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(meteorobs) Fwd: Leonid VLF/Electrophonic Sound Confirmation Data/Recordings
>cc: robkrit@yahoo.com
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Clear skies!
Lew Gramer <owner-meteorobs@atmob.org>
[Attachments removed...]
> -----Original Message-----
> From: Rob Kritkausky [mailto:robkrit@yahoo.com]
> Sent: Thursday, November 14, 2002 2:58 AM
> To: dedalus@alum.mitdot edu
> Cc: meteorobs@atmob.org
> Subject: Leonid VLF/Electrophonic Sound Confirmation Data/Recordings
>
>
> Lew & Friends
> While doing some research for this years Leonids, I
> came across your e-mail discussions via meteorobs
> from 1999 to 2001. I was interested to hear your
> intelligent discussions, observations, and opinions
> on this subject. You rekindled my interest in this
> phenominon that started a year ago and somewhat
> consumed me for a couple weeks after my/our
> experience.
>
> In 2001, I was documenting(via dv camcorder) the
> meteor
> shower when I heard a sonic boom shortly after a big
> Leonid. I have heard sonic booms before & I
> immediately
> thought the sound to be one.(while I now realize that
> it could not be a conventional sonic boom) Even more
> incredibly, my friend who's somewhat of a celebrity in
> the field of amateur astronomy(Steve Kates "Dr.Sky")
> was doing a national radio show at that time about 180
> miles from my location. He also heard a "sonic boom"
> following a large Leonid and commented on it live on
> the radio. Note: this was on the nations largest
> nightly radio show "Coast to Coast with Art Bell"
> (about 8 million listeners)
> Subsequently, we have this recording from two separate
> sources and there was about 16 witnesses at Steve's
> location, while I was the only one still awake at my
> location unfortunately. While there is more to the
> story, I will stop here for now. However, I have
> included some e-mail conversations I had with a
> scientist specializing on this subject. He seems to
> have the most plausible theory in my opinion.
> (electrophonic sound) and his interest in our digital
> recordings was great. However, his project seems to
> have been shut down almost overnight($?) ending our
> contacts with him and kind of placing our involvement
> in this area on the back burner.
> Coming across your conversations has got my mind
> focussed on this subject once again. I hope you enjoy
> this info. and I would love to hear your thoughts on
> this subject.
> Thanks
> Rob Kritkausky
> Phoenix, AZ USA
>
>
> > --- Dejan Vinkovic <dejan@ccsdot ukydot edu> wrote:
> > > hello!
> > >
> > > > > How many observers from your vicinity heard a
> > > sound
> > > > > from that meteor,o
> > > > > and how many observers did not hear it? :
> > > > > only one observer as all others were sleeping
> > >
> > > So, one additional observer (in addition to you) was
> > > there and he/she
> > > heard the sound. Is that correct?
> > >
> > > > Dejan please note I have not yet tried to
> > > digitally
> > > > isolate the noise from the background noise I
> > > heard
> > > > from the waterfall. This background noise seems to
> > > > have drowned out the hissing nodefiantlyefinatly
> > > not
> > > > the boom. (wattachedttatched)
> > > > Let me know your thoughts on this.
> > >
> > >
> > > The sound is interesting and worth of more detailed
> > > analysis. This cannot
> > > be a sonic boom because it would require a couple of
> > > minutes to reach the
> > > ground. It is not so odd to have an electrophonic
> > > sound a moment after the
> > > meteor.
> > >
> > > The intriguing part of your story is that you heard
> > > that hissing noise
> > > prior the boom. What we learned from our study of
> > > the electrophonic sounds
> > > (http://fizika.org/ilwcro/) is that they are most
> > > probably produced by
> > > electromagnetic disturbances below ~250Hz. This
> > > would explain the boom
> > > ("pop"-sound). On the other hand, the hissing sound
> > > has much higher
> > > frequency! The way to make these sounds is corona
> > > discharge. This is a
> > > tiny invisible spark on sharp objects and it was
> > > favorable explanation of
> > > electrophonic sounds prior the Keay's work in the
> > > 1980's (actually, from
> > > his lab experiments is not clear if he recorded
> > > sounds due to oscillations
> > > - as he claims - or corona discharge).
> > >
> > > However, in a research like this (when we have some
> > > instrumental
> > > recording) I have to be the devil's advocate and
> > > look for any other
> > > possible explanation of this sound. If you are
> > > willing to help, I would
> > > suggest the following. Do not make any filtering or
> > > digital distortion
> > > (e.g. compression) of the recording. The background
> > > sound has to be
> > > identified through its spectral characteristics.
> > > Also, I would need a long
> > > file, several hours, if available, of recordings
> > > during that night. By
> > > going through spectral analysis of such recording, I
> > > will be able to
> > > isolate the most similar sounds to this potential
> > > electrophone. If such
> > > sounds do not exist or are very rare then this
> > > becomes a very valuable
> > > electrophonic sound recording.
> > >
> > > In this case, the exact look (a photo or short
> > > video) of the place where
> > > the recording took place is also useful. For
> > > example, I would look for a
> > > flat object, which can easily oscillate. Such an
> > > object could explain the
> > > boom. Some sharp metal objects could explain the
> > > hissing noise.
> > >
> > > By the way, a moment before the boom, I can hear
> > > something like a spark.
> > > Is this what you heard, that is, is it real?
> > >
> > > Let me know if you could help in a study like this.
> > > Thank you and best
> > > wishes,
> > >
> > > Dejan Vinkovic
> > >
> > --------------------------------------------------------------
> > ------------
> > > Department of Physics and Astronomy | Center for
> > > Computational Sciences
> > > University of Kentucky | University of
> > > Kentucky
> > > 177 CP-bldg | 325 McVey
> > > Hall
> > > Lexington, KY 40506-0055 | Lexington, KY
> > > 40506-0045
> > > e-mail: dejan@padot ukydot edu | e-mail:
> > > dejan@ccsdot ukydot edu
> > > http://www.padot ukydot edu/~dejan |
> > > http://www.ccsdot ukydot edu/~dejan
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