I’m currently in Wellington, New Zealand. At latitude 41°S, it’s the southernmost national capital city in the world. This is about as far south as you can be without hiking through Patagonia.

Being south of the equator once again, this time I actually remembered to personally debunk an old myth: The statement that water drains “backwards” in the southern hemisphere. Backwards as in clockwise. This is said to occur due to the Earth’s rotation. Well, I tried the sink several times and behold – it didn’t drain backwards.

Funicular railway, Wellington Taking the funicular railway.

The reason is that the Earth’s rotation is too weak to affect the direction of water flowing. Water whirls both ways, depending on the construction of the sink. Or to be more accurate, the Coriolis force is so small that it cannot determine the direction of rotation of a draining sink.

Reine at Mount Victoria, Wellington Taking in the view from Mount Victoria.

On the other hand, I’ve seen videos where you get different results depending on whether you are in northern hemisphere, southern hemisphere or right on the equator. I guess someone will still have to convince me.

2 comments

  • avatar
    Sofia
    09 Jan, 2007

    Really? Theresa did the same experiment when she was in Australia and claimed water did in fact drain backwards. Now you’ve gone and ruined it all for me! ;)
    Damn them all to hell!

  • avatar
    11 Jan, 2007

    Maybe me and Theresa agreed on making opposing statements, just to make you go here and see for yourself. :)

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