If you're anything like me, you've got a stack of old games on CD and DVD sitting somewhere in your house. Have you had a look at them lately? Working, were they?
Archiving digital materials is really hard. All around the world there are storehouses full of information which would be of great use and interest to scientists, historians and researchers of all kinds - only the equipment used to get at it has been destroyed, lost or otherwise rendered unusable.
And that's when the storage medium survives the march of time; don't think your Saturn, PSOne, Dreamcast, PS2 and Xbox games are safe just because they're on plastic discs. Old CDs and DVDs are susceptible to several forms of decay, as many a gamer has learned to their dismay in opening a PC CD-ROM game from the 1990's. They just weren't built to last.
Luckily, someone's taking the problem seriously: the US Library of Congress. According to a report in The Atlantic, the organisation is conducting experiments to find out what causes CDs and their ilk to manifest "edge rot" or "bronzing," be it via oxidisation or other methods.
You can donate your own old, unwanted discs to the project, and maybe you should. Archivists and academics are coming late to this research - too late for many 1990's products. With the games industry's lackadaisical approach to archiving its own materials, your box of retro games might one day be the only record we have - assuming it survives.