Tuesday, September 4, 2012



The general knowledge is that the toilets that flush in a clock-wise motion north of the equator, flush counter-clockwise when one gets south of the equator.

But is this true?  Homeschool Atheist Momma's crack mythbusting team set to find out.

We know several things.  First, people in America are absolutely amazed, concerned, and perplexed with this issue.  Although we don't know why that is so, it is darn near the first question everyone asks us!  Secondly, we have seen many different toilets here in Australia and our discovery seems to be universally true.  Thirdly, the water in the northern hemisphere has a strong and distinctly clock-wise rotation each and every time.  And Fourthly, we know that hurricanes do, in face, spin one way in the northern hemisphere and cyclones spin the other.

We gathered around the local...watering hole...and watched as The Doctor started the initial flush to illustrate what we already know:

The flush here is very different.  It does not rotate at all, but rather gush-fills and drains straight down the bottom in one quick egress...er...movement, so to speak.

So we turned our attentions to the sink, hoping to solve this below-the-equator drain dilemma.

Bonobo and I filled the sink and our Water-Down-the-Down-Under-Drain experiment proceeded.

Our discovery?

Difficult to see, but Clockwise

Counter clock-wise!

clearly counter clockwise, as the bubbles show

No rotation at all

Did we see that correctly?  The water went counter clockwise the first time, clockwise the second time, no rotation at all the third time!  Did the amount of bubbles have something to do with it?  (Bubbles were added to make the movement more apparent.)  Did the shape or size of the sink have anything to do with it?
It turns out that we did see it correctly.

Major weather storms (such as hurricanes & cyclones) swirl counter-clockwise in the Northern hemisphere and clockwise in the Southern, due to Coriolis forces arising from Earth's rotation.

Small-scale phenomena such as water swirling down a drain are influenced far more by the design of the basin and drain than by Coriolis effect forces, which are tiny indeed in a toilet, north or south hemisphere.  Here in the southern hemisphere, the Coriolis effect does not seem to effect our small drains and toilets.  Therefore, spin direction can be attributed more to shape and consistency of the draining...er...fluids.

Just read this explanation from the Just Answer website. 

Who wouldn't post a comment regarding a science experiment that involves flushing the toilet? ____________________________________

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  1. Hello! I wandered over from Penelope Trunk's homeschooling blog, and just wanted to say this made me laugh :) Welcome to Australia! Hope you all enjoy all our mystical watery wonders.

  2. Cute guys and so urrr...hummmmm...a..scientific! I'm enjoying your posts, Karen.

  3. Lol!!! Well you learn something new everyday!! Welcome to Australia!!! I an also a homeschooling mum from Brisbane :)

  4. My blog is http://lifeslittledistractions-bianca.blogspot.com.au

    Bianca :)


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