Scientists have now levitated small live animals using sounds that are, well, uplifting. In the past, researchers at Northwestern Polytechnical University in Xi'an, China, used ultrasound fields to successfully levitate globs of the heaviest solid and liquid—iridium and mercury, respectively. The aim of their work is to learn how to manufacture everything from pharmaceuticals to alloys without the aid of containers. At times compounds are too corrosive for containers to hold, or they react with containers in other undesirable ways. "An interesting question is, 'What will happen if a living animal is put into the acoustic field?' Will it also...