To prevent dilution of energy while propagating a signal, certain methods can be used such as a waveguide, which acts like a canal does for water, or how a gun barrel restricts hot gas expansion to one dimension in order to prevent loss of energy transfer to a bullet.

Radar energy expands during both the signal transmission and the reflected return, so the inverse square for both paths means that the radar will receive energy according to the inverse fourth power of the range. The fundamental cause for this can be understood as geometric dilution corresponding to point-source radiation into three-dimensional space. In science, an inverse-square law is any scientific law stating that the observed 'intensity' of a specified physical quantity is inversely proportional to the square of the distance from the source of that physical quantity. Thus the field intensity is inversely proportional to the square of the distance from the source. The density of flux lines is inversely proportional to the square of the distance from the source because the surface area of a sphere increases with the square of the radius. The total number of flux lines depends on the strength of the light source and is constant with increasing distance, where a greater density of flux lines (lines per unit area) means a stronger energy field. The lines represent the flux emanating from the sources and fluxes. S represents the light source, while r represents the measured points.

Equation for intensity of a light wave