For a good take on this kind of thinking, I'd recommend reading Larry Niven and Jerry Pournelle's "Lucifer's Hammer" (http://en.wikipedia.org/wiki/Lucifer's_Ham

For a good take on this kind of thinking, I'd recommend reading Larry Niven and Jerry Pournelle's "Lucifer's Hammer" (http://en.wikipedia.org/wiki/Lucifer's_Hammer http://en.wikipedia.org/wiki/Lucifer's_Hammer). From the wikipedia page: "Some advanced technical knowledge was maintained by the means of the preservation of the book The Way Things Work, which had been wrapped in impermeable plastic and submerged in a septic tank prior to Hammerfall and later retrieved by a resourceful character who realized its potential value and likely scarcity in a post-Hammer world." I found myself inspired by this book — now I often think about what I could build all by myself in a post-apocalyptic world.