Editing UFOs An International Scientific Problem (section)

== Alternatives to the Extraterrestrial Hypothesis ==
The UFO problem is one for which prudence dictates a studied application
of Chamberlain's "method of multiple hypotheses". Since I have in previous
discussions1'8 cataloged the eight alternative hypotheses under which I like
to scrutinize UFO data, I shall not recapitulate them here. When I say to
you that my present position, based on months of study of UFO cases and UFO
investigations, is one of favoring the hypothesis that UFOs are some form of
extraterrestrial surveillance devices, I am saying that I feel that all of
the obviously competing alternative hypotheses seem inadequate; by a process
of elimination I come to the extraterrestrial hypothesis, as have others.
Although argument by elimination is logically sound, it is not the type
of argumentation that scientists like to see used in a difficult problem.
They much prefer positive arguments. The reason for this preference is
simple enough: Success of argument by elimination demands that you have in
your initial set of considered hypotheses all possible hypotheses, and one
may not be so clever or so unbiased as to start from that point. With respect
to UFOs, to put it in simple terms, one would prefer "solid evidence" - in
the form of a tail fin, a jettisoned "motor", a crashed UFO, a lot of good
photos, etc. Such positive evidence does not seem to exist, despite stories
to the contrary. That there seem to be no crashed UFOs can be whimsically
explained away by asserting that "they" seem to have attained Zero Defects.
Droll, but scarcely overwhelming argumentation (even if it might prove
essentially correct).

Hoaxes, illusions, hallucinations, frauds and fabrications must con-
tinually be considered, with frauds and fabrications by far the most trouble-
some from the viewpoint of report-evaluation. Suggestions that UFOs are

advanced vehicles of a secret terrestrial technology seem absurd when one
scrutinizes UFO reports and then examines the nature and state of advancement (16)
of global technologies. I omit further comment here because I feel sure
that CAST members need no long arguments on that hypothesis.
The leading alternative to the extraterrestrial hypothesis seems to be
that of "misidentified natural phenomena", viewed in terms broad enough to
include misidentified conventional aircraft, satellites, balloons, etc. The
Bluebook position has for years been that UFOs are almost entirely such
"misidentifieds", and Bluebook has repeatedlyasserted that their small per-
centage of UNIDENTIFIEDS would fall into thatcategory if more adequate data
were at hand. I do not agree, after studyinghundreds of their cases. Rather
I say that adequate and open-minded scientific scrutiny of the roughly 12,000
UFO cases now on file at Air Force Bluebook'Project would probably raise the
percentage of UNIDENTIFIEDS from the acknowledged few per cent (figure varies
from year to year) to perhaps 30-40 per cent. An extremely important point
to recognize is that intelligence personnel at the airbase levels from which
the bulk of Bluebook's reports originate simply do not bother to go through
the quintuplicate-filing process on any UFO report that they feel involves
somebody seeing Venus, or seeing a strobe-light, or an aerial reconnaissance
plane, etc. They operate with a degree of airbase-level flexibility on UFO
reporting that serves effectively to filter out the obvious misidentifieds
(as well as a lot more, I fear). Few persons sense this important point. The
system is so loosely organized and depends so much on the interest and zeal of
the individual base intelligence personnel that some obvious misidentifieds do
get up to Bluebook, but by no means the large numbers that one might guess.
The net result is that the Bluebook files are fascinating - not boring as I
suspect many USAF officials with little scientific training think to be the
case.

In addition to being fascinating, I found the Bluebook files to be
extremely irritating, because after looking at the reported observational
material one next looks at the official "explanation", and from a scientific
viewpoint there is usually an unbelievable gap between the report-content and
the official categorization. When one then tries to query, on scientific
grounds, the USAF personnel responsible for those categorizations, one finds
he cannot engage in anything like a scientific discussion because scientif-
ically skilled personnel are not involved in the Bluebook operation. It is
entirely clear that this has been true for the past fifteen years; and still
earlier cases unfortunately point in the same direction, even back in the
1952 period of temporarily energetic investigatory work.
So, when one hears that the USAF position is that the bulk of the UFO
reports they get are misidentifieds, it is necessary to probe much further
to get at the truth.

