 The episode was written by Bill Oakley and Josh Weinstein , and directed by Wes Archer . The writing staff wanted to do an episode where the Simpsons family traveled to Australia , because they thought everyone in Australia had a good sense of humor and that they " would get the jokes " . The staff had previously poked fun at several American institutions on the show and they thought it would be interesting to poke fun at a whole nation . They designed Australia and the Australian people very inaccurately and many things were completely made up for fun . The animators , however , got two Australian tourist guides to help them out with the design of the Australian landscape and buildings , as well as the American Embassy . The writers did research on the Coriolis effect for this episode . Lisa 's explanation of the effect is incorrect ; it affects global weather patterns and is caused by the spinning of the globe on its axis . The amount of water in a toilet or sink is much too small to be affected by it . 
