----- Original Message -----
From: "Mike Richter" <[log in to unmask]>
> You are thereby collecting the best information on longevity of the media
> you have. The way to test lifetime is by letting time pass. If there are
> effective models of the aging process, accelerated life test can be used.
> In fact, it's used where there is no justification, hence the claims of
> 100-200 years for a written CD-R. But in fact the data haven't been
> collected - except as you're doing it.
> Of course, the result depends on storage conditions and the specific
> medium. One Diamond Disc is likely to age as another will of the same
> composition, but that won't give much information on its contemporary
> Polydor. Behavior in Florida is more dependent on how the air-conditioning
> is set than it would be in Maine.
Okeh, then...what I can say is this:
Based on approximately 25-30 years of actual observation, and another up to
75 years of implied observation, "shellac" phonorecords appear to have a
near-infinite lifespan provided they are not dropped, knocked from high
places by the cat (or other fauna, including the owner of both cat and
stored underwater (a plugged drain in the basement), subjected to
above 40 degrees Celsius (left in parked Mustang convertible in Florida all
day), exposed to methanol, ethanol or other solvents (probably prohibition-
era rotgut when the disc was new), or otherwised kept in inappropriate
storage conditions (various incidents involving incompetent amateur
at least in southern Ontario!
Steven C. Barr