=== Reflections and Mirages - Menzel’s Views ===

However, it is not only Bluebook that stresses misidentifieds. For about
15 years, [[D H Menzel|Dr. D. H. Menzel]], former Director of Harvard College Observatory,
has been saying that UFO reports fall almost entirely in that category. His
two books11'13, other writings, and many television and lecture discussions
have invariably emphasized that position. It has been of particular scien-
tific interest to me that a majority of his alternative explanations fall
within my own area of interest, atmospheric physics. Consequently I have
examined his arguments rather carefully and must say that they do not at all
convince me. Since I have cited specific examples and discussed specific
objects elsewhere1'8, I shall not give numerous examples here.
But one category of Menzel's explanations that has evidently influenced
Bluebook thinking of recent years (since similar explaining shows up in
official files) deals with "reflection" of light from atmospheric inversions
and "haze layers." Menzel's explanation of the August 20, 1949, Las Cruces
N.M., sighting by [[Clyde Tombaugh|Dr. Clyde Tombaugh]] is a case in point (11, p. 266). Menzel
argues that lights from windows on some house, reflected off an elevated
inversion layer produced the appearance of six yellowish rectangles that
Tombaugh, along with two members of his family, saw shooting across the sky
in that famous sighting. Tombaugh first spotted the geometric array of six
pale-yellow rectangles almost directly overhead. Menzel suggests that they
were reflections of window lights on an inversion layer at which haze had
collected (despite Tombaugh's strong emphasis on the unprecedented transpar-
ency of the air that night!). Since only collimated beams like searchlight
beams can yield distinct spots on haze layers, one seems left only with the
notion that when Menzel says "reflection" he means just that. Let us examine
the possibility that atmospheric inversion layers could yield perceptible
reflectivity at near-normal incidence such as would have to be involved if
Menzel's suggestion is to be acceptable.

For ideally sharp refractive index discontinuities, the Young-Fresnel
equation (see, for example, 14, p. 420) gives the reflectivity R across a 2
discontinuity between two media of relative refractive index n as

   R = [ (n - 1) / (n + 1) ] 2 g

for normal incidence. Even for off-normal incidence angles out to several g
tens of degrees, the order of magnitude of R is well-estimated by that famil-
iar optical relation. Menzel's qualitative discussions about how UFO appari- O
tions stem from reflection off atmospheric discontinuities frequently involve §
such near-normal incidence. Hence the question becomes that of asking about £
how large n can become. For visible light in air at NTP, the refractive index ®
relative to a vacuum is about 1.0003, and temperature effects across an inver- >
sion boundary (even if idealized as mathematically sharp) make changes only
in about the fifth or sixth decimal place of that parameter. Clearly, then,
one will make a gross overestimate of R to go the extreme case of an "inver-
sion" separating standard air from a perfect vacuum, i.c., by inserting into
the Young-Fresnel relation the magnitude n = 1.0003. The result is seen to
be roughly 
   R = 1Q_7

This negligibly small reflectivity could not conceivably yield window-reflec-
tions of the type adduced by Menzel to account for sightings such as Tombaugh's,
despite its grossly overestimating the actual "inversion-layer" reflectivity
that might be encountered in the real atmosphere. Such quantitative consider-
ations are what are not found in Menzel's defense of his discussions of UFO
misidentifications, even in areas where his particular professional background
ought to have made him sense the orders of magnitude likely to be involved.
In the February issue of Air Force/Spacf> Digrrt^^ will be found a Letter
discussing an observation of an odd aerial apparition seen by Lt. Col. R. G.
Hill, and treated by AF/SD as an example of UFO reports that are explainable
if only one looks far enough. I have spoken with Col. Hill to get a few
further details and can only wonder if Menzel's "inversion-reflection" ideas
and Bluebook's misuse of the same have not misled Hill and the editors of
AF/FD. The four luminous discs which Hill saw on a November evening a half
dozen years ago are tentatively explained in Hill's communication as "Possibly
the result of some atmospheric phenomenon that caused two interfacing layers
of air to reflect the light from a nearby source such as the mercury vapor
lamps illuminating the parking lot at the shopping center where these objects
appeared." As I have stated to Col. Hill and to AF/Fb, this is quantitatively
quite out of question, Menzel's and Bluebook's arguments notwithstanding.
Indeed, everyday experience with window-glass, whose refractive index
relative to air is about 1.5, ought to have served to prevent the widespread
misimpression concerning UFOs caused by "inversion-reflections." Window-glass
gives an unimpressive normal-incidence reflectivity of about 4 per cent; yet
it is obvious that it must be orders of magnitude more reflective than adjoin-
ing air layers could ever be.

That type of UFO explanation is being so seriously misapplied, by Blue-
book staff and consultants, that I believe it may be well to carry the counter-
arguments one step closer to the real atmosphere, for deserved emphasis. One
never actually deals with mathematically sharp index-discontinuities in the
earth's atmosphere, only with layers across which density may vary in some
smooth, even if locally steep manner. For such "transition layers" in the
index distribution, one cannot apply the Young-Fresnel equation. The mathe-
matical problem is generally quite difficult, but Rayleigh16 has found one
model that permits useful mathematical analysis of wave-propagation at the
kind of inversions that can occur in our atmosphere.

