July 2013 - philphysmunich

Talk by James Owen Weatherall at MCMP (Fri. 19. July)
by Dardashti, Radin July 13, 2013

July 13, 2013

Speaker: James Owen Weatherall (UC Irvine) Friday 19th July 2013 Ludwigstr.31 Room E021 Time: 6 to 8 pm Title: Inertial Motion, Explanation, and the Foundations of Classical Space-time Theories. Abstract: There is an influential view in physics and philosophy of physics, originating with Einstein and Eddington, that holds that general relativity is distinctive in the history of physics because it can be used to "explain" inertial, or unforced, motion. In this talk, I will describe how a reformulation of Newtonian gravitation may be used to provide insight into claims concerning the (allegedly) distinctive explanatory resources of relativity theory. I will then argue that Newtonian gravitation can be understood to explain inertial motion in much the same way as general relativity. However, a careful comparative study of the status of inertial motion in the two theories reveals that neither explanation is as clean or straightforward as adherents to the view noted above believe. I will conclude by presenting a view about the interdependencies of the central principles of physical theories that I will argue provides some insight into a sense in which inertial motion is explained in both of these theories.

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Talk by Michael Stoeltzner at MCMP (Wed. 17. July)
by Dardashti, Radin July 11, 2013

July 11, 2013

Speaker: Michael Stoeltzner (South Carolina) Wednesday 17th July 2013 Ludwigstr.31 Room E021 Time: 6 to 8 pm Title: Feynman Diagrams as Models Abstract: While Feynman considered his diagrams as pictorial representation of (real and virtual) physical processes, Dyson took then as a mere bookkeeping tool for mathematical expressions in a perturbation series. This split perspective has persisted since, especially when Feynman diagrams gradually extended their sway into modern particle physics. I argue that the modern debates on models in science can build a bridge between both perspectives by granting Feynman diagrams some explanatory autonomy and representative features. While a single Feynman diagram remains isomorph to a mathematical expression, it also represents a family of diagrams that model a measurable physical effect.

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Talk by Tom Pashby at MCMP (Thu. 11. July)
by Dardashti, Radin July 6, 2013

July 6, 2013

Speaker: Tom Pashby (Pittsburgh) Wednesday 11th July 2013 Ludwigstr.31 Room E021 Time: 6 to 8 pm Title: Letting Things Happen: Quantum Mechanics as a Theory of Events Abstract: In this paper I argue for two controversial claims. The first is that Ordinary Quantum Mechanics, which represents observables by self-adjoint operators on a Hilbert space and propositions by projections, is inadequate for the description of many experimental setups involving non-instantaneous measurements. Ordinary QM thus fails to be empirically adequate. The second claim is that quantum mechanics, properly understood, is not a theory of wavefunctions and their dynamical evolution but of conditional probabilities for the occurrence of events at particular times. Moreover, I argue that the second claim follows from addressing the first. That is, I claim that in order to accommodate experiments of the type that Ordinary QM fails to describe one is led towards the view that quantum mechanics concerns the occurrence of physical events rather than the dynamical evolution of a material object. There are two steps in the progression. First, I advocate the use of so-called event time or time of occurrence observables, which do not correspond to self-adjoint operators. Second, to accommodate multi-case conditionalisation I advocate the use of the Extended Schroedinger Equation, which applies to functions of time and space rather than of space alone and so is not a dynamical equation for a spatial wavefunction.

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