U.S. viewers of Doctor Who are currently being treated to a goosebump-inducing two-parter penned by Steven Moffat, who also wrote the genuinely terrifying "The Empty Child" episode a few seasons back. In his latest offering, Moffat presents us with a library haunted by flesh-eating shadows. The library itself is a wonderful conceit: in the 51st century, e-books and neural downloads and [insert exotic paperless technology here], are all so ho-hum that the people of the future decide to reprint every book ever published on good old fashioned paper. Not surprisingly, it takes an entire planet to store the resulting tomes. It all sounds completely absurd until you realise that books are currently holding up a lot better than digital technologies when it comes to long-term archiving. Early adopters of electronic storage now find that their data is stuck on obsolete formats—the National Air and Space Museum in D.C. has a whole bunch of photographs stored on videodisc, that ill-fated 1980s-era forerunner of the DVD, for example. (And let's all hope we don't have anything really important on VHS cassettes.) Compare this to a book—currently sitting on my desk is a copy of Galileo and The Inquisition by Richard Robert Madden, which I recently consulted when editing 20 Things You Didn't Know About The Solstice for DISCOVER. The book was published in 1863, yet using it involved no fuss, no struggling with incompatible software versions, no rooting through a cupboard for my last floppy-disk reader, just opening a page and reading. Admittedly, I couldn't automatically search the book by keyword, but a well-organized table of contents meant I didn't have to. The only solution right now for data obsolescence is to spend money and migrate the data to a new electronic format before all the equipment required to read the old format breaks down—and then be prepared to do it all again in another 10 or 20 years as yet another new digital storage technology takes over. So while we can't devote an entire continent, let alone a planet, to paper storage, it might be worth while making hard copies of, say, the photographs of your child's first birthday party and sticking them into a real-world photo album--just to make sure you'll still be able to embarrass your kids in front of their dates when the time comes.