7 particle hexagonal cyrstal

Animations for "Ordered clusters and dynamical states of particles in a vibrated fluid"
Greg A. Voth, B. Bigger, M.R. Buckley, W. Losert, M.P. Brenner, H.A. Stone, and J.P. Gollub

This page shows animations of some of the time dependent patterns that form when spherical particles are vibrated in a fluid. The images are looking down on particles that are experiencing vertical vibrations. All the animations are taken at a vibration frequency of 20 Hz.

Animations: QuickTime format (.mov)
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1. (1.3 Mb) Time dependent dance of 7 particles, where 2 particles circle each other in the center of 5 others. The nondimensional acceleration is Gamma=3.7. The shadows on the right reveal the vertical motion of the particles since the illumination is at an oblique angle (36 degrees from vertical).

2. (0.5 Mb) Animation showing 46 particles in a hexagonal crystal at Gamma=2.9. Note that only the particles at the edges show significant motion.

3. (1.0 Mb) Here at Gamma=3.7, the particles near the edge of the cluster have been separated by the repulsion, but the center particles remain crystalized. Other measurements clearly show that the amplitude of the vertical motion of the center particles is significantly smaller than that of those at the edges.

4. (1.3 Mb) At Gamma=3.9, all the particles have separated from each other. An interesting feature of this state is that the preferred distance between particles results in the formation of filled shells. In this case there are two more particles than fit into the filled shells, so these "valence" particles move much more freely around the perimeter. Sometimes, a valence particle will exchange with an inner particle, but there are always two valence particles.

5. (1.3 MB) Here at Gamma=4.4, the motion of the particles is clearly chaotic. The cluster forms a bound state with no long range order, a mesoscopic liquid.

6. (1.3 Mb) At Gamma=5.3, the individual particles move rapidly in a chaotic manner but the cluster remains bound in a circular shape.