How come the axis of the earth changes flow of water down a sink/bath?

Answer 1

To be fair, while most of the answers here are correct, it is possible to show the effect of Coriolis on water going down a plughole. You should do the experiment close to one of the poles. Coriolis is proportional to the sine of the latitude so it is strongest at the poles and zero at the equator.

You should get a large tank of water and keep it at constant temperature and vibration free for a few days to allow the water to become completely still with no convection currents. You should then, very carefully so as not to disturb the water, remove the plug from the bottom of the tank. If you have taken the utmost care in preparation, the water should spiral out of the tank anticlockwise near the north pole and clockwise near the south pole. It won't always do it but it will do so more often than not.

I understand the experiment has been done successfully at one of the major US universities, Princeton I think.

Answer 2

It actually doesn't.

While the Coriolis force is constantly credited for the fact that water swirls down a drain, it's really vanishingly small except with really big things like hurricanes.

You can prove this with a simple test: fill a sink with water and drain it; note the direction it spins in. Now fill it up again, and give the water a little push in the other direction before draining it again. The water will spiral out the other way.

If the Coriolis force was strong enough to actually cause the swirling, then the act of getting into bed would induce dizziness and nausea. Does this happen with you? Not for me either.

Answer 3

There is a propensity for water to have a particular angular direction of flow in different hemispheres. The force that initiates this direction of flow is the angular energy that increases as one moves from either pole toward the plane of earth's equator. Energy of rotation in the northern hemisphere moves in the direction of that mass. In the southern hemisphere the energy of rotation moves against the direction of moving mass, causing a 25' rise in mass at the equator in that region that does not exist in the northern hemisphere.

Answer 4

It's actually because of earth's rotation around it's axis. This phenomenon is called "the Coriolis Effect" where water or air rotates counterclockwise in the northern hemisphere and clockwise in the south.

Answer 5

it doesnt it goes the same way it's just an old myth realy its how the sink/bath was manufasured the way the jets push water out etc.

Answer 6

It's the Earth's magnetic field.

Answer 7

It doesn't. That's a myth... hey, I think even the Mythbusters may have done that one!