I agree, initially for a different reason to the other commenters here - text doesn't take up that much room. If you assume that each book is translated in eac

I agree, initially for a different reason to the other commenters here - text doesn't take up that much room. If you assume that each book is translated in each language then the figure is way short. But it's probably better to interpret it as each book in its original language. I've read a figure of 7000 languages (http://en.wikipedia.org/wiki/Ethnologue http://en.wikipedia.org/wiki/Ethnologue). A survey discussed here (http://answers.yahoo.com/question/index?qid=1005120803482 http://answers.yahoo.com/question/index?qid=1005120803482) suggests up to 175 million books ever published. That's 1.2 trillion uniques. But if we just worked with the 175 million figure then 50 petabytes would allow 300 megabytes per book. In fact assuming say 3 megabytes (base 2, mibibytes) per book you could fit just under 18 billion books. My figures are a little off from just using base 2 instead of base 10 but you get the gist of these back of the napkin numbers.