This is very cool... I did a search online and couldn=B9t find much in the =
5
seconds I had.
Mark =AD would love to hear this if you can get back there to record it.
Cheers,
Simon.
On 7/10/07 2:40 PM, "umashankar" <> wrote:
>
>
>
>
> when we were children, there used to be a lot of 'table fans' around. one
> entertainment was to sing loudly into the fan, while it is spinning. at s=
ome
> distances, it would break the voice up in very interesting ways. i think =
this
> is a similar effect, happening at very low frequencies and probably at hi=
gh
> amplitudes.
>
> umashankar
>
> i have published my poems. you can read (or buy) at
> http://stores.lulu.com/umashankar
>
> ----- Original Message ----
> From: Mark Fischer < <aguasonic%40yahoo.com> >
> To:
> <naturerecordists%40yahoogroups.com>
> Sent: Sunday, October 7, 2007 9:00:24 AM
> Subject: [Nature Recordists] An un-recordable sound, re-visited
>
> Dear Nature Recordists,
>
> A while back I posted about an un-recordable sound I had heard, a
> mile+ downwind of some of the largest windmills in the world... doing
> the math lead to numbers that did not make much sense, as far as prop
> rates, and the resultant frequencies of any generated waves... and,
> yet, there was a sound, coming from these windmills...
>
> Well, today, I was downwind, maybe a quarter mile, of a single, much
> smaller windmill (not a whole field of giants, with the possibilities
> of harmonics, constructive and destructive interference, and so on)
> and watched the sound being made.
>
> No kidding.
>
> It appears to be an interaction between the blades and the tower. As
> each blade passes in front of the tower, in interferes with the
> windflow. On/off, On/off, what results is a wave of pulses downstream
> from the tower. The blades do not make it, by themselves. The tower,
> by itself, makes no sound. Put the two together, in a steady breeze...
>
> Of course, I did not have my recorder with me. But now I know what
> conditions bring this about. I bet there is some function
> (relationship) of the distance between the blades and the tower, and
> the wavelengths of the resulting sound.
>
> Stay tuned...
>
> Mark
> ~~~~
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause
>
> Yahoo! Groups Links
>
> __________________________________________________________
> Pinpoint customers who are looking for what you sell.
> http://searchmarketing.yahoo.com/
>
>
>
>
"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause
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