Related Experiment Video
Updated: Aug 15, 2026
10:21
Evanescent Field Based Photoacoustics: Optical Property Evaluation at Surfaces
Published on: July 26, 2016
Acoustic wave scattering by spatiotemporal interfaces
J Galiana-Nieves1, J Redondo1, R Picó1
1Instituto de Investigación para la Gestión Integrada de Zonas Costeras, Universitat Politècnica de València, Paranimf 1, 46730 Gandia, Spain.
The Journal of the Acoustical Society of America
|August 14, 2026
Summary
This study explores acoustic wave interactions with spatiotemporal interfaces. Researchers derived analytical solutions for scattering and frequency conversion across different velocity regimes.
Area of Science:
- Acoustics
- Materials Science
- Wave Physics
Background:
- Space-time materials involve modulating physical media with traveling-wave perturbations.
- Spatiotemporal interfaces, abrupt transitions in material parameters, are fundamental building blocks.
Purpose of the Study:
- Investigate acoustic wave interaction and scattering with single and double spatiotemporal interfaces.
- Analyze different velocity regimes: subsonic, intersonic, and supersonic.
Main Methods:
- Developed analytical expressions for frequency conversion and scattering coefficients.
- Employed an equivalent Finite-Time-Difference-in-Frequency (FTFD) scheme for numerical simulations.
Main Results:
- Derived analytical solutions for acoustic wave scattering and frequency conversion.
- Validated analytical results against numerical simulations.
Conclusions:
- Spatiotemporal interfaces offer a novel approach to manipulating acoustic waves.
- The study provides a theoretical framework for designing advanced space-time acoustic materials.
Related Concept Videos
01:07Propagation of Waves
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
01:06Echo
The human ear cannot distinguish between two sources of sound if they happen to reach within a specific time interval, typically 0.1 seconds apart. More than this, and they are perceived as separate sources.
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
02:18Interference and Diffraction
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
01:07Interference and Superposition of Waves
When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect of the waves is the sum of the individual waves' effects. However, it does not imply that the individual waves affect the propagation of other waves.
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
00:53Sound Waves: Interference
Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When two identical waves from the same source superimpose on each other, the combination of two crests or two troughs results in amplitude reinforcement known as constructive interference. If two identical waves, that are initially in phase, become out of phase because of different path lengths, the combination of crests with troughs...
01:10Interference: Path Lengths
Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...