Even without delving into the science behind it, a recently released video of small objects levitating and moving about in the air is mesmerizing. Scientists from the University of Tokyo and the Nagoya Institute of Technology are behind a series of experiments using sound to control the movement of tiny foam balls and even small screws. This is Harry Potter-worthy science.
The power of sound waves to lift lightweight objects into the air is well-known, but new work with aiming ultrasonic phased arrays at a focal point gives researchers the seemingly magical power to move things around in the air in three dimensions in space. Look, ma, no hands.
The researchers have published their work under the title "Three-dimensional Mid-air Acoustic Manipulation by Ultrasonic Phased Arrays."
Lest you dream of Hogwarts abilities, know that we're still pretty far from being able to lift anything much bigger than a millimeter or so in size. The research team was able to raise up and move a feather, droplets of alcohol, soap bubbles, and a small resistor electronic component.
The secret science sauce behind this is the power of standing waves. The small items get caught in nodes created by these waves. The arrangement of the ultrasonic speaker array then allows them to be moved around, which is what gives this project a true sense of magic.
Fortunately for onlookers, the ultrasonic frequencies are at the very edge of human hearing, so the experiments are essentially silent. Now we can all dream about having an ultrasonic speaker array big enough to lift up something really impressive, like a model of the USS Enterprise. Check out the anti-grav action: