The invasion of physics by information theory

27 10/2014

Monday, 27 Oct. 2014, 17:30 - 19:00

Presenter: Rob Spekkens
Host: Caslav Brukner
Where: Lise-Meitner-Hörsaal, 1. Stck., Strudelhofgasse 4, Wien

Many revolutions in physics have been preceded by the discovery of a novel perspective on an existing physical theory. The discovery of least-action principles, symmetry principles, and thermodynamic principles are good historical examples.  Information-theoretic principles may well play a similar role in physics today. To make the case for this idea, I will discuss some of the highlights of two resource theories: the resource theory of asymmetry, which characterizes the relations among quantum states that break a symmetry; and the resource theory of athermality, which characterizes the relations among quantum states that deviate from thermal equilibrium.  In particular, I will discuss how Noether's theorem does not capture all of the consequences of symmetries of the dynamics, and how the second law of thermodynamics does not capture all of the constraints on thermodynamic transitions. Finally, I will show that both asymmetry and athermality are informational resources, and that rehabilitated versions of Noether's theorem and the second law can both be understood as constraints on data processing. Considerations such as these---as well as evidence from other fronts of the invasion---make a compelling case for the revolutionary cause of reconceiving physics from an information-theoretic perspective.