Sadia, in her four episodes on unsolved problems in physics (first episode here), was clearly heavily inspired by the work of Julian Barbour. So we invited Julian to join us for an episode and got a chance to ask him questions about his theories. Julian is a world-renowned physicist and author of several books on physics including The Janus Point, The End of Time, and The Discovery of Dynamics.  His theories include a challenge to the prevailing theory of entropy (i.e. heat death) and even hint at possible apparent teleology in cosmology (in this case a tendency towards novelty and variety.) We are very excited to have him on the show and to answer our questions about his theories.