Is it true that water runs clockwise down a plughole in the western hemisphere and anticlockwise in the south?

Question

It might be the other way round, but is it true? I was in Australia recently and forgot to check!!!!! And can anyone tell me why this happens (in simple English please, I am only a gorgeous fluffpot and not a physics professor).

Answer 1

This is one of the most commonly asked questions in this category.

It is a myth - completely and utterly false.

Even Michael Palin was caught out by fraudsters in his Pole to Pole - but apologised in the video of the series.

The Coriolis effect is far, far too weak a force to have an effect over such small distances.

But don't believe me - Google it and you'll find hundreds of webpages, some scientific, some not that confirm this is an Urban Myth.

Fraser.

Answer 2

YOU ask a complicated question to expect a simple answer, Sorry!!!!
In "Theory" Yes. Now, here the problem. Though there is the "Coriolis effect", it is really not noticeable in a plughole, and from what I going to give for reference the plughole may need to be designed to revel the Coriolis effect. So, Technically the answer may be NO. Even though the Theory says YES.
Fred W. Decker, professor emeritus of oceanic and atmospheric science at Oregon State University states;
"Really, I doubt that the direction of the draining water represents anything more than an accidental twist given by the starting flow. The local irregularities of motion are so dominant that the Coriolis effect is not likely to be revealed. An empirical test could help."
Brad Hanson, a staff geologist with the Louisiana Geological Survey states;
"Do bathtubs drain in different directions in the two hemispheres? If you had a specially prepared bathtub, the answer would be yes. For any normal bathtub you are likely to encounter in the home, however, the answer is no.

Answer 3

The erroneous bit of folk wisdom you refer to says that water always drains in a clockwise direction in the Southern Hemisphere, and in a counterclockwise direction in the Northern Hemisphere. The supposed reason for this "fact" is the Coriolis effect, which has to do with the effect of the earth's rotation on moving objects.

Well, there is such a thing as the Coriolis effect. It explains why macroevents such as hurricanes rotate in a clockwise direction in the Southern Hemisphere and counterclockwise in the Northern Hemisphere. However, when you get down to itty-bitty phenomena such as the water draining out of your bathtub, the Coriolis effect is insignificant, amounting to roughly three ten-millionths of the force of gravity (in Boston, at least, which is where they happened to do the measuring).

The boring truth is that water drains every which way no matter what hemisphere you're in, for reasons which have to do mostly with the shape of the drain, the way you poured in the water in the first place, and so on.

All this was demonstrated way back in 1962 by one Ascher Shapiro, a researcher at the Massachusetts Institute of Technology. Shapiro filled a circular tank six feet in diameter and six inches high in such a way that the water swirled in a clockwise direction. (Remember, now, that Coriolis forces in the Northern Hemisphere act in a counterclockwise direction.)

Shapiro then covered the tank with a plastic sheet, kept the temperature constant, and sat down to read comic books or whatever scientists do while they wait for their experiments to percolate. When he pulled the plug after an hour or two, the water went down the drain clockwise, presumably because it still retained some clockwise motion from filling.

On the other hand, if Shapiro pulled the plug after waiting a full 24 hours, the draining water spiraled counterclockwise, indicating that the motion from filling had subsided enough for the Coriolis effect to take over. When the plug was pulled after four to five hours, the water started draining clockwise, then gradually slowed down and finally started swirling in the opposite direction.

Needless to say, unless you are a consummate slob, you do not wait 24 hours (or even 4-5 hours) to drain your bathtub. Hence the influence of the Coriolis effect may be safely described as slight.

Answer 4

No, that statement is actually bad science. The Coriolis effect only works over large distances of the earth like big weather systems. A drain in a sink is way too small for the effect to take place. It's considered on of the worst mistakes in science that people believe in. The way the water spins depends on currents flowing in the water and the shape of the sink or tub.

Try here;

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

Answer 5

I seem to bear in mind years in the past that a digital camera group from a teenagers television programme, in all probability Blue Peter, aimed the lens down directly to a field of water with a hollow in the backside. This leaking field replaced into carried around the Equator. The process rotation replaced into pronounced to alter as a results of fact the field crossed from one fringe of the equator to the different.

Answer 6

No it's not true. It's a popular misconception that this is due to the coriolis effect, but this effect only influences large scale movements such as weather systems. It doesn't influence bathroom plugholes.

Here's a good explanation :

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

Answer 7

Yes

Answer 8

Yes. Apparently it has something to do with the gravity of the world, but dont ask me anything more scienfic cause I too am only a gorgeous fluffpot (in my dreams!!)

Answer 9

Penny Century is right.
It's just a myth. Many experiments have been Completed and it does not change direction.

Answer 10

Yes, but it's northern and southern not western as in your question. Also right on the equator it goes straight down.