And, speaking of the end of civilization...here is
an article written by an astrobiologist about what might be needed to start civilization over again.
As for myself, I have a hardbound copy of
"The Way Things Work". This book describes all sorts of technology from the simple to the complex because you never know when you might need to know something that you don't. I believe it is the sort of thing that every prepper should have on hand. Edited: BTW...used in good condition hardcovers are about $6 on Amazon.
BTW...while I'm on the topic of books. I'm reading
this now. Nice little end of the USA by way of EMP attack story.