cosmic ray

noun Physics.

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

Origin of cosmic ray

An Americanism dating back to 1920–25 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for cosmic rays


British Dictionary definitions for cosmic rays

cosmic rays

pl n

radiation consisting of particles, esp protons, of very high energy that reach the earth from outer spaceAlso called: cosmic radiation
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

cosmic rays in Science

cosmic ray

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

cosmic rays in Culture

cosmic rays

Elementary particles, mainly protons, that are produced by the sun and other stars and then strike the upper atmosphere of the Earth. Some of these particles are absorbed, some help form the Van Allen belt, and some reach the Earth's surface, where they form a part of the background radiation that constantly surrounds us.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.