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.

[glossary]
[Reference(s) to this entry by made by: {alpha particles}{bit decay}{cosmic rays}{link rot}{schroedinbug}{software rot}{sunspots}]