The Toilet Flushing Direction Myth: Do Toilets Really Flush in Different Directions in Different Hemispheres?
Despite the Coriolis Effect, toilets don’t flush backwards in Australia (or on the other side of the world, or in different hemispheres, or on one side of the equator). The direction of toilet flush has nothing to do with geographic location; it has to do with the shape of the basin.
The Coriolis Effect, the effect that makes air spin in different directions on each hemisphere, is real and affects large weather systems. However, the Coriolis Effect is far too weak to effect a toilet flush in any meaningful way. The myth that it changes the direction in which water goes down a drain has persisted over many decades despite the mechanics of the Coriolis effect being known.
Coriolis Effect: IDTIMWYTIM
FACT: Since there is no correct way for a toilet to flush (clockwise or counter-clockwise) there is technically no “backward.” If we based water direction strictly on the Coriolis Effect and pretended that the effect was strong enough to affect the direction water goes down the drain, then toilets would flush clockwise in Australia and “backward” or counter-clockwise in America.
FACT: Despite a large amount of misinformation, toilets, drains, and even tornadoes are too small to be affected by the Coriolis, whose force would only begin to directly influence a storm’s swirling mass if it were approximately three times larger than the supercell storm systems that typically generate tornadoes.
- Do toilets flush backward in the southern hemisphere? No.
- Do toilets flush backward in the Northern hemisphere? No.
- Does anything change the way water goes down the drain? The only thing that affects which way the water goes down the drain is the shape of the basin leading to the drain.
Get the details on the science behind the Coriolis Effect, or watch these fun videos busting the old toilet flushing myth.
TIP: You are supposed to sync up the two videos below, one was done in the Northern hemisphere and the other Southern. These videos offer real-time proof of the flushing myth.
The Truth About Toilet Swirl – Northern Hemisphere.
The Truth About Toilet Swirl – Southern Hemisphere.