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Science and the UFO phenomenon:

"Statement on Unidentified Flying Objects"

This statement has been submitted by Dr. James E. McDonald, Senior Physicist, Institute of Atmospheric Physics, and professor, Department of Meteorology, The University of Arizona, Tucson, Arizona, to the House Committee on Science and Astronautics at July 29, 1968, Symposium on Unidentified Flying Objects, Rayburn Bldg., Washington, D.C.

I created a table of content below; which was not part of the original scientific publication. The 56 pages publication is some 250Kb and I broke it in several files for acceptable web access speed.

Please go to the Science section of this website for more scientific papers by James E. McDonald and other scientists, plus comments and information regarding scientists' work and position about the UFO phenomenon.

Table of content

Dr. James E. McDonald.

Some remarks on interviewing experience and types of UFO cases encountered:

1. Sources of cases dealt with:

Prior to 1966, I had interviewed about 150-200 persons reporting UFOs; since 1966, I have interviewed about 200-250 more. The basis of my post-1966 interviewing has been quite different from the earlier period of interviewing of local witnesses, whose sightings I heard about essentially by chance. Almost all of my post-1966 interviews have been with witnesses in cases already, investigated by one or more of the private UFO investigatory groups such as NICAP or APRO, or by the official investigative agency (Project Bluebook). Thus, after 1966, I was not dealing with a body of witnesses reporting Venus, fireballs, and aircraft strobelights, because such cases are so easily recognizable that the groups whose prior checks I was taking advantage of had already culled out and rejected most of such irrelevant material. Many of the cases I checked were older cases, some over 20 years old. It was primarily the background work of the many independent investigatory groups here and in other parts of the world (especially the Australian area where I had an opportunity to interview about 80 witnesses) that made possible my dealing with that type of once sifted data that yields up scientifically interesting information so quickly. I wish to put on record my indebtedness to these "dedicated amateurs", to use the astronomer's genial term; their contribution to the ultimate clarification of the UFO problem will become recognized as having been of basic importance, notwithstanding the scorn with which scientists have, on more than one occasion, dismissed their efforts. Although I cite only the larger of these groups (NICAP about 12,000 members, APRO about 8,000), there are many smaller groups here and abroad that have done a most commendable job on almost no resources. (Needless to add, there are other small groups whose concern is only with sensational and speculative aspects.)

2. Some relevant witness-characteristics:

By frequently discussing my own interviewing experience with members of those non-official UFO groups whose past work has been so indispensable to my own studies, I have learned that most of my own reactions to the UFO witness-interview problem are shared by those investigators. The recurrent problem of securing unequivocal descriptions, the almost excruciating difficulty in securing meaningful estimates of angular size, angular elevation, and angular displacements from laymen, the inevitable variance of witness descriptions of a shared observation, and other difficulties of non-instrumental observing are familiar to all who have investigated UFO reports. But so also are the impressions of widespread concern among UFO witnesses to avoid (rather than to seek) publicity over their sightings. The strong disinclination to make an open report of an observation of something the witness realizes is far outside the bounds of accepted experience crops up again and again. In my interviewing in 1947 sightings, done as a cross check on case material used in a very valuable recent publication by Bloecher (Ref. 8), I came to realize clearly for the first time that this reluctance was not something instilled by post-1947 scoffing at UFOs, but is part of a broadly disseminated attitude to discount the anomalous and the inexplicable, to be unwilling even to report what one has seen with his own eyes if it is well outside normal experience as currently accepted. I have heard fellow-scientists express dismay at the unscientific credulity with which the general public jumps to the conclusion that UFOs are space ships. Those scientists have certainly not interviewed many UFO witnesses; for almost precisely the opposite attitude is overwhelmingly the characteristic response. In my Australian interviewing, I found the same uneasy feeling about openly reporting an observation of a well-defined UFO sighting, lest acquaintances think one "has gone round the bend." Investigators in still other parts of the world where modern scientific values dominate world-views have told me of encountering just this same witness-reluctance, The charge that UFO witnesses, as a group, are hyperexcitable types is entirely incorrect. I would agree with the way Maj. Gen. John A. Samford, then Director of Air Force Intelligence, put it in a 1952 Pentagon press conference: "Credible observers have sighted relatively incredible objects."

