This means that if the position of an error can be identified, it can be corrected. All digital systems include some form of error detection and correction process. There are three main reasons for this. 2.1 Decay of Existing Carriers All types of information carrier are decaying. Some types are decaying faster than others.
Historic manuscripts are often in better condition than documents on modern paper.
The underlying fact, however, that cannot be escaped is that ALL documents whether on paper, vellum, parchment, papyrus, clay tablets, carved in stone, on magnetic tape, shellac discs or on photographic film are decaying. We can slow the processes but we cannot stop them. We can, however, easily accelerate decay by bad handling practices and bad storage. The carriers used to hold information in the new, large capacity storage systems are themselves liable to decay. The rate of decay is probably going to mean a safe life of about 50 years.