School of Natural Sciences
A classic problem posed by long gamma ray bursts (GRB) is that the energy output requires gravitational energy release so deep within the host star that the prompt gamma rays should, upon naive consideration, have been obscured. It is suggested that photons emitted along the direction of the emitting plasma's motion are indeed geometrically blocked by optically thick baryonic matter, and that we usually see the photons that are emitted nearly backward in the frame of the emitting plasma. Many puzzling observations concerning GRB then fall into place.
We will discuss the notion of loops in linguistic structures, mainly in dictionaries. In a simplified view, a dictionary is a graph that links every word (vertex) to a set of alternative words (the definition) which in turn point to further descendants. Iterating through definitions, one may loop back to the original word. We will examine possible links between such definitional loops and the emergence of new concepts during the evolution of languages. Potential relation to living systems will be briefly discussed.