A floating butterfly created by the Multimodal Acoustic Trap Display. (Credit: Eimontas Jankauskis)

With the help of sound waves and a small plastic ball, researchers in the U.K. have designed a machine that generates truly 3D holographs.

The whole system is slightly smaller than a shoebox and makes simple images, like a butterfly or smiley face, that are less than an inch tall. Described in Nature, the device is one of the first 3D image generators that also responds to touch and produce