A whole chapter in my book on the sociology of information will be about information permanence and impermanence and so this posting by David Pogue caught my eye: "Should You Worry about Data Rot?" It's text of an interview that was a part of a video piece he did for CBS a few weeks ago. The basic idea is that we store our data on media that are subject to degradation and that require for play back hardware or software that have short lifetimes. We are left with the problem of constantly "migrating" our data to new formats.
An important observation : the pace at which data recording formats become obsolete and unreadable is accelerating. The experts cited in the piece suggest we are currently at the ten year mark -- at this point, one needs to migrate to new media every ten years.
The video piece ends with the observation that there's never been, nor ever will be, a data recording technology that lasts forever. Of course, one's first thoughts go to clay tablets from ancient Persia, which seem to have held up rather well. True, but of all the clay tablets ever produced, we have, in all likelihood, but a small fraction. But then, given what's on most of them (e.g., records of grain sale transactions or inventories of food storage), it's not clear that the information order is impoverished by their absence. Of what fraction of our current information holdings could the same be said of. One wonders, but one migrates one's own data, just in case.