To give great benefit of doubt to inversion-reflection, one might imagine
an inversion layer of such meteorologically improbable intensity that the air
above the layer was 20°C hotter than that below, and in which all of this
absurdly large temperature jump was concentrated within a transition layer of
the unreasonably small thickness of a mere 1 centimeter. I emphasize that sue
intense inversions are not known in the atmosphere, so I shall still be seri-
ously overestimating reflectivities by applying the Rayleigh theory to such a
case. The computed reflectivity, again treating normal incidence, is found to
be
   R = IO"19

I repeat; even this is an overestimate by a very large margin of what to expec
in the real atmosphere.
Mirage phenomena are very real; but involve angles of incidence so far
from near-normal that the small, but significant, gradients across real inver-
sions do give refractive anomalies of readily perceptible magnitude. But
one's line of sight must strike the inversion layers at almost grazing angle
(order of only tens of minutes departure from the horizontal in most in-
stances), whereas Menzel has treated miraging in his UFO discussions as if it
could occur with lines of sight that often depart by many degrees from the
horizontal, which is quantitatively absurd.
I could discuss other aspects of atmospheric physics that seem to me to
be mishandled in Menzel's treatment of UFOs, but wish to turn to another,
newer effort to account for many UFO reports in terms of another alleged type
of atmospheric-physical phenomena - "plasma-UFOs", as recently discussed by
Klass.

Corona, Ball Lightning, and Plasma-UFOs - Klass's Views
In working from the method of multiple hypotheses, one needs to look in
all directions for possible alternatives. Quite early in my own examination
of the UFO problem, I was confronted by colleagues at the University of
Arizona with challenges on the ground that UFOs could be some unrecognized
form of plasmoid. For example, scientists at our Lunar and Planetary Labora-
tory proposed that, since the wake of an entering meteoroid is a plasma and
since a meteoroid sets up a highly turbulent wake-flow, perhaps vortical
motions on the meteor-wake boundary could spin off masses of incandescent
plasma that descend into the lower atmosphere and are reported as a UFO. I
pointed out seemingly insuperable difficulties centering around rapid ion-
recombination and buoyancy of hot plasmoids that would have made it most
improbable that any such plasmoids could penetrate from entry-levels to the
near-surface levels where innumerable "UFOs" have been reported. But mainly . I stressed the more basic point that the type of UFO reports that are provoc-
ative are not mere balls of luminosity but structured objects described by
seemingly quite credible witnesses as resembling machines of some type.

=== Klass' Plasma-UFO Theory. ===

I reiterate that latter strong objection to
the "plasma-UFO" concept when I turn next to the recent writings of Aviation
Week Senior Avionics Editor, Philip J. Klass. My most basic objection to the
position he is now defending concerning plasma-UFOs is that I feel he does
not confront the fact that the interesting UFO reports do not involve hazy,
glowing amorphous masses, but involve reportedly sharp-edged objects often
exhibiting discernible structural details, carry discrete lights or port-
like apertures, and maneuver for time-periods and in kinematical patterns that
are extremely difficult to square with his plasma-UFO hypothesis. And to that
objection I add the same one I raise against so much of Menzel's UFO argumen-
tation - it fails to deal quantitatively with parts of the argument that are,

in terms of existing scientific knowledge,' amenable to quantitative analysis. O
(May I interject here that my just-cited objection can and should be 2
turned against my own position as to the extraterrestrial hypothesis on the O
grounds that we do now know something about prospects of interstellar travel <
and certain quantitative objections about propulsion difficulties can be "n
raised against such travel. Indeed - and many have already cited these quan- q
titative difficulties, including Purcell, von Hoerner, and Markowitz. I 2
reiterate (see 1, 8) that my lame yet not necessarily invalid defense is that n
we may not yet know all there is to know about the technology of interstellar »
travel and hence our attempts at quantitative assessment of the extraterres- p
trial surveillance hypothesis may be inconclusive. Beyond that I cannot go.) Un
Klass has developed his position in two magazine articles17 and a just- §
published book18. He does not assert that all UFOs are plasma-UFOs; other u
misidentifications contribute, he feels. But he does argue that most student^
of the UFO problem (and he specifically cites me as an example) seem to have 2
missed the "plasma fingerprint" which he sees in so much of the UFO evidence. >
He disclaims any view that the UFO problem is a "nonsense problem"; rather he
suggests that it is one of keen scientific interest because it comprises a ' body of phenomena from which careful study of the plasma-hypothesis will
generate valuable new knowledge of atmospheric physics and atmospheric elec-
tricity .

Now one puzzling and far from understood phenomenon of atmospheric elec-
tricity that does seem to lie in the plasma category is "ball lightning",
which, for brevity, will be identified here as BL. Only within about the past
decade has BL been admitted as a real phenomenon rather than some kind of
illusion. In this sense, the history of BL studies is amusingly parallel to
that of UFOs. It can be stated unequivocally that, in 1968, students of
atmospheric electricity have not yet succeeded in developing an adequate
theoretical understanding of the baffling phenomena reported under this head-
ing. The fact that BL reports, like UFO reports, come largely from untrained
observers who happen suddenly to become witnesses to the phenomenon hampers
data-gathering. Also, it is sufficiently uncommon that it has been discourag-
ing to try to set up special recording systems to gather instrumental data on
the phenomenon (as is true also for UFOs). And the range of BL behavior
characteristics is so wide that no single mathematical model has fit very
satisfactorily the reported effects as well as the known atmospheric electri-
cal facts. As I noted earlier above, there even exist parallels to the UFO
problem in the sense that a semantic difficulty arises: One is not at all
sure, in looking at published summaries of BL reports, that one is dealing
with a single phenomenon. One suspects that, mixed into the alleged BL
sample, are some other quite different phenomena, so that one may be trying
to explain more than necessary.

