refraction

noun

re·​frac·​tion ri-ˈfrak-shən How to pronounce refraction (audio)
1
: deflection from a straight path undergone by a light ray or energy wave in passing obliquely from one medium (such as air) into another (such as glass) in which its velocity is different
2
: the change in the apparent position of a celestial body due to bending of the light rays emanating from it as they pass through the atmosphere
also : the correction to be applied to the apparent position of a body because of this bending
3
: the action of distorting an image by viewing through a medium
also : an instance of this

Illustration of refraction

Illustration of refraction
  • a light ray
  • b reflected ray
  • c refracted ray

Did you know?

The root of refraction is seen in the notion that the path of a ray of light or wave of energy is "broken" when it is deflected or turned. The effects of refraction can be seen in a rainbow, which is formed when light rays passing into (and reflecting out of) water droplets are bent at different angles depending on their color, so that the light separates into bands of color. The amount of refraction depends on the angle and the type of matter; refraction can occur even when passing through different kinds of air. A mirage, such as you might see in the desert or over a patch of asphalt in the summer, occurs when light passing through warm air meets the very hot air near the surface; reflecting the sky, it often resembles a lake.

Examples of refraction in a Sentence

Recent Examples on the Web Imagine a ray of light that travels through an optical system, undergoing a series of reflections, refractions and absorptions. IEEE Spectrum, 16 Jan. 2024 Then a physics lecture on light refraction brought an epiphany — and a change of majors. Martha Ross, The Mercury News, 25 Jan. 2024 Samsung’s nano-prisms use diffraction, rather than refraction, to bend the angle of incoming light. IEEE Spectrum, 13 Dec. 2023 Interspersed with explanations of electromagnetism and refraction are notes about which scientist was a poor singer (Ernest Rutherford), which scientist didn’t like that one (Robert Hooke and Isaac Newton), and which scientist felt threatened by his protégé (Humphry Davy and Michael Faraday). Angelina Torre, WSJ, 16 Nov. 2023 The blueish color is due to much the same light refraction pattern as that which produces a blue daytime sky here on Earth. Eric Berger, Ars Technica, 9 Nov. 2023 Moorjani’s taken her time to prep with the whole Fable & Mane line (pre-wash oil, shampoo and conditioner, leave-in conditioner and finishing oil) and her hair now seems to have the refraction index of a sheet of metal: i.e. ultra, mega shiny. Parizaad Khan Sethi, Vogue, 7 Nov. 2023 This number, a sort of impressionistic refraction of a glossy classic-era Hollywood romance, is the high point of the movie’s staging, though not its most inventive sequence. Richard Brody, The New Yorker, 16 Oct. 2023 For Kendall, a sequined limoncello midi dress by Bottega Veneta reflected the spirit of the City of Light, the fabric's refractions mirroring her strappy white sandals and buttery baguette bag in turn. Calin Van Paris, Vogue, 27 June 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'refraction.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1603, in the meaning defined at sense 1

Time Traveler
The first known use of refraction was in 1603

Dictionary Entries Near refraction

Cite this Entry

“Refraction.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/refraction. Accessed 19 Mar. 2024.

Kids Definition

refraction

noun
re·​frac·​tion ri-ˈfrak-shən How to pronounce refraction (audio)
: the bending of a ray when it passes at an angle from one medium into another in which its speed is different (as when light passes from air into water)
refractive
-ˈfrak-tiv
adjective

Medical Definition

refraction

noun
re·​frac·​tion ri-ˈfrak-shən How to pronounce refraction (audio)
1
: the deflection from a straight path undergone by a light ray or a wave of energy in passing obliquely from one medium (as air) into another (as water or glass) in which its velocity is different
2
a
: the refractive power of the eye
b
: the act or technique of determining ocular refraction and identifying abnormalities as a basis for the prescription of corrective lenses

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