= B =
bit rot n.
[common] Also bit decay. Hypothetical
disease the existence of which has been deduced from the
observation that unused programs or features will often stop
working after sufficient time has passed, even if `nothing has
changed'. The theory explains that bits decay as if they were
radioactive. As time passes, the contents of a file or the code in
a program will become increasingly garbled.
There actually are physical processes that produce such effects
(alpha particles generated by trace radionuclides in ceramic chip
packages, for example, can change the contents of a computer memory
unpredictably, and various kinds of subtle media failures can
corrupt files in mass storage), but they are quite rare (and
computers are built with error-detecting circuitry to compensate
for them). The notion long favored among hackers that cosmic
rays are among the causes of such events turns out to be a myth;
see the cosmic rays entry for details.
The term software rot is almost synonymous. Software rot is
the effect, bit rot the notional cause.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.