There's an ironic twist to this great digital age. We probably store more information about ourselves now than was kept by all past generations combined, yet when future archaeologists start digging back to 2013, they may find precious little.
The dangers of decay and obsolescence threaten everyone with digital files, from those wanting to preserve precious family pictures and movies, to governments, businesses and universities that would grind to a halt without their computer records.
No one is completely sure yet how long digital files will last. It depends a great deal on what they are stored on, how they are cared for, and how long it will be before the software needed to open them is outdated and no longer available.
Some tips on how to preserve digital files at home will come later, but first consider the case of the Domesday Book, William the Conqueror's survey of England, written on sheepskin parchment 927 years ago, and still readable today.
The BBC decided to create a modern version of the book in 1986, using digital material submitted by schoolchildren about their local communities. It was stored using the latest technology, on 12-inch laser disks, to guard against obsolescence.
Only 15 years later, laser disks were just that - obsolete - and the whole project was in danger of being lost because the data could not be read by modern software. It was finally saved on more up-to-date media, but the task proved difficult and expensive.
Thousands of people now face similar problems with old technology like floppy disks or VHS or Beta cassettes, or with files created in old formats that refuse to open, or which display gobbledegook even after downloading a promised "fix" from the internet.
Data archiving analyst Owen O'Neill has wrestled with similar predicaments for years. He is now part of a team working on a strategy to preserve the University of Melbourne's digital records, and says it will take several more years to complete.
"Digital information deteriorates on different levels," he says. "The media itself can break down. Nobody's sure yet how long CDs or DVDs will last because they are still relatively new, but they will degrade over time with humidity and regular use.
"They're not really built for long-term storage, and if they hold important information, they should be backed up, stored safety, and new copies made every few years. Another strategy is to transfer the data into new formats when the software and hardware required to read them becomes outdated," O'Neill says.
Those basic rules apply no matter what kind of digital file or storage medium is involved. "Digital media is quite fragile, but the problem is most people haven't caught up to the fact that it's necessarily an issue," he says.
"You should never keep all your eggs stored in one basket. Keep files in multiple locations and on multiple forms of media if you want to ensure they are going to last long term. Storing things on the cloud is another way to back them up."
Of course, preserving digital files for many years is useless if the software required to open them is unavailable or no longer works on a modern computer, and experts recommend creating and storing files in open formats wherever possible.
"From a preservation point of view, an open format is superior because the code is released publicly, so anyone can use it to develop software that will read the relevant file's content," O'Neill says. "If it's a closed format - and the biggest one around is MS Word - you need to have Microsoft software to open it. They keep their codes secret, so the world is really relying on them to maintain their software and to enable older files to be opened.
"Microsoft is unlikely to disappear any time soon, but converting any Word document to pure text will preserve it in an open format that will be accessible in the long term."
Linda Tadic, who heads the Audio Visual Archive Network, an independent non-profit digital library and preservation service, has specific advice about storing digital images and home movies. Her first rule is to not use your camera as a storage device.
"Cameras can break or not be connectable in the future, so you need to transfer their files on to your computer in their native format. With tape cameras that's likely to be a .DV or .HDV file," she says.
"Be mindful of what format you are copying to, because if you change the original file format into a proprietary format like Windows Media or QuickTime, your great grandchildren may not be able to access it in 80 years.
"You need to store two versions. The camera's original file will always have the highest quality, so you need to store that away and only use it to make copies in the most current format - and keep copying into new formats as they take over."
Files should be backed up on DVDs or an external hard drive.
Archivists give similar advice for still images. The US Library of Congress, a leader in digital preservation, recommends using a camera's highest possible resolution and immediately transferring the images to a hard drive in their native format.
Storing copies as a .tiff file will retain the original's full quality, and the library says files should be checked at least once a year to make sure they can still be read, and that copies in new media should be created at least every five years to avoid data loss.
- FFX Aus