What is Diffraction

Diffraction is the bending and spreading of waves when they encounter an obstacle or pass through a narrow opening.


Key Points:

  • It occurs with all types of waves: light, sound, water, and even electromagnetic waves.

  • The effect is more noticeable when the size of the opening or obstacle is comparable to the wavelength of the wave.

  • Result: After passing through the gap or around the object, waves spread out instead of continuing in a straight line.


Examples of Diffraction:

  • Light: Light bends around the edges of a slit, producing patterns of bright and dark fringes (used in diffraction grating and spectroscopy).

  • Sound: You can hear someone speaking even if they are around a corner—because sound waves diffract.

  • Water waves: When ocean waves pass through a gap in a breakwater, they spread out into a semicircular shape.


Visual Explanation (Imagine):

If light passes through a tiny slit, instead of making a straight beam, it creates a series of rings or bands—this is a diffraction pattern.

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