We think you are located in South Africa. Is this correct?

Huygen'S Principle

Success in Maths and Science unlocks opportunities

Sign up to get a head start on bursary and career opportunities. Use Siyavula Practice to get the best marks possible.

Sign up to unlock your future

6.3 Huygens principle (ESBNG)

Christiaan Huygens described how to determine the path of waves through a medium.

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 6.2.

f0fe67f1ccfdc72e4e9216b67f366cc9.png
Figure 6.2: A single wavefront at time t acts as a series of point sources of circular waves that interfere to give a new wavefront at a time \(t+\Delta t\). The process continues and applies to any shape of waveform.

Worked example 1: Application of the Huygens principle

Given the wavefront,

8865a5feb155f525dd1a0ff300bf62df.png

use the Huygens Principle to determine the wavefront at a later time.

Draw circles at various points along the given wavefront

f835567b5e741257fbfc9972b2a3c7d4.png

Join the circle crests to get the wavefront at a later time

a9796e93ab45c39d496e8fd93cf06aa3.png