Flying saucers or UFO's have been with us for a long time. June 24, 1968 marked the 21st anniversary of the sighting of nine bright disks moving rapidly along the hogback of Mount Rainier. However, similar sightings go far back in history, where they have assumed various forms for different people. Old records refer to them as fiery dragons, fiery chariots, wills-o'-the-wisp, jack-o'-lanterns, ignis fatuus, firedrakes, fox-fire, and even the devil himself.

And now a new legend -- a modern myth -- has arisen to explain a new rash of mysterious sightings. Certain UFO buffs argue that the peculiar properties and maneuvers of these apparitions, as reported by reliable people of all kinds, are so remarkable that only one explanation for them is possible. They must be vehicles from outer space, manned by beings far more intelligent than we, because the operators have clearly built vehicles with capabilities far beyond anything we can conceive of.

On the face of it, this reasoning sounds much like that of Sherlock Holmes. who said on several occasions: "It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth."

I am willing to go along with this formula, but only after we have followed Holmes and excluded every possibility but that of manned UFO's. And we must also show that no further possible solutions exist.

The believers are too eager to reach a decision. Their method is simple. They try to find someone, whom they can establish as an authority, who will support their views. They then quote and often misquote various authorities or one another until they believe what they are saying. Having no real logic on their side, they resort to innuendo as a weapon and try to discredit those who fail to support their view. The UFO magazines refer to me as the arch-demon of saucerdom!

I concede that the concept of manned spaceships is not an absolute impossibility. Neither are the concepts of ghosts, spirits, witches, fairies, elves, hobgoblins, or the devil. The only trouble with this last list is the fact they are out of date. We live in the age of space. Is it not natural that beings from outer space should exhibit an interest in us? But, when we consider that these beings -- if indeed they are beings -- have been bugging us for centuries, why should one not have landed and shown himself to the President of the United States, to a member of the National Academy of Sciences, or at least to some member of Congress?

Please don't misunderstand me. I think it is very possible that intelligent Life -- perhaps more intelligent than we -- may exist somewhere in the vast reaches of outer space. But it is the very vastness of this space that complicates the problem. The distances are almost inconceivable. The time required to reach the earth -- even at speeds comparable with that of light -- range in hundreds if not thousands of years for our near neighbors. And it takes light some billions of years to reach us from the most distant galaxies, times comparable with that

for the entire life history of our solar system. The number of habitable planets in the universe is anybody's guess. Any figures you may have heard, including mine, are just guesses. I have guessed that our own Milky Way may contain as many as a million such planets. That sounds like a lot, but the chances are the nearest such inhabited planet would be so distant that if we send out a message to it today we should have to wait some 2000 years for a reply. Alas, the evidence is poor for intelligent life in our solar system, though I do expect some lower forms of life to exist on Mars.

With respect to UFO's my position is simply this: That natural explanations exist for the unexplained sightings. The Air Force has given me full access to their files. There is no vast conspiracy of either the Air Force or CIA to conceal the facts from the public, as some groups have charged. The basic reason for continued reporting of UFO's lies in the possibility -- just the possibility mind you -- that some of them may derive from experimentation or secret development by a hostile power. And I don't mean hostile beings from outer space!

The Air Force has made its mistakes. They never have had enough scientists in the project. They have failed to follow up certain sightings of special importance. Their questionnaire is amateurish, almost cleverly designed in certain cases to get the wrong answer and lose track of the facts. The Air Force is aware of my criticism and, on a voluntary basis, I have helped them improve the questionnaire. It was not an easy job. Especially when the Air Force rejected some vital questions as "an invasion of the privacy of the individual."

From 1947 until 1954 a bewildered group of Air Force personnel tried honestly and sincerely to resolve the UFO problem. Many highly reliable persons had reported seeing "objects" moving at fantastic speeds, and apparently taking evasive action in a manner impossible for known terrestrial craft. By 1952 a sizable number of those in the Air Force group had concluded that extraterrestrial vehicles were the only explanation. Some of this unrest leaked out. Popular writers exploited these ideas and soon various UFO clubs came into existence. In 1958, a committee of scientists, headed by the late H. P. Robertson of California Institute of Technology met at CIA to consider a number of the Air Force's most convincing cases. They immediately solved many of them. Others could not be solved because of poor or insufficient data. They concluded that all cases had a natural solution. There was no evidence to support the idea that UFO's are vehicles from another world.

