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Re: undamped bridge oscillations

OK, no one (YET) has come CLOSE to convincing me of the PC
(Pedagogically Correct!) position that the Tacoma Narrows Bridge is
not an EXCELLENT example of of a resonant oscillation driven by
vortex shedding. Yes, death grips ARE hard to release but this seems
to be every bit as much a resonance phenomenon as many others
(including the particle resonances).

(but hey, I'm 'just' a HS teacher, who thinks that concepts are important.)



At 10:25 AM -0500 12/8/00, John Denker, you wrote about undamped
bridge oscillations:


At 08:45 AM 12/8/00 -0500, Chuck Britton wrote:
> John, you are then AGREEING that Galloping Gerty is an
>example of resonance? (yes/no)

Where does this "yes/no" come from?

I didn't realize I was scheduled for cross-examination today. Lawyers may
be allowed to demand yes/no answers -- but only of hostile witnesses, and
they have to get permission first.

I have a long-standing policy of not answering yes/no to misleading questions.

What I actually said (09:39 PM 12/7/00 -0500) was
>The bridge presumably had a fairly high-Q resonance even in
>no-wind conditions. A high-Q bridge or flagpole is vulnerable to
>high-amplitude excitation by mischievous adolescents. But that is far from
>being the whole story of this bridge. The interesting part of the story is
>to explain why the damping decreased to zero or beyond when the
wind came up.

and I stand by that.

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Chuck Britton Education is what is left when
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