Down the Plughole
 

A golden oldie that appears to have puzzled scientists, Universities, sink manufacturers and laymen alike for Centuries, is WHY water apparently swirls down the plughole anticlockwise in the Northern hemisphere and clockwise in the Southern.

I have surfed the web on this elementary subject until my keys ran hot and have seen it all from complex scientific explanations by Universities, scientists, sink manufacturers and just about everybody from the sublime to the ridiculous, until I ran out of steam. Result ? NONE, totally inconclusive.

Some say that Coriolis has an effect, some say it does not.

If I could see positive information that the majority of people in the Northern hemisphere saw their sinks drain ACW and the majority of people in the Southern hemisphere saw their sinks drain CW, then I would start to believe there is definitely a scientific phenomena present and therefore there must be a scientific solution. Other than that, it is just a myth.

Meanwhile I support this conclusion :-

One can find both counterclockwise and clockwise flowing drains in both hemispheres. Some people would like you to believe that the Coriolis force affects the flow of water down the drain in sinks, bathtubs, or toilet bowls. Don’t believe them! The Coriolis force is simply too weak to affect such small bodies of water.

So what do you think about this schoolboys riddle that has beaten science for a very long time ?

Re: Down the Plughole
 

Its not a total myth though? Its a proven effect.

it is proven in terms of cyclones and other weather systems that they rotate in different directions above and below the equator.

Re: Down the Plughole
 

It's a myth when put against the small amounts of water in a sink or a tub.

Re: Down the Plughole
 

Those large masses of air and moisture are subject to the Coriolis effect, which is a proven factor. Water in sinks is far too tiny a mass for Coriolis to have any effect whatsoever. Hence the controversy.

Large long range ballistic artillery shells are subject to Coriolis.

---------- Post added at 13:41 ---------- Previous post was at 13:36 ----------

That is what I think Hugh in company with others, but nevertheless it is still inconclusive.

They say it takes 24 hours for a full sink to settle before you pull the plug. But even pulling the plug can determine which direction the vortex takes. It only takes a tiny disturbance to dictate which way the vortex spins.

Re: Down the Plughole
 

This here.

Re: Down the Plughole
 

IIRC there was a TV prog many years ago that showed what happened at the equator. First the water went one one way they it changed direction to the other. Not sure how the manner of pulling a plug creates that. What happens when no plug is involved and the water simply flows?

Re: Down the Plughole
 

We will all be watching our plugholes now. Since I got involved in this subject, I have to confess I watch mine. It has always vortexed ACW so far.

Re: Down the Plughole
 

Interesting, some water had been standing in the washbasin for a few hours. I carefully pulled the plug and guess what? No swirl whatsoever, just simply drained out.

Re: Down the Plughole
 

Heero,

My opinion is consolidated by your comments - it is a myth. But some leading egg-heads in the scientific world do not agree. You know what you and I say to them ? Unprintable.

The only factors that I know of which Earth can exert to cause reversal are :-

1. Coriolis.
2. Polar magnetic reversal.
3. The resultant vector force between gravity - a line drawn though the viewer and object to intersect the Earth`s CG and the centrifugal force - a radial line drawn through the viewer and object at right angles to the Earth`s rotational axis.

I cannot see any of these causing vortex spin and certainly not reversal between the hemispheres.

Coriolis is non-effective on such small masses.
Water is said to be non-magnetic - not strictly true, since water is composed of atom molecules and all molecules react to electromagnetism, but good enough to dispense with the magnetism issue.
The resultant force vector ? Remotely plausible, bit theoretical, but not convincing.

So, it is a myth.

Re: Down the Plughole
 

"leading egg-heads in the scientific world do not agree"?

How dare those "egg-heads" who only have decades of specific knowledge in this area, leading scientific facilities (including High Performance Computing), tens of thousands of hours of experimentation, and peer review of their findings by other experts in their field, think they know better than those of us who have spent a couple of hours on the Internet looking up the subject? ;)

Re: Down the Plughole
 

Well Hugh, those leading egg-heads with all that astronomic experience, don`t actually know much more than we who have only spent a few hours plonking on the web do they ? They have not succeeded in cracking a schoolboy riddle in countless decades and even completely disagree among themselves, otherwise the web would not be crammed full of plughole controversy.

It would all have been solved yonks ago, as clearly as that apple of Isaac Newtons if these egg-heads really knew their stuff.

don`t lets nitpick on each others comments. Please stick to the subject.

Re: Down the Plughole
 

They can explain it for you, they can't understand it for you..... :D

Re: Down the Plughole
 

They can`t even understand it for themselves, let alone explain it to me.
But if you say so Hugh, you must be right of course. Endgame. Pardon the expression, but "Over and Out" on that diversion.

Re: Down the Plughole
 

Well that was easy :D

Re: Down the Plughole
 

https://www.cableforum.co.uk/images/...2015/03/1.jpeg

https://www.cableforum.co.uk/images/...2015/03/12.jpg

Re: Down the Plughole
 

Condensing what I found in passing... coriolis effect applies under laboratory controlled conditions, but in real life other perturbations are likely to start the rotation in one direction or the other.

Re: Down the Plughole
 

In a sink, bath or anything with a plug, the removal of the plug will most certainly start a vortex disturbance, by simple volume displacement and if the plug tilts, which it always does, you get a paddle effect created by the upward pull and hence a rotating vortex.

Bang goes the rather likeable myth.

Re: Down the Plughole
 

Seems like there's plenty online to suggest it is a myth, for example from Wiki (which although I'm sure you'll point out can be edited by anyone)..

Re: Down the Plughole
 

And funnily enough, UCL, one of the world's leading Universities, think it's a myth as well....

http://www.ucl.ac.uk/maths/research/fluids-gateway/faq

Re: Down the Plughole
 

That episode of the Simpsons has a LOT to answer for it seems.

Re: Down the Plughole
 

Seems like the consensus of opinion is that it is a myth.

We need a few Aussies on the Forum.

Re: Down the Plughole
 

Well I suggest most people don't care either way..There are much more wondrous things to observe in the world and the universe. ;)

Re: Down the Plughole
 

Yup - like ME!!!!!! ;) :)

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I worked in Auckland 12 months in two years, and there was no discernible different pattern - sometimes one way, sometimes the other.

Re: Down the Plughole
 

I'm guessing it depended on what you ate...? :disturbd: