2902 Experiments on Isotropy or Anisotropy in Growth

Friday, February 18, 2011: 8:30 AM
147A (Washington Convention Center )
Yves Couder , Ecole Normale Supérieure, Paris, France
Growth generates very different patterns, depending on whether it occurs in isotropic or anisotropic systems. In physics experiments such as viscous fingering, diffusion limited aggregation or crystal growth it had been shown, some time ago, that it was possible to shift from one type of morphology to the other simply by tuning the anisotropy at the tip of growing structures. More recently it was noticed that in plant growth, the same two archetypes could be observed. The observed anisotropy of growth of vascular plants was then shown to be self-induced. As in the physical systems the removal of this mechanism leads to isotropic growth and a completely different morphology.