The fourth TORRO Conference on ball lightning (BL) brought together a set of first-class speakers, many well-known for their contributions to the subject. The meeting was chaired by Bob Pritchard of the London Weather Centre, whose voice is instantly recognisable to anyone who listened to the weather forecasts on Radio 4 [until about two years ago when the B.B.C. television forecasters work was expanded to include radio broadcasts]. The conference was structured into two parts, BL reports and BL theory.
The Conference commenced with Dr. Eric Wooding (Department of
Physics, Royal Holloway and Bedford New College, University of
London) who stated that very few scientific observations of BL
had been made, and it was necessary to obtain accurate
measurements in order to develop a model which would adequately
explain BL. The best methods to maximise the chances of observing
BL under scientific conditions were discussed - which is made
rather difficult by conflicting basic analyses, e.g. one source
reports that 95 % of BLs were observed during thunderstorms,
while another reports that only 2.6 % occur during thundery
weather and the bulk - 90 % - during dry, cloudy weather (these
radically differing figures are believed to be the result of the
use of differing criteria, such as the latter which may contain a
high number of earthquake lights, marsh gas reports, etc). Eric
concluded that at a site in central England, a camera left
running during thunderstorms would record BL once in 1,000 years
!
Next, TORRO's own Adrian James (BL Division, Archives
Director) reported on fatalities attributed to BL, drawing on TORRO's
BL database of almost 500 reports; again a difficult area to
handle, as data quality is often low - when a newspaper reports a
ball of fire, does it mean BL, the flash from a very close
lightning discharge, the vapourisation of material or St. Elmo's
Fire ? There are a number of reports of BL causing death, but
many reports can be interpreted as death by conventional
lightning; a number of ambiguous reports were quoted as examples.
An interesting statistic is that the average time lag between the
occurrence of a BL event and the report ending up in the TORRO
archives is 60 years ! Adrian also concluded that BL events must
be well-documented for detailed comparisons to be made.
Quite interestingly, it was not until the third lecture that
the very existence of BL was considered (were we all wasting our
time by being at the conference?), by someone whose name will
probably be familiar to many UFOlogists - sceptic Steaurt
Campbell.
Actually, I was impressed with Steaurt's presentation, which I
found well-argued. By means of examples, he believed that BL
(which he assumed to be an electrical phenomenon) could be
explained by conventional lightning, optical effects, etc., or by
the erroneous reporting of the event (by the witness, media,
etc.). Damage attributed to BL and photographs and video footage
believed to show BL could likewise be explained. Steaurt
concluded that as there is no conclusive evidence to support the
existence of BL, it is likely that BL does not exist. (Yes, it
looked like we were wasting our time !). There followed an
interesting discussion, as one of the later speakers (Prof.
Jennison) reported that he had experienced BL on more than one
occasion at close quarters, including once in an aircraft and on
another occasion when the BL moved down his back and arm !! So
perhaps we weren't wasting our time after all.
Prof. Roger Jennison (Department of Electronics, University of
Kent) discussed the assessment of BL reports, which encompassed
observation, theory and experimental techniques. He pointed out
that it is very difficult to assess the diameter of BL, unless it
moves in front of relatively close objects - and consequently, BL
reports should include indicators of data reliability. One
thought-provoking comment was that BL may occur quite frequently,
but as an invisible entity; the electromagnetism believed common
to luminous BL is present, but is not strong enough to create
luminosity. (Now, what would be the result of an invisible, and
therefore weak, BL structure entering someone and then
intensifying to a point beyond the threshold of luminosity -
spontaneous human combustion by any chance ?! [Jenny, Jenny !]).
We then all broke for lunch in Oxford Polytechnic's dining
hall, where business cards were being passed left, right and
centre, the finer points of plasma physics were being discussed
and the very existence of BL was still being debated. However,
one thing certain to me was that the gateau was some of the best
that I've ever tasted !
