That’s how long microfilm lasts. (You wouldn’t have read any farther if the title of this post had been MICROFICHE! now would you?) Of course that’s just an estimate; we've been storing information on film to save space only since the 1800s. Disks—including hard drives—degrade from use, temperature, and development of new storage technologies (How many floppies did you toss without checking to see what was on them once you’d learned how to burn disks? How many files did you leave on your hard drive when you handed your old computer over to Goodwill?), but microfilm is less delicate and stores information in language readable by anybody with a magnifying glass.
Work not typed into computers, that is, work done on paper, that is, almost everything written before 1985, is saved for space on microfilm, if it's been saved. (Although information manipulation companies are digitizing as fast as they can.) That’s why you’ll find extensive microfiche files and microfilm readers and printers on the second floor of the downtown library.
To see APL's holdings of periodicals--including microfilm holdings--from our home page, click
--> research tools
--> Faulk Central Library Periodicals Search
then enter the title of a periodical, or use the browsing links. (Here's an example of an end result: New York Times Book Review.) Have your library card number handy; we've linked to our digitized holdings of the Book Review on that same page.
If you'd like to read more about long-term information storage, here's a link to a related APL post: The Future of the Book.