Sound waves whose geometry is determined by a single dimension, plane waves, obey the wave equation
where designates the speed of sound in the medium. The monochromatic solution for plane waves will be taken to be
where is the frequency and is the wave number. The sign chosen in the argument determines the direction of movement of the waves.
Here is a plane wave moving on a three-dimensional lattice of atoms:
Here is a plane wave moving through a three-dimensional random distribution of molecules:
Sound waves whose geometry is determined by two dimensions, cylindrical waves, obey the wave equation
The monochromatic solution for cylindrical sound waves will be taken to be
Here is a cylindrical wave moving on a three-dimensional lattice of atoms:
Here is a cylindrical wave moving through a three-dimensional random distribution of molecules:
Sound waves whose geometry is determined by three dimensions, spherical waves, obey the wave equation
The monochromatic solution for spherical sound waves will be taken to be
Here is a spherical wave moving on a three-dimensional lattice of atoms:
Here is a spherical wave moving through a three-dimensional random distribution of molecules:
The mathematical description of sound waves can be carried to higher dimensions, but one needs to wait for Four.js and its higher-dimensional successors to attempt visualizations.