Comments on ‘The abrupt ending of a spinning disk’

Abstract

We make some crucial remarks about the recent presentation by Cross (2019 Eur. J. Phys. 40 065002) for pedagogical purposes considering his results. The possible deformations will influence significantly the role of (high) spots played in an abrupt stop of Euler’s disk as claimed by Cross. We thought Cross should consider the crucial role of the deformations (in a spinning disk as well as the surface or small contact area) in rolling friction and energy dissipation as already proposed by Moffatt and other researchers (2000 Nature 408 540).