Understanding and controlling solution flows is vital to studies of crystal growth. The flow appears to be caused by differences in the density of solutions which, in the presence of gravity, create fluid motion around the growing crystal. The solution nearest the crystal surface deposits its chemical material onto the crystal surface, thereby reducing the molecular weight of the solution. The lighter solution tends to float upward, thus creating fluid motion. This experiment recreates the phenomenon of gravity-driven fluid motion and makes it visible.

This animation demonstrates the behavior of unsalted, colored plain water in a beaker-full of salt water. An mpeg (0.15 MB) or quicktime movie (1.2MB) is available of this same experiment. (Set the frame rate to 6 frames per second or slower to see the buoyancy-driven convection best. To see movies of liquid convection in low gravity, read the tutorial!

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