How the epic, dystopian novel took over bookshelves

Have we exhausted the literary capacity of the earth?
 With a whiff of apocalypse accompanying our daily scroll through the news, there is something oddly reassuring about rehearsing doomsday scenarios in the comforting form of fiction. Katie Roiphe reflects on why several critically acclaimed novelists have lately turned toward science fiction, dystopian worlds and sweeping epics.