How liquid droplets spread on solid surfaces is pretty well understood, but researchers have looked less at the related problem of how a gas spreads. In a recent paper, scientists have examined the spreading dynamics of bubbles impacting an immersed solid. As the bubble contacts the surface, it quickly squeezes out water trapped between the bubble and the gas layer trapped at the solid surface. The bubble squishes as surface tension tries to flatten the liquid-gas interface. Buoyancy also helps flatten the bubble. The spreading is remarkably fast, taking only about 10 milliseconds. That’s good news for the many insects who use trapped air bubbles like these to breathe underwater. Check out the video below to learn about some of these natural scuba divers. (Image credit: H. de Maleprade et al., source; video credit: Deep Look)
Spreading Bubbles Help Nature’s Scuba Divers
