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


Scientific explanation[edit]



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]