# How does the wavelength of a water wave affect diffraction?

by ranger275
Tags: diffraction, effect, water, wave, wavelength
 P: 17 If I send a single wave toward a corner won't it bend around the corner? If so, how does the wavelength of that single wave (is wavelength defined for a single wave?) effect how much it bends? Every picture/illustration I have found on diffraction shows a series of lines (plane waves) approaching a gap and shows how the waves bend more if the gap is made smaller. What I haven't seen is a picture keeping the gap the same and changing the wavelength. I don't see how the distance between crests has anything to do with how much each crest bends as it leaves the gap.
 Thanks P: 1,948 What do you mean by a single wave? do you mean a single crest? If so than you have to understand that short wave packets such as your single crest wave can be Fourier expanded into a sum of multiple crest waves (Principle of superposition). Each component of that expansion will diffract according with its wavelength.
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P: 1,948
 Quote by ranger275 I don't see how the distance between crests has anything to do with how much each crest bends as it leaves the gap.
Interesting that it does, isn't it?

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P: 11,923
How does the wavelength of a water wave affect diffraction?

 Quote by ranger275 If I send a single wave toward a corner won't it bend around the corner? If so, how does the wavelength of that single wave (is wavelength defined for a single wave?) effect how much it bends? Every picture/illustration I have found on diffraction shows a series of lines (plane waves) approaching a gap and shows how the waves bend more if the gap is made smaller. What I haven't seen is a picture keeping the gap the same and changing the wavelength. I don't see how the distance between crests has anything to do with how much each crest bends as it leaves the gap.
What is the difference? If the geometry is described in units of 'a wavelength', the absolute size of things is not relevant. The scale of the picture that's drawn may alter but the angles don't, for a given ratio of gap to wavelength.
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P: 11,574
 Quote by ranger275 What I haven't seen is a picture keeping the gap the same and changing the wavelength.
Here you go. This video shows changing the wavelength of a water wave through an aperture.