Back in the 1990s, historical societies, museums and symphonies across the country began transferring all kinds of information onto what was thought to be a very durable medium: the compact disc.
Now, preservationists are worried that a lot of key information stored on CDs — from sound recordings to public records — is going to disappear. Some of those little silver discs are degrading, and researchers at the Library of Congress are trying to figure out why. …