Stone skipping

"Skipping stones" redirects here. For the Orson Scott Card short story, see Skipping Stones. For the Alexz Johnson EP, see Skipping Stone.
A stone skipping on calm water

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.

Championships and records

The North American Stone Skipping Association (NASSA), founded by Coleman-McGhee, in 1989 and based in Driftwood, Texas, sanctioned world championships for four years from 1989 through 1992 in Wimberley, Texas. The next official NASSA World Championships is expected to be held at Platja d'en Ros beach in Cadaqués, Catalonia, Spain.

The world record according to the Guinness Book of Records is 88 skips by Kurt "Mountain Man" Steiner, age 48. The cast was achieved on September 06, 2013[1] at Red Bridge in the Allegheny National Forest, Pennsylvania. The previous record was 65 skips, by Max Steiner, set at Riverfront Park, Franklin, Pennsylvania. Before him, the record was 51 skips, set by Russell Byars on July 19, 2007, skipping at the same location. [2] Kurt Steiner also held the world record between 2002 and 2007.

A stone skipping championship of a different nature takes place every year in Easdale, Scotland, where distance is measured as opposed to number of skips, as tends to be the case outside the US.[3] Every year since 1997, competitors from all over the world have taken part in the World Stone Skimming Championships in a disused quarry on Easdale Island,[4] using stones made from Easdale slate. The 2007 winner was Dougie Isaacs (Scotland). Eric Robertson won in 2008. David Gee was the 2009 winner. Dougie Isaacs won the title again in 2010, 2011,2013 and 2014, making him the champion with the most world titles in the competition's history. In 2014 he also won the Wales Open with a throw of 120m, the longest recorded throw in open competition. Helen Mannion (GB) is the 2014 World Women's Champion. Lucy Wood (England) won the Women's title in 2012 and 2013, and is the current European Ladies champion 2014. [5] The current European Champion for the third consecutive time is Paul Crabtree (England). The repeat English Open Champion is Ron Long (Wales) who was also World Champion 2012. There is no official world record for distance.

Scientific explanation

Stone skipping

An early explanation of the physics of stone-skipping was provided by Lazzaro Spallanzani in the 18th century.

The stone generates lift in the same manner as a flying disc, by pushing water down as it moves across the water at an angle. Surface tension has very little to do with it. The stone's rotation acts to stabilize it against the torque of lift being applied to the back.

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.[6] Bocquet and his colleagues were surprised to discover that changes in speed and rotation did not change this fact.[6] Work by Hewitt, Balmforth and McElwaine has shown that if the horizontal speed can be maintained skipping can continue indefinitely.[7] Earlier research reported by Bocquet calculated that the world record of 38 rebounds set by Coleman-McGhee, unchallenged for many years, required a speed of 12 m/s (25 mph), with a rotation of 14 revolutions per second.[6]

Names

Further reading

See also

References

  1. ↑ http://www.guinnessworldrecords.com/world-records/1/most-skips-of-a-skimming-stone
  2. ↑ Silver, Jonathan D. (2007-09-30). "A stone's throw and then some to a Guinness record". Pittsburgh Post-Gazette.
  3. ↑ Scots dominate in stone skimming. BBC News, 25 September 2005
  4. ↑ World Stone Skimming Championships 2007
  5. ↑ http://www.stoneskimming.com/results/index.htm
  6. ↑ 6.0 6.1 6.2 Clanet C, Hersen F, Bocquet L (January 2004). "Secrets of successful stone-skipping". Nature 427 (6969): 29. doi:10.1038/427029a. PMID 14702075.
  7. ↑ I. J. Hewitt, N. J. Balmforth, and J. N. McElwaine (2011). "Continual Skipping on Water". J. Fluid Mech. 669: 328–353. doi:10.1017/S0022112010005057.
  8. ↑ http://www.slang.gr/search/user/8273
  9. ↑ Český jazykový atlas 1 (Czech Language Atlas 1), Academia, Praha, 2004, p. 110–113, (dělat) žabky
  10. ↑ The Secrets of Stone Skipping, Coleman-McGhee, 1996, ISBN 1-883856-01-9

External links

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