Summaries of BL reports have been given by Brand19, Dewan20, Rayle21 and
McNally22; and others have published accounts of smaller numbers of individual
reports. BL models have been discussed by so many workers that no catalog of
individual papers is in order here. Dewan2 ' has presented a brief summary
of models developed up to about 1963, and other notions are to be found in
a volume edited by Coroniti24. None of these models, or those subsequently
offered by others such as Uman and Helstrom22 can be viewed as entirely
satisfactory.

However, one major feature of reports and mathematical models is that
the majority of the former and all of the latter suggest that BL is a phenom-
enon closely related to ordinary thunderstorm lightning.
Fair-Weather Ball Lightning. The notion that "ball lightning" can be
generated in fair weather free of all thunderstorm activity has been
developed by Klass, and defended on the ground that, in the literature of
atmospheric electricity, one can find a half-dozen or so reports of lightning
discharges in clear air. He also defends it on the ground that, in some of
the above-cited summaries of BL reports, are luminous masses that were called
"ball lightning" by the witness or the data-collector, yet occurred in the
absence of thunderstorms. This is a confusing situation. We do not yet know
precisely what we shall mean by "ball lightning", do not know how Nature pro-
duces it, and have to concede that we may lump under that one heading phe-
nomena of diverse nature. To illustrate that, consider Klass' citing (18,
p. 121) an observation made from a USAF F-100 flying over the British Isles
at 11,000 ft near midday, where a luminous orange ball with a tail streaming
behind it "somewhat like a flaming meteorite" was sighted by the pilot under
clear-weather condition. Klass uses that observation to support his asser-
tions that BL can not only occur under clear-air conditions, but can move
through the atmosphere at relatively high speeds. But, one must emphatically
object, it is by no means obvious that it is correct to call this a BL report.
Far more reasonable would be to call it an observation of a bright daylight
meteor, many of which are on record in the annals of meteoritics. The very
fact that the original account compares the tail to that of a meteorite ought
to prompt this identification in preference to the BL identification. I urge
you to read Klass' book in full to see if you do not agree that just such easy
slipping of a wide range of odd observations into his plasma category has led
his arguments seriously a*stray. At no place in his book does he defend his
assumption that plasmoids can move through the atmosphere at speeds of hun-
dreds of meters per second, except in one special and quite interesting case -
when they are electrically attracted to aircraft bearing tribo-electrically
induced charges. Let us examine that notion, therefore.

The suggestion which Klass makes that BL can form under fair-weather condi-
tions is, like many of his other suggestions, shown to be quantitatively
absurd by some elementary computations. The fair-weather earth-air current
is known (28, p. 150) to average about 10“ 12 amp/m2, and the fair-weather
potential gradient averages about 100 V/m. If, then, we ask for the area of
the earth's surface over which we would have to collect current to have Joule-
heating within a slab, say, 100 meters deep in amount equal to a modest esti-
mate of 100 watts (of. 25, where 1000 watts is taken as perhaps more repre-
sentative) , we obtain an area of 10,000 km2 as our answer! Obviously the
assumption of a slab 100 m deep was quite arbitrary, but it would seem to give
benefit of doubt to Klass' argument, so the figures suffice to make the notion
of fair-weather ball lightning seem rather far-fetched.

Attraction of Plasma-UFOs to Aircraft. Klass takes note of the fact that
UFOs have been seen following aircraft in flight, and proposes a theory to
explain this. Remarking that aircraft often develop strong net charges due to
contact with snow, rain, or dust particles, he suggests (18, p. 124) that "an
airplane having, say a strong positive charge comes within reaction distance (21)
of a plasma whose surface has a negative charge" with the result that "the
two will be attracted to each other, like two magnets..." He remarks that,
since the aircraft has far greater mass than the plasma, the latter "will be
drawn towards the aircraft rather than the reverse."

Is this subjected to any quantitative assay? No.
Let's examine that idea quantitatively here, then.

