Bubbles in water have been caught doing backflips for the first time

After colliding with a tilted wall, air bubbles in water execute a backflip and hit the wall for a second time because they get caught in their own wake. These acrobatics could be harnessed for cleaning

By Karmela Padavic-Callaghan

When they collide with a tilted surface in water, some air bubbles bounce away then reverse course and hit the surface again in a “backflipping” motion. These acrobatics are caused by the flow of fluid around a bubble and could potentially be harnessed for cleaning.

Alireza Hooshanginejad at Brown University in Rhode Island and his colleagues shot differently sized air bubbles in a tank of water towards a glass slide that was held at various angles between flat against the top of …