Physics Colloquium
Friday, September 26, 2003 4 P.M.

Michael P. Marder

Department of Physics
and Center for Nonlinear Dynamics
University of Texas

How Things Break

Every child learns early that brittle objects break easily. Yet on a bit of reflection the process should seem mysterious. Weak forces applied on large length scales spontaneously break strong bonds at the atomic scale. I will begin by discussing how that occurs, and by discussing the engineering science that has grown up to explain it. Then I will move on to discuss some fracture experiments whose explanations require ideas that start with atoms and move up to the laboratory scale. These include:

• How cracks in plastic and glass go unstable,
• Why popping a balloon breaks a speed limit,
• Why silicon single crystals should break differently in liquid nitrogen and at room temperature, and finally
• How to use fracture as a testing ground for the foundations of numerical materials science.

Refreshments: 3:30 PM, E200 Math/Science Center