11.5 CHAPTER 11. 2D AND3D WAVEFRONTS
- grey line + grey line =trough + trough = constructive interference
- black line + grey line= grey line + black line = peak + trough = trough +
peak = destructive interference
On half the picture below, we have marked theconstructive interference with a solid
black diamond and thedestructive interferencewith a hollow diamond.A� �B �
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������������������To see if you understandit, cover up the half we have marked with diamonds and try to
work out which points are constructive and destructive on the other halfof the picture.
The two halves are mirror images of each other so you can check yourself.11.5 Diffraction
ESCFD
One of the most interesting, and also very useful, properties of waves is diffraction.DEFINITION: Diffraction
Diffraction is the abilityof a wave to spread outin wavefronts as the
wave passes through a small aperture or arounda sharp edge.