Not only is the charge of notoriety-seeking wrong, not only is the charge of hyperexcitability quite inappropriate to the witnesses I have interviewed, but so also is the easy charge that they see an unusual aerial phenomenon and directly leap to some kind of "spaceship hypothesis." My experience in interviewing witnesses in the selected sample I have examined since 1966 is that the witness first attempts to fit the anomalous observation into some entirely conventional category. "I thought it must be an airplane." Or, "At first, I thought it was an auto-wrecker with its red light blinking." Or, "I thought it was a meteor - until it stopped dead in midair," etc. Hynek has a very happy phrase for this very typical pattern of witness-response: he terms it "escalation of explanation", to denote the often rapid succession of increasingly more involved attempts to account for and to assimilate what is passing before the witness' eyes, almost invariably starting with an everyday interpretation, not with a spaceship hypothesis. Indeed, I probably react in a way characteristic of all UFO investigators; in those comparatively rare cases where the witness discloses that he immediately interpreted what he sighted as an extraterrestrial device, I back away from what is likely to be a most unprofitable interview. I repeat: such instances are really quite rare; most of the general population has soaked up a degree of scientific conventionalism that reflects the net result of decades, if not centuries, of scientific shaping of our views. I might interject that the segment of the population drawn to Hypothesis 8 above might be quick to jump to a spaceship interpretation on seeing something unusual in the sky, but, on the whole, those persons convinced of Hypothesis 8 are quite uninterested in observations, per se. Their conviction is firm without bothering about such things as observational matters. At least that is what I have sensed from such exposure as I have had to those who support Hypothesis 8 fervently.

3. Credibility of witnesses:

Evaluating credibility of witnesses is, of course, an ever-present problem at the present stage of UFO studies. Again, from discussions with other investigators, I have concluded that common sense and previous everyday experience with prevaricators and unreliable persons lead each serious UFO investigator to evolve a set of criteria that do not differ much from those used in jury instructions in our courts (e.g., Federal Jury Instructions). It seems tedious to enlarge here on those obvious matters. One can be fooled, of course; but it would be rash indeed to suggest that the thousands of UFO reports now on record are simply a testimony to confabulation, as will be better argued by some of the cases to be recounted below.

4. Observational reliability of witnesses:

Separate from credibility in the sense of trustworthiness and honesty is the question of the human being as a sensing system. Clearly, it is indispensable to be aware of psychophysical factors limiting visual discrimination, time estimation, distance estimation, angular estimation, etc. In dealing with the total sample of all observations which laymen initially label as UFOs, such factors play a large role in sorting out dubious cases. In the type of UFO reports that are of primary significance at present, close-range sightings of objects of large size moving at low velocities, or at rest, and in sight for many seconds rather than fractions of a second, all of these perceptual problems diminish in significance, though they can never be overlooked.

A frequent objection to serious consideration of UFO reports, made by skeptics who have done no first-hand case investigations, is based on the widely discrepant accounts known to be presented by trial-witnesses who have all been present at some incident. To be sure, the same kind of discrepancies emerge in multiple-witness UFO incidents. People differ as to directions, relative times, sizes, etc. But I believe it is not unfair to remark, as the basic rebuttal to this attack on UFO accounts, that a group of witnesses who see a street-corner automobile collision do not come to court and proceed, in turn, to describe the event as a rhinoceros ramming a baby carriage, or as an airplane exploding on impact with a nearby building. There are, it needs to be soberly remembered, quite reasonable bounds upon the variance of witness testimonies in such cases. Thus, when one finds a half-dozen persons all saying that they were a few hundred feet from a domed disk with no resemblance to any known aircraft, that it took off without a sound, and was gone from sight in five seconds the almost inevitable variations in descriptions of distances, shape, secondary features, noises, and times cannot be allowed to discount, per. se, the basically significant nature of their collective account. I have talked with a few scientists, especially some psychologists, whose puristic insistence on the miserable observing equipment with which the human species is cursed almost makes me wonder how they dare cross a busy traffic intersection. Some balance in evaluating witness perceptual limitations is surely called for in all of these situations. With that balance must go a healthy skepticism as to most of the finer details, unless agreed upon by several independent witnesses. There is no blinking that anecdotal data are less than ideal; but sometimes you have to go with what you've got. To make a beginning at UFO study has required scrutiny of such anecdotal data; the urgent need is to get on to something much better.

