Acoustic levitation – which works both in normal and reduced gravity – is a phenomenon that uses the power of sound waves to make solids, liquids, and heavy gases float.
Standing at no more than a few millimeters wide, the water-and-soap droplets were flattened into a thin disk and curled into a bubble within a split second.
The team caught the rapid process – showing one device shaping the bubble as another one was keeping it levitated – with a high-speed camera capable of recording motion with exposures shorter than 1/1,000 of a second.