2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/230252Elasticity theory calculations predict the number N of depressions that appear at the surface of a spherical thin shell submitted to an external isotropic pressure. In a model that mainly considers curvature deformations, we show that N only depends on the relative volume variation. Equilibrium configurations show single depression (N=1) for small volume variations, then N increases up to 6, before decreasing more abruptly due to steric constraints, down to N=1 again for maximal volume variations. These predictions are consistent with previously published experimental observations.Soft Condensed Mattertext