[Prev][Next][Index][Thread]

Re: (meteorobs) Fireballs & sonic booms

At 12:09 PM 1999-07-07 -0400, you wrote:
>The question really boils down to this: OTHER than superior will-power
>and mental acuity in some observers - a factor which is, if I can put it
>delicately, difficult to calibrate(!) - what can explain the random and
>unprompted observation of this effect by some observers, and the total
>lack of its incidence among others? This is an interesting question!

Let me toss this observation into the equation.

I lived in the Los Angeles area for nigh on 18 years, finally escaping for
my beloved plains and midwestern states in '82. Prior to that, like any
Southern Californian, I'd experienced a number of minor earthquakes and
tremors and aftershocks, including the disastrous one in the San Fernando
valley with all its aftershocks through the next several months.

I thought I had noticed, several times, that I actually *heard* several
such tremors and aftershocks at the moment they struck, BEFORE the building
or other stuffs inside the building began rattling. And in any case, being
hard-of-hearing (to which Lew, having observed with me one night last Fall,
can testify), I don't hear the relatively-high-frequency of small objects
rattling on shelves, etc. But I would have sworn that during several of
those shocks, I could "sense", if not actually hear, the tremor itself or
its effects upon large structures. Others around me sometimes noticed the
same thing; but most did not, I'm sure because most people don't pay much
attention to their environment unless it kicks them in the rear end. Being
hard-of-hearing, I *think* my body has tried to compensate by more-finely
attuning other available senses.

My point is that perhaps some people are more sensitive to very-low
frequency acoustic or shock waves, such as what some larger meteoroids may
cause as they strike and plunge through the atmosphere; that is, perhaps
what some folks are "hearing" is the actual atmospheric shock. If so, then
a very-low-frequency acoustic receiver system may be a valuable tool to
gauge the frequency, magnitude, and perhaps even the time delay of such a
shock.

The time delay is what most interests me: if this shock wave is truly
acoustic in nature, then the acoustic shock wave should show much the same
time delay as what one would expect for sound traveling from the upper
atmosphere to the ground. On the other hand, it is also known that a "blast
wave" from large explosions travels much, much more rapidly than sound
waves. Could it be that some folks are actually "sensing" such a blast wave
effect?

I think it's critical that some system of acoustic and electromagnetic VLF
receivers, in conjunction with some sort of video record, be established,
to gather more complete data. Perhaps a sensitive pressure sensor might be
of value, too.

Further, I've been at some experiments where I was able to observe and
record electromagnetic data during relatively-low-intensity "explosions",
such as missile tests and the like. Some of our equipment operated into the
VHF and UHF range and as high as 12 GHz. I've noticed that there seemed to
be some small evidence of a broadband electromagnetic pulse, perhaps
similar to the EMP that occurs from a high-altitude nuclear explosion. I'm
not a physicist; but it would seem to me that the sudden release of gobs of
energy, such as a meteor plunging through the atmosphere, might also create
some sort of broadband electromagnetic pulse if the energy release were
sufficiently quick, such as a very fast meteor suddenly hitting the
atmosphere and beginning to burn.

Clear skies,

SteveH
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
Follow-Ups: References: