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Re: [ARSCLIST] Hard disk drives and DAT

----- Original Message ----- 
From: "Don Cox" <doncox@xxxxxxxxxxxxxx>
> On 31/03/07, Steven C. Barr(x) wrote:
> > ----- Original Message ----- 
> > From: "Don Cox" <doncox@xxxxxxxxxxxxxx>
> >> I think an archival digital format that would last as long as
> >> Sumerian clay tablets could be developed if the market was there.
> >>
> >> It would have to use physical pits rather than dye or magnetism.
> >> Possibly some kind of toughened ceramic material would be suitable.
> >>
> >> Multiple layers, as on many consumer discs, would not be practical.
> >>
> > And what happens if these Sumerian clay tablets get wet and stay wet
> > for any length of time? Most forms of mud dissolve under those
> > conditions (an argument against building "my adobe hacienda"...)
> The Sumerian tablets are probably not fired, but they easily could be.
> Any modern material would not be soluble in water. There are many
> specialised ceramic materials used in engineering today.
> >From ultrahardmaterials.com:
> "There are three exceptional properties of engineering ceramics:
>  (1) Their very high hardness enabling products made from them to wear less
and last longer.
>  (2) Their ability to operate at very high temperatures.
>  (3) Their capacity to withstand very harsh and corrosive environments such as
acids, alkalis and organic solvents."
> The technical problem is to design a laser setup that can burn accurate
> pits in a disk of such a material. This shouldn't be that much more
> difficult than making a glass master disk.
> See here for a useful summary of materials:
> http://www.machinedesign.com/BDE/materials/bdemat7/bdemat7_2.html
> We can do better than shellac, I think.
1) Well, modern ceramics, being essentially "improved man-made rocks,"
are probably as indestructible as it gets! However (as you note) that
could make them difficult to record information onto...

2) The remarkable thing about "shellac" (the shellac-based compound
from which 78rpm records were made) is the fact that "long-lasting"
was NOT among the reasons it was selected for record making! This
being well before the era of "poly-wotevers," it was the only thing
they could find that was easily press-able and wouldn't wear out
after a half-a-dozen or so plays...

Steven C. Barr

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