gamma ray

American  

noun

Physics.

1. a photon of penetrating electromagnetic radiation gamma radiation emitted from an atomic nucleus.

2. a photon emitted by an electron as a result of internal conversion.

3. electromagnetic radiation with wavelengths shorter than approximately one tenth of a nanometer.

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gamma ray Scientific  

1. A stream of high-energy electromagnetic radiation given off by an atomic nucleus undergoing radioactive decay. Because the wavelengths of gamma rays are shorter than those of x-rays, gamma rays have greater energy and penetrating power than x-rays. Gamma rays are emitted by pulsars, quasars, and radio galaxies but cannot penetrate the Earth's atmosphere.

2. See more at radioactive decay

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Etymology

Origin of gamma ray

First recorded in 1900–05

Example Sentences

See Examples For:

gamma ray

It then releases a gamma ray to reach a stable state.

From Science Daily ● Apr. 14, 2026

Measurements show that this distant supernova closely matches the brightness and spectral features of SN 1998bw, a well known supernova linked to a gamma ray burst that exploded much closer to Earth.

From Science Daily ● Dec. 28, 2025

Answers may come with the construction of a huge new gamma ray telescope called the Cherenkov Telescope Array.

From Science Daily ● Oct. 18, 2025

A gamma ray detector on a device developed by a Cornish company is being used to assess soil quality.

From BBC ● Nov. 26, 2024

And to observe these few coming from the distance of Pluto would require a larger gamma ray detector than any that have been constructed so far.

From "A Brief History of Time: And Other Essays" by Stephen Hawking