For simplicity, assume a spherical plasmoid, with the greatest allowable
surface charge density, namely, that which brings the surface electric field
intensity to the dielectric breakdown strength of air, E, of the order of
20,000 V/cm at typical aircraft altitudes. Similarly, let the aircraft be
roughly modelled as a sphere, also charged (with assumed opposite sign) to
that same breakdown limit (this will actually overestimate net aircraft
charge by something like an order of magnitude, giving more benefit to Klass'
assumed model). Since the surface charge density o will satisfy E = 4iro,
each object will then hold a charge Q = r2E (esuj, where r is the object-
radius and E is taken as 20,000 V/cm ± 65 esu/cm. If d is the separation of
the centers of aircraft and plasmoid, then the force F (cgs) acting between
the two entities is

F = OaQp/d2 = ra2rp2E2/d£

where subscripts a and p correspond, respectively, to aircraft and plasmoid.
For present rough purposes, we may generously set both radii equal to ten
meters, and we may let the plasmoid tag along behind the aircraft that is
dragging it, on Klass' hypothesis, through the air at a lag-distance d =
100 meters. We get, then, F = 4xl07 dynes.
To fulfill Klass' assumed requirements, this Coulomb attraction F must
equal the effective aerodynamic drag force D, to which the fast-moving plas-
moid is subjected (if it is not to be torn apart or brought to rest). Call-
ing the drag coefficient C, the air density p, and the speed of aircraft and
the trailing plasmoid V, we have,

D = h p v2CirP 2
P

and setting D = F to determine the allowed airspeed V,
V2 = (2r 2E2)/(npCd2) . a.

Thus the radius of the UFO plasmoid disappears from the V-relation. Using
p = 7xl0~^g/cm3, C = 0.2 for the high Reynolds number regime here involved,
and the previously suggested values for the other parameters, we get

   V = 4xl02 cm/sec * 9 mph

Thus, even upon assuming a large maximally-charged aircraft and plas-
moid, and limiting the trailing-distance to no more than 100 meters, we
obtain so low a value for the allowed V that it is absurd.

But the conclusions are even more negative for Klass' hypothesis than is
suggested by the limit V = 9 mph, since it is known from experience with air-
craft charging 2 6,27 that steady leakage of autogenous charges keep surface
field strengths down to values generally under 103V/cm (a factor of twenty
lower than assumed above for the aircraft), and even that value would not be
found in flying through clear air free of snow or dust. And neither Klass
nor I have proposed any basis for assuming that his airborne plasmoids will
be so decidedly non-neutral as to have surface charge densities anywhere near
the breakdown limit, as assumed in the above calculation to give Klass full
benefit of doubt on that socre. When some allowance is made for those
factors, it is seen that a plasmoid could not be drawn through the atmosphere
at the pace of even a very slow walk by the Coulomb interactions which Klass

invokes to fit his hypothesis of plasma-UFOs, hence his ideas on plasma-
UFOs pacing aircraft are quantitatively untenable. He states that they do
not come very close to the charged aircraft because the aircraft's "wind-
stream serves as a protective sheath", another qualitatively ad kaa assump-
tion that can now be seen to be irrelevant.
In one of his articles1', Klass explains inability of jet interceptors
to close on UFOs as resulting from the circumstance that aircraft and plasma
have the same charge, so that the interceptor repels the plasma-UFO and can
never catch up with it. This is equally absurd.

Other objections could be raised: Klass fails to confront his hypoth-
esis with cases where UFOs were neither attracted to nor repelled by air-
craft, yet UFOs have made close passes coming from all relative directions
and exhibited many unusual maneuvers not fitting his model. For example, a
very famous UFO sighting, the July 24, 1948, Chiles-Whitted sighting over
Montgomery, Alabama, is briefly alluded to on p. 118 of his book, so Klass
must know that Chiles and Whitted saw the object (which they said had a
double row of windows, a length comparable to a B-29, a cherry-red wake, and
a blue glow from nose to tail along its undersurface) come almost directly
at their DC-3 on a near-collision course before it passed them and then did
an abrupt pullup before it disappeared. Coulomb attractions at work? Innu-
merable other aircraft-observed UFOs could be cited that would not fit Klass'
Coulomb-attraction model, even if it did make quantitative sense for trailing
UFOs. It can only be concluded that Klass has not provided an explanation
for why UFOs sometimes come near aircraft.

Not only does Klass suggest that "highly charged aircraft" can attract
his plasma-UFOs, but also (18, p. 125-6) suggests that charged automobiles
attract "low-altitude UFOs". Then, carrying the idea to its full absurdity,
he proposes that a charged pedestrian "who encounters a very low-altitude
UFO may find it is drawn slowly toward him or that it backs off as he
approaches it." The question of whether it shall be attracted or repelled
depends, Klass adds, on the sign of the charge of the UFO and that "of the
very slight charge on the person". To make such assertions without any
attempt at inserting numbers into the elementary calculations that disclose
their low plausibility is quite typical of Klass' book.
[it might be added, in this final version of the draft presented at the
Montreal CASI meeting, that my use of the figure 20,000 V/cm in my rough
check of Klass' aircraft-pacing model was challenged from the floor by
Klass. He stated that this figure must obviously be incorrect, for he had
information that helicopters flying over dusty terrain can be charged up to
500,000 volts (see 18, p. 171). As I pointed out by way of clarification,
Klass was confusing "volts" with "volts per centimeter"; and to reconcile
his figure with mine we need only be sure that the helicopter had a clear-
ance above ground of at least 25 cm (since 25 cm multiplied by 20,000 V/cm
equals 500,000 volts). Here again, one is startled to encounter confusion
over such elementary electrical concepts. That the dielectric breakdown
strength of air is of order of 10,000 to 30,000 V/cm, depending on electrode
geometry and air pressure is certainly not open to question.]

