La leyenda urbana del efecto coriolis en los lababos

La direccion de la rotacion de los lababos en cada hemisferio es una leyenda urbana, o mas bien, un error cientifico comun...
Se pueden encontrar mas explicaciones, pero recorreremos a la wikipedia.

Draining bathtubs/toilets

A popular misconception is that the Coriolis effect determines the direction in which bathtubs or toilets drain, and whether water always drains in one direction in the Northern Hemisphere, and in the other direction in the Southern Hemisphere. The Coriolis effect is a few orders of magnitude smaller than other random influences on drain direction, such as the geometry of the sink, toilet, or tub; whether it is flat or tilted; and the direction in which water was initially added to it. If one takes great care to create a flat circular pool of water with a small, smooth drain; to wait for eddies caused by filling it to die down; and to remove the drain from below (or otherwise remove it without introducing new eddies into the water) – then it is possible to observe the influence of the Coriolis effect in the direction of the resulting vortex. There is a good deal of misunderstanding on this point, as most people (including many scientists) do not realize how small the Coriolis effect is on small systems.^[1] This is less of a puzzle once one remembers that the earth revolves once per day but that a bathtub takes only minutes to drain. When the water is being drawn towards the plughole, the radius with which it is spinning around it decreases, so its rate of rotation increases from the low background level to a noticeable spin in order to conserve its angular momentum (the same effect as bringing one's arms in on a swivel chair making it spin faster).

Pues eso...