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9/22/2017 12:11:25 AM
Posted: 8/31/2005 11:59:56 AM EDT
So our toilets, or any other water draining down a pipe, spins one way, but in the southern hemisphere it spins the other way.

1. Do all northern hemisphere hurricanes spin the same way Katrina did and southern hemisphere hurricanes go the other way?

2. What about toilets right on the Equator? Does the water spin at all?
Link Posted: 8/31/2005 12:07:25 PM EDT
The thing about toilets is mostly a myth, but more info here:

http://www.abc.net.au/science/k2/moments/s1244639.htm
Link Posted: 8/31/2005 12:22:49 PM EDT
Link Posted: 8/31/2005 12:30:57 PM EDT
The toilet spinning thing is an urban legend. The rotation of the Earth does have an influence, but it's one billionth of the influence of the water's movement, the tub/drain's design, etc.
Link Posted: 8/31/2005 12:35:38 PM EDT

Originally Posted By RS39:
Parents did a safari in Africa, videotaped a guy at the equator with a bucket draining water out the bottom's center hole, and some bark floating on top. In under 100yds, it changed direction.



if true, this is due to something other than the coriolis effect. Like the momentum the water acquires when you move it 100 yards in a bucket...



Link Posted: 8/31/2005 12:36:21 PM EDT
[Last Edit: 8/31/2005 12:41:51 PM EDT by krpind]
If your toilet was 1000 miles across and the water stood long enough the rotation of the earth would influence it.
What happens is the water at the equator is moving faster than the water 100 miles south of the north pole. This is an extreme example but it gives you the idea.


This is the correlius (sp?) effect

The water on both sides of the toilet re moving the same speed.....or at least there is no way to measure any difference.

EDIT, I should not have said the water is moving faster. A single point on the map is moving faster at the equator than a spot 100 miles south of the north pole. Due to the rotation of the earth.
This speed difference is the effect you are describing. As you can see this would never effect a toilet or bucket of water.
Link Posted: 8/31/2005 12:52:03 PM EDT
+1 to the debunkers of the Coriolis effect on minute scale. It is true that hurricanes, tornadoes and even the jet stream, in general, circulate differently in the Northern and Souther hemispheres. However, the effect is only present in large systems. Every time I fly to the Southern Hemisphere, I am reminded of this problem for about an hour either side of the equator. Prticularly in the spring and fall, the turbulence at the equator can be rather severe, with big differences in the direction and velocity of the winds aloft.
Link Posted: 8/31/2005 12:52:38 PM EDT
If you ever broke a toilet, you would understand why the water flows in a certain direction. They are made with tangential nozzles...

Now on hurricanes and tornadoes, that is from the Earth's rotation.

This also affects a bullet but over LONG distances. Our piddling 1000 yard shots can BARELY discern the effect but to a 155mm arty, it makes a difference.
Link Posted: 8/31/2005 1:42:00 PM EDT
Always check here first:

Snopes
Link Posted: 8/31/2005 1:47:30 PM EDT

Originally Posted By RS39:
Parents did a safari in Africa, videotaped a guy at the equator with a bucket draining water out the bottom's center hole, and some bark floating on top. In under 100yds, it changed direction.



Swishing the bucket slightly while walking, or even the angle in which you pour the water, and you can affect the residual swirl. The water is still swirling for quite a while even if it looks still, as can be demonstrated with food coloring and a dropper.

The coriolis effect on a small bucket of water is almost incomputably small.

Jim
Link Posted: 8/31/2005 1:52:44 PM EDT

Originally Posted By KS_Physicist:
The coriolis effect on a small bucket of water is almost incomputably small.

Jim

About like trying to compute the gravitational effect of two marbles in a bag. It's there, but imperceptibly small.
Link Posted: 8/31/2005 1:53:12 PM EDT

Originally Posted By KC_MO_shooter:
Always check here first:

Snopes



Snopes is wrong. I saw this on an episode of the Simpsons. It was on TV, so is has to be true!
Link Posted: 8/31/2005 2:15:23 PM EDT

Originally Posted By RS39:
Parents did a safari in Africa, videotaped a guy at the equator with a bucket draining water out the bottom's center hole, and some bark floating on top. In under 100yds, it changed direction.




Fakery of the first water (so to speak).
There are charlatans operating at a tourist trap in Nanyuki, Kenya. In this little town, located right on the equator, a local mountebank works for tips as he glibly cons busloads of tourists into believing that the rotation of the Earth causes water draining from a container to spin clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere. (Yes, you read that correctly, the charlatan fakes it backwards. You would think that if he were going to sucker people, he would at least get his directions the same as what really happens in large weather systems.)

This man’s nonsense was captured (and endorsed) by Michael Palin in one episode of his BBC TV special, From Pole to Pole, which is often aired on PBS. The presentation went as follows:




But, how is the fraud accomplished? The Coriolis force is so tiny that it cannot cause the rotation in the faker’s draining pan; indeed at only ten meters to either side of the equator, it is so tiny that it could influence neither the carefully performed experiment (described above) nor the large scale motions of weather systems.

So, the faker must be forcing the rotation by other means, and by a sufficiently unobtrusive way that the busloads of tourists do not spot the means. Indeed, a colleague of mine, who witnessed the performance first hand and knew it was a cheat, was not able to spot how the fraud was perpetrated. (It is an interesting sidelight that when back on the bus, he informed his fellow tourists that they had just witnessed fakery --- the Earth did not cause the rotation they had just seen --- there was widespread disappointment. The tourists preferred the fantasy to the reality.)



source
Link Posted: 8/31/2005 4:22:13 PM EDT

Originally Posted By mjohn3006:

Originally Posted By KC_MO_shooter:
Always check here first:

Snopes


It was on TV, so is has to be true!



You win; TV always trumps the internet.
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