Philosophy of Physics Seminar (Thursday - Week 7, TT26)

Abstract: In this talk, I revisit the problem of defining spacetime singularities in classical general relativity. In particular, I argue that singularities are best conceptualized as extrinsic, non-local, but localizable, properties of spacetime regions (of any size), and that there is no unique, best definition of a singular region of spacetime. There is, however, a schema that any adequate definition instantiates. Moreover, the question of what kind of incomplete curves witness singular structure is intimately connected to the question of what kind of curves represent possible trajectories of observers in "physically reasonable" motion. Finally, I discuss a sense in which singular regions can be “small” and present a result which proves the existence of such “small” singular regions in any singular spacetime.

Registration: If you do not hold a university card, please contact the seminar convenor or admin@philosophy.ox.ac.uk at least two working days before a seminar to register your attendance.