Jim talks with Nick Ormrod and V. Vilasini about their use of categorical probability theory to analyze the measurement problem. We discuss categorical probability theory, which allows them to abstract from particular mathematical formulations of quantum mechanics to more general ideas about states and measurements and observers than found in Hilbert space formulations. They use this to look at the various properties of quantum mechanics and how they relate to each other, in particular how relativity affects the measurement problem.Show Notes: http://frontiers.physicsfm.com/75