Coriolis effect
The plot of the episode is based on the story of Michael Fay, an American teenager who was caned in Singapore in 1994 for vandalizing cars. This episode perpetuated a popular myth that the Coriolis effect affects the motion of drains in the Northern and Southern Hemispheres. In reality, the Coriolis effect affects global weather patterns. The amount of water in a toilet or sink is much too small to be affected by it.