Acoustics

Acoustic Cloaking(January 11, 2008)
Physicists imagine an object invisible to sound waves.

Hyper-Focusing a Sound Wave(September 13, 2002)
Using a technique called "time-reversed acoustics," researchers have focused a sound wave to a tiny spot, much smaller than allowed by traditional methods.

Acoustic Lens(January 2, 2002)
Scientists in Spain are the first to use a "sonic crystal" to focus sound waves at audible frequencies.

Sound-Activated Filter(November 6, 2001)
Sound waves lead to an efficient, switchable fluid filter.

Acoustic Crystallization (June 1, 2001)
Ultrasound can be used to crystallize helium.

Ultrasound Diagnosis of Burns (November 11, 1999)
In an important development for medical ultrasound, researchers can now take ultrasound pictures of the inside of the body--including painful areas containing serious burns--with devices that do not require physical contact with the patient.

Acoustic Compressor (December 3, 1997)
See how ultrapowerful sound waves can replace mechanical parts in air conditioners and refrigerators to compress gas molecules.

The Sonoluminescence Process (August 5, 1996)
A depiction of sonoluminescence, the conversion of sound energy into light.

Sonoluminescence and Medical Ultrasound (July 29, 1996)
Some of the sound energy used in medical ultrasound may be converted into flashes of light.

Sonoluminescence Photo (July 26, 1996)
Photograph of a cell producing sonoluminescence, in which sound energy is converted into light.