If you live in the Northern Hemisphere, you may have heard a rumor that if you ever travel to the Southern Hemisphere, the toilets and sinks will all drain in the opposite direction! (Those living in the Southern Hemisphere may have heard a similar rumor about being in the Northern Hemisphere.) – Is this true, and if so, why does it happen??

In spite of the popularity of this myth, the truth is that location doesn’t have very much to do with whether a drain or toilet spins clockwise or counterclockwise. – Mostly, the direction water spins as it drains depends on the appliance’s shape and the direction of the water as it came into the basin or bowl. (With the right amount of effort, you could get any drain to flow in whatever direction you wanted.)

The idea that drains spin differently depending on hemisphere comes from something known as the Coriolis Force, which is the force that pulls air counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Although the Coriolis Force is strong enough to influence the spin of big things (like hurricanes), it is not strong enough to influence the direction of draining water in a sink or toilet.