Two self-assembled colloidal clusters, as seen under the optical microscope. The cluster on the left, a tri-tetrahedron, and the cluster on the right, an octahedron, have the same energy. But in an experiment where both clusters are allowed to form randomly in solution, the less symmetric tri-tetrahedron occurs more than twenty times as often as the highly symmetric octahedron because of the many more ways to form the tri-tetrahedron. The findings reported recently in Science illustrate, in a tangible way, what entropy is and how it determines the structures of small self-assembled materials.
For
more details, see press release here:
http://www.seas.harvard.edu/news-events/press-releases/using-magnetic-to...
and
article here: