How long can different mediums store information?

Factual Questions
1

I’ve been thinking lately about different formats and how they store information, both analog and digital. I’m interested in the life expectancy of different formats. I beleive I read before that CDs made professionally that don’t use Aluminum are expected to last forever if they are kept from oxidizing, but then from other sources I’ve read that no one really knows how long a CD will last.

What about cartridges? Atari 2600 cartridges have been working for around 30 years now. When are they expected to stop working if they are treated properly?

I’m interested in DAT tapes, LPs, CDs, Videogame cartridges (if some formats last longer than others?), Laserdiscs, DVDs, VideoDiscs, Floppy Discs, Harddrives, and any others I can’t currently think of.

My guess is the most long-lived data medium would be some sort of granite monolith in a dry climate.

2

Just a little anecdotal evidence - a couple of my CDs are already becoming unplayable due to corrosion of the metal layer. Google for “CD rot” for info. Apparently this was due to shoddy materials being used at a particular pressing plant (PDO) in the early 90s.

Naturally, the CDs affected are fairly rare and now out of print. I’ve made back-up copies on CD-R, but still :mad:

3

Here’s a link http://www.clir.org/pubs/archives/ensuring.pdf to an article written mby a RAND researcher on this topic.

He argues that for most media, the player will become inoperative and replacements unavailable before the media fails.

In general, I’d say that tape-based media are the shortest lived, and are certainly the ones most sensitive to heat and magnetic damage.