gamma ray

noun

: 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

These tardigrades were exposed to heavy doses of gamma rays—high-energy photons that are one form of ionizing radiation—and researchers then studied how their systems responded. —Tom Hawking, Popular Science, 24 Oct. 2024

Scientists have long known that thunderstorms can produce gamma rays, extremely high-energy light that is more often associated with astrophysical phenomena, such as exploding stars and matter-devouring black holes. —Lee Billings, Scientific American, 21 Oct. 2024

Scientists think that gamma rays emerge in thunderstorms when electrons accelerate through strong electric fields in the clouds. —Rudy Molinek, Smithsonian Magazine, 4 Oct. 2024

The plane also detected two types of gamma ray bursts never before recorded. —Paul Smaglik, Discover Magazine, 3 Oct. 2024

Word History

First Known Use

1903, in the meaning defined above

Kids Definition

gamma ray

noun

: 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

noun

: a photon emitted spontaneously by a radioactive substance

also : a high-energy photon

—usually used in plural