conference on the Ontology of Spacetime. Montreal, June 2006.
“Alternatives in Early Universe Cosmology.” Seventh International Conference on the History of General Relativity. Tenerife, March 2005.
“Causation and Gravitation.” UCLA conference in History and Philosophy of Science, Nov. 2004. Conference co-chair.
- Students should go to the respective course websites at WebCT / OWL for updated schedules, reading materials, and other materials.
- Philosophy 2032G: Einstein for Everyone
- Philosophy 9635: Graduate Proseminar
Previous Courses at Western
- Philosophy 2500: Introduction to Theory of Knowledge
- Philosophy 3320: Philosophy of Quantum Mechanics
- Foundations of Relativity Theory (graduate seminar)
- Explanation and Evidence (graduate seminar)
Previous Courses at UCLA
- Introduction Philosophy of Space and Time
- Philosophy of Science (introductory level)
- Historical Survey of the Philosophy of Science
- Seventeenth Century Natural Philosophy
- Philosophy of Space and Time (graduate seminar)
- Realism (graduate seminar taught with Sheldon Smith)
- Kant’s Metaphysical Foundations of Natural Science (graduate seminar taught with Sheldon Smith)