I had always heard that when you change hemisphere, the water vortex in the sink, changes direction. Water leaves clockwise on one side of the earth, anti clockwise on the other side.
So, just before I had my flight for Australia, a ran the test, together with Gim Wee and her niece, my friends from Singapore – Here are my two accomplices.
At the beginning, we couldn’t see anything, but we had the good idea to add food colorants in the water. So, in case you don’t open your eyes while brushing your teeth, this is how it works in general :
Last week, before leaving Auckland, I ran the same taste, adding coffee to the water – sorry, this is not looking nice.
Do you see any difference ? No, you don’t !
And this is for a good reason : This story is a urban legend !!!
Contrary to popular misconception, water rotation in home bathrooms under normal circumstances is not related to the Coriolis effect or to the rotation of the earth, and no consistent difference in rotation direction between toilets in the Northern and Southern Hemispheres can be observed.
The Coriolis (*) effect can be helpful for understanding large-scale movements (such as storms, airplanes, and wind), but it’s inconsequential when it comes to something as small as a bathtub. The Coriolis effect is roughly 30 million times less significant than the force of gravity when it comes to describing water going down a typical drain.
(*) The Coriolis effect is a deflection of moving objects when they are viewed in a rotating reference frame. In a reference frame with clockwise rotation, the deflection is to the left of the motion of the object; in one with counter-clockwise rotation, the deflection is to the right.
Yes, this is Professor Nimbus speaking…
So, iI know this is a lot to process. Should you feel overwhelmed, just remember one thing THIS IS A URBAN LEGEND !