Books and other paper goods will all decay into dust after humanity is gone, no matter how well we try to preserve them. They'll be eroded by the singular fury of the elements. So one of the few monuments to the idea that humans worshiped a force larger than themselves will be the crumbling remains of the statue of Christ the Redeemer that stands outside Rio de Janiero. The irony of erecting a monument to the Prince of Peace overlooking one of the most dangerous cities in the world will probably be lost on our visitors, but at least they'll see we knew how to grow bitchin' mustaches.