Why does water from a tap run down the drain in different directions depending where you are in the world?

Question

What is the exact explanation?? Water running from a tap goes down the drain in a clockwise direction if you're in Europe and the opposite way if you're in Australia! How's that??

Answer 1

See Coriolis Effect in Wikipedia and how a rotating frame of reference affects a moving object.

However....
According to Wikipedia:
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. This myth is perpetuated by the Simpsons episode, Bart Vs. Australia. In reality, 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. Note that toilets typically are designed to only flush in one rotation, by having the flush water enter at an angle.

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 drain, 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 ice skaters bringing their arms in to cause them to spin faster).

Answer 2

The answer you are looking for is the coriolis effect. This idea involves that the rotation of the earth causes the water to flow in a certain pattern.

However, water does not follow a pattern dictated by global position when going down a drain. It can go clockwise or counter clockwise. Various factors can determine how it will go. Is there already movement in the water? Is the drain shaped in a way to force the water to move in a way? Things like that.

Here are a couple of links about it.

http://www.snopes.com/science/coriolis.htm

http://en.wikipedia.org/wiki/Coriolis_effect

http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html

Answer 3

The reason tap water goes down the drain different ways when you are in different hemispheres is due to an effect called the coreolis effect. You can check it out on wikipedia if you want to know more.

It's basically due to the rotation of the earth about its axis which causes a slight tendency for objects to go one way or the other depending on the hemisphere. This also affects trade winds etc.

Answer 4

Urban legend.
The shape of the bowl determines the direction of the spin. Bring your same sink with you, and the water will spin the same direction in it anywhere in the world.

The Coriolis effect is far too weak to have a visible effect before the water's all gone down the drain.

Answer 5

It is actually an illusion. The water is swirling in the same direction from the earth's point of view.
But because you are looking at the spiral of water from below when you are in Australia it appears that is is swirling the opposite direction.

Try this. Hold out your finger and trace a circle in the air in a clockwise direction. You will see that at the top of the circle your finger is moving from your left to your right. Now point your finger at someone and trace the circle in the same way. Ask them what direction the circle is being drawn. They will say counter clockwise, or as the top of the circle is being drawn it is from their right to left.
But the thing is the circle you are drawing is the same as your clockwise roation circle. The only difference is the viewpoint of that rotation.

Answer 6

it isn't real. the conception is that the earth's rotation imparte a rotary area of the water, yet the style of element may be outweighed by technique of environmental impacts, mutually with the precise route of the toddler's kick contained in the bathwater.

Answer 7

Its called the coriolis effect.