What does Post-Apocalyptic Mean?

Inspired by a talk given by Alan Moore (The Watchmen), I feel it's necessary to discuss this point.  This is partially because when people say "The world is ending," it isn't clear what that means.  If we check the wide body of post-apocalyptic science fiction literature, we start to see a pattern.  We see a very interesting commonality, or strain of thought running through many, if not most, pieces.


It seems to be that the world coming to an end could have two meanings.  The first, and perhaps most intuitive meaning, is that when the world ends, Planet Earth ends.  Perhaps a large celestial object obliterates Earth, or perhaps the sun supernovas.


I think this meaning is almost never explored in post-apocalyptic literature.  This is for several reasons (I think).  First, there's no story that one easily recognizes as being post-apocalyptic.  Perhaps there is a story where humans escape Earth and then Earth is destroyed.  This doesn't strike me as post-apocalyptic (though this is just my intuition).


"The world" seems to be read more carefully in this context.  When the world ends, the end is fundamentally an end in the realm of ideas, concepts, ideologies, social and political structures.  The end is usually brought about through an abrupt change (virus, atomic bomb, meteor crash, etc) that devastates old paradigms, while not immediately replacing them.  So consider changes of power.  In Chile 1973, there was a coup.  However, the democratic structures were replaced almost immediately by totalitarian structures.  This is why, I think, an apocalypse involves a devastation (of some kind) without immediate replacement.


When we say "the world ends," all we are talking about are ideas ending.  No atomic bombs need be dropped or wild plagues or alien viruses.  And indeed, it doesn't seem far fetched to have an apocalypse on a planet other than Earth, or on a space station, or an underwater society (like with Bioshock)


These are just my thoughts.  Perhaps I am wrong.  I encourage all of you to pay closer attention to the finer details in post-apocalyptic stories.  See for yourself whether I am right or wrong.