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Undulatory movements which are propagated in more than one dimension constitute wavefronts, and are formed by points in phase. The crest of a wave is a good example of a wavefront. A small source emits spherical waves, whereas a plane one emits plane waves. However, at a great distance from the source, the wavefronts may always seem plane.
When the wavefronts meet a small opening or obstacle in their path there is diffraction:
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Diffraction is when the wavefronts are propagated in all directions after passing through an opening or round an obstacle. The phenomenon is more perceptible when the size of the opening or obstacle is similar to the wavelength of the wavefront. |
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