An acoustic wave is a mechanical disturbance that propagates through an elastic medium via successive compressions and rarefactions of particles, transporting energy but not net mass. Described by solutions to the linearized equations of fluid or solid mechanics, acoustic waves obey characteristic relations between pressure, density, and particle velocity fluctuations, with propagation speed determined by the medium’s elastic moduli and mass density. They can be longitudinal or, in solids, include transverse components, and are characterized by parameters such as frequency, wavelength, impedance, and attenuation, which govern reflection, refraction, scattering, and mode conversion in acoustically relevant phenomena and applications.
A team of researchers has for the first time successfully used lasers to generate guided sound waves on the surface of a microchip. These acoustic waves, akin to the surface waves produced during an earthquake, travel across ...
Optics & Photonics
Oct 23, 2024
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In the context of sensory modalities, eyes work like tiny antennae, picking up light, electromagnetic waves traveling at blistering speeds. When humans look at the world, their eyes catch these waves and convert them into ...
Nanophysics
Oct 18, 2024
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Cornell University researchers have demonstrated that acoustic sound waves can be used to control the motion of an electron as it orbits a lattice defect in a diamond, a technique that can potentially improve the sensitivity ...
Condensed Matter
Aug 26, 2024
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When a train approaches or an ambulance with its siren blaring nears us, we hear the sound with an increased frequency, gradually decreasing slightly. As it passes, the frequency changes abruptly to a lower one, then decreases ...
General Physics
May 23, 2024
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137
Acoustic waves may be able to control how particles sort themselves. While researchers have been able to separate particles based on their shape—for example, bacteria from other cells—for years, the ability to control their ...
Bio & Medicine
Jun 16, 2023
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137
The rapidly advancing field of nanophononics focuses on the study of hypersound, which are acoustic waves in the gigahertz to terahertz range, at the nanoscale. These high-frequency acoustic vibrations, also known as acoustic ...
Nanophysics
Apr 11, 2023
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