(meteorobs) Fw: [MIAC-L] re simultaneous meteor sounds.
With Dr. Jeremy Tatum's kind permission I am forwarding a message he
sent to the MIAC list regarding the paper, "Instrumental Recording of
Electrophonic Sounds from Leonid Fireballs", by Zgrablic et al. I thought
that the readers of meteorobs would find his comments interesting. I will
forward any serious comments to him.
----- Original Message -----
From: * JEREMY TATUM Subject: [MIAC-L]
I have read the paper "Instrumental Recording of Electrophonic
Sounds from Leonid Fireballs" by Zgrablic et al.
Since I am perhaps Unbeliever-in-Chief in the alleged phenomenon,
maybe I should comment.
It may surprise those who have heard me discuss this topic
before that my impressions of this paper are remarkably positive.
I would have to say that is the ONLY paper I have seen that comes close
to being a convincing demonstration of the reality of electrophonic
sound. Most evidence to date, copious though it may be, has been
anecdotal and nowhere close to meeting normal scientific criteria.
I have long insisted that, however many anecdotal stories we hear,
there has not to date been convincing instrumental detection of
undoubted electrophonic sound, and this is indeed recognized by the
authors. Their paper does supply convincing evidence of the
reality of simultaneous sound and its instrumental detection under
carefully-controlled and designed scientific experiment.
The observations used human observers, acoustic detectors, and EM
detectors simultaneously, all under controlled conditions, and stringent
conditions were placed on what was accepted as a successful detection.
Two successful detections of meteors seen and heard and recorded
simultaneously by acoustic detectors were achieved; simultaneous
electromagnetic detection was not obtained - either because the detectors
were insensitive at audio frequencies or because the Keay mechanism is
Members will have to read the paper in full to get all the details,
but I would have to say, as Unbeliever-in-Chief, that this has come
far closer to convincing me than anything to date. I would not go so far
as to say that this establishes the phenomenon once and for all beyond
all possible doubt in the sense that no one ever need to repeat similar
observations. Indeed the paper has established that further experiments
of this nature are highly desirable and a worthwhile scientific pursuit.
I would venture a few small comments. Offhand, I would have thought
that shower meteors of cometary origin were rather less likely to produce
electrophonic sound than a genuine asteroidal fireball, and therefore that
claims of electrophonic sound from shower meteors need a particularly
high standard of proof. Also, since Leonid meteors were occurring
almost continuously at the peak of activity, coincidence between
visual, aural and instrumental detections were likely - although the
authors placed stringent constraints on temporal coincidenceand took
into account the different qualititative natures of simultaneous and
I would criticize the claim that "the phenomenon has been firmly
accepted as physically real". This is not the case. It may have been
firmly accepted by some, but there are still scientists who are not
fully convinced and some who are downright disbelievers. Further work
in the area is undoubtedly necessary before the reality of electrophonic
sound can be placed on as firm a footing as the Third Law of
I also INSIST - and it is all the more important now - that
simultaneous sound must not be described as "electrophonic sound"
unless it has been unequivocally shown to have been electrophonic,
nor must it be dismissed as "psychological" unless it has been
unequivocally shown to be psychological. In nearly all cases, all
that has been established is that a witness has reported SIMULTANEOUS
SOUND, and that is the phrase that must be used to describe it unless
there is proof that it is either electrophonic or psychological. If
anyone claims that ALL instances of reported simultaneous sound are
electrophonic and none are due to faulty observation or imagination,
then I'm sorry - my response is that I don't believe it for a moment.
(Martin, you may recall that I mildly mentioned this to you with
respect to your and Luigi's paper on 900-odd instances of
I also feel that the word "fireball" should not be used (notwithstanding
the IAU definition) for shower meteors of cometary origin. Meteors
brighter than -4 can be seen any night, and in any case no one can
possibly estimate their magnitude (The Croatian observations MEASURED
their magnitudes.) The word fireball should be restricted to
genuine fireballs of asteroidal origin and are of meteorite-dropping
In any case, while I do not believe the book is closed on this topic,
I believe the Croatian observers are to be congratulated on their excellent
and thorough experiment; a few more like that, and few doubters will remain.
> PS I see that dejan is requesting reports of reported simultaneous
> sound. I am a Web-hater, so I am not strongly motivated to contribute
> to the web form, but I did record, in Pub. Astron. Soc. Pacific 112,
> 1487 (2000) the circumstances of the seven reports of simultaneous
> sound described for the 1998 April 15 Vancouver Island fireball.
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