Formation of Plasma-UFOs in Wingtip Vortices■ For the most part, Klass
offers his readers no hint of the origin of the plasmoids to which he wishes
to equate UFOs. But one case on which he appears to offer an idea of origin
is in connection with aircraft. Klass (see below) has the idea that pollu-
tion products exert a helpful influence in plasma-formation. Aircraft
engines emit pollution products. Therefore Klass suggests that pollutants,
along with the charges which he believes are collected in the tip vortices
(18, p. 168), somehow form a plasma-UFO.

23
Let's go over that in more detail. First, to repeat, impact charging
of aircraft in clear, particle-free air is negligible. One must have rain,
snow, or dust impacting on the aircraft surfaces to generate strong auto-
genous charges 26,17, so Klass is in serious initial trouble on this score
alone. Furthermore, when an aircraft is undergoing such impact-charging,
what actually occurs is that the surface charge densities build up to an
equilibrium value such that the leakage-rate just equals the charging rate.
(One great value of charge-dissipating whips on wing trailing edges is that
they boost the effective discharge rate to so high a value that the steady-
state values of total aircraft charge are low.) Under the steady state that
is quickly attained on entering a dust or snow cloud, the air passing off the
wing has zero net charge, since the leakage charge just balances the residue
left over from the impact charging. Thus, Klass will not get plasmoids bear-
ing any significant net charge by such a process, so his aircraft-chasing
UFOs are not accounted for by the only model that he offers his reader to
get his plasmoids airborne.

But the difficulties are much more serious than absence of significant
net charge. To have a plasmoid in the usual sense of the term requires high
concentrations of free electrons, whereas all that will be sweeping off the
trailing edge of an aircraft wing when flown under conditions favoring charg-
ing (dust, snow, rain) will be "ions" in the sense employed in atmospheric
electricity. All free electrons will attach to oxygens in microseconds; and
exhaust pollutants will further demobilize the small ions that are thus
formed. Between this and ordinary ion-recombination processes, nothing
remotely resembling a luminous plasmoid can possibly be expected to appear
within the trailing vortices of an aircraft. When Klass states (18, p. 168)
that "an aircraft could accumulate electrical energy and focus it into peri-
odic discharges which could create a plasma-UFO in its wake when conditions
were right," and then adds that these plasmoids would be left behind so that
"another pilot flying along the same airway a few minutes later might encoun-
ter a glowing plasma," he is using arguments that would collapse if he were
to try to put numbers into them. The temporal and spatial instability of
plasmoids is one of their most outstanding characteristics. Klass, accounts
neither for their formation nor for their survival in this context of air-, craft-related plasmas.

Diurnal Variations of UFOs. Klass suggests that UFOs are a mystery of
atmospheric electricity. Students of that subject will certainly find some
surprising mysteries of an atmospheric-electrical nature on pp. 164-167 18.
Klass cites Vallee's evidence for an evening maximum of low-altitude UFO
sightings, between 6 p.m. and 10 p.m., roughly. Klass notes that Brand19
finds a diurnal peak frequency of BL sightings at 5 p.m. Klass feels that
this rough temporal correlation indicates a genetic relation between BLs and

UFOs. Meteorologists could suggest to him that a 5 p.m. peak in BL observa-
tions would match the generally late-afternoon peak of thunderstorm activity.
I believe that the early evening peak of UFO reports is the result of greater
likelihood of detecting a luminous object at night than a non-luminous object
by day. I gather that Klass shares some of the latter view; but he proceeds
to a further idea that plasmas are formed with diurnal peak frequency in the
early evening. The route by which he gets there is curious indeed.
First, he discusses the diurnal variation of the atmospheric electric
field-strength near the earth's surface and calls attention to a tendency
for most land-stations to have a maximum of field-strength near 7 p.m. He
glosses over the point that more UFOs are seen in summer than in winter, and
that during summer most land stations have a strong maximum of field strength
in the mid-morning. But where his physics goes astray is that he mistakenly
attributes the peak field-strength to a concurrent maximum of radon gas that
produces much of the air-ionization in the lowest atmosphere.

