gamma ray

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.

gamma ray

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

Word History and Origins

Origin of gamma ray¹

First recorded in 1900–05

Example Sentences

Although humans can't see them, radio waves are a form of light in the sense that they are part of the electromagnetic spectrum, which also includes X-rays and gamma rays.

From BBC

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

From BBC

The gamma rays detected on Earth tell us a great deal about these sources, since they travel through space undisturbed.

From Science Daily

Astrophysicists at the University of California, Berkeley, now argue that the axion could be discovered within seconds of the detection of gamma rays from a nearby supernova explosion.

From Science Daily

Light that reaches our telescopes ranges in wavelength from long radio waves to energetic gamma rays.

From Salon