Nevertheless, the UFO buffs believe, almost as an article of faith, that "trained observers," such as military or airline pilots, could not possibly mistake a meteor, a planet, a star, a sundog, or a mirage for a UFO. This viewpoint is absolutely nonsense and the Air Force files bear witness to its falsity! They contain thousands of solved cases -- sightings by "reliable individuals" like the pilots: But such persons have made huge errors in identification.

A huge meteor flashes in the sky! The co-pilot thinks it is going to strike the plane and takes evasive action. The pilot disagrees and he is right. The UFO proves to be a fireball or meteor a hundred miles away! Such occurrences are frequent, not rare. They have even increased with the growing number of re-entries and spectacular decay of satellite debris from the space operations of the U.S.A. and the U.S.S.R.

Distances overhead are uncommonly hard to estimate -- either on the ground or in the air. A bird's feather, shining brightly in the sun and floating a mere 20 feet overhead may seem to be a distant object moving at very high speed. Conversely, a pilot may think that a bright object on the horizon, in reality a star or planet, lies just beyond his wing tip. Sometimes, a layer of warm air, sandwiched between 2 layers of cold air, can act as a lens, projecting a pulsing, spinning, vividly colored, saucer-like image of a planet. Pilots, thinking they were dealing with a nearby flying object, have often tried to intercept the image, which evades all attempts to cut it off. The distance may seem to change rapidly, as the star fades or increases in brightness. Actual "dog fights" have been recorded between a confused military pilot and a planet. I myself have observed this phenomenon of star mirage. It is both realistic and frightening.

Such observations fortified the UFO legend -- that these objects "maneuver as if under intelligent control." But the pilots failed to realize that the "intelligent control" came from within themselves. And I think that Air Force personnel of Project Blue Book still do not appreciate this important UFO phenomenon.

Mirages are not the only apparitions that appear to maneuver. I think I was the first person, to point out that a special kind of reflection of the sun (or moon), sometimes called a sun dog (or moon dog), also can perform evasive action. Layers of ice crystals are necessary, like those found in cirrus clouds. An aviator flying through cirrus sometimes sees a peculiar metallic appearing reflection, a reflection of the sun or moon. He may elect to chase it. The apparition will recede if approached, or approach if the pilot reverses his course. The object seems to execute evasive action! As the pilot runs out of ice crystals, the UFO will seem to put on a burst of speed and disappear into the distance.

But such behavior does not imply, as the UFO addicts argue, the presence of an intelligent pilot to guide it. No! It's like chasing a rainbow, which recedes as you approach it or advances as you move away.

As we look over the Air Force files, we find that some 90 per cent of the solved cases result from the presence of material objects in the atmosphere. I list some of these objects. Reflections from airplanes, banking in the sun, simulate saucers. Momentarily, a bright reflection appears and then vanishes. The plane is invisible in the distant haze. An imaginative person concludes that an interplanetary vehicle has come in fast, reversed course, and rapidly receded into the distance. Often the observers say "It couldn't have been a plane," because "no noise was heard" or because "it moved too swiftly." And yet careful study proves beyond doubt that the object was indeed an aircraft. The brilliant landing lights of a plane can almost dazzle a person on the ground. Sometimes such lights may appear to be very close -- only a few hundred feet away.

You'd be surprised at the variety of mundane objects that people have reported as UFO's. Balloons, child's balloons, weather balloons lighted or unlighted, and especially those enormous plastic balloons as large as a ten-story building, which carry scientific instruments to altitudes of 100,000 feet! Reflecting full sunlight while the earth below lies in dim twilight, these balloons shine more-brilliantly than Venus! Advertising planes or illuminated blimps frequently become UFO's.

Birds, by day or night, often reflect light from their shiny backs. Windblown kites, hats, paper, plastic sacks, feathers, spider-webs, seed pods, dust devils have all contributed their share of UFO sightings. Insects single or in swarms. Saucer-shaped clouds, reflections of searchlights on clouds! Special space experiments, such as rocket-launched sodium vapor releases or balloons from Wallop's Island have also produced spectacular apparitions! Ball lightning and the Aurora Borealis occasionally contribute.

Reflections from power lines, insulators, television antennas, radars, radio telescopes, even apartment windows! These, too, have produced realistic UFO's.

I could add to this list almost indefinitely. But the chief point I want to make is that simple phenomena like the above have tricked intelligent people into reporting a UFO.

But there are a few other phenomena that can produce UFO's of a type that, as far as I know, the Air Force still does not recognize.

