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Re: (meteorobs) "Electrophonic" Fireball sound nonsense

At 08:27 PM 8/14/2002 -0400, you wrote:
>Well, I believe the 0.003uW/cm^2 RF background includes all frequencies.

To make a fair comparison, it's necessary to know what fraction is VLF and 
what fraction is not.  If the ambient VLF background is 0.0003uW/cm^2, for 
example, the argument that meteors cannot rise above the background noise 
no longer holds.

What you write below is certainly possible, but I'm not convinced. One 
thing is clear, though: Ft. Collins would be a great place for physicists 
and psychologists to converge for a study of this phenomenon!

>Certainly, there are many powerful VLF transmitters around the world. I 
>see about 60 of them listed below 30khz in one list, and WWVB the NIST 
>time standard broadcasts 50Kw on 60khz, which creates a strong enough 
>field by itself to allow "atomic" wristwatches to sync up all over the 
>continental US using just the wristband as an antenna. In fact, I suspect 
>residents in Fort Collins, CO would be exposed to greater VLF fields than 
>even a "beamed" field from a meteor plasma, as Keay proposes. But, I 
>havent heard of reports of strange electrophonics from that city, or 
>anywhere else near one of these powerful VLF sources. I don't think the 
>plasma instabilities in a meteor wake would be sufficient to produce ERP's 
>of gigawatts, which would be necessary (at 60km) to match the strong local 
>VLF ambients in many areas.
>
>--- "Dr. Tony Phillips" <phillips@spacescience.com> wrote:
> > Hi Mike,
> >
> > You noted that the ambient RF power we experience
> > every day is about an
> > order of magnitude greater than that radiated from a
> > single distant
> > fireball.  That comparison might be misleading
> > because of the frequencies
> > involved. The ambient RF we experience
> > everyday--like 900 MHz from cordless
> > phones--is not the sort of VLF (very low frequency,
> > few-kHz) radiation
> > advocated by, e.g., Colin Keay as the cause of
> > meteor sounds.
> >
> > Furthermore, VLF waves from plasma instabilities
> > (which Keay says form in
> > the wake of fireballs) can be beamed. This happens,
> > for instance, in
> > Jupiter's magnetosphere where plasma instabilities
> > in the auroral zones
> > create conical emission beams that sometimes sweep
> > past Earth, causing
> > outbursts of ~18 MHz radiation that HAMs can easily
> > detect at
> > home.  Perhaps such beaming of waves from meteors
> > enhances the local power
> > available to drive electrophonic sounds.
> >
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