bit rot

jargon A 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.

People with a physics background tend to prefer the variant

"bit decay" for the analogy with particle decay.

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 detection

circuitry to compensate for them). The notion long favoured

among hackers that cosmic rays are among the causes of such

events turns out to be a myth.

Bit rot is the notional cause of software rot.

See also computron, quantum bogodynamics.

[Jargon File]

(1998-03-15)