Posted by grant kinsley on 12/31/07 18:36

On Mon, 31 Dec 2007 07:51:56 GMT, "JR" <igoturspaminmy@sat.nz> wrote:

>
>"L Alpert" <alpertl@xxgmail.com> wrote in message
>news:j5Odj.184$jJ5.15@newssvr11.news.prodigy.net...
>> Big Daddy wrote:
>>> "Leroy" <we3v543erferet567y6@swe.com> wrote in message
>>> news:Xkwdj.37761$DP1.5659@pd7urf2no...
>>>> He's right.
>>>
>>> no, he's not.
>>>
>>>> The data is very close to the top of the disk so they HAD to put an
>>>> extra coating on it.
>>>
>>> Has nothing to do with "rotting". The disks are not "prone" to
>>> rotting.
>>
>> Rotting? Polycarbonate "rotting"? Never heard of this. There can be
>> damage due to UV exposure, though if this is a problem for a specific
>> device, there can be UV inhibitors used in the base polymer.
>>
>> The disc itself should outlive the useful life of the technology.
>
>Thats what they said about DVD and CD's and they are rotting all over the
>place now.
>
>Bitrot is another name for it. more common on burned Cd's DVD's but still
>were not getting the "lifetime" of safe starage like they claimed. more like
>6-15 years.
>

disc rot is very rare and has everything to do with defective sealing
of the protective layer, I have about 50 LDs and about a thousand CDs
and DVDs, I have had exactly 1 disc rot in that time ( a poor pressing
of an eric burdon greatest hits.) I've had CD since 1983 and DVD since
inception.

Bottom line is that defects occur in anything manufactured, optical
media is much less likely to deteriorate over time than just about any
other media.

As far as burned CDs and DVDs, that's a different problem as the
technology relies on a dye, not physically pressed pits, the dyes are
subject to breakdown over time.

GK

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