The afternoon session commenced with Mark Stenhoff, TORRO's
BL Division Scientific Director, who considered the physical
evidence for the existence of BL. One important point that was
made was the limited usefulness of particularly anecdotal BL
reports, as the accuracy of a witness' recollection drops rapidly
after the observation. In fact, after one day, about half the
reports are clearly erroneous while after five days more
imagination than truth is reported. Consequently BL (and UFO!)
reports need immediate investigation if the reports are to prove
useful for research. An example of a spectacular satellite re-
entry in 1968 highlighted reporting distortions; many observers
reported seeing windows and hearing noises (things which seem to
recur with regularity in UFO reports!). The TORRO BL
database was utilised in this presentation, but again the problem
of damage interpretation was emphasised; assuming BL does exist,
damage caused by it may be indistinguishable from that caused by
a ground flash or side flash - which, if this is the case, will
make the understanding of BL considerably harder. Furthermore,
most of the damage reported to have been caused by BL could be
attributable to ordinary lightning - so a BL suspected to have
caused damage consistent with a high energy may actually have
been the result of a low-energy BL and an ordinary lightning
strike. In conclusion, it was stated that most of the damage
reported to have been caused by BL could also have been caused by
linear lightning; there were only a few cases where the damage
was more likely to have been caused by BL than by linear
lightning.
The second part of the conference considered BL theory and not
surprisingly the technicality moved up a gear, stalling the
brains of a few delegates in the process I suspect. Dr Geert
Dijkhuis of Zeldenrust College and Convectron NV (The
Netherlands) considered BL statistics and structure. With
increasing numbers of BL reports being published (especially from
Europe, U.S.A. and Japan), structural theories must take into
account the variability of BL and experimental work needs to
produce BL which mimics the behaviour of natural BL;
laboratory-created BL is still smaller and shorter-lasting than
its natural counterpart.
It was at about this time that an active cold front cleared
the area; the passage was marked by heavy rain and gusty winds.
Conference participants were seen to glance out of the windows,
perhaps expecting a BL to materialise and join the congregation.
I suppose it was asking a bit too much for BL to appear during a TORRO
BL conference, but nevertheless a tornado did occur only 15 miles
away and a site investigation was already underway by the
evening. If only BL investigations were executed with such
rapidity ... A brief history of electromagnetic plasmoid models
of BL was given by Dr. Geoff Endean (School of Engineering and
Computer Science, University of Durham), and who then outlined
the problem of energy containment in BL - how sufficient energy
could be contained in a small space and be not just emitted
continuously and steadily, but also sometimes very suddenly. He
then presented some of his own recent work which may explain the
energy containment problem for the electromagnetic plasmoid model
of BL. He pointed out that a very-rapidly rotating electric field
can exist in a plasma without a magnetic field and with no
apparent limit to the electrical field strength; this helps to
construct a realistic model of BL.
The conference was concluded by Dr. Xue-Heng Zheng (Department
of Engineering, University of Cambridge), who discussed how BL
could exist for the time-span reported by observers (typically 10
seconds). The long life of BL may be explained by the existence
of a maximum rate for microwave radiation to be transferred into
heat in plasmas. If I remember rightly, this ended up in a lively
and rather top-gear mathematical discussion which, for the
layman, boiled down to "you can't do that" and "oh
yes I can".
All in all, a very enjoyable conference; those interested in
BL but who were unable to attend certainly missed something. But
they'll be glad to know that copies of the 88 page softbound
Conference Proceedings with 8 figures and 13 tables are available
from the TORRO Ball Lightning Division at P.O. Box 164,
Richmond, Surrey, TW10 7RR, and are priced at £ 10 each plus £
1.10 p&[ (in the U.K.; plus £ 3.00 p&p overseas). Please
make cheques payable to TORRO Ball Lightning Division.
AND DON'T FORGET - ANY RECENT BL EVENTS SHOULD BE REPORTED TO TORRO
A.S.A.P. - THE BL DIVISION HAS A 24-HOUR ANSWERPHONE ON (081 940
9413. Older reports (from any year and any continent) should be
posted to the address above. David Reynolds. TORRO.
Staffordshire.
