Stable Hard-Sphere Packings with Arbitrarily Low Density A new strategy for packing hard spheres of

Stable Hard-Sphere Packings with Arbitrarily Low Density

A new strategy for packing hard spheres of different sizes could lead to novel ways of creating strong, lightweight materials.
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To create structures that are light and strong, researchers leverage the interplay between internal compression and tension, removing unnecessary material that does not contribute to this balance of forces. Because packed assemblages of hard spheres lack internal tension, the conventional wisdom is that reducing the density of such structures eventually leads to instabilities, establishing limits on how strong and lightweight they can be. Now, Robert Dennis and Eric Corwin at the University of Oregon have found a way to pack hard spheres at vanishingly small densities such that their structures are as light as desired while remaining mechanically stable [1].