5. Problem of witness' prior knowledge of UFO knowledge:

In interviewing UFO witnesses, it is important to try to ascertain whether the witness was, prior to his reported sighting, familiar or unfamiliar with books and writings on UFOs. Although a strong degree of familiarity with the literature of UFOs does not negate witness testimony, it dictates caution. Anyone who has done a lot of interviewing at the local level, involving previously unsifted cases, will be familiar with occasional instances where the witness exhibited such an obvious enthusiasm for the UFO problem that prudence demanded rejection of his account.

However, in my own experience, a much more common reaction to questions concerning pre-sighting interest in UFO matters is some comment to the effect that the witness not only knew little about UFOs beyond what he'd happened to read in newspapers, but he was strongly disinclined to take the whole business seriously. The repetitiveness and yet the spontaneity with which witnesses of seeming high credibility make statements similar to, "I didn't believe there was anything to all the talk about UFOs until I actually saw this thing," is a notable feature of the interview-experience of all of the investigators with whom I have talked. Obviously, an intending prevaricator might seek to deceive his interrogator by inventing such an assertion; but I can only say that suspicion of being so duped has not been aroused more than once or twice in all of the hundreds of witnesses I have interviewed. On the other hand, I suppose that, in several dozen instances, I have lost interest in a case because of a witness openly stressing his own prior and subsequent interest in the extraterrestrial hypothesis.

Occasionally one encounters witnesses for whom the chance of prior knowledge is so low as to be almost amusing. An Anglican missionary in New Guinea, Rev. N. E. G. Cruttwell (Ref. 9), who has done much interviewing of UFO witnesses in his area, has described testimony of natives who come down into the mission area from their highland home territory only when they are wallaby-hunting, natives who could not read UFO reports in any language of the world, yet who come around, in their descriptions of what they have seen, to the communications-shortcut of picking up a bowl or dish from a nearby table to suggest the shape they are seeking to describe in native tongue. Little chance of bias gained from reading magazines in a barber-chair in such instances.

6. Types of UFO accounts of present interest:

The scope of the present statement precludes anything approaching an exhaustive listing of categories of UFO phenomena: much of what might be made clear at great length will have to be compressed into my remark that the scientific world at large is in for a shock when it becomes aware of the astonishing nature of the UFO phenomenon and its bewildering complexity. I make that terse comment well aware that it invites easy ridicule; but intellectual honesty demands that I make clear that my two years' study convinces me that in the UFO problem lie scientific and technological questions that will challenge the ability of the world's outstanding scientists to explain - as soon as they start examining the facts.

a) Lights in the night sky.

("NLs" as they are called by the NICAP staff, on the basis that the profusion of reports of "damnable lights" meandering or hovering or racing across the night sky in unexplainable manner are one of the most common, yet one of the least useful and significant categories of UFO reports.) Ultimately, I think their significance could become scientifically very substantial when instrumental observing techniques are in wide use to monitor UFO movements. But there are many ways that observers can be misled by lights in the night sky, so I shall discuss below only such few cases as are of extremely unconventional nature and where the protocols of the observations are unusually strong.

b) Close-range sightings of wingless discs and cigar-shaped objects.

This category is far more interesting. Many are daytime sightings, many have been made by witnesses of quite high credibility. Structural details such as "ports" and "legs" (to use the terms the witnesses have adopted to suggest most closely what they think they have seen) are described in many instances. Lack of wings and lack of evident means of propulsion clearly rule out conventional aircraft and helicopters. Many are soundless, many move at such speeds and with such accelerations that they defy understanding in terms of present technology. It is to be understood that I speak here only of reports from what I regard as credible observers.

c) Close-range nighttime sightings of glowing, hovering objects, often with blinking or pulsating discrete lights.

In these instances, distinct shape is not seen, evidently in many cases because of the brilliance of the lights. Less significant than those of the preceding category, these nonetheless cannot be accounted for in terms of any known vehicles. Frequently they are reported hovering over vehicles on the ground or following them. Sometimes they are reported hovering over structures, factories, power installations, and the like. Soundlessness is typical. Estimated sizes vary widely, over a range that I do not believe can be accounted for simply in terms of the known unreliability of distance and size estimates when one views an unknown object.

d) Radar-tracked objects, sometimes seen visually simultaneously by observers on the ground or in the air.

