Description:

Abstract: Diffusion is pervasive in the natural world. Over one hundred years ago Einstein created a remarkably simple and powerful theory describing the behavior of a single diffusing particle. That theory has since been applied countless times to successfully model widely disparate systems. However, researchers from the University of Oregon and Columbia University believe that for large numbers of particles diffusing in the same environment, this theory does not work because it neglects the effects of the shared environment in which all particles coexist. As a consequence, the Einstein theory dramatically fails to predict the behavior of extreme diffusion, i.e. outlier particles which have moved the farthest from their starting points. The team plans to demonstrate, both experimentally and theoretically, using very different systems of colloids, fluorescent dyes, and optical photons, that systems with identical diffusion coefficients can have radically different outlier behavior dependent on the microscopic correlations present in the environment. By synthesizing their experimental measurements and theoretical results they hope to define a new extreme diffusion coefficient to succinctly describe these behaviors and thus create a new theory of Extreme Diffusion. Understanding the behavior of outliers will have wide ranging applicability to physical, biological, epidemiological, economic, and social systems where outliers often determine behavior.

Speaker: Eric Corwin, Associate Professor, University of Oregon

Host: Professor István Kovács