Stone skipping
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Stone skipping is a pastime which involves throwing a stone with a flattened surface across a lake or other body of water in such a way that it bounces off the surface of the water. The object of the game is to see how many times a stone can be made to bounce before sinking.
The pastime is also called stone skipping and ducks and drakes in England and stone skiffing in Ireland. The North American Stone Skipping Association (NASSA), formed in 1989 and based in Driftwood, Texas, holds world championships each year; the next is expected to be held at Playa Ros beach in Spain.
The current world record according to the Guinness Book of Records is 38 skips, set by Jerdone Coleman-McGhee at the NASSA world championship in 1992.
Research undertaken by a team led by French physicist Lydéric Bocquet has discovered that an angle of about 20° between the stone and the water's surface is optimal. Bocquet and his colleagues were surprised to discover that changes in speed and rotation did not change this fact.
Earlier research reported by Bocquet calculated that the world record of 38 rebounds required a speed of 12 m/s (25 mph), with a rotation of 14 revolutions per second.
See also
External links
- NASSA homepage (http://www.yeeha.net/nassa/a1.html)