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

Because of this, he views the data as a strong candidate for long-sought gamma ray emission from dark matter.

From Science Daily • Nov. 29, 2025

The measured gamma ray energy spectrum, which describes how the intensity of the emission varies, closely matches model predictions for the annihilation of hypothetical WIMPs with masses roughly 500 times that of a proton.

From Science Daily • Nov. 29, 2025

The estimated frequency of these annihilation events based on the observed gamma ray intensity also fits within expected theoretical ranges.

From Science Daily • Nov. 29, 2025

"It could be that these gamma ray bursts and supernova explosions are not necessarily directly linked to each other and they could be separate processes going on," he told BBC News.

From BBC • Apr. 12, 2024

In order to observe a primordial black hole one would have to detect several gamma ray quanta coming from the same direction within a reasonable space of time, such as a week.

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