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). Factual note: Alpha particles cause bit rot, cosmic rays do not (except occasionally in spaceborne computers). Intel could not explain random bit drops in their early chips, and one hypothesis was cosmic rays. So they created the World's Largest Lead Safe, using 25 tons of the stuff, and used two identical boards for testing. One was placed in the safe, one outside. The hypothesis was that if cosmic rays were causing the bit drops, they should see a statistically significant difference between the error rates on the two boards. They did not observe such a difference. Further investigation demonstrated conclusively that the bit drops were due to alpha particle emissions from thorium (and to a much lesser degree uranium) in the encapsulation material. Since it is impossible to eliminate these radioactives (they are uniformly distributed through the earth's crust, with the statistically insignificant exception of uranium lodes) it became obvious that one has to design memories to withstand these hits. [Jargon File]

Cosmic rays are high-energy protons and atomic nuclei that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy,

Cosmic Ray Subsystem (CRS, or Cosmic Ray System) is an instrument aboard the Voyager 1 and Voyager 2 spacecraft of the NASA Voyager program, and it is an experiment to detect cosmic rays. The CRS includes a High-Energy Telescope System (HETS), Low-Energy Telescope System (LETS), and The Electron Telescope (TET).

A cosmic-ray observatory is a scientific installation built to detect high-energy-particles coming from space called cosmic rays. This typically includes photons (high-energy light), electrons, protons, and some heavier nuclei, as well as antimatter particles.

The Cosmic Jokers were a German krautrock supergroup, though they were never a proper ensemble per se; their music was created from sessions put together by label head Rolf-Ulrich Kaiser and Gille Lettman in early 1973, without the performers' knowledge. They were a primary example of space rock.

The Cosmic Cube is a fictional object appearing in American comic books published by Marvel Comics. There are multiple Cubes in the Marvel Universe, all of which are depicted as containment devices that can empower whoever wields them.

The Cosmic Ray Deflection Society is a satirical/environmental pseudoscientific organization, based in New Orleans, Louisiana. A worldwide membership of over 250 members, the group believes the "deadly cosmic rays" are getting in through the hole in the ozone layer.