CD-eating fungus discovered

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AlienTech

In the zone
Geologist Victor Cardenes says he stumbled across the microscopic creature while visiting Belize.

The discovery came after friends complained that one of their CDs had developed an odd discoloration that left parts of it virtually transparent.

Using an electron microscope, Cardenes and colleagues at the Madrid-based Superior Council for Scientific Research later observed that fungi had burrowed into the CD from the outer edge.

It had then devoured the thin aluminium reflecting layer and some of the data-storing polycarbonate resin.

Cardenes said: "If you look at the CD from the shiny side, in the places where the fungus has been you can see all the way through to the painted surface on the other side.

"It completely destroys the aluminium. It leaves nothing behind."

Biologists at the council concluded that the fungus belonged to a common genus called Geotrichum but had never seen this particular species before.

*www.whatreallyhappened.com/
 
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AlienTech

In the zone
Fred Langa explains how to ensure that your recordable CDs remain archived for a decade or longer.
By Fred Langa
InformationWeek



Almost three years ago, in "Is Your Data Disappearing?" we discussed the likely lifespan of burn-it-yourself CD-Rs--an important consideration when you're using CDs to archive data for long-term storage. At that time, even the cheapest CD blanks were thought to be good for at least 10 years after burning, with some premium rewriteable CR-ROMs possibly good for as long as a century.
Those estimates were based on accelerated aging tests performed on the various dyes used in CD-Rs or CD-RWs: The dye layer is what actually contains the data in a CD, and also is what gives the disk its characteristic color--blue, silver, green, etc. You can find abundant technical details in the original article, in "CD-R Media Longevity" or in Andy McFadden's ever-excellent "CD-Recordable FAQ", especially in the section called "How long do CD-Rs and CD-RWs last?"

But the conventional wisdom about CD-R longevity was called into question several months ago with a series of tests originally presented in the Dutch PC-Active magazine and widely recirculated on English-language Web sites, including the Register and Slashdot. Those tests suggest that many CDs may fail in as little as two years! Of course, accelerated aging tests--while normally quite reliable--are only a simulation of aging. There's no way that a carefully controlled laboratory test will precisely reproduce every random aspect of actual aging in real-life conditions. But two years seems very, very short, unless the storage conditions were poor. And some environmental conditions can be quite unexpectedly harsh on CDs. For example, way back in 2001, we reported on the existence of certain special fungi that actually can consume the dye, foil and substrate in some CD types! An article in the science journal Nature had said:


After visiting Belize in Central America, Victor Cardenes of Madrid's National Museum of Natural Sciences, found one of his CDs discoloured, transparent and unreadable.... The disk's aluminium and polycarbonate layers were riddled with fungus, Cardenes and his colleagues have discovered ... Burrowing in like worms from the side of the disk, "the fungus destroyed crucial information pits", says team-member Javier Garcia-Guinea. Pits in a CD's aluminium and polycarbonate sandwich store binary data, which is read by a laser ..." (Full story "Fungus eats CD")
But premature failures like that seemed like a fairly low-probability issue--how many people expose their CDs to rain forest fungi?--until the PC-Active article. That article sent many of your fellow readers (and me!) back into our libraries of old CDs to see how they're holding up.

more... *www.informationweek.com/story/showArticle.jhtml?articleID=15800263&pgno=2
 
Sourabh

Sourabh

Laptoping
when were cds good backup media ??

they can break, they can get scratched, there can be probs while writing, so many issues
 
Q

quad master

In the zone
I have CD's which i have burnt 4-5 years Ago still no problem
with it but i take good care of my CD's i clean my CD's every 6months
with a soft cloth.

I have kept my CD's with utmost care and not even a single CD is such
that is not detectable by my CD/DVD Drives.

I have seen people keeping there cds like anything
- Thrown in drawers [leads to scratches]
- Not placed in there case
- Mishandling - Some people just keep on touching the readable surface

Well these are the things which i have noticed with my friends.
With things like this how can our CD's live long

I am having cds of most brands from cheap to costly ones not even a single cd has fungus like stuff.

Brands i have :- HP,Sony,Samsung,Princo,Mosaer Baer,Unbranded both side blank,Writex,BASF,Verbatim,Some Chinese Brands.

But all are working without problems
So all i have to say is how well you keep your Cd's is that matters.
 
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gamefreak14

Journeyman
If you want cds that'll last for 10yrs with no problem whatsoever, just buy gold media. I've a kodak gold cd, written 8-9 years back on the first writer available...and it still runs fine!
 
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pradeep_chauhan

Cyborg Agent
I think the CD reliability also depends as to how you store the media if you store the CD in a cold dark place the data retention life of the media increases many folds
 
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A

AlienTech

In the zone
I have some 15 year old cd's still working fine. I dont use them much. They were kodak gold's which at the time cost over $25 or more each, dont remember exactly but I know I was shocked ot hear the price and it was a big hucnk of my pay but the writer cost over $2000 so guess it was about even. But they were the only ones available at the time. The new cheap cd's dont last at all. Maybe a few years. like the silver and colored ones. (at the time I paid over $1000 for a 90 meg drive (cheap at the time considering 20 megs were that price 2 years before) so getting 650 megs was cheap for anything under $100.)
 
S

Scorpion

Journeyman
So, CD's are out Dated. Get DVD's now.
Will this Virus eats away DVDs too? MAy be then its time for some blue rays, or a massive immunization campaign!
 
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A

AlienTech

In the zone
I have DVDs less than 5 years old which do not work any longer. These are originals sold in the US for over $20 each, not the fakes from Singapore sold for $5 like in India and the middle east. I don't know what the problem is (since they are pressed disks and the groves should not go away like burnt media) but they become transparent semi translucent and develop read errors. And writable are far more fragile. But only have ones less than an year old so don't know how long they will last. Also I think the weather makes a big difference, for places like India, anything degrades 5 times faster than like in sterile countries like the US.

At first I thought it was the weather or fungus or what ever, but it only happaned on a few dvd's and not the rest. Also I had ot use rubbing alchole to get rid of the white fungus on the surface of almost all cd's dvd's here. Just like video tapes.. and my bags and cloths all became white.. It was like something weird growing on everything. My bags especially were hard to clean. The black suit cases were fully white inside and out.
 
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detj2004

Broken In
Are CDs rotting?

According to research done by Proff. Michele Youket, 150 degrees of humidity and a time of about 10 years are enuf for getting the CDs rot.

Experts say 2day's music CDs r built 4 longevity -- but only as long as they r kept in their cases, unscratched, at room temperature, away frm extreme moisture. "If its stored carefully then it may come close to human's lifetime.", says Alan Sahakian, a proff of Electrical & Computer engineering at Northwestern University. Jerry Hartke(president of media science) adds that the error correction in the CDs are so powerful that they'll still play even after drilling a 2mm hole.

They are saying that CDs develop deadly pricks over time, usually called 'constellation of pinpricks'
source: Span Magazine Vol. XLV No. 6

Seems like CDs will start giving error like floppies... :!: :!:
 
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