I quote from an article on "Vision" in Volume 14 of the McGraw-Hill Encyclopedia of Science and Technology. "... any observant person can detect swirling clouds or spots of 'light' in total darkness or while looking at a homogeneous field such as a bright blue sky." If you want to see flying saucers just look up. If you don't see them, you probably are not "observant."

I see them most clearly in a dark room or on a moonless night with the sky even darker with heavy clouds. I find stars somewhat distracting. Just lie down on your back, open your eyes and see the saucers spin. The show is free. You will almost surely see bright, irregular patches of light form. Most of them seem grey green, but I occasionally see silver or gold and occasionally red. I can imagine windows in some of them. As you move your eyes they will cavort over the sky. To speed up the action just rub your eyes like a person coming out of a sleep. Occasionally the whole field becomes large and luminous. Now, I ask you, how canyon be sure that the UFO reported by an airline pilot is not one of these spurious images? And even if an alerted co-pilot confirms it, he might also be responding to a similar effect in his own eyes!

The chemistry and physiology of the human eyes are certainly responsible for many UFO sightings. The eye responds in different ways to different kinds of stimuli. A sudden burst of bright light, like that from a flash bulb, for example, exerts an enduring effect on the eye. The light from the flash produces an immediate change in the so-called visual purple of the retina. In a sense the retinal spot on which the image fell becomes fatigued. For some minutes after the flash

you will be able to see a bright, usually greenish, floating spot, which could be mistaken for a UFO by someone unfamiliar with the problem.

Let me take an actual case, which is typical of a large number actually in the files of Project Bluebook. A child, going to the bathroom turns on a bright light and accidentally awakens one of his parents who is blinded by the sudden illumination. The light goes off and the parent gets up to investigate and just happens to glance out of the window. He is startled to see a peculiar spot of light floating over the trees and making irregular, jerky motions. He watches the UFO for a minute or two until it finally disappears.

He cannot be blamed for failing to realize that the erratic and often rapid movements of his UFO are those of the after-image, drifting with the similar movements of his own eye. The UFO appears in the direction he happens to be looking. That is all. And yet he may describe it graphically as a luminous object "cavorting around in the sky."

Many such stimuli are possible by day or night. Some time ago I was driving directly toward the setting sun. When I came to a stop-light and looked out the side window of the car, I was startled to see a large, black object shaped something like a dirigible, surrounded by dozens of small black balloons. I suddenly realized that they were after-images of the sun. The big one was where I had been looking most fixedly. The spots were images where my eye had wandered. A UFO buff could have sworn that he was seeing a "mother ship" and a swarm of UFO's in rapid flight,

I once had another similar experience. I suddenly glanced up and was surprised to see a whole flotilla of UFO's flying in formation across the blue sky. They looked like after-images, but I hadn't been conscious of the visual stimulus responsible. I quickly retraced my steps and found it: sunlight reflected from the shiny surf ace of the fender of a parked car.

I am sure that many UFO's still unknowns, belong to this class. Look fixedly at the full moon for at least 30 seconds and then turn away. A greenish balloon will swim over your head and perform maneuvers startling or impossible for any real object. I'm been able to attain the same effect with the planet Venus, when near maximum brilliance. Yet most observers will swear that such UFO's are true objects. And the Air Force questionnaire, failing to recognize even the existence of this kind of UFO, contains not a single question that would help them to identify it. In fact the words signifying UFO, unidentified flying object, show the state of mind of the Air Force personnel who invented this abbreviation. What I am saying is that the UFO's are not unidentifiable, they are often not flying, and many are not even objects. It is this point of view -- to regard the apparitions as actual solid objects -- that has retarded to solution [sic] so long.

After-images possess still other complicated characteristics. A colored light tends to produce an after-image with complementary color. A green flash will cause a red after-image and vice versa. Color-blind persons and persons with defective vision will often experience effects different from those of people with normal eyesight.

Another optical phenomenon that can produce an illusion of flying objects lies within the eye itself. Again, look at some uniformly bright surface -- sky or ceiling. Relax your eyes. By that I mean focus your eyes on infinity. The changes are that you will see an array of dark spots. These specks, which may seem to be near like a swarm of gnats or as ill-defined objects at a distance, are either on or in your eye. They may be dust floating on the lens, minute imperfections in the cornea, or possibly blood cells on the retina. These, too, can simulate evasive and erratic movement

The eyeball jumps a little every time you blink. Walking transmits vibrations to the eye at every step. Many individuals think they see stars, planets, or satellites oscillating when the movement is actually that of the eye itself. Here is an example.

