Which way does the water swirl if you flush a toilet exactly on the equator?

Question

A wise old tale says toilets flush to the right above the equator, and to the left below the equator due to the Earth's gravitational pull. What happens ON the equator is somewhat of a mystery...

Answer 1

How the water drains depends on how it was introduced into the bowl and on what forces have affected it since. This true anywhere on earth, not just at the equator. The question seems to be based on the false, but often asserted, premise that the earth's rotation causes basins and toilets to drain counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. This is certainly true of cyclones and other large-scale weather phenomena, but the coriolis force is so weak that it simply cannot affect a system as short lived as a basin full of water.

Answer 2

The Coriolis effect does indeed present a slight (weak) bias to cause whirlpools to spin in opposite directions north and south of the equator. This should affect toilets and draining bath tubs too. A pump used to drain a large tank once failed because the tank was manufactured in North America and shipped to South America where vanes at the tank discharge port encouraged rather than discouraged the formations of whirlpools (or vortexes). The pump became air bound.

The Coriolis effect is so weak in a bath tub or toilet that you can easily force the whirlpool to start in the unnatural direction. That being the case, slight irregularities in the toilet (a ceramic?) or directional water injectors or drain piping likely can overcome any Coriolis effect. It is only a bias and not a strong force. On the equator even the bias of the Coriolis force is gone and other effects take over completely. Great question.

Answer 3

Very good question,
basicaly you want to know which way water would swirl uneffected by the earths magentic feilds

it would depend on the shape of your toilet bowl and what you have put in it mostly :-P

if it were in a bath it would probably spin which ever way you wanted it to, eg. you could swirl your hand around the plug and it would start to spin the otherway the equator isnt necisarily the halfway mark between magnetic feilds north may be more powerfull than south, i am not sure

most likley of all it would spin positivly towards the closest ocean in theory, water is positivly charged if you have had alot of iron recently and you plonked a floater in there with it it might alter the results too,

good luck in your quest for the answer

:-)

Answer 4

If you could identify the exactly... and I mean EXACT gravitational (not geographical) equator of the earth you would get a flush of water that would flow straight down.
Now... this is so difficult I couldn't even imagine how you would do it.
As far as weather the flush goes the opposite direction in the southern hemisphere... I go to Brazil every year and I can personally vouch for it.
But don't take my word for it... take a look at the link to read more about the Coriolis effect. It is the physical property that drives your flush direction!

Answer 5

If you could get it exactly on the center of the equator it would theoretically go straight down but you would always be just a little bit off so it would flush in the respective direction of which side of the equator you were still on.

Answer 6

That actually is an old wives tale only; the Coriolis effect does determine which way a hurricane for example will rotate, different north and south of the equator, however that does not affect draining toilets.

Answer 7

Actually it is which ever direction the toilet was designed to swirl in!
The centrifugal force of the Earth rotation isn't strong enough to effect toilets!
Although, a perfectly designed drain would probably prove this theory!
; )

Answer 8

Ha! This is a great myth. It has absolutely nothing to do with location on the earth. It is determined by the direction the tank water is directed into the bowl. Coriolis and gravitational forces are not strong enough to act on something as small as a toilet bowl. Sorry:)

Answer 9

The twisting effect of the Coriolis force is real and does influence certain large things like the movement of air masses, but the effect is so small that it plays no role in determining the direction in which water rotates as it exits from a draining sink or toilet. The Coriolis effect produces a measurable effect over huge distances and long periods of time, neither of which applies to your bathroom. Toilets and sinks drain in the directions they do because of the way water is directed into them or pulled from them. If water enters in a swirling motion (as it does when a toilet is flushed, for example), the water will exit in that same swirling pattern; as well, most basins have irregular surfaces and are not perfectly level, factors which influence the direction in which water spirals down their drains. The configuration of taps and drains is responsible for the direction of spin given to water draining from sinks and bathtubs to a degree that overwhelms the slight influence of the Coriolis force.

The belief that the Coriolis force influences the direction in which water drains from plumbing fixtures is widespread and has been repeated as fact in a number of venues, including popular television shows (such as world traveler Michael Palin's Pole to Pole) and even in textbooks. We can only speculate on why people are so enamored of this snippet of misinformation, guessing that it has something to do with the desire to find some of the mysteries of science in the realm of the everyday.

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A popular misconception is that the Coriolis effect determines the direction in which bathtubs or toilets drain, and whether water always drains in one direction in the Northern Hemisphere, and in the other direction in the Southern Hemisphere. The Coriolis effect is a few orders of magnitude smaller than other random influences on drain direction, such as the geometry of the sink, toilet, or tub; whether it is flat or tilted; and the direction in which water was initially added to it. If one takes great care to create a flat circular pool of water with a small, smooth drain; to wait for eddies caused by filling it to die down; and to remove the drain from below (or otherwise remove it without introducing new eddies into the water) – then it is possible to observe the influence of the Coriolis effect in the direction of the resulting vortex.

This is less of a puzzle once one remembers that the earth revolves once per day but that a bathtub takes only minutes to drain. When the water is being drawn towards the plughole, the radius with which it is spinning around it decreases, so its rate of rotation increases from the low background level to a noticeable spin in order to conserve its angular momentum (the same effect as ballet dancers bringing their arms in to cause them to spin faster).

Answer 10

Actually, everything just disappears from the toilet with no flushing necessary because the aliens who inhabit the Bermuda Triangle transport it directly to their labs for experimentation so it.