Friday, November 11, 2011

(empo-tuulwey) Do you want to read this blog post fifty years from now?

A lot of us are involved in the production of information. Maybe you're just planting crops on your farm, or perhaps you are writing the leading business blog of Ontario, California, but in either case you are creating information that will be stored somewhere.

Will you be able to retrieve that information the day after you created it? In many cases, you will be able to do so?

How about a year from now? Ten years from now? Fifty years from now?

The answer to that question partially depends upon how the data is stored.

Enter the microfilm folks. Take, for example, Heritage Microfilm, who has a particular mission:

Our Mission

It is the mission of Heritage Microfilm to be the world's leading provider of historical newspaper content, focusing on individual people and the events that impacted their lives. Through constant improvement, we are committed to providing a high volume of quality content via innovative and useful delivery methods. Heritage Microfilm will demonstrate this commitment by empowering creative employees who possess a high level of personal accountability and a dedication to excellence.


As can be ascertained by its company name, the company uses microfilm as its preferred preservation tool. Needless to say, Heritage Microfilm explains why they made this choice:

The life of digital images stored on magnetic media (hard disks or tapes) is about three to five years. After that the files begin to deteriorate. Systems that rely on tapes for long-term storage require a "refresh" by copying the data onto new tapes every 3 to 5 years. Most CD's have a media life of 5 to 10 years. Most CDs contain a layer of light reflective/reactive material that decays over time. These same LE's apply to DVD's. Microfilm, as created by Heritage Microfilm, has an LE of 500. (Film created prior to about 1980 was on a type of plastic [acetate] that gave the film an LE of 100 years.) Poor processing, poor handling, environmental contaminants, and especially humidity and heat will substantially shorten the LE of microfilm. Overall, microfilm has an LE of at least 25 times that of any other available media. ADVANTAGE: Microfilm.

Of course, it's always valuable to check multiple sources - especially when you consider that Heritage Microfilm might be a tiny bit biased regarding non-microfilm media. Especially when some of the claims violate common sense:

Dear Cecil:

In 1994 I read an article in the British music journal The Wire that claimed that compact discs have a life expectancy of ten years. I have seen references to an article in Scientific American making the same claim and heard that this has been confirmed many times by other studies. The only thing is, uh, I've had a few CDs for more than ten years, and they play fine. So what exactly is the deal? Does the speed of degradation have to do with how often the CD is played? I mean, most of the time, my CDs are sitting in their cases on my shelf. Please tell me whether I should be getting my Sonny Rollins fix from some other recording technology (like, say, vinyl).

— Michael R., Chicago


Cecil Adams provided a comprehensive answer to Michael's question, noting in passing that sometimes the true problem is not the preservation of the media, but the preservation of ways to access the media. (Can YOU play your eight-track tapes?) But in answer to Michael's specific question, Adams notes that the statistics quoted by Heritage Microfilm aren't quite as cut and dry as was implied:

The longevity of CDs and other optical storage media is controversial. CD manufacturers generally claim their products will last 100 years and possibly much longer, based on "accelerated aging" tests. (Typically these involve subjecting the media to heat.) Skeptics say five to ten years is more like it, but that seems alarmist where nonrewritable CDs are concerned. The "CD rot" stories that circulated years ago apparently sprang from substandard disks sold by a CD bootlegger in Italy, in which the aluminum oxidized after a short time. That won't or at least shouldn't happen with a properly made CD, nor will such a disk wear out with repeated use (although scratches and other abuse may cause it to fail).

Adam's conclusion:

The truth is, nobody knows.

But there's one medium that has stood the test of time. Jeff Rothenberg, author of the Scientific American article that Michael R. and Cecil Adams both referenced, subsequently expanded the article into a paper Rothenberg's 1999 paper includes a picture (on page 4 of 18) of various types of media storage, including paper tape, magnetic tape, 5 1/4" floppy disks, 8" floppy disks...and a replica of the Rosetta Stone. Rothenberg comments:

In addition to being quite legible after nearly 22 centuries, the Rosetta Stone’s preservation is directly attributable to the fact that its import (i.e., that it consisted of three versions of the same text, one of which, being Greek, might provide the key to deciphering the lost Egyptian scripts) was visually apparent to the French lieutenant (Pierre Francois Xavier Bouchard) who was in charge of the squad that discovered the stone. The digital storage media shown surrounding the replica have already failed to remain readable for 1/100th as long as the Rosetta Stone.

(It should be noted that Rothenberg defines "readable" to refer to both the physical preservation of the media and, as noted above, the preservation of ways to access the media.)

So if I really thought that this post merited preservation for future millennia, I would write it in stone (eHow explains how to do this) and translate it into other languages (using a facility such as translate.google.com).

I don't know that this post is really worth preserving.

أنا لا أعرف أن هذا المنصب هو حقا يستحق المحافظة عليه.

(Just in case I'm wrong.)
blog comments powered by Disqus