Granular Sand by Julien Chopin, PhD Candidate in Physics

Abstracts of Talks for College Visits

Members of our department have prepared talks oriented to undergraduate physics majors at New England colleges and universities. We generally require 2-4 weeks notice and are willing to drive a maximum of 3-4 hours.

Please contact Sujata Davis at 508-793-7169 to arrange a visit by one of our faculty.

Charles Agosta
"Playgrounds for electrons: Organic conductors in high magnetic fields."
It is surprising that organic materials can act as good metals, but the fact that organic conductors are also superconductors at low temperature is amazing. I will discuss superconductivity and other correlated electron states found in organic conductors as well as methods for generating record breaking magnetic fields that can be used to investigate these materials.

Arshad Kudrolli
"Physics in a sand box"
Why are Brazil nuts found near the top of a can of mixed nuts? What causes an avalanche of rocks or snow? These systems are a collection of grains and examples of granular matter. The behavior of a single grain is easily understood, but the properties of a collection of grains is very complex. I will demonstrate and discuss a surprising range of collective behavior such as convection, size separation, and pattern formation displayed by granular materials.

Ranjan Mukhopadhyay
"Physics of Red Blood Cells"
A human red blood cell normally assumes the shape of a flattened biconcave disc. However, it has been known for more than 50 years that, under a variety of chemical or physical treatments, the cell undergoes a sequence of dramatic (but reversible) shape transformations. Because a red blood cell has no internal structure, its shape is governed by the physics of its membrane. Using simple physical models, we can compute the full sequence of shapes; the computed shapes are in surprisingly detailed agreement with observations. I will discuss how our results make it possible to use shape transformations as a quantitative tool to probe the physics and biochemistry of cell membranes.