Why a curling stone curls remains controversial. Yes there are computer models which generate similiar trajectories, but they rest on assumptions of "melt water", and other scientists who research ice tribology find no evidence that ice melts at the associated temperatures and pressures.
I believe the motion of curling stone is essentail to the emergence of a new science of motion, i.e , as the motion of a cannon ball was to the emergence of a science of mechanics in Galileo's time. http://www.youtube.com/watch?v=Sic7CckO-js Harry
