Acoustic levitation is the use of a very intense sound wave to keep a body suspended in mid air. It is fascinating, but not obviously useful for very much outside the space research lab -this despite being allegedly capable of lifting masses of up to a few kilograms.
Today’s invention attempts to apply this effect. Imagine the usual CD system with two speakers. As well as having the loudspeakers play music (or what currently passes for it), they would also emit low-frequency sound waves from a ‘high’ slot in one speaker and a ‘low’ slot in the other.
Although inaudible (to all but a passing, infrasound-tuned elephant) these standing waves would be capable of levitating a single compact disc. It would also be possible to use small pressure fluctuations to spin the disc about a vertical axis, just about as precisiely as is achieved by the motor in a discman-type device (See eg this).
The disc reading optics could be held near the disc surface on a single, elegant arm. This system would not only look stunning but it would do away with the cost, and noise, of a conventional motor.
