Information density inversely proportional to durability?
This semi-recent New York Times post is about DVD’s being unreadable four years after they were recorded. It ties into one of my musings over the years — whether a medium’s information density is inverse to durability or recoverability. Or phrased differently, is the high storage density of electronic media a crippling strength, because the data becomes too “fragile”?
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The sturdy clay tablets of Sumeria have lasted thousands of years.
Paper and animal hide can store far more information per kilogram, but rarely last as long - if the Nag Hammadi Library or the Dead Sea Scrolls were stored in an area with any appreciable moisture (say, Vancouver, BC, Canada) they probably wouldn’t've survived the nearly two thousand years until rediscovery! Fortunately, copies are easier to make.
And electronic storage is the densest — but least durable — of all. (Four years?!)
A DVD can hold >4 GB of data — a phenomenal amount! At the moment, the English Wikipedia (without images) seems to be about 2 GB, based on a quick scan of the web.
The good implication is that electronic storage means the data is portable enough for millions of duplicate copies of Wikipedia to be floating out there. The loss of the ancient Library of Alexandria — wrongly pinned on Julius Caesar — may have been catastrophic. But with relatively-infinite copies of the data floating around, we should be able to preserve this storehouse of knowledge.
The bad implication is that,if the copies only last a few years… that’s not very durable. One would need to continually keep making new copies! (Admittedly, solid-state memory should be more durable than DVD’s.) However, this density of data is dependent on multiple sub-systems such as:
- computer in which to read the DVD / solid-state memory
- stable electric power to run the computer
Ten years ago, I was worried about the ability to provide electric power. However, with the assortment of hand-powered radios, cellphone rechargers and so forth, I’m not as worried. Providing we have continuity-of-technology, we should hopefully be OK. (I don’t want to express a stronger confidence because — as a student of classical Greek history — I’ve been made well aware of the dangers of hubris.)