- LONDON (Reuters) - So that's
how they do it.
-
- If you have ever wondered how insects like water striders
walk on water or skim across the surface of ponds, rivers and oceans, scientists
in the United States 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 60 inches per second.
-
- Professor John Bush of the Massachusetts Institute of
Technology and his colleagues who uncovered 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 uncovered the secret by using sophisticated
tracking and a high-speed video camera that showed the curlicue patterns
they made.
-
- They also created a mechanical water strider, called
Robostrider, based on the real thing.
-
- It is made out of a drinks can, with stainless steel
wire legs and an elastic band and pulley as its middle legs.
-
-
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