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Coriolis Effect
Name: ceci
Status: N/a
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993
Question:
Is it true that water in the southern hemisphere swirls the other
way? Why?
Replies:
Martin Gardner, in "The Ambidextrous Universe," a book I
recommend to anybody, mentions some enterprising people in Kenya, which lies
right on the equator. There was a line in the village where the equator was,
and a few of these guys had some frying pans with a little hole in the middle.
They would put water in and a twig on the water to make it easier to see, and,
sure enough, on the north side of the line the water swirled out of the pan
one way, and on the south side it went the other way! They apparently were
quite good at this, and made quite a bit of money... Basically, nobody has
ever (properly) demonstrated this effect with water in ANY size bathtub. The
Coriolis effect is simply too weak to have any effect on an ordinary quantity
of water. It does have a strong effect on the circulation of air in the
atmosphere, however, and hurricanes in the southern hemisphere do indeed swirl
in the other direction. An easy way to imagine the Coriolis effect is to
think of the effect it has on missiles launched on a North-South trajectory.
If the missile is launched north from the equator, it has a certain East-West
speed as well due to the rotation of the earth. At higher latitudes, the
rotational speed is lower because the distance to the rotational axis is lower
(at the poles the rotational speed is zero), but the missile retains its
initial speed in that direction, and thus appears to be bending out of its
initial north-south direction relative to the ground. If launched south, the
"handedness" of the bending is reversed. There has been concern expressed
that the waste heat from large- scale fusion reactors could be significant.
If current concerns about global warming are valid, we should give careful
consideration to the potential effects of additional heating of the
atmosphere.
A. Smith
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Update: June 2012
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