Comments on: Which Way Does Water Spin Down a Drain?

By: Tom LeBlanc

Tom LeBlanc — Sun, 15 Jan 2012 21:23:43 +0000

The way I see it is that the earth is spinning fastest at the equator because that is the widest place on the globe. Any point at the equator must travel faster because it has farther to go to make its way around one revolution.

Likewise, the points on the earth move gradually slower as you move away from the equator.

Now picture a drain. Stand next to your toilet bowl and identify which side is closer to the equator. That part of the water will move faster and the opposite side will move slower. I picture the world rotation from left to right

To me, that makes it easy to understand why the water flows CCW in the northern hemisphere and CW in the southern hemisphere.

By: Liar

Liar — Sun, 04 Dec 2011 21:45:53 +0000

listen ppl dont say that this is lying! its the truth that it doesnt matter northern or southern it will go down the drain either way! my toilet goes down counter-clockwise and the tub and sink go down clockwise

By: dan

dan — Thu, 10 Nov 2011 09:21:28 +0000

Ok explain this one. I’m at work and the water turns to the right down the stool and sink. But I am holding a coffee urn in hand standing next to a water fountian. As the water hit the urn and fills up the wqater in the center of the pot turns to the left. How is that?

By: Nick

Nick — Tue, 06 Sep 2011 05:11:03 +0000

I live in Seattle in the northern hemisphere. I was in Harrare Zimbabwe, Africa two years ago and FORGOT to do this experiment. RATS!!!

Anyway, I trust the guy on the boat and the guy in Quito. And frankly all these similar results and responses taken as a whole provide evidence to me that this DOES INDEED effect water in a drain.

I get it, I get it. The force is very weak. Water in a drain TENDS to be influenced by the shape of the bowl and the dynamics of the plug-hole and drain.

But a little common sense here, please…… If this force EXISTS, OF COURSE it will act on EVERYTHING big and small. The earth’s magnetic field is very weak, yet it acts on tiny compass’ for instance.

I happen to know the rotation of the earth can effect relatively small things. When I worked at the Pacific Science Center in Seattle we had this huge Spirograph (I know there must be a more technical term for this thing), a heavy table suspended by wires from a 40 foot high ceiling. When pushed it would move back and forth as expected BUT as it continued rocking for 15 minutes or so, the lines drawn would slowly change their orrientation, CLEARLY in response to this very effect.
Nick

By: ecuadorena

ecuadorena — Fri, 02 Sep 2011 14:33:00 +0000

I am sorry to tell you but what you are explaining here an aparent “proof” is completely wrong. I live in Quito Ecuador, in the EQUATOR and I have been to the latitud 00″00″00″ and done the experiment (weel actually they let you do it and prove it yourself) in the south hemisphere, the north hemisphere and in the actual equator and let me tell you it goes clockwise in the south, counter-clockwise at the north and straight down in the centre. So I am not sure what kind of effect makes this happen but it is certainly not a MYTH!

By: imagery

imagery — Fri, 29 Jul 2011 04:25:07 +0000

The math is a bit complicated, but it proves the Coriolis force is very weak on free-floating small rotating objects. But I’ll say this … if your sink is perfectly circular, the drain is directly in the middle, the water is perfectly still, and you let the water drain veeeeery slowly (over a period of 20 minutes or more with no interference), the Coriolis force may present itself in the rotational motion of the draining water. But it would be very hard to do this.