In caves in Lascaux, France, magnificent artworks were discovered from 17,300 years ago. Cuneiform clay tablets written over 5,000 years ago are still readable today (if you happen to know Akkadian, Eblaite, Elamite, Hattic, Hittite, Hurrian, Luwian, Sumerian, Urartian, or Old Persian). Egyptian hieroglyphic writing was more or less contemporary with cuneiform and papyrus manuscripts dating from about 4,600 years ago have survived. The Greeks and the Romans carved letters in stone and these are still eminently readable over 2,000 years later.
Vellum and parchment manuscripts dating to 4,400 years ago still exist, albeit in fragmentary form. On the other hand, illuminated manuscripts on parchment or vellum dating from 1000 A.D. are still magnificent in appearance and eminently readable if one is familiar with the Latin or Greek of the period and the stylized penmanship of the age.
In art galleries and museums, we enjoy paintings dating from the 15th century and frescoes from even earlier times. We find Chinese block printing on paper from the 8th century, 1,200 years ago. The rag paper used before the 19th century leaves us with books that are still well preserved. We even have photographs on glass plates or on tin that date to the 1800s.
Perhaps by now you are noticing a trend in the narrative. As we move toward the present, the media of our expression seems to have decreasing longevity. Of course, newer media have not been around as long as the older ones so their longevity has not been demonstrated but I think it is arguable that the more recent media do not have the resilience of stone or baked clay. Modern photographs may not last more than 150200 years before they fade or disintegrate. Modern books, unless archival paper is used, may not last more than 100 years.
I have written more than once in this column about my concerns for the longevity of digital media and our ability to correctly interpret digital content, absent the software that produced it. I won't repeat these arguments here, but a recent experience produced a kind of cognitive dissonance for me on this topic. I had gone to my library of science fiction paperbacks and pulled out a copy of Robert Heinlein's Double Star that I had purchased about 50 years ago for 35 cents. I tried to read it, but out of fear for breaking the binding, and noting the font was pretty small, I turned to the Kindle library and downloaded a copy for $6.99, or something like that, and read the book on my laptop with a font size that didn't require glasses! So, despite having carefully kept the original paperback, I found myself resorting to an online copy for convenience and feeling lucky it was obtainable.
It seems inescapable that our society will need to find its own formula for underwriting the cost of preserving knowledge in media that will have some permanence.
This experience set me to thinking again about the ephemeral nature of our artifacts and the possibility that the centuries well before ours will be better known than ours will be unless we are persistent about preserving digital content. The earlier media seem to have a kind of timeless longevity while modern media from the 1800s forward seem to have shrinking lifetimes. Just as the monks and Muslims of the Middle Ages preserved content by copying into new media, won't we need to do the same for our modern content?
These thoughts immediately raise the question of financial support for such work. In the past, there were patrons and the religious orders of the Catholic Church as well as the centers of Islamic science and learning that underwrote the cost of such preservation. It seems inescapable that our society will need to find its own formula for underwriting the cost of preserving knowledge in media that will have some permanence. That many of the digital objects to be preserved will require executable software for their rendering is also inescapable. Unless we face this challenge in a direct way, the truly impressive knowledge we have collectively produced in the past 100 years or so may simply evaporate with time.
The Digital Library is published by the Association for Computing Machinery. Copyright © 2016 ACM, Inc.