The "coin-through-the-rubber" trick: an elastically stabilized invagination
Popular Physics
2015-09-23 v2 Soft Condensed Matter
Abstract
A spectacular trick of close-up magicians involves the apparent passing of a coin through a rubber sheet. The magic is based on the unusual elastic response of a thin rubber sheet: the formation of an invagination, stabilized by friction and elasticity, which holds the coin. By pressing on the coin, the invagination becomes unstable, and the coin is released. We describe the deformation analytically using a simple Hookean description, and examine the stability of the invagination. We finally compare the prediction of the Hookean analysis with numerical solutions of the neo-Hookean model, and provide a brief commentary on the origins of the trick.
Cite
@article{arxiv.1509.06232,
title = {The "coin-through-the-rubber" trick: an elastically stabilized invagination},
author = {Fanlong Meng and Masao Doi and Zhongcan Ouyang and Xiaoyu Zheng and Peter Palffy-Muhoray},
journal= {arXiv preprint arXiv:1509.06232},
year = {2015}
}