Presented by: Professor Charles Wolgemuth, Professor of Physics, Professor of Molecular and Cellular Biology
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Abstract: In biology, there are many scenarios where two phases coexist in the same region. For example, the insides of our cells are composed predominantly of water, but there is also an elastic network of filaments of actin that help define cell shape and drive movement. Therefore, in any small region inside a cell, a fraction of the volume is occupied by liquid, with the remaining volume occupied by an elastic solid. As another example, many swimming bacteria live in water. If the bacteria get dense enough the fluid-bacteria system becomes an active medium with complex dynamics that appears almost turbulent at times. I will describe our work to describe the dynamics of these two-phase suspensions and how it has led us to an accurate theory for the general dynamics of suspensions. Indeed, this theory answers an over 50 year old problem in low Reynolds number fluid dynamics on the speed of a sedimenting suspension, and also takes us beyond Einstein in determining the effective viscosity of a suspension of spherical particles.
Refreshments served in PAS 218, 2:45pm - 3:00pm
Note: All Department of Physics Fall 2022 colloquium are in-person only