Topic: "Time: Problems and Arrows" (Video)
Abstract: After briefly reviewing some of the physicist's many problems with time, I focus on issues surrounding the "arrow of time," the directionality that dominates much of physics, and indeed almost everything else. By formulating the arrow as a preference for one kind of boundary problem over another, different thermodynamic scenarios are explored. In particular I examine situations in which regions with opposite pointing arrows could mutually survive. Simulations and other methods suggest that there could be observational tests of the presence of such matter. Signalling in a limited sense is also possible.