Pacific Institute for the Mathematical Sciences - PIMS

Pattern Formation, Taken from the Real World to the Lab

This talk will describe three pattern formation experiments where natural systems were imported directly into the laboratory. The overall shape and subsequent rippling instability of icicles is a complex free-boundary growth problem. It has been linked theoretically to similar phenomena in stalactites. We grew hundreds of laboratory icicles to determine what controlled their growth dynamics. Washboard road is the result of the instability of a flat granular surface under the action of rolling wheels. The rippling of the road sets in above a threshold speed and leads to waves which travel down the road. We studied these waves both in the laboratory and using 2D molecular dynamics simulation. Columnar joints are uncanny formations of ordered cracks in certain lava flows. We studied these both in a lab analog system and in the field. Each of these three cases nicely illustrates the pleasures and pitfalls of such "naturalistic" pattern formation experiments.

Location: LSK 460

Professor Stephen Morris was an undergraduate and Master’s student in the Physics Department at UBC. He received his PhD in experimental physics at the University of Toronto, before winning a postdoctoral fellowship at theUniversity of California at Santa Barbara. He then moved back to Toronto where he has since been professor. His research spans experimental nonlinear physics, nonequilibrium an geophysical pattern formation, and the mechanics of granular media.