Scientists Say Physics

Scientists Say: Diffraction

When light hits an object, this is how it finds a way around

diffracted laser

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)

By Bethany Brookshire

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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Power Words

More About Power Words

atmosphere     The envelope of gases surrounding Earth or another planet.

diffraction     The bending of waves when they hit an object. The pattern produced by those waves can be used to determine the structure of very tiny objects, such as the width of a human hair.

hologram     An image made of light and projected onto a surface, depicting the contents of a space.

laser     A device that generates an intense beam of coherent light of a single color. Lasers are used in drilling and cutting, alignment and guidance, in data storage and in surgery.

particle     A minute amount of something.

sun     The star at the center of Earth’s solar system. It’s an average size star about 26,000 light-years from the center of the Milky Way galaxy. Or a sunlike star.

wave     A disturbance or variation that travels through space and matter in a regular, oscillating fashion.

About Bethany Brookshire

Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.

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