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How to differentiate between refraction and diffraction of waves?

  1. Mar 14, 2014 #1
    I seem to not be able to differentiate between the two of these phenomenons. Please give me some example in daily life to show the difference between them.
  2. jcsd
  3. Mar 14, 2014 #2


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    The way I think about it is: refraction is a property of rays. Insofar as a wave (whether it be light, sound, water, etc.) can be approximated by ray propagation, it can be refracted as it passes across an interface or through an area of changing speed (see: Snell's[/PLAIN] [Broken] law).

    Diffraction is a property of waves. When a wave encounters an object which has size comparable to its wavelength, then you no longer use the ray approximation to model the interaction. For example, when a "ray" of light encounters a narrow slit, you find out that the light is actually a field of waves. Only some of the waves "exit" from the other side of the slit, causing various diffraction effects such as spreading of the wave.
    Last edited by a moderator: May 6, 2017
  4. Mar 14, 2014 #3


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    Let's start from the beginning. Do you know what "refraction" and "diffraction" are? What are they, in your own words?

    Without knowing what you already know, it is difficult to describe to you the differences between the two.

  5. Mar 14, 2014 #4


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    Staff: Mentor

    Google searches on those two words should lead you quickly to the Wikipedia and Hyperphysics pages about them. If you could tell us what you specifically find to be confusing about them, it would help us give useful answers.
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