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Re: [ARSCLIST] Audio History In a Nutshell?
I've seen this happen t pre-recorded CDs,too.You haven't seen what the New Mexico sun can do.
Roger
Mike Richter <mrichter@xxxxxxx> wrote: Roger and Allison Kulp wrote:
> Assuming we perfect a CD,that doesn't become de-laminated,and peel over time,or after exposure to the elements,leaving only a 5" clear plastic disc,with a hole in it.Our broken 78s discussed in an earlier thread,might yeild nore information.
A CD isn't laminated, so that part needs to be dropped. Both CD-R and
pressed discs can be destroyed by damaging the polycarbonate lower layer
enough. Otherwise, as long as the metal layer is undamaged a pressed
disc retains its information. That will also kill a CD-R, but it can
also fail due to the dye layer.
The dye in a CD-R is metastable. In time, it will revert to a neutral
state with ones and zeros lost to retrieval. That time for a quality
disc recorded well is guessed to be of the order of 100 years. So your
archeologist will have a useless disc.
Mike
--
mrichter@xxxxxxx
http://www.mrichter.com/
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