Present Future
I’m excited to present some new work on “Global Spacetime Similarity” at the IPP2 at UC Irvine later this week (March 20 & 21). Here’s the abstract for my talk:
There are two classes of topologies most often placed on the space of Lorentz metrics on a fixed manifold. As I interpret a complaint of Geroch (1970, 1971), however, neither of these standard classes correctly captures a notion of global spacetime similarity. In particular, Geroch presents examples to illustrate that one class, the compact-open topologies, in general seems to be too coarse, while another, the open (Whitney) topologies, in general seems to be too fine. After elaborating further the mathematical and physical reasons for these failures, I then construct a topology that succeeds in capturing a notion of global spacetime similarity and investigate some of its mathematical and physical properties.
Beyond the intrinsic value of being able to compare spacetimes globally, having such a notion also provides a way to make the concept of an approximate (global) spacetime symmetry precise. Cosmologists and astrophysicists often idealize certain systems of interest (e.g., the universe or an isolated star or black hole) as having particular perfect symmetries, such as being homogeneous and isotropic, or static and spherical symmetric. One would like to say something definite about why (certain) inferences from these idealized models can produce reliable knowledge about their physical target systems. I take part of the story to consist in an account of which kinds of inferences are stable when one moves from perfect to approximate symmetry.
After the conference, from March 23 to April 15, I’ll be in the Steel City to visit Profs. Robert Batterman and John D. Norton at the University of Pittsburgh’s Departments of Philosophy and History and Philosophy of Science, respectively. This trip is the second part of the DDIG-sponsored excursion I’ve mentioned before. I’m looking forward to much discussion about idealization, approximation, and intertheoretic reduction in the physical sciences with them and other dear colleagues at the beautiful Cathedral of Learning.
Near Future
But the biggest and most exciting pieces of news of the season come from Bavaria and the Upper Midwest! In late June I will join the Munich Center for Mathematical Philosophy at Ludwig Maximilians Universität for 14 months as a Marie Curie Fellow. Specifically, I will be supported through an International Incoming Fellowship from the Marie Curie Actions program of the European Commission. I’d encourage other researchers in philosophy to check out this program: although the fellowships are very competitive, they provide some of the most generously funded research opportunities in Europe.
Then, in late August of 2015, I will move to the Minneapolis/St. Paul area to join the Department of Philosophy at the University of Minnesota, Twin Cities as an Assistant Professor. I’m especially eager to work with my new colleagues there to provide outstanding curricula for students and to be part of all the exciting things happening at the Minnesota Center for Philosophy of Science.
Samuel C. Fletcher 