You’ve heard the stories of how toilets in the US flush counterclockwise while toilets in Australia flush clockwise. On your next trip to the Land Down Under, you’ll likely be tempted to check out of curiosity.

The problem? It’s a myth.

A lot of people believe this story to be true thanks to the Simpsons episode “Bart vs. Australia,” where Lisa tells her older brother that water rotates in the opposite direction in the Southern Hemisphere. And not just in the toilets – it’s supposed to be true for sinks and drains, too. However, this myth was in place long before Bart found himself in trouble with the Commonwealth.

Ask a science geek, and he’ll tell you that the clockwise flushing, if it were true, would be a direct result of the Coriolis effect. The theory states that the motion of moving objects is determined by how they deflect off the inside of rotating objects. For a real world example, we only have to look at hurricanes, cyclones, and tornadoes. These storms always rotate counterclockwise in the Northern Hemisphere (with the exception of the rare tornado) and clockwise in the Southern because of the way the Earth rotates on its axis.

But there’s a catch. The Coriolis effect is far less applicable when demonstrated in a small-scale example like your tub drain. These circular forces are much more profound large-scale, and they certainly don’t play a part in how your toilet flushes.

So what is it, then? Generally, the designs of the toilets themselves. Toilet bowls are shaped in a certain way to drain the water one direction or the other and in the same direction every time. As Neil Degrasse Tyson put it, “It’s irrelevant whether you live above or below the equator.”

Are you in need of a drain cleaner, or do you have a plumbing question? Contact our drain cleaners and SOS Drain & Sewer.