Diffraction

Another property that light exhibits is that it diffracts, which loosely speaking means it bends around the corner when it passes through an opening. This is illustrated below.

  

Figure 10.9: Diffraction through a slit

For reasons that we will see later, we don't normally encounter diffraction of light in our everyday lives. However, we can readily demonstrate the diffraction of sound: if one speaks through an open door, someone standing directly around the corner of the doorway (indicated by a star in the figure) can readily hear the sounds. One says that the sound has diffracted around the doorway.