Date: Thu, 2 Jul 1998 22:47:22 -0600
Reply-To: kenstich <kenstich@BEWELLNET.COM>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: kenstich <kenstich@BEWELLNET.COM>
Organization: Central Intelligence
Subject: Re: spacers and sproings - Coriolis effect an Urban Legend
???????? - long
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Larry,
Thanks for the correction - I had it splained in my dynamics class as a part
of a lecture whilst studying 3-dimensional moving coordinate systems - the
applications/problems I worked were not actually toilet water, but instead
were machine parts (linkage systems) so that we could calculate the stresses
due to the inertial loads. Guess that you just can't trust these engineering
professors (who can you trust anymore ?).
Well shucks, I found this very interesting website -
http://hepweb.rl.ac.uk/ppUK/PhysFAQ/bathtub.html (check it out for the full
text) - that goes into detail on this very subject - imagine that - The
following excerpt:
---------------------
Question: Does my bathtub drain differently depending on whether I live in the
northern or southern hemisphere?
Answer: No. There is a real effect, but it is far too small to be relevant
when you pull the plug in your bathtub.
Because the earth rotates, a fluid that flows along the earth's surface feels
a "Coriolis" acceleration perpendicular to its velocity. In the northern
hemisphere, Coriolis acceleration makes low pressure storm systems spin
counterclockwise; however, in the southern hemisphere, they spin clockwise
because the direction of the Coriolis acceleration is reversed. This
large-scale meteorological effect leads to the speculation that the small
scale bathtub vortex that you see when you pull the plug from the drain spins
one way in the northern hemisphere and the other way in the southern
hemisphere. . . . . . . . .
-----------------------
explains that the coriolis effect is quite real and not the "urban legend" as
you suggest, but that is is also insufficient to produce the "twirling" to
which I attributed it - Oh well.
Well shucks Larry - its all very interesting - but my point with Steven is
still valid I believe - And you know - it sounds like - well - sort of like
- you think that education is a waste of time - maybe you're just being a
little flippant - Oh well
Thanks again for the "correction"
Best Regards,
Ken Stich
Larry Hamm wrote:
>
> kenstich wrote:
> >
> > Ken's Final Komments:
> > Its unfortunate that one cannot always take experiential data and translate
> > that into intuitive understanding - but if that were the case, I wouldn't have
> > had to spend 10+ years in college. Toilets flushed in the northern hemisphere
> > twirl one way - in the southern hemisphere the opposite way. I needed a course
> > in Dynamics to actually understand Coriolis acceleration and why this was so -
> > I couldn't tell from looking at the toilet
>
> I think you spent a few too many years in college, Ken. The Coriolis
> effect is nonexistant in toilets and bathtubs. Urban legend?
> Larry
