Water striders’ ability to walk on water mystified researchers for generations, but now new research published in Langmuir sheds light on this curious phenomenon. Scientists developed a new understanding of this seemingly gravity-defying talent using a trick of their own — studying the bugs’ leg shadows. The researchers placed a white sheet of paper at the bottom of a lab aquarium housing water striders and installed a light source above the water. The insects’ stick-straight legs cast shadows that were rounded, representing the curvature of the water and the expelled water volume from which the floating force and weight can be calculated, the researchers say. Also, from these measurements, the striders’ slightest shifts in weight and body angle could be detected for the first time. The study offers more than just satisfaction of intellectual curiosity, however. Researchers say this knowledge could someday by cross-applied to help design robots capable of walking on the water.
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