On our return across Minnesota we had an experience which I have always remembered as illustrative of the fallacy of all human testimony about ghosts, rappings, and other phenomena of that character. We spent two nights and a day at Fort Snelling. Some of the officers were greatly surprised by a celestial phenomenon of a very extraordinary character which had been observed for several nights past. A star had been seen, night after night, rising in the east as usual, and starting on its course toward the south. But instead of continuing that course across the meridian, as stars invariably had done from the remotest antiquity, it took a turn toward the north, sunk toward the horizon, and finally set near the north point of the horizon. Of course an explanation was wanted.

My assurance that there must be some mistake in the observation could not be accepted, because this erratic course of the heavenly body had been seen by all of them so plainly that no doubt could exist on the subject. The men who saw it were not of the ordinary untrained kind, but graduates of West Point, who, if any one, ought to be free from optical deceptions. I was confidently invited to look out that night and see for myself. We all watched with the greatest interest.

In due time the planet Mars was seen in the east making its way toward the south. "There it is!" was the exclamation.

"Yes, there it is," said I. "Now that planet is going to keep right on its course toward the south."

"No, it is not," said they; "you will see it turn around and go down towards the north."

Hour after hour passed, and as the planet went on its regular course, the other watchers began to get a little nervous. It showed no signs of deviating from its course. We went out from time to time to look at the sky.

"There it is," said one of the observers at length, pointing to Capella, which was now just rising a little to the east of north; "there is the star setting."

"No, it isn't," said I; "there is the star we have been looking at, now quite inconspicuous near the meridian, and that star which you think is setting is really rising and will soon be higher up."

A very little additional watching showed that no deviation of the general laws of Nature had occurred, but that the observers of previous nights had jumped at the conclusion that two objects, widely apart in the heavens, were the same.

Those words came from a book called "Reminiscences of an Astronomer," published in 1903 by Simon Newcomb, who was in charge of the American Nautical Almanac office from 1877 until 1897. The event actually occurred in 1866. The similarity to modern UFO's is overpowering. A star cavorting across the sky! Military officers as responsible witnesses!

In his delightful book, "Light and Colour in the Open Air," the well-known Dutch astronomer, M. Minnaert, wrote.

This is the phenomenon of "Telekinesis," the apparent erratic motion of an object caused by the erratic motion of the human eye. I have seen a number of UFO reports in which the observer stated that the object could not have been a meteor or a satellite because it moved irregularly.

For you who wear eyeglasses there is still another way of seeing a UFO. Look directly at some bright light, with your head turned slightly to the left

or right. You will probably see a faint roundish out-of-focus spot. This is light reflected from the front surface of your eyeball, back to the lens, and then back into the pupil of your eye. A bright source, to one side and slightly behind you, can also reach your eye through reflection from the internal surface of the spectacle lens.

To this moment I have not mentioned still another method of detecting saucers -- one not subject to the vagaries of the human eye. I mean radar, of course. Radar is a machine. It can't make mistakes. Or at least that is the common argument advanced by UFO buffs.

Radar is cursed with all the potential afflictions that any complicated electrical gadget can suffer. But let me mention only one: mirage. Let me explain briefly what a radar does. It sends out a pulse of radio waves. We know the direction, Northeast for example. We know the elevation above the horizon. An echo returns. From the interval between transmission and reception of the pulse, we know how far away the object is that reflected the pulse back to us. We think we detect a plane -- or a UFO in flight -- because the radar directs the pulse upward.

We have no way of following the pulse in its path toward the target. A layer of warm, dry air or even a layer containing a few bubbles of warm air will bend the radar beam back to earth. The reflection may be from a distant building, a train, or a ship. No wonder that planes, sent to intercept radar UFO, find nothing. In one such case, a well-known writer on flying saucers wrote: "The discovery of visible saucers had been serious enough. -- The discovery now of invisible flying saucers would be enough to frighten anyone." Small changes in the atmosphere can make the UFO seem to maneuver at fantastic speeds, executing right-angle turns or suddenly vanishing completely from the radar scope. I was very familiar with such effects from having worked with them during Naval Service in World War II. The greatest radar saucer flap of all times occurred in the hot, dry month of July 1952, when a whole fleet of UFO's were detected by radar at Washington National airport. Subsequent research by the Weather Bureau completely confirmed what the UFO buffs pointedly refer to as my "Hot Air Theory." After all why should one be surprised to find hot air over Washington?

I know of no reliable case of simultaneous visual and radar sightings. In view of the physical properties of the eye, the surprising fact is that so few cases have been reported.

