Beschreibung:
Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. An example, given at the end of the following section, shows that if the incoming wave vanishes except on a small bundle of rays, then almost all of the energy is transported along the refracted rays.
An example, given at the end of the following section, shows that if the incoming wave vanishes except on a small bundle of rays, then almost all of the energy is transported along the refracted rays.