First thought was that this is unnecessary because enough people will always keep a local cache of Wikipedia or whatever handy. Second thought was a conversati

First thought was that this is unnecessary because enough people will always keep a local cache of Wikipedia or whatever handy. Second thought was a conversation between an electrical engineering professor I had in college and one of my classmates. We were learning about flip-flop circuits, which led to a discussion of computer memory in general. The conversation went: Prof: Flip-flops and latches will lose their memory when powered off, so not necessarily the best solution for storing something important. Classmate: Then how does my USB memory stick store data when it's unpowered? P: [explanation of floating-gate MOSFETs, which can hold data intact practically forever, although actually forever is a different story] C: What's the best way we know of of storing data for the longest possible time? P: Carve it into the side of a mountain.