When a layer of soap bubbles (diameter ~1mm) is
placed on a flat glass substrate, a hexagonal pattern (or bubble raft)
is automatically formed (see image below). The soap bubble
raft is known to be a good model that demonstrates the characteristic
behavior of a 2D crystalline system. We use the bubble raft as a model
system for studying defect motion in a 2D crystaline system, and
results are compared with a theory based on the coupled
Ginzburg-Landau equations of a nonequilibrium system(L.
Tsimring, PRL, vol 74, 4201(1995).).
Tammy Tam, Darrick Ohata and Mingming Wu, Dynamics of a penta-hepta defect in a hexagonal pattern, Physical Review E, Vol 61, R9(2000). Paper in postscript file
To see a movie of defect motion, click Movie