gamma ray


: a photon emitted spontaneously by a radioactive substance
also : a photon of higher energy than that of an X-ray

Examples of gamma ray in a Sentence

Recent Examples on the Web Fortunately, Earth’s atmosphere blocks most gamma rays from space, but that also means the only way to observe gamma-ray bursts is through a space telescope like Swift. Amy Lien, Discover Magazine, 19 Apr. 2024 Just as ultraviolet radiation, or UV rays, make sunscreen a necessity lest one risk skin cancer, gamma rays would also require a form of physical protection. Max Bennett, Discover Magazine, 18 Mar. 2024 The baby black hole would produce jets of highly energetic particles moving near the speed of light, powerful enough to pierce through the remains of the progenitor star, emitting X-rays and gamma rays. Jennifer Ouellette, Ars Technica, 22 June 2023 Plus, beta radiation isn't as harmful as, say, gamma rays. Rhett Allain, WIRED, 23 Feb. 2024 But the particles should occasionally collide, resulting in tiny bursts of gamma rays. Michael D. Lemonick, Scientific American, 1 Jan. 2024 Alpha particles are just the nuclei of helium atoms, beta particles are electrons, and gamma rays are a type of very high-frequency electromagnetic radiation. Rhett Allain, WIRED, 23 Feb. 2024 One way to identify the sources is to backtrack the paths that high-energy cosmic neutrinos traveled on their way to Earth since they are created by cosmic rays colliding with matter or radiation, producing particles that then decay into neutrinos and gamma rays. Jennifer Ouellette, Ars Technica, 29 June 2023 The Moon’s surface is not protected from solar particles and cosmic rays, particularly gamma rays, but here too, the tardigrades would be able to resist. Laurent Palka, Discover Magazine, 1 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'gamma ray.' 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

1903, in the meaning defined above

Time Traveler
The first known use of gamma ray was in 1903

Dictionary Entries Near gamma ray

Cite this Entry

“Gamma ray.” Dictionary, Merriam-Webster, Accessed 24 May. 2024.

Kids Definition

gamma ray

: a ray that is like an X-ray but of higher energy and that is given off especially by a radioactive substance

Medical Definition

gamma ray

: a photon emitted spontaneously by a radioactive substance
also : a high-energy photon
usually used in plural

More from Merriam-Webster on gamma ray

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