Posted on 08/26/2014 9:52:12 AM PDT by a fool in paradise
Many institutions have their archives stored on CDs — but the discs aren't as stable as once thought. There is no average life span for a CD, says preservationist Michele Youket, "because there is no average disc."
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Back in the 1990s, historical societies, museums and symphonies across the country began transferring all kinds of information onto what was thought to be a very durable medium: the compact disc.
Now, preservationists are worried that a lot of key information stored on CDs — from sound recordings to public records — is going to disappear. Some of those little silver discs are degrading, and researchers at the Library of Congress are trying to figure out why.
In a basement lab at the library, Fenella France opens up the door to what looks like a large wine cooler. Instead, it's filled with CDs. France, head of the Preservation, Research and Testing Division here, says the box is a place where, using temperature controls, a CD's aging process can be sped up.
"By increasing the relative humidity and temperature, you're increasing the rate of chemical reaction occurring," she says. "So we're trying to induce what might potentially happen down the road. That gives us a feel for how long things are going to [take to] age."
France says part of what they are trying to do here is determine the minimal conditions needed for libraries and archives everywhere to preserve CDs.
"Smaller institutions don't have the resources to control environments tightly," she says. "One of the things we try to do is sort of look at how wide can that range be, as long as it doesn't fluctuate too much. And [if] it's stable, then that's usually the best thing."
Unfortunately, this testing has also found that not all CDs are the same. Michele Youket, a Library of Congress preservation specialist, plays a CD of classical piano rhapsodies by Erno Dohnanyi. It crackles, and eventually the sound just cuts out.
This is a variant of what's called "CD rot," Youket explains. In this case. it's what's called "bronzing." The outer coating of the CD erodes, leaving a silver layer exposed. And when you leave silver exposed, it tarnishes.
"So it's actually changing the composition, and that's why you hear the scratching there," Youket says.
And here's the thing about CDs: Youket says part of what makes it hard to preserve CDs is that they are not uniform. There were a lot of different standards of manufacturing, depending on the year and the factory.
"This phenomenon of bronzing was particular to only discs that were manufactured at one particular plant in Blackburn, Lancashire, in England," and only between 1988 and 1993, Youket explains.
"Everyone always wants to know the answer to the same question, 'How long do CDs last? What's the average age?' " Youket says. But "there is no average, because there is no average disc."
The Library of Congress has around 400,000 CDs in its collections, ranging from congressional records to popular music, and the library regularly gets donations of CDs.
Real estate records and titles were also moved from microfilm to CD beginning in the 1990s all around the country, says Jim Harper, president of the Property Records Industry Association.
"They just made the move because they thought anything that was digital, anything that was electronic, was going to be far superior to anything from the past," Harper says. "And it turns out that that was indeed wrong."
With budgets tight for local governments, Harper says most are not going to be able to move to another form of storage in the near future.
PRIA has been taking Youket out to speak to county officials, to at least make certain they understand the problem they're facing.
"We've been working very hard to ... say, 'Listen, if you're going to use these things, you better be careful what you buy, because it's not all created equally,' " Harper says.
Increasingly, CDs aren't being created at all. The record shops that sold them are going out of business, and new computers don't come with CD drives any more. Even so, many of us still have dozens or hundreds of CDs. All Tech Considered Museums Give Video Games Bonus Life, But The Next Level Awaits
Researcher France says many of them can actually last for centuries if they're taken care of. "The fastest way to destroy those collections is to leave them in their car over summer," she says — "which a lot of people do."
Sadly, your favorite CDs — the ones you've played a lot — are often the ones that are most likely to be damaged.
These days, the Library of Congress is starting to archive material on servers, which France acknowledges could pose an entirely different set of still-unknown problems in the future.
It costs me several liters of Bio-mimemtic gel per Exo-byte, but it is worth it.
Have you checked the research into that stuff though? One baryon sweep and all--and I mean ALL--of the data is gone.
You're better off putting it into some kind of harmonic distribution matrix...multiple ones, at that. Then if one is hit by a pleotonic burst, you've got the others for backup.
[ Have you checked the research into that stuff though? One baryon sweep and all—and I mean ALL—of the data is gone.
You’re better off putting it into some kind of harmonic distribution matrix...multiple ones, at that. Then if one is hit by a pleotonic burst, you’ve got the others for backup. ]
That is why I store my data rods in a Baryon Insulating storage sleeve.
CDs and DVDs typically go bad by degradation of the aluminum reflecting layer. Single sided disk allow protection of the layer by the label (paper is not a good barrier material). Double sided disks, on the other hand, have a fairly good barrier to corrosion, since anything corrosive to the aluminum reflector has to get through the plastic outer layer.
You must have money to burn. But hey, if you can afford it...
[ That is why I store my data rods in a Baryon Insulating storage sleeve.
You must have money to burn. But hey, if you can afford it... ]
Yeah this nice Ferengi Merchant sold it to me, guaraneteed it would block all bayons..... He seemed so trustworthy...
glad to know about TY.
Allot of good information posted and some not so good. Check out “archival gold” from Delkin for 300 year archival quality CD’s & DVD’s. They use a 24KT gold layer where other manufacturers use aluminum (the cheapest and most prone to oxidation) and silver (more expensive and less susceptible to oxidation). The major brands today are using silver substrate and dyes that inhibit “rot”. With proper care (shield from ultraviolet light, heat & humidity) the data will last decades. My opinion is based on working in the industry since the late 90’s. Delkin is a competitor of mine but then when you’re selling a Chevy is Mercedes really a competitor? Check out the Delkin website for good G2 on the process of optical media manufacturing.
Not all Ferengis are crooks. Don’t be such a racist.
Not all Ferengis are crooks. Don’t be such a racist.
I bought it from Rom, I trust Rom, LOL
Isn’t it funny how they sterotyped all the races in Trek, the Ferengi were greedy, the Klingons were wariors, the Romulans were back stabbing, the Cardassians were Fascists, and the Federation were perfect, LOL
How very tolerant of them.
And all it took was the self respect of ONE starfleet officer....
And all it took was the self respect of ONE starfleet officer....
I forgot about Cardiasin original Cardiarian not this Hollyweird fake family
Umm, no, that’s actually a really BAD idea. If there’s a manufacturing defect, they WILL fail at the same time. Backing up on two hard drives is by itself a splendid idea, but go for two different brands and you avoid the issue of bad batches ruining you.
I can remember as a kid, going into my grandparents barn, and finding quarter inch thick Edison records of my great grandparents, and trying to play them on my record player. The suckers played, and didn't sound that much different than the LP's I had. Even after 50 summers and winters in a barn.
Vinyl is Final not only applies to home siding.
A newer type disk with a possible 1000 year lifespan...”M-Disk”... you need an M-Disk burner (couple dozen models available), but can be played back on standard DVD/Blu-ray payers. http://www.mdisc.com/what-is-mdisc/
Make a copy. As long as you do so for personal use, do not copy for others, and keep the original disc it's legal. Copy music into HD as well and copy from that. I never keep my original licensed CD's in a vehicle
Then, all you will need are backwards compatible software and hardware to get the data.
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