Morzine: Chris Smeenk: Theories of Origins

Lecture given at the International Summer Institute in Philosophy of Physics on the Philosophy of Cosmology and the Philosophy of Quantum Gravity
Hosted by the University of Geneva - University of Illinois Chicago Cosmology Beyond Spacetime project
Morzine, France
26 June - 1 July 2022
Note: Some of the Q&A has low audio quality.
Please find the downloadable slides and links to supplementary materials at beyondspacetim....
Chris Smeenk: Theories of Origins
Abstract: There is a sharp divide between different ways of approaching a theory of the origins of the universe. One approach aims to select an initial state in some sense, rather than treating initial conditions as merely contingent facts. This ‘selection’ takes several forms, ranging from constraints needed to account for thermodynamic asymmetries (versions of the ‘Past Hypothesis’), to new theoretical principles that select a specific state (such as the no boundary proposal, or the more recent CPT symmetric universe), to (more controversially) anthropic selection from an ensemble. The opposing approach aims to minimize the impact of the initial state, by showing that dynamics with appropriate features will generate an output state with desirable features for suitably ‘generic’ initial conditions. The aim of the first lecture is to provide an overview of the more philosophical aspects of these debates, and develop an argument current versions of ‘dynamical’ theories are not self-sufficient: they require substantive constraints on the initial states, and hence require some appeal to selection.