DiffractionThis is a phenomenon that occurs when a wave hits something of a similar dimension as their wavelength: many smaller waves come out from the corners. Imagine a sea wave hitting a rock. More can be found on BBC Bitesize. PhotonThis is the particle of light. The name comes from the Greek word “photos,” which means light. PhononThis is the particle of sound. The name comes from the Greek word “phonos,” which means sound. Sonar SONAR: a sound-based device that is used to determine the size and the distance of objects underwater.
Originally invented for detecting submarines, it is now used to detect fishes during fishing trips, obstacles during navigation and sunken ships. It works using different acoustic sources that interfere with each other to create a scanning beam. The acronym “sonar” stands for “SOund, NAvigation Spain phone number list and Ranging”. More on Britannica Kids. Acoustic Lens Acoustic lens: a “lens” is a common device when we are talking about light. For example, a magnifying glass or the lenses used in spectacles to correct shortsightedness or in telescope objectives. An acoustic lens is a device that has the same effects, but for sound. A converging lens (for sound) would focus the emission of a loudspeaker in a spot.
A diverging lens (for sound) might be used to send the high-frequency of a loudspeaker over large angles. More on lenses for light on Britannica Kids. Acoustic Metamaterials: ↑ It is a new type of materials, where the properties do not come from the chemistry of the base material, but from how it is engineered. The key point is that the engineering needs to be precise enough to work at a scale smaller than the wavelength. More on the definition of what is a metamaterial can be found here.