G'day folks.
In the interest of science and at the request of my brother in law Dom, I have investigated a phenomenon that has been the debate of many a university bar or pub table over the years.
Which way does water go down a plug hole in which hemisphere?
Is it an urban myth?
Here is the science bit.
"There is an effect called the Coriolis effect which is due to the fact that the earth spins around. On a large scale it can have an effect on weather systems. Hurricanes and tornadoes almost always spin anti-clockwise in the Northern hemisphere and clockwise in the Southern hemisphere."
So does this translate to water down the plughole?
Opinion seems to point to the fact that sink shape, hole position, how the plug is removed and stillness of the water prior to plug removal all have more to do with the likely direction of vortex flow on such a small scale. If you used the same sink and managed to keep all other variables constant (in which case they would no longer be variables!) and performed the experiment in both hemispheres then you might just get the opposite effects in each. The effect is supposedly stronger the closer to the poles you get.
So that's it for small sinks and plugholes. However on a larger scale the Coriolis effect may be more evident.
So in the interest of science and Dom I have found the biggest plug hole I could find in the Southern hemisphere and had to fly 1000miles to do so. Yes Dom, I shall be seeking a full refund!
Here is the result.
So in essence it should follow that : Northern Hemisphere = anticlockwise
Southern Hemisphere = clockwise
Please 'Click' on play for the result.
BIG PLUGHOLE
SOUTHERN HEMISPHERE
As you can see from this video from the centre of Australia the water is going anticlockwise. Doh!
Just before anyone says it. The water is filled by four inlets, equally space and ejecting at 90 degrees to the pool edge so they should not be influencing direction.
However I did not have a spirit level with me to check that the pool and therefore the hole edge wasn't on the tilt or had any slight deformity which would without doubt affect direction.
So I conclude that it was a wasted trip and in the interest of true science I shall have to return with my spirit level!
There you go Dom. Job done!
Too easy mate! as they say here.
Cheers all.
Quod erat demonstrandum
