Related Experiment Video
Updated: Oct 10, 2026

Simulating Imaging of Large Scale Radio Arrays on the Lunar Surface
Published on: July 30, 2020
[Sound propagation over large distances. On the history of the phenomenon]
Abstract:
Reports of cases of extremely wide-ranging sound propagation can be traced to the 17th century. It was noticed that a "zone of silence" exists between the zone of direct audibility near the source of the sound and a zone more than 150 km distant from it, where the sound can be heard again. Numerous scientists offered explanations for this astonishing phenomenon; it turned out that the solution of the problem required an interdisciplinary approach. In this paper, the author describes the path of arguments leading to the explanation accepted nowadays.
Related Concept Videos
Echo
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...
Propagation of Waves
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...
Interference: Path Lengths
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...
Shock Waves
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...
Sound Waves
Sound waves are longitudinal in most fluids because fluids cannot sustain any lateral pressure. In solids, however, shear forces help in propagating the disturbance in the lateral direction as well. Hence,...
Deriving the Speed of Sound in a Liquid
The speed of sound in fluids can be derived by considering a mechanical wave propagating...

