James E. McDonald statement, Symposium on UFOs, House Committee on Science and Astronautics

of _any_ "cloud-reflection phenomenon" that could produce anything remotely resembling a distinct object. Clouds
of droplets or ice crystals do not provide a source of specular reflection (except in the case of horizontally-floating
ice crystals observed from above with a bright luminary, such as sun or moon, in the distance - undersun). What
Menzel could possibly have in mind when he talks loosely about such cloud reflections (and he does so on many
different places in his books), I cannot imagine.
Inversions are invoked by Menzel, and in official evaluations, to account for certain UFO sightings. Inversions
produced by radiational cooling or by atmospheric subsidence are relatively common meteorological phenomena. In
some cases, quite sharp inversions with marked temperature differences in rather small vertical distances are known
to occur. It is such inversion layers that are responsible for some of the most striking desert mirages of the looming
type. To experience a looming mirage, the observer's eye must be located in or near the atmospheric layer wherein
the temperature anomalously increases with height (inversion layer), and the miraged target in the object-field must
also lie in or near the inversion layer. Inversion layers are essentially horizontal, and the actually-encountered values
of the inversion lapse rates are such that refraction anomalies are confined to very small departures from the
horizontal, as noted above under remarks on mirages. All of these points are well-understood principles of
meteorological optics. However, Menzel has attempted to account for such UFOs as Dr. Clyde Tombaugh saw
overhead at Las Cruces in August 1949 in terms of "inversion" refraction or reflection effects. Since I have
discussed the quantitative unreasonableness of this contention elsewhere, I will not here elaborate the point, except
to say that if inversions were capable of producing the optical disturbances that Menzel has assumed, astronomers
would long since have given up any attempt to study the stars by looking at them through our atmosphere.
Other atmospheric-optical anomalies have been adduced by Menzel in his UFO discussions. He has repeatedly
suggested that layers of haze or mist cause remarkable enlargement of the apparent images of stars and planets. By
enlargement, he makes very clear that he means radial enlargements in all directions such that the eye sees not a
vertical streak of the sort well- known to astronomers as resulting from near horizon refraction effects, but rather a
circular image of very large angular size. Menzel even describes a sighting that he himself made, over Arctic regions
in an Air Force aircraft, in which the image of Sirius was enlarged to an angular size of over ten minutes of arc (one-
third of lunar diameter). I have discussed that sighting with a number of astronomers, and not one is aware of
anything that has ever been seen by any astronomer that approximates such an instance. In fact, it would require
such a peculiar axially-symmetric distribution of refractive index, which miraculously followed the speeding aircraft
along as it moved through the atmosphere, that it seems quite hopeless to explain what Menzel has reported seeing
in terms of refraction effects.
Dr. Menzel's writings on UFOs have evidently had, in some quarters, a marked effect on attitudes towards UFOs. I
regard that effect as deleterious. If I felt that we were dealing here with just a slight difference of opinion about
rather controversial scientific matters on the edge of present knowledge, I would withhold strong comment.
However, I wish to say for the record, that I regard the majority of Dr. Menzel's purported meteorological- optical
UFO explanations as simply scientifically incorrect. I could, but shall not here, enlarge upon similar critique of
official explanations that have invoked such arguments.
3. Atmospheric Electricity:
One phenomenon in the area of atmospheric electricity to which appeal has been made from the earliest years of
investigations of the UFO phenomena is that of ball lightning. For example, a fairly extensive discussion of ball
lightning was prepared by the U.S. Weather Bureau for inclusion in the 1949 Project Grudge report (Ref. 6). It was
concluded in that report that ball lightning was most unlikely as an explanation for any of the cases which were
considered in that report (about 250). Periodically, in succeeding years, one or another writer has come up with that
same idea that maybe people who report UFOs are really seeing ball lightning. No one ever felt this idea worth
pursuing very far, until P.J. Klass began writing on it. Although his ideas have received some attention in
magazines, there is little enough scientific backup to his contentions that they are quite unlikely to have the same
measure of effect that Menzel's previous writings have had. For that reason, I shall not here elaborate on my strong
objections to Klass' arguments. I spelled them out in considerable detail in a talk presented last March at a UFO
Symposium in Montreal held by the Canadian Aeronautics and Space Institute. Klass has, in my opinion, ignored
most of what is known about ball lightning and most of what is known about plasmas and also most of what is
known about interesting UFOs in developing his curious thesis. It cannot be regarded as a scientifically significant
contribution to illumination of the UFO problem.