In many of these cases, the clues to the non-conventional nature of the radar target is high speed (estimated at thousands of miles per hour in certain instances); in others, it is alternate motion and hovering; in still others, it has been the unconventional vertical motions that make the radar observations significant. Clearly, most important are those instances in which there was close agreement between the visual and radar unknown. There are far more such cases than either scientists or public would guess.

Those four categories do not exhaust the list by any means. But they constitute four commonly encountered categories that are of interest here. Examples will be found below.

7. Commonly encountered questions:

As Mark Twain said, "Faith is a great thing, but it's doubt that gets you an education."

There are many questions that one encounters again and again from persons who have done no personal case-checking and who maintain a healthy skepticism about UFOs. Why don't pilots report these things if they are buzzing around in our skies? Why aren't they tracked on radar? Why don't our satellite and astronomical tracking systems get photos of UFOs? Why are they always seen in out-of-the-way rural areas but never over large cities? Why don't large groups of people ever simultaneously see UFOs, instead of lone individuals? Why don't astronomers see them? Shouldn't UFOs occasionally crash and leave clear-cut physical evidence of their reality? Or shouldn't they at least leave some residual physical evidence in those alleged instances where the objects have landed? Shouldn't they affect radios and produce other electromagnetic effects at times? If UFOs are a product of some high civilization, wouldn't one expect something of the nature of inquisitive behavior, since innate curiosity must be a common denominator of anything we would call "intelligence"? Why haven't they contacted us if they're from somewhere else in the universe and have been here for at least two decades? Is there any evidence of hostility or hazard? Are UFOs seen only in this country? Why didn't we see them before 1947, if they come from remote sources? And so on.

In the following sections, I shall show how some of these questions do have quite satisfactory answers, and how some of them still defy adequate rebuttal. I shall use mostly cases that I have personally investigated, but, in a few instances (clearly indicated), I shall draw upon cases which I have not directly checked but for which I regard the case-credentials as very strong.

8. Useful source materials on UFOs:

Hoping that Committee staff personnel will be pursuing these matters further, I remark next on some of the more significant items in the UFO literature. All of these have been helpful in my own studies.

One of the outstanding UFO references (though little-known in scientific circles) is The UFO Evidence, edited by R. H. Hall and published by NICAP (Ref. 10). It summarizes about 750 UFO cases in the NICAP files up to about 1964. I have cross-checked a sufficiently large sample of cases from this reference to have confidence in its generally very high reliability. A sequel volume, now in editorial preparation at NICAP, will cover the 1964-68 period. Reference 8, by Bloecher, is one of the few sources of extensive documentation (here primarily from national newspaper sources) of the large cluster of sightings in a period of just a few weeks in the summer of 1947; its study is essential to appreciation of the opening phases of the publicly recognized UFO problem. Reference 7 is another now-accessible source of extremely significant UFO documentation; it is unfortunate that no generally accessible version of Reference 6 exists, though the Moss Subcommittee, through pleas of Dr. Leon Davidson, has managed to get it into a status of at least limited accessibility. I am indebted to Davidson for a recent opportunity to study it for details I missed when I saw it two years ago at

The 1956 book by Ruppelt (Ref. 5) is a source whose authenticity I have learned, through much personal cross-checking, is far higher than I surmised when I first read it a dozen years ago. It was for years difficult for me to believe that the case-material which he summarized could come from real cases, References 5 and 6, plus other sources, do, however, now attest to Ruppelt's generally high reliability. Similarly Keyhoe's books (Refs. 3 and 4) emerge as sources of UFO case material whose reliability far exceeds my own first estimates thereof. As a scientist, I would have been much more comfortable about Keyhoe's books had they been shorn of extensive direct quotes and suspenseful dramatizations; but I must stress that much checking on my part has convinced me that Keyhoe's reportorial accuracy was almost uniformly high. Scientists will tend to be put off by some of his scientific commentary, as well as by his style; but on UFO case material, his reliability must be recognized as impressive. (Perhaps it is well to insert here the general proviso that none of these sources, including myself, can be expected to be characterized by 100 per cent accuracy in a problem as intrinsically messy as the UFO problem; here I am trying to draw attention to sources whose reliability appears to be in the 90+% range. )

A useful collection of 160 UFO cases drawn from a wide variety of sources has been published by Olsen (Ref. 11), 32 of which he obtained directly from the official files of Project Bluebook, a feature of particular interest. A book devoted to a single short period of numerous UFO observations within a small geographic area, centering around an important sighting near Exeter, N.H., is Fuller's Incident at Exeter (Ref. 12). Having checked personally on a number of features of the main Sept. 3, 1965, sighting, and having checked indirectly on other aspects, I would describe Reference 12 as one of the significant source items on UFOs.

