Christiaan Huygens described how to determine the path of waves through a medium.
- Definition 1: The Huygens Principle
Every point of a wave front serves as a point source of spherical, secondary waves. After a time t, the new position of the wave front will be that of a surface tangent to the secondary waves.
Huygens principle applies to any wavefront, even those that are curved as you would get from a single point source. A simple example of the Huygens Principle is to consider the single wavefront in Figure Figure 1.
Example 1: Application of the Huygens principle
Given the wavefront,
use the Huygens Principle to determine the wavefront at a later time.
Draw circles at various points along the given wavefront
Join the circle crests to get the wavefront at a later time