Over the years I have read in numerous books that water goes in a clockwise spiral as it goes down a drain in the northern hemisphere, and counter-clockwise in the southern hemisphere.

Well, it sounded plausible, so I assumed it was correct.

Then I got around to actually observing what was happening in the bathtub, and lo and behold, sometimes it spins clockwise, sometimes it spins counter-clockwise, sometimes it reverses itself!

So way do all these books say it doesn't?

You'd think it would go either one way or the other, after all. What makes it decide to go one way as opposed to the other?

How about hurricanes? They spin in a predictable fashion according to the hemisphere, don't they?

I know it's trivial, but I really am wondering if the science community has any comment or explanation.

- LH