The actual situation is/8 that increased ionization would, per se,
increase the air's conductivity and thus decrease the observed atmospheric
electric field strength - precisely the opposite of what Klass claims.
Briefly, the earth-ionosphere potential difference may here be treated as
constant (we may ignore the well-known universal diurnal variation), whence
vertical current densities will remain sensibly constant so long as diurnal
factors only alter the conductivity in a relatively shallow air layer near
the earth's surface. But with constant current density, the atmospheric
electric field intensity must adjust itself to vary inversely with air con-
ductivity. Pollutants decrease air conductivity; ionization processes
increase it. The well-known evening increase in field intensity is due to
development of an evening low-level inversion that traps pollutants, the
pollutants attach small ions to generate large ions of low mobility, the
air conductivity consequently goes down, and the observed field intensity
must, to maintain fixed current density, go up.
If radon-trapping were the dominating factor here, as Klass evidently
thinks, evening would be a time of minimal, not maximal, field-intensity I

He extrapolates the above to a claimed explanation for the higher fre-
quency of UFO sightings in rural areas vs. urban areas; but again it is
based on the above misconception of the role of inversions, so that this
deduction of Klass' is also invalid.

But even beyond the confusion engendered by Klass' thoroughly confusing
the physics of the diurnal variations of conductivity and potential gradient,
there lie further basic shortcomings that warrant emphasis. One must ask,
just what does he have in mind in talking about all this? How does it relate
to formation of luminous, active plasmas? Evidently the answer is to be
found on p. 166 (18), where he asserts that these cyclical variations of
"pollution and electrification" serve to set the stage "for the chance trig-
gering of a plasma-UFO by a corona discharge on a high-tension line or per-
haps by a brief power surge in a high-power TV or radio transmitter.

Let's examine these two categories separately.

One can only conclude that Klass believes that an increase of atmos-
pheric ionization by the small factor (less than about 2) which he had in
mind when he became confused over the foregoing diurnal-variation arguments
can exert an important "triggering" action on power-line corona. That he is
not clear as to the physics of corona-formation seems evident when he states
earlier (18, p. 22) that "under freak conditions an electrical avalanche
occurs." He must be unaware that corona discharge from power structures is
not dependent upon unusual concentrations of atmospheric ions but only upon
establishing sufficiently strong field strengths that the continually form-
ing free electrons (ejected by cosmic-ray or air-radioactivity bombardment of
neutral air molecules) shall be accelerated within one free path to energies
sufficiently high to cause an additional impact-ionization event. Being con-
fused on this point, he draws the erroneous inference that if he could
account for some extra air-ionization, he'd account for extra "corona dis-
charge on a high-tension line." Also, coronas don't detach from power lines.

Next consider the idea of a "brief power surge in a high-power TV or
radio transmitter. A clear-channel radio broadcasting station is permitted
50,000 watt output. TV stations are typically operated at outputs in the
neighborhood of 150,000 watts, though some can legally emit as much as twice
this wattage. Let's take a generously large value of 300,000 watts for the

power output from an elevated TV antenna, and, for wavelength reasons, we'll
be generous to Klass in assuming an effective emitting area of only 1 m2.
From the Poynting equation, we then wish to estimate the maximum electric
field strength prevailing near the antenna with a flux density of 3xl05
watts/m2. Since P = 1.3 x 10-3Eo2 (P in watts/m- , Eo in V/m) , we find by
this order-of-magnitude estimate that Eo = 150 V/cm. Even after allowing
for the reduction in dielectric strength of air at the radio frequencies
involved, this generously high estimate of 150 V/cm is more than an order of
magnitude too low (in fact, probably about two orders of magnitude too low)
to initiate rf-breakdown and plasma-formation (see, e.g., 35, p. 185 and
36, p. 156). Thus, far more than "a brief power surge" will be required to 2
cause plasmas to appear around an antenna - and a mere two-fold variation q
of air-ionization would be entirely inconsequential in abetting this improb- m
able event. So Klass appears to be in difficulty here, too, even if he had n
not made the prior mistakes with respect to the diurnal variations in atmos-
pheric-electrical parameters that led him into all this. -<

mi
Air Pollution as a Plasma Promoter. In the foregoing, there have now O
been several allusions to an underlying idea that runs through much of Klass' 2
book: Air pollutants are alleged to aid in the formation of plasma-UFOs.
This is such a curious idea, and the source of this notion is treated so
casually by Klass (18, p. 153) that few readers are likely to realize how it ft
arose. Because Klass weaves it into so much of his argument, it warrants c
closer examination.

