Longevity of DVD-R and CD-R (Was MagTapes)

[Eric Smith]

I wrote:
> It was my understanding (perhaps wrong?) that RW media uses a phase
> change to store the data, and that it takes significantly more energy
> to induce the phase change than to induce a chemical change in dye
> for write-once media.  That's why it can't be written as quickly.
> If it really works that way, one would reasonably expect RW media to
> have *better* longevity than write-once media.

Jim wrote:
> Based on my experience, this isn't true by a longshot.

I'm not disputing your experience or those of others.  I'm just trying
to understand *why* it has poor longevity, when the scant information
I have about how it works suggests that it should be better.

Eric