Oberlin College and Conservatory

Department of Physics & Astronomy Lecture Series

Wednesday, November 6, 2019 at 4:35pm to 5:45pm

Wright Laboratory of Physics, Wright Lecture Hall, W201
110 N. Professor Street, Oberlin, OH 44074

"Science on the Edge:  Critical Phenomena in Granular Systems" is the title of the talk to be presented by Susan Y. Lehman, professor of physics at the College of Wooster.

Abstract:  A granular system behaves in some ways like a liquid with an ability to flow, and in some ways like a solid with a stable fixed structure if undisturbed.  A tiny stimulus to the pile most often results in only a small response, but the same small stimulus can also create an unpredictable and catastrophic collapse of the pile. 

These collapses occur both in natural settings, with hazards such as landslides and snow avalanches, and in industrial situations, where granular materials like sand or agricultural grains need to flow freely.  We use a simple experimental system – a 3D conical pile of uniform beads – in order to model these real-world physical systems. 

We investigate the dynamic response of the pile by recording avalanches from the pile over the course of tens of thousands of bead drops.  The resulting behavior is well-characterized by universal power laws and scaling functions, relating this work to the broader study of critical systems.

A reception for Professor Lehman begins at 4:10 p.m. in the Anderson Lounge, Wright Lab, second floor.

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Academic, Physics and Astronomy

Photo Alternate Text

speaker, Susan Y. Lehman sitting on a rock overlooking a hillside.

Contact Person

Diane Doman

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