Comment on "Long-Lived Giant Number Fluctuations in a Swarming Granular Nematic"

doi:10.1126/science.1153456

Account Information

Guest Alerts | Access Rights | My Account | Sign In

Technical Comments

Comment on "Long-Lived Giant Number Fluctuations in a Swarming Granular Nematic"

I. S. Aranson,¹^* A. Snezhko,¹ J. S. Olafsen,² J. S. Urbach³

Narayan et al. (Reports, 6 July 2007, p. 105) reported giantnumber fluctuations attributed to curvature-driven active currentsspecific for nonequilibrium nematic systems. We present datademonstrating that similar results can be found in systems ofspherical particles due either to inelastic clustering or persistentdensity inhomogeneity, suggesting two alternative explanationsfor their results.

¹ Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.
² Department of Physics, Baylor University, One Bear Place, Box 97316, Waco, TX 76798–7316, USA.
³ Department of Physics, Georgetown University, Washington, DC 20057, USA.

^* To whom correspondence should be addressed. E-mail: aronson{at}msd.anl.gov

Read the Full Text

The editors suggest the following Related Resources on Science sites:

In Science Magazine

TECHNICAL COMMENTS Response to Comment on "Long-Lived Giant Number Fluctuations in a Swarming Granular Nematic": V. Narayan, S. Ramaswamy, and N. Menon (2 May 2008)
Science 320 (5876), 612d. [DOI: 10.1126/science.1154685]
| Abstract » | Full Text » | PDF »

REPORTS Long-Lived Giant Number Fluctuations in a Swarming Granular Nematic: Vijay Narayan, Sriram Ramaswamy, and Narayanan Menon (6 July 2007)
Science 317 (5834), 105. [DOI: 10.1126/science.1140414]
| Abstract » | Full Text » | PDF » | Supporting Online Material »