Klass contacted [[[J R Powell|Dr. J. R. Powell]] concerning some interesting laboratory §
work done at Brookhaven National Laboratory (APS abstract in BNL 10625, E
entitled "Laboratory Production of Self-sustained Atmospheric Luminosities", E
by Powell, Zucker, Manwaring, and Finkelstein). Using a 75 MHz rf arc dis- >
charge as the primary power source, and feeding its output into a walk-in
size resonant cavity filled with selected gases at atmospheric pressure, the
Brookhaven group were studying luminosities with radii in the decimeter
range and lifetimes of order of a second or more after shutoff of the rf
power supply. Early work indicated that such luminosities could be produced
in air, N2, O2 , or N2O, though not in A or CO2 . It was hypothesized that
the rf "pumping" stored energy in certain energetically accessible long-
lived (metastable) states of N2, or O2, or N20, and that vaporized electrode
atoms (e.g., Cu) produced the visible radiation after acquiring energy in
collisions of the second kind with the excited chamber-gas atoms. Possible
relations to the ball lightning problem were noted by the investigators.
The important points to note here are that this experiment appears to
involve three crucial features: 1) a tuned cavity, 2) an rf power source
feeding into it, and 3) a gas, filling the cavity at 1 atm pressure and
selected to have metastable states with lifetimes of the order of seconds
such as to constitute an energy reservoir upon which the light-emitting
species (metal vapor atoms) can feed repetitively during the post-shutoff
glow period. (Whether the interpretations put on this promising experi-
mental work stand the test of time need not bother us here; they do appear
plausible.)

Upon hearing of this laboratory work, Klass jumped via several erroneous
steps to his idea that pollutants from aircraft, cars, and factories will
enhance the likelihood of forming plasma-UFOs.
His first error lay in mistakenly identifying what he terms "nitrous
oxides" (his plural) with the "nitrogen oxides" of air pollution literature
(18, p. 153). As a matter of fact, nitrous oxide, N„O, is a natural
constituent of air, not considered an atmospheric pollutant (29, p. 156),
and is therefore not even mentioned in most air pollution literature on the
problem of the nitrogen oxides (30, p. 3-12; 31, p. 83). NO is copiously
produced in all combustion processes, including those in aircraft and auto-
mobiles, and oxidizes quickly in air to NO;., the primary photon-acceptor in
photo-oxidation air pollution of the Los Angeles type. N.O, a rather stable
compound, always present in concentrations about twice that of all other
nitrogen oxides characterizing polluted atmospheres, plays no part at all in
any pollution problems, since it "is dangerous only in concentrations of
about 90 per cent and then has mainly an anoxic effect" (32, p. 149). Indeed,
chemical analysis of the "nitrogen oxides" in polluted atmospheres was not
meaningful until tests, such as the phenoldisulfonic acid method (29, p.159),
were developed to react to all N-oxides except N2O! Briefly, through an
error of interpretation of elementary chemical terminology, Klass misidenti-
fied the N2O of the Brookhaven experiments with true pollutants and was off
on one of the many error-chains that so weaken his treatment of the UFO
problem.

Next, he failed to appreciate relevant quantitative aspects concerning
the "air pollutants" he thus began to discuss. Average concentrations of
N2O at sea level are near 0.5 ppm (parts per million by volume). Average
concentrations of all pollutant-N-oxides in Los Angeles run about half that
(31, p. 84). To suggest that any gas present in such trace quantities could
play the energy-reservoir role of the test-gases with which the Brookhaven
group filled their tuned cavity is to miss completely a basic quantitative
aspect of the experiments. Yet this is what Klass suggests; so here we have
the next stage in his error-compounding. If the metal atoms have to make a
million or more collisions, on the average, before finding one of Klass'
pollutant molecules, not much light would be coming from the system.
In fact, it will have to be interjected somewhere here that, once one
understands what Powell and co-workers think happens in their chamber, it
becomes somewhat unreasonable to talk about adding anything to ordinary air
by way of abetting the process, for they clearly assert that the N2 and O2
of ordinary air do quite well in providing suitable metastable energy levels
to make the process work. In view of this point, all of Klass' discussion
about diurnal variation in pollutant concentrations, about pollutants swept
into tip vortices, and about alleged concentrations of pollutants near high-
ways is seen to be irrelevant and based on a network of misconceptions.

But, finally, the most basic error of Klass' attempts to fit the Brook-
haven experiments into his thesis lies in ignoring the very special nature
of the energy source used in the laboratory work, and in casually overlook-
ing the complete absence of anything even roughly similar to it in the out-
door environments in which he claims plasma-UFOs are being formed. The
buildup of fields in the standing-wave pattern of the Brookhaven tuned cav-
ity fed at the resonant frequency (75 MHz) provides excitation conditions
that simply cannot be blandly assumed to exist aft of a wing-tip, or under
an inversion in a rural area, or above an automobile speeding down a highway
- or even near a high-power TV antenna, as shown above.
In the light of the preceding points, it is interesting to re-read the
kinds of inferences Klass attempts to draw: He asks (18, p. 153) if it is
"merely coincidence" that "both air pollution and UFOs have experienced a
dramatic increase within the past two decades"; and then goes on in similar
vein. "Is it also merely coincidence that many low-altitude UFOs are seen
near highways, where growing numbers of autos spew out their pollution
products? And is it coincidence again that many of the high-altitude UFOs
are reported by pilots while flying along well-traveled airways, where air-
craft also leave a trail of combustion-engine pollution products in their
wake?"

27