Air Ball: The Physics of Crumpled Foil
The image above shows five aluminum balls resting on a sheet of physics homework. UMass Amherst physicist Narayan Menon and former doctoral candidate Dominique Cambou examined the fundamental mechanisms occurring inside a crumpled sheet of foil or paper. Among other things it's mostly air, it pushes against itself, and it's least dense at its core, unlike natural spherical structures. Menon and Cambou used X-ray microtomography that assembles three-dimensional images from thousands of two-dimensional, cross-section images to explore how this architecture creates stiffness. Learn more.
Image credit: Benjamin Ett