Does water really spin clock-wise in the southern hemisphere? and why?

Answer 1

This is true on a very large scale, such as weather systems, but not on the scale of shower drains or toilets. The cause of this phenomenon is the Coriolis effect. Objects that are moving in a straight line in the inertial frame of reference appear to travel along a curved trajectory when observed from within a rotating frame of reference. And the Earth is a rotating frame of reference. The result is that wind and water appear to be deflected towards the right in the northern hemisphere and towards the left in the southern. For fluid streaming inwards, this is counter-clockwise in the northern hemisphere and clockwise in the southern (which is the opposite of the claim typically made of toilets and drains).

This affect only dominates fluid flow on very large scales, such as weather systems that are tens or hundreds of miles wide. For small systems like a draining tub or toilet, the Coriolis effect is orders of magnitude smaller than influences such as the geometry of the drain or the presence of air and water currents. Even a tornado is too small to be dominated by the Coriolis effect; they usually have the same spin direction as the larger cyclonic storm from which they form (which is dominated by the Coriolis effect), but between 1% and 2% of tornadoes do rotate anticyclonically.

Answer 2

Not really, at least in toilets and sinks no. They are too small for it to have an effect, and if the water does change, its the design of the toilet.

Try it with a sink, swish the water counter-clockwise and it will drain that way, but swish it clockwise and it will drain that way too.

However, this does happen with tornadoes/cyclones and storms. Tornadoes are the North's version of the South's cyclones, and they spin different directions due to something called the Coriolis effect.

Answer 3

No, the spin is the same in either hemisphere.

Answer 4

Yes, they do down under
everything spin the same way, except down under, you'll see everything upside down.

Answer 5

because of the way the earth spins