cosmic ray

American  

noun

Physics.

1. a radiation of high penetrating power that originates in outer space and consists partly of high-energy atomic nuclei.

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cosmic ray Scientific  

1. A ray of radiation of extraterrestrial origin, consisting of one or more charged particles such as protons, alpha particles, and larger atomic nuclei. Cosmic rays entering the atmosphere collide with atoms, producing secondary radiation, such as pions, muons, electrons, and gamma rays. Cosmic rays (and secondary radiation) can be easily seen in a cloud chamber.

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Etymology

Origin of cosmic ray

An Americanism dating back to 1920–25

Example Sentences

Instead, the evidence points to cosmic rays as a key factor.

From Science Daily

They evaluated long-term exposure to cosmic rays, changes during magma evolution, and contamination from meteorites.

From Science Daily

To test this process, the researchers placed glycine inside the chamber and exposed it to simulated cosmic rays using an ion accelerator at HUN-REN Atomki.

From Science Daily

New work from astrophysicists at Michigan State University may help resolve a scientific question that has lingered for more than a century: where do galactic cosmic rays come from?

From Science Daily

Other theories propose that cosmic rays start the process because the charged particles they produce accelerate within existing electric fields.

From Science Daily