Weird Science

While sitting on the couch last night watching the SBC National Championship Game (college football)we taped last Saturday (don't tell me how it ends!), The Lovely Wife turns to me and says:

TLW: "SO-and-so was telling me something interesting. Did you know that when you flush a toilet in..."
Mike: "Heh, let me guess, it swirls the other way in the Southern Hemisphere? You mean the Coriolis effect. I'll stop you there. It's not true."

TLW: "What the hell is the Corioliolius effect? And how is it that you already know what I was going to say?"
Mike: "Don't ask me why I remember these things. I just know it's not true*"

TLW: "Are you sure? You're going to have to take it up with So-and-So, then."

TLW then stumped me by asking me to define the Coriolis effect, which I could not do adequately (or even fake it in a believable manner). So, after much careful googling and wikipedia-ing and snopesing -- it turns out that yes, I'm right in this. The Coriolis force (aka coriolis effect) is not the reason that toilets may flush and sinks may drain in any particular direction in either hemisphere.

Just so that you don't have to do all the snopesing and googling and wikipedia-ing that I did, let me boil it down to three simple** points:

1) The Coriolus force, which can affect the way large winds rotate around a low pressure center, is the reason that hurricanes spin counter clockwise in the northern hemisphere and clockwise in the southern hemisphere.

2) The Coriolis force is not strong enough to determine how a sink might drain; there are too many other factors at work (sink shape, disturbing the water, other exogenous forces). Toilets flush the way water is directed into them.

3) Your high-school teachers who told you that sinks and toilets run opposite in the other hemisphere (c'mon, admit it) were taking liberties, applying known scientific concepts to common problems without checking. Also, they were probably told by their high-school teachers.

So there you have it.

I now have two questions for you: Is unlearning something as impossible as unseeing something? And, what other doubtful things have you learned in your life which you recklessly promulgate at parties, bars, and to unwitting children?


Coriolus at Wikipedia

Bad Coriolis

Coriolis at Snopes

Plausible Lies and False Truths at (a funny read which also will (mis)inform you that a duck's quack will not echo and that you cannot feel the weight of a bird in a box if it's flying.)

*I say stuff like this all the time, and sometimes I'm even right and don't have to apologize for being such a pompous ass.
** They're simple for a reason. I'm no scientist. Nor do I play one on TV. Nor did I stay in a Holiday Inn Express last night.

Don't forget to Delurk!

Posted bythemikestand at 8:51 AM  

7 stepped up to the mike:

Steph said... 11:37 AM, January 12, 2007  

Huh. Apparently the toilets and drains in Brazil had me duped.

Mabel said... 12:35 PM, January 12, 2007  

I give you an A+ on your deduction. If you ever care to know the nitty gritty details, let me know. I'll be happy to give you more information than you want, complete with calculus and greek symbols.

The short answer, though is the Coriolis effect is due to a physical balance between the Earth's rotation and pressure -- like how when you stir your coffee you get a whirl-pool. You can stir your coffee cup either clockwise or counter-clockwise. The direction of the planet's "stirring" depends whether you're closer to the north or south pole. Perhaps not surprisingly, your toilet and sink are more like your coffee cup than a hurricane.

corgimom said... 5:05 PM, January 12, 2007  

I spent years talking about a creature called a brontosaurus, even though it was debunked back in 1964. Seems a mad, and lazy, scientist put one 'osaur's head on another's body and called it brontosaurus.
Thanks for the brief lesson on the Coriolis Force.

Christine said... 5:37 PM, January 12, 2007  


what do you know about the side hill gouger?

Lesley said... 5:49 PM, January 12, 2007  

Since high school I have "known" things about kangaroos. Because I was told them by my high school biology teacher. Turns out, as I was taught by my husband as I went to teach these things to my son at the dinner table (we were of course, talking about kangroos, as a family often does), that I had been misinformed. Since he was a biology major in university, I had to defer to his expertise in this matter (but I trust him more than my high school bio teacher...Phil has a more recently acquired knowledge base as well as no rum smell coming off coffee cup). I cannot tell you how many 3-5 year olds came home from daycare excitedly telling their parents "Hey guess what I learned about kangaroos today!!!" Oops.
BTW...excellent use of the Holiday Inn reference, very nicely done!

Elizabeth said... 10:23 PM, January 12, 2007  

Delurking to say hi! So the toilet flushing thing is false, huh? Good to know.

themikestand said... 11:14 PM, January 12, 2007  

christine: I know nothing of the side hill gouger. Enlighten me?

Lesley: You must tell me so I can learn and then immediately unlearn!

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