Long-Lived Giant Number Fluctuations in a Swarming Granular Nematic

+ See all authors and affiliations

Science  06 Jul 2007:
Vol. 317, Issue 5834, pp. 105-108
DOI: 10.1126/science.1140414

You are currently viewing the abstract.

View Full Text


Coherently moving flocks of birds, beasts, or bacteria are examples of living matter with spontaneous orientational order. How do these systems differ from thermal equilibrium systems with such liquid crystalline order? Working with a fluidized monolayer of macroscopic rods in the nematic liquid crystalline phase, we find giant number fluctuations consistent with a standard deviation growing linearly with the mean, in contrast to any situation where the central limit theorem applies. These fluctuations are long-lived, decaying only as a logarithmic function of time. This shows that flocking, coherent motion, and large-scale inhomogeneity can appear in a system in which particles do not communicate except by contact.

View Full Text