Jean Rajchenbach
Alphonse Leroux
Laboratoire de Physique de la Matière Condensée
Université de Nice-Sophia Antipolis
France
Didier Clamond
Laboratoire Jean-Alexandre Dieudonnée
Université de Nice-Sophia Antipolis
France
Image Credit: Jean Rajchenbach, Alphonse Leroux, and Didier Clamond (CNRS and Université de Nice, France)Snapshot of a wave with five-fold symmetry in a vibrating Newtonian liquid.
Waves at the surface of water are described by a set of nonlinear equations. These nonlinearities can induce the emergence of new patterns. In this experiment, a container partly filled with a Newtonian fluid is vibrated vertically. (Newtonian fluids include most common liquids and gases; examples are water and air.) The vibrations give rise to the formation of standing waves at the free surface of the fluid, a phenomenon known as the 'Faraday instability.'
This image shows a surface wave alternating in shape between a pentagon and a star. The order of the symmetry (in this case, five) can be varied according to the frequency and amplitude of the vibrations. Surprisingly, this number does not depend on the container's size or shape. The geometry of the standing wave can be interpreted as resulting from nonlinear resonant couplings between three waves.
This project has been partially supported by CNRS, Société ACRI and Région PACA.
This image can be freely reproduced with the accompanying credit: "Jean Rajchenbach, Alphonse Leroux, and Didier Clamond (CNRS and Université de Nice, France)."
G28.00010 Observation of star-shaped surface gravity waves
Jean Rajchenbach
Physique de la Matiere Condensee CNRS UMR 7336
Universite de Nice - Sophia Antipolis
Parc Valrose
28 Avenue Valrose
06108 Nice Cedex 2
Telephone (+33) 4 92 07 67 65
Fax: (+33) 4 92 07 67 54
Email: Jean.Rajchenbach@unice.fr
Homepage: http://www.unice.fr/rajchenbach