When gods get together they tell the story of one particular planet whose inhabitants watched, with mild interest, huge continent-wrecking slabs of ice slap into another world which was, in astronomical terms, right next door – and then did nothing about it because that sort of thing only happens in Outer Space. An intelligent species would at least have found someone to complain to. Anyway, no one seriously believes in that story, because a race quite that stupid would never even have discovered slood. <br><br>Terry Pratchett.