|Also called: cosmic radiation radiation consisting of particles, esp protons, of very high energy that reach the earth from outer space|
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.
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.
cosmic raysn. Notionally, the cause of bit rot. However, this is a semi-independent usage that may be invoked as a humorous way to handwave away any minor randomness that doesn't seem worth the bother of investigating. "Hey, Eric -- I just got a burst of garbage on my tube, where did that come from?" "Cosmic rays, I guess." Compare sunspots, phase of the moon. The British seem to prefer the usage `cosmic showers'; `alpha particles' is also heard, because stray alpha particles passing through a memory chip can cause single-bit errors (this becomes increasingly more likely as memory sizes and densities increase).