Moving Pattern Formation from the Real World to the Lab, and the Reverse
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 laboratory icicles determined the motion of their ripples. 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.
Stephen Morris, University of Toronto, Canada
Collaborators: Antony Szu-Han Chen, Nicolas Taberlet, Jim McElwaine, Lucas Goehring and L. Mahadevan