What’s the News:
For a mosquito, venturing out during a heavy rainstorm means risking collisions with droplets 50 times its weight—but this doesn’t deter it from living in humid, rainy climes. In fact, researchers have discovered that the mosquito’s low mass, along with a sturdy exoskeleton, helps it weather (so to speak) the impacts of raindrops without much trouble.
How the Heck:
Sandfish lizards jostle back and forth, bending their bodies into a slithery S-curve to swim through the sands of the Sahara. Like scorpions and several other native desert species, they long ago mastered the difficult art of moving through the myriad grains of a sandy expanse to escape predators or the blistering African sun. And now physicists are close to cracking their secrets.
Daniel Goldman’s team has been trying to figure out just how the sandfish lizards do it for years now; in 2009 they built a robot to simulate the creature’s slithering motion. This time, for a study in the Journal of the Royal Society Interface, the scientists tried to model the physics of an animal knocking around so many grains of sand and see how the lizards burrow with such efficiency.
The team found sine-wave-like movement allows the lizard, and their robot, to push forward in sand, but creating computer models for the experiments proved problematic. Simulating all of the tiny sand grains required a lot of money to purchase time on powerful computers. So, the team performed the same experiments using 3-millimeter-wide glass beads instead of sand. “We wanted something easy to simulate that had some predictive power. We got lucky, because it turned out [the lizard and robot] swim beautifully in the same way through larger glass beads,” Goldman said. [Wired]