The 'Indian wire trick' via parametric excitation: a comparison between theory and experiment

A seemingly paradoxical experiment is described whereby a length of wire is stabilized upside down by vertical periodic oscillation of its support. The experimental results reveal an upper and a lower bound on the excitation frequency for stability. The results of recent theories are presented and used to explain the essential details of the observations. The theory relies on a novel phenomenon of so-called resonancetongue interaction. The result is verified via asymptotic calculations based on a one-dimensional rod model and numerical results on a spatially discretized system of links. This gravity-defying effect has potential application to the stabilization of other spatially extended systems via parametric excitation.