Scientists can levitate objects in the air using only sound, TIME reports. Video footage shows four speakers that emit supersonic sound, which is inaudible to the human ear. A powerful vibrating force between the speakers means that tiny beads and small drops of water can rise off the table. Speakers have long been shown to make objects vibrate. The video shows small objects actually rising off the table and hovering in midair.
Previous studies involved lining speakers up in a row to bounce sound off a hard surface, but the new experiment from researchers at the University of Tokyo consists of four speakers facing inwards on a square of open space about 21 inches long. Once the objects are suspended in midair, the scientists can move them around by manipulating the waves. The longest object levitated in the video is a 3-cm long piece of wood that looks like a match. The device emits sound at 40 kHz.
“Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its center is also utilized. The other is the manipulation principle by which a localized standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays,” the scientists explain in the video, which expands on a paper they submitted to a science publishing website maintained by Cornell University last month.
The scientists also believe that the technique could be useful for moving objects in low-gravity environments, such as in space. The use of sound waves is already making its way into everyday life, as companies discover how to use the invisible waves to improve existing technology. For example, McLaren has announced that they are eliminating windshield wipers on their cars. Instead they will reportedly utilize ultrasonic vibrations to repel water from the windshield, reports Wired. The future applications of the technology are limitless if scientists can figure out how to make the technology more autonomous. It could be particularly valuable for institutions like NASA, which cannot always use humans for space missions.