How can you not love this man . A national treasure . <| sep |> Thanks a lot for the great answer . Nice website you have set up . Cheers ! <| sep |> Generally , the postapocalyptic genre takes for granted the assumption that the human population was sufficiently diminished that institution such as the supply chain required to maintain nonrenewable energy sources , manufacturing of basically everything , and . Okay , I know jack all about pressure dynamics , let alone its practical applications , and Google has failed me . My point is not that the science failsthe science works the same as it did beforebut the systems that use the science need humans for direction and maintenance or fuel or whatever , and the humans are gone .