Mechanism that puts the curl in curling stone revealed
Researchers from Sweden cliam to have found out the mechanism behind the curved path in the curling stone.
Washington: Researchers from Sweden cliam to have found out the mechanism behind the curved path in the curling stone.
Harald Nyberg, Sara Alfredsson, Sture Hogmark and Staffan Jacobson at Uppsala University in Sweden, who usually study friction and wear in technical and industrial material systems, described in their article that the curved path is due to the microscopic roughness of the stone producing microscopic scratches in the ice sheet.
Their research found that as the stone slides over the ice the roughness on its leading half will produce small scratches in the ice and the rotation of the stone gives the scratches a slight deviation from the sliding direction.
And when the rough protrusions on the trailing half shortly pass the same area, they cross the scratches from the front in a small angle.
When crossing these scratches they have a tendency to follow them and it is this scratch-guiding or track steering mechanism, which generates the sideway force necessary to cause the curl.
While working on their model the researchers experimented with pre-scratching of the ice in various ways, and were then able to observe that non-rotating stones could also be guided.
Stones with very smooth, polished sliding surface were however not affected by the scratches. The researchers also investigated the microscopic scratches made by the stones by moulding replicas of the ice, which were subsequently studied in microscopes.
The research has been published in scientific journal Wear.