Remember the original TV version of Mission Impossible? I always loved the start when Jim Phelps got his orders from a reel-to-reel tape recorder rounding off with the classic line "This tape will self destruct in five seconds" after which the tape magically went up in smoke. Self-destructing tapes are still not commonplace even today but we do have a problem with information that inexplicably disappears.
I've had several cases of files that I've stored on a USB memory stick that suddenly became corrupted and about as useful as a second-hand Mission Impossible tape recorder. My digital camera suffered a similar fate this summer when one day's photos became corrupted data overnight. Back to a favourite theme then; how long can you trust a memory stick to actually store what you put on it? How long will a CD or DVD last?
I read an fascinating article in Dagens Nyheter (in Swedish) about the growing concern about digital preservation. The problem is how we are going to preserve all the digital films, photos and documents on all the world's servers. According to one test around 40% of all DVD-R discs will be unreadable within 15 years and similar figures apply for many other storage forms. All archived material has to be reformatted regularly otherwise the next generation of computers will not be able to read them and just this task will be a full-time never-ending job for a lot of people. In contrast paper can be preserved for hundreds of years.
An interesting example was the BBC's project to produce a digital domesday book to celebrate the 900th anniversary of the first one. One million people contributed to this epic which was produced on a laser disc. Sadly 15 years later the material was unreadable because the technology which could read the files had become obsolete. Furthermore it costs $12,000 a year to preserve a digital movie and a mere $1,000 to keep a traditional film version in a suitable archive.
It's reassuring to read that there are now projects and organisations dedicated to trying to find solutions to this enormous problem. It would also be nice if the industry could cooperate by trying to ensure more compatibility between applications and especially backward compatibility. Otherwise we face losing vast amounts of information, documentation, culture and entertainment for ever.
The Swedish Centre for Long-term Digital Preservation is just one of many international groups working with this. There's also an EU project called CASPAR. Good luck to them!