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.
[glossary]
[Reference(s) to this entry by made by: {bit rot}{Commonwealth Hackish}{line noise}{sunspots}]