'Shadow method' reveals locomotion secrets of water striders

(American Institute of Physics) Intrigued by the floating mechanisms of water striders and the updated Archimedes' principle, which states that floating force equals the expelled liquid volume, researchers in China sought to discover how the pressed depth and supporting force of water surface acted upon a water strider's six legs. Now, they report this week in Applied Physics Letters that they have developed a 'shadow method' based on the refraction of light to make these measurements.