What role does wavelength play in diffraction?

Wavelength plays a crucial role in diffraction as it determines the degree of bending of waves around obstacles or through openings.

In the phenomenon of diffraction, waves bend around obstacles or spread out after passing through small openings. The extent of this bending or spreading is directly related to the wavelength of the wave. The longer the wavelength, the more the wave will diffract. This is why low-frequency (long wavelength) sounds can be heard around corners, but high-frequency (short wavelength) light cannot.

The relationship between wavelength and diffraction can be understood through Huygens' principle, which states that every point on a wavefront can be considered as a source of secondary wavelets. These wavelets spread out in the forward direction, at the same speed as the wave. When the wave encounters an obstacle or a gap, the wavelets at the edge will spread into the 'shadow' of the obstacle or gap. The amount of spreading (diffraction) depends on the size of the obstacle or gap compared to the wavelength of the wave. If the gap or obstacle is much larger than the wavelength, there will be little diffraction. However, if the gap or obstacle is about the same size as, or smaller than, the wavelength, there will be significant diffraction.

In the case of light, which has a very short wavelength, diffraction effects are usually only noticeable when light passes through very small openings or around very small obstacles. This is why we don't usually see light bending around corners. However, in the case of sound or radio waves, which have much longer wavelengths, diffraction effects are much more noticeable. This is why you can hear sounds around corners or behind obstacles.

In summary, the wavelength of a wave plays a significant role in diffraction, determining the degree to which waves bend around obstacles or spread out after passing through openings.