Question

Sound waves and light waves are two dimensional or three dimensional?

Answer 1

Generally three dimensional

Explanation:

Before we start we should know that by two dimensional or three dimensional waves we mean that the wave is traveling in two or three dimensions respectively.
For a three dimensional wave the wave equation is of type
`(del^2psi)/(delx^2)+(del^2psi)/(dely^2)+(del^2psi)/(delz^2)=1/v^2 (del^2psi)/(delt^2)`
Where `psi` is the wave function , `v` is the wave velocity and `x, y, z` are position coordinates.
Hence if we assume that the sound wave or the light wave is originating from a source i.e. traveling in three dimensional space then they can be considered as three dimensional waves.

However if we could restrict waves to travel only in one dimension like sound waves going down a narrow tube then we can convert even three dimensional waves to one dimensional.
We can do similar things even to make light wave a one dimensional wave.
If we force waves to move only in two dimensions then we can also make them two dimensional.