Time will not permit me to elaborate on still other relevant phenomena. For example the Air Force appears to have neglected completely the psychological angle of which mass hallucination is just one phase. Back in 1919, in Spain, a not unrelated phenomenon occurred. Thousands of people -- reliable people -- swore that they had seen images of saints rolling their eyes, moving their hands, dripping drops of blood, even stepping out of their panels. One person would call out, others would imagine they had seen something! There are many similar events recorded through the ages.

There are hundreds of known hoaxes, such as the ingenious one perpetrated by students of the University of Colorado. Spurred by the allotment of an Air Force grant for studying UFO's to the University of Colorado, enterprising pranksters made hot-air balloons from candles and plastic bags, the kind used for packaging dry cleaning. The show was spectacular. And it gave the University investigators a good opportunity to see how poor the evidence can be, a fact well-known to the legal profession. This is still another point that the Air Force has sometimes failed to realize. Moreover their poor questionnaire only further confused an already confused picture. A recent similar sighting south of Denver, later identified as plastic-bag balloons and candles, produced fantastic reports from "reliable" witnesses.

Several times I have used the phrase "UFO's cavorting across the sky." I did so deliberately because it seems to be a favorite phrase of my good friend Dr. J. Allen Hynek of Northwestern University and consultant to the Air Force Project Blue Book. He has sometimes expressed doubts about the UFO because stars don't "cavort" across the sky. What I have tried to show is that many kinds of optical stimuli can produce weird effects.

With all these kinds of phenomena masquerading as UFO's, many of them, like those related to physiology of the human eye still practically not investigated, I think I can reasonably claim, applying the criterion of Sherlock Holmes, that we

have not excluded all the impossibles. I have shown that the arguments advanced in favor of the interplanetary nature of UFO's are fallacious. Their alleged high speeds and ability to maneuver have completely natural explanations.

I think the time has come for the Air Force to wrap up Project Blue Book. It has produced little of scientific value. Keeping it going only fosters the belief of persons that the Air Force must have found something to substantiate belief in UFO's. In making this recommendation I am not criticizing the present or recent administration of the project. But it is time that we put an end to chasing ghosts, hobgoblins, visions, and hallucinations.

More than twenty years of study by the Air Force and an additional year of analysis by the University of Colorado have disclosed no tangible evidence supporting the popular view that UFO's are manned interplanetary vehicles. An irresponsible press, which has overpublicized the sensational aspects of the phenomenon, has been largely responsible for keeping the subject alive. Both newspapers and leading magazines must bear the blame for mishandling the news. But such publications are not scientific journals. They present incomplete data and draw sensational conclusions without supporting evidence.

The question of UFO's has become one of faith and belief, rather than one of science. The believers do not offer additional clear-cut evidence. They repeat the old classical cases and base the reliability of the sighting on the supposed honesty of the observer. I have shown that many honest observers can make honest mistakes.

The press has recently played up a story to the effect that, even in the U.S.S.R., an official UFO investigation has been started, under government sponsorship. Nothing could be farther from the truth! But the newspapers failed to retract after an official statement from the National Academy of the U.S.S.R. appeared in Pravda, to the effect that the reported study was the work of an unofficial and irresponsible amateur-group. The Academy statement further disclaimed any support whatever for the view that UFO's are other than, badly misinterpreted natural phenomena, and certainly not manned extraterrestrial vehicles.

I am aware that a small but highly vociferous minority of individuals are pressing for further studies of UFO's supported -- of course -- by huge Congressional appropriations. The heads of a few amateur UFO organizations urge their members to write Congress, asking for investigations of both UFO's and the Air Force. The members have responded enthusiastically, and Congress reacted by financing a special study, which led to the project at the University of Colorado. And now, when it seems likely that the report from this study will be negative, the same vociferous group is again turning to Congress with the same appeal but with no more chance of success. Time and money spent on such efforts will be completely wasted. Congress should strongly disapprove any and all such proposals, large or small. In this age, despite the doubts expressed by a very small group of scientists, reopening and reopening the subject of UFO's makes just about as much sense as reopening the subject of Witchcraft.

Within the vast field of atmospheric physics, there exist many imperfectly understood phenomena which deserve further study, such as ball lightning and atmospheric optics. But any investigations of such phenomena should be carried out for their own sake, not under the cloak of UFO's.

I express my appreciation to Congressman Roush for the invitation to present my views on UFO's. I append herewith my telegram to him dated July 24, 1968.