Several books by the Lorenzens, organizers of APRO, the oldest continuing UFO investigating group in this country, contain valuable UFO reference material (Ref. 13). Through their writing, and especially through the APRO Bulletin, they have transmitted from South American sources numerous unusual sightings from that country. I have had almost no opportunity to cross-check those sightings, but am satisfied that some quite reliable sources are being drawn upon. An extremely unusual category of cases, those involving reports of humanoid occupants of landed UFOs, has been explored to a greater extent by APRO than by NICAP. Like NICAP, I have tended to skirt such cases on tactical grounds; the reports are bizarre, and the circumstances of all such sightings are automatically charged in a psychological sense not found in other types of close-range sightings of mere machine-like devices. Since I shall not take up below this occupant problem, let me add the comment that I do regard the total number of such seemingly reliable reports (well over a hundred came just from central France in the outstanding 1954 sighting wave in that country), far too great to brush aside. Expert psychological opinion is badly needed in assessing such reports (expert but not close-minded opinion). For the record, I should have to state that my interviewing results dispose me toward acceptance of the existence of humanoid occupants in some UFOs. I would not argue with those who say that this might be the single most important element of the entire UFO puzzle; I would only say that most of my efforts over the past two years, being aimed at arousing a new degree of scientific interest among my colleagues in the physical sciences, have led me to play down even the little that I do know about occupant sightings. One or two early attempts to touch upon that point within the time-limits of a one-hour colloquium taught me that one loses more than he gains in speaking briefly about UFO occupants. (Occupant sightings must be carefully distinguished from elaborate "contact-claims" with the Space Brothers; I hold no brief at all for the latter in terms of my present knowledge and interviewing experience. But occupants there seem to be, and contact of a limited sort may well have occurred, according to certain of the reports. I do not regard myself as very well-informed on this point, and will say little more on this below.)

It is, of course, somewhat more difficult to assess the reliability of foreign UFO references. Michel (Ref. 13) has assembled a day-by-day account of the remarkable French UFO wave of the fall of 1954, translated into English by the staff of CSI (Civilian Saucer Intelligence) of New York City, a now-inactive but once very productive independent group. I have spoken with persons having first-hand knowledge of the French 1954 episode, and they attest to its astonishing nature. Life and The New Yorker published full contemporary accounts at the time of the 1954 European wave. An earlier book by Michel (Ref. 14), also available in English, deals with a broader temporal and geographic range of European UFO sightings. A just-published account of about 70 UFO sightings that occurred within a relatively small area around Stoke-on-Trent, England, in the summer and fall of 1967 (Ref. 15) presents an unusual cross-section of sightings that appear to be well-documented. A number of foreign UFO journals are helpful sources of the steady flow of UFO reports from other parts of the world, but a cataloging will not be attempted here. Information on some of these, as well as on smaller American groups, can be found in the two important books by Vallee (Refs. 16 and 17).

Information on pre-1947 UFO-type sightings form the subject of a recent study by Lore and Denault (Ref. 18). I shall return to this phase of the UFO problem below; I regard it as being of potentially very great significance, though there is need for far more scholarly and scientific research before much of it can be safely interpreted. Another source of sightings of which many may ultimately be found to fall within the presently understood category of UFO sightings is the writings of Charles Fort (Ref. 19) . His curious books are often drawn upon for material on old sightings, but not often duly acknowledged for the mine of information they comprise. I am afraid that it has not been fashionable to take Fort seriously; it certainly took me some time to recognize that, mixed into his voluminous writings, is much that remains untapped for its scientific import. I cannot imagine any escalated program of research on the UFO program that would not have a subgroup studying Fortean reports documented from 19th century sources.

To close this brief compilation of useful UFO references, two recent commentaries (not primarily source-references) of merit may be cited, books by Stanton (Ref. 20) and by Young (Ref. 21).

Next, I examine a number of specific UFO cases that shed light on many of the recurrent questions of skeptical slant often raised against serious consideration of the UFO problem.

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