Scientists Say: Diffraction
When light hits an object, this is how it finds a way around

This is a diffraction pattern made when a laser beam passes through a tiny circular hole in a plate.
Wisky/Wikimedia Commons (CC-BY-SA 3.0)
Diffraction (noun, “Dih-FRACK-shun”)
This is the bending or turning of a wave when it hits an object. The term often comes up in discussions of light hitting an edge or slit. The light wave is scattered in a pattern after hitting that slit or edge. The size of the scatter is related to the size of the object that caused the light to bend.
In a sentence
Using a laser pointer and the principles of diffraction, you can find out the thickness of a single human hair.
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