1 - The Black Vault

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' CHARACTERISTICS
Color
Shape
Movement
Dynamics
Sound
Lifetime
·Size
UFO-Ball Lightning Observations Compared
·::·
EXETER UFOs
Usually reddish-orange and/
or bluish-white, sometimes
green.
Rou~d, oval or dome-shaped
Often hovering or moving
upfdown slowly. Also moves
horizontal!~ at slow or high
speed.
BALL LIGHTNING
Multi-colored,
dominating
white.
with red
pr bluish·
Spherical,· -ellipsoidal
doughnut-shaped.
or
SometimeS hangs motion·
less or moves vertically
and horizontally at slow
or high speed.
Often seems to move with Appears to bounce or roll
rocking or undulating rna- in horizontal direction.
tion. Sometimes appears to Sometimes exhibits .spin·
be spinning. · ning motion.
No sound, or slight humming
or hissing.
Sometimes exhibits a siz·
zling or hissing sound.
Frof!l several minutes to up From few seconds to
to half an hour.
many minutes.
Difficult to estimate by most
observers during night sight·
ings, but those given range
from basketball size to 200
ft in diameter.
Daytime sightings (in
brighter ambient ·- light)
usually are a few ihches
in diameter but have
ranged up to 15 It
charge expands into a larger plasma seen in proximity to wires or :::.tPu:.:.
with ball lightning characteristics. tures. It is usually airborrie or partially·
_ Present limited knowledge of both airborne, moving randomly in space or
phenomena complicates this problem. · along electric conductors. It often ex­
But the similarity of electric corona dis- hibits rolling, tumbling or spinning
charge and natural lightning discharge motions.
which is known to induc_e ball lightning · Small-diameter ball lightning has
would seem to support strongly the been reported _inside houses and other
theory presented here.
· buildings. Recently an Air Force Stra·:
Despite long years of experience with tegic Air Command flight crew reported
corona, the experts disagree even over seeing it· inside an aircraft during flight, · ·
the effect of temperature, barometric AVIATION WEEK & SPACE TECHNOLOGY.
pressure and humidity in inducing was told by a scientist working in the ·
corona. The reason is that power line field.
corona is difficult to duplicate realisti- Many of the ball lightning sightfngs
cally fo? study under controlled con-· reported by persons surveyed by Me-'
. ditions. To do so would require con- Nally occurred on or near power lines.~struction
of a huge facility, large enough Many different theories and mathe- -~to
house ·a long transmission line :Within rnatica] models have been advanced by
a chamber so that barometric pressure· scientists here and abroad to explain the
and temperature could be varied while _,·· basic mechanism which generates ball
a variety of atmospheric contaminants · lightning and the internal-external
were introduced. forces that enable it to survive for ex• ~-
There is considerably less scientific tended periods.
information available on ball lightning, Within ·recent months two Westing·
although a number of conflicting theo- . house Electric research laboratory scienries
have been advanced to explain it. tists, Dr. Martin A. Uman and Dr. C.
Several years ago Dr. J. Rand McNally, W. Helstrom published a mathematical
Jr. of the Atomic Energy Commission's model that Predicts many of the unusual
Oak Ridge National Laboratories made properties of ball lightning. The Wesan
ijnformal survey of 1,962 persons in tinghouse research was partially funded
the laboratory. Surprisingly, he found by the Office of Naval Research.
. that 110 of them, or 5.6% of the total This theory suggests that ball lightsample,
had observed ball lightning at ning is a luminous, high-temperature
some time. Usually it was associated region of air having high electrical
with a conventional stroke of lightning; conductivity that has been heated to
but not always.
the required lemperature by a 'troke of
Analyzing the returns, McNally con- lightning under suitable conditions.
eluded thai ball lightning can originate When cloud-to-ground lightning currandomly
in space but is most often . renls are symmetrical through the ball,
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Aviation Week & Space TechnoloQy, August. 22, 1966
55