[TriLUG] Safest long-term media

[Peter Neilson]

Steve Litt wrote:

> By the way, I keep [CDs] in a fairly dark place.

Yes. Dyes that can be written by laser light can apparently be bleached 
by sunlight or less. With the exception of (now abandoned as obsolete) 
Polaroid color prints, all color photography I've come across bleaches 
out. The chemistry behind Polaroid instant color is astonishing. Hmmm... 
a Polaroid print is maybe 15 megapixels or better. Should we resurrect 
the Polaroid process for data storage?

Marks chiseled in stone last for millennia, as does metallic-oxide paint 
on covered stone in the desert. Mosaic tiles and glass beads are fairly 
permanent. Clay tablets when baked work well. Silver photography (if 
properly stopped and fixed and rinsed) seems permanent if kept in the 
dark; my grandfather's photos from 1890 are in fine shape. Faint or 
erased ink on paper (or vellum or parchment) is readable through fancy 
techniques.

The instruction manual for the Antikythera Device was engraved on 
bronze, and about 95% of it has now been read, by X-ray or nuclear 
techniques. Long-term preservation of information without copying is 
possible, but not certain.