why does water swirl clockwise into the drain?
478834
Because you live in the Southern Hemisphere...In the Northern Hemisphere it goes the other way. Look up the term 'Coriolis effect' for more info.
1081908
The Coriolis Effect has nothing to do with water down a drain. It is a broad phenomenon that mainly acts on the atmosphere as the earth rotates. On the small scale of a drain and the high density of water versus air, the Coriolis Effect is completely drowned by the force of gravity and fluid currents. In a normal sink, water goes down a drain randomly - left, right and straight down - no matter where it is in the world. In order for the Coriolis Effect to be seen in draining water, a VERY large amount of water has to SLOWLY drain over a LONG time.\n\nhttp://stratus.ssec.wisc.edu/courses/gg101/coriolis/coriolis.html
819545
Yes they all do, for the same reason that water swirls when it goes down a plughole; conservation of angular momentum.  A star starts off as a large cloud of gas and dust which clumps together under gravity.  If there's even a little bit of swirling motion, as there always is, in the cloud or the water in the bath, then as it comes closer together the rotational speed increases.  Similarly when a rotating ice skater brings her outstretched arms together.  What determines speed of rotation?  The total angular momentum of the system to begin with.  Your angular momentum about an axis is equal to your speed perpendicular to that axis times your distance from it.  Add that up for each particle in the cloud or water molecule in the bath and you've got total angular momentum.  Two particles moving in opposite directions cancel out, but the chances of a large mass having zero net angular momentum are zilch.
444674
if you drop something in the water, it displaces water, and that displaced water moves other water, the rock going down in teh water pushes some up, which then pushes some down, and so on and so on.
65968
The water in the toilet is inside a "knee", basically an s-shaped combination of curved tubes. If the far side of the tube develops underpressure, some of the water will be pulled over into the far side, and water level will sink.\n\nPressure on the far side can oscillate. Usually the waste water system is connected to outside pressure via a separate chimney. On windy days, this chimney may act like a jet pump, reducing the inner pressure of the canalisation, so that water will be sucked into the falling side when the oscillation goes that way, lowering the water level.\n\nAnother possible source of oscillation are huge amounts of water flushed at once, moving down the tube pushing all the air below and leaving lower pressure above.\n\nBarometric pressure shouldn't really come into this, since canalisation and the open air are connected. However high or low the pressure, it ought to be the same inside the canalisation unless strong wind makes the chimneys act like jet pumps.\n\nNow, at which air pressures do you observe strong wind?
467226
Many of the 3D drains with the integrated plugs are also cast out of steel or aluminum, which allows a greater strength part because of the different thicknesses.  Also, in the past some of these were forged but that process tends to be expensive and is therefore not often used any more
424906
Usually when the waste pipe goes outside the building there is a T piece, one branch travels downwards towards the sewer network, the other heads to the roof for natural ventilation and to ease pressure build up. So when the wind blows across the top of the open vent it will slightly affect the level of water in your toilet bowl through pressure displacement.
24156
No!  Yet more bad science frequently stated in classrooms around the world.  Students in science classes are often told that the coriolis effect causes water spiral out the toilet and drains in opposite directions in different hemespheres.  This is not true.\n\nCyclones (tornadoes, hurricanes, typhoons, etc) DO spiral in opposite directions in the two hemespheres as a result of the coriolis effect, counter-clockwise in the northern hemisphere, and clockwise in the southern hemisphere.
353639
they do not turn clockwise....... clocwise is a term that was coined after the invention of a clock.......the inventor decided to make the hands move in the same direction as the sun dial of the past.....
300739
I always thought that the water fell down the drain different directions in the world.  When I was watching Dr. Know the other night, he said that this myth was not true and it really doesn't matter where you are located in the world, it depends on how the drain is made.
246971
Once I heard about a very serious physics study on that /   I'll try to find it for ya.\n\nHERE IT IS> When the simulation was complete, it showed that the spray drove a vortex. The center of this vortex—much like the center of a cyclone—is a low-pressure region. This low-pressure region is what pulls the shower curtain in. The vortex rotates around an axis that is perpendicular to the shower curtain. It is a bit like a sideways dust devil. But unlike a dust devil, this vortex doesn't die out because it is driven continuously by the shower.
615846
The Coriolis effect can be observed in a small system such as a sink, but it is usually superseded by other factors such as "leftover spin" from filling the basin, basin geometry, convection currents etc.
224113
The same reason toilets flush in counterclockwise rotation in the southern hemisphere, the rotation of the earth.
322179
From SPACE.COM:\n\nBack home, all of this has almost nothing to do with your bathtub drain, which creates another spiral shape.\n\nThere is a popular myth, though, owing to the rotational direction of a hurricane, that says the water in bathtubs rotates a certain direction in the Northern Hemisphere.\n\nIt's not true.\n\nThe Coriolis effect does not determine which way the water swirls in your house. The effect is too tiny to impact such a minor, localized process, all experts agree.\n\nThat means water is free to swirl in either direction in tubs in both hemispheres. Which way it goes is determined by the geometry of a particular basin or, if things are perfectly aligned and balanced, then by chance.
557791
Not only is the Earth's rotation too weak to affect the direction of water flowing in a drain, tests you can easily perform in a few washrooms will show that water whirlpools both ways depending on the sink's structure, not the hemisphere.
241749
It depends on the toilet, not the hemisphere.\n\nYou are thinking of something called "the coriolis effect".  This is the effect which causes water to try to spin clockwise in the southern hemisphere and clounter-close wise in the northern hemisphere.  Although this effect is real, it has a negligible effect in everyday life, like in the draining of toilets.  Compared to other factors, the coriolis effect is extrememly weak and for all intensive purposes, does not influence the effect of water draining out of a toilet.
1102874
You are referring to something called the "Coriolis effect".\nAlthough the Coriolis effect is indeed real, it is a very weak force in reality and does not practically influence the direction a liquid will drain in a toilet.\nThe water in the toilet will drain in the direction it is induced to, the Coriolis effect is totally negligible in this case since it is so weak when compared to the many other forces acting on the water.