walking on water uncovered|
Insects use legs to create vortices in water
|If you have ever wondered how insects like water striders walk on water or skim across the surface of ponds, rivers and oceans, scientists at MITref have the answer. Rather than move by creating waves, as some researchers had thought, the insects use one of their three sets of hairy legs like oars to create vortices or spirals in the water that propel them forward at speeds of up to 150 cm (60 inches) per second.|
Figure legend: A water strider leaves a trail of whirling water in its path. A blue chemical was sprinkled on the surface of
the water and special illumination from below was used to highlight the convection pattern created by the strider's walk.
John Bush and colleagues at the Massachusetts Institute of Technology, who discovered the secret said that although tiny waves were created, they were not the main driving force. The momentum transfer is primarily in the form of subsurface vortices, Bush said in a report in the science journal Nature.
Water striders, also known as skimmers,
come in hundreds of different species ranging in size from one centimeter
(about half an inch) to the giant Vietnamese variety 20 times bigger and
still able to walk on water.The
researchers discovered the secret by using sophisticated tracking and a
high-speed video camera that showed the curlicue patterns they made 9see
"Robostrider" facing a real water strider.
|reference 1: The hydrodynamics of water strider locomotion, by|
|reference 2: Animal locomotion: How to walk on water.|