Speaker: Dr. Dwight Barkley

Host: Mike Schatz

Title: The spatiotemporal route to turbulence

Abstract: "What we really cannot do is deal with actual, wet water running through a pipe. That is the central problem which we ought to solve some day, and we have not."

This statement by Richard Feynman captures how the seemingly simple motion of fluid through a pipe can present such an immense scientific challenge. After years of missteps, controversies, and uncertainties, we are at long last converging on a unified and fascinating picture of the transition to turbulence in flows such as pipes, channels, and ducts. What is remarkable about this story is the connection it has established to many other complex phenomena such as epidemics, wildfires, and neuron action potentials. We now understand that the route to turbulence in many flows occurs via spatiotemporal intermittency and falls in the class of non-equilibrium statistical phase transitions known as directed percolation. In this talk I will explain the big picture of why we care about the transition to turbulence. I will the describe the spatiotemporal nature of the problem and how universality manifests itself. Finally, I will present recent theoretical work aimed at capturing the origins of these phenomena.

Bio: Dwight Barkley is a Professor of Mathematics at the University of Warwick. He obtained his PhD in Physics from the University of Texas at Austin and held postdoctoral positions at Caltech, Princeton, and ENS Lyon. His research lies at the interface of high-performance computation, pattern formation, and nonlinear phenomena. He has studied instabilities, nonlinear waves, and patterns in fluid, chemical, and biological systems. His current work focuses on the onset of turbulence and magnetic field reversals. In 2005, he was awarded the SIAM J. D. Crawford Prize. He is a Fellow of APS, SIAM, Euromech, and IMA.