Now for some math.<p>Assume an average of 200 pages per book.<p>Assume 50kB per page, based on this rather interesting document that I just Googled:<p><a href="http://www.archivebuilders.com/whitepapers/22009p.pdf" rel="nofollow">http://www.archivebuilders.com/whitepapers/22009p.pdf</a><p>It multiplies out to 1200 TB to store an (admittedly fairly low quality) black-and-white scanned image of every book page in the world.<p>Newegg has <i>external</i> 2TB hard drives, at <i>retail</i>, for $110. So the cost of the modern Library of Alexandria, which would ship on 600 such drives, is down to less than $66k.<p>I am not the richest person in my town, let alone in my state or my country, yet I can now afford, with a relatively modest consumer loan, to own the libraries. All of them.<p>And if we assume that the so-called "Kryder's Law" continues to hold:<p><a href="http://en.wikipedia.org/wiki/Mark_Kryder" rel="nofollow">http://en.wikipedia.org/wiki/Mark_Kryder</a><p>costs will continue to drop by 50% every two years, and the universal library will be down to $515 -- less than the cost of my iPad -- by 2024.<p>How blessed I am to have lived to see this day, a day in which the ultimate dream of history's librarians is not only within reach, but could become commonplace within my lifetime. In twenty years, owning a digital copy of every book in the world could be... kind of boring. [1]<p>(Of course, we will likely spend the rest of my life and more wrangling over the legal right to copy the last 15% or so of these libraries from one set of drives to another. But you can't have everything. ;)<p>---<p>[1] Alhough at some point we'll have to come up with some really fast data buses, or copying that petabyte of data is going to take some serious time. Then there's the indexing and retrieval problems...