Composition and Luminosity (Ufology, by James M. McCampbell)

. . . A scientist, by definition, is concerned with an objective evaluation of data; he applies proper figures and cites correct facts; he is unbiased as far as humanly possible, in drawing his conclusions; his dedication is to progress in the search for truth. s1- Immanuel Velikovsky

Quite apart from the general appearances of UFOs as established by their sizes, shapes, and structural details, they also seem to be very colorful. From a compilation of 923 instances of close encounters with UFOs, approximately half of the witnesses had something to say about the color. (1) As these descriptions vary in the extreme, a satisfactory mental image of a UFO can not be readily conceived. What sense can be made of such diverse and conflicting expressions as "silvery," "luminous," "brilliant blue," "glowing orange, "and "blinding"? But this bewildering mélange will yield some surprising and valuable insights into the UFO phenomenon when it is examined carefully. All such descriptions certainly can not apply at the same time, hence, it must be understood that UFOs take on a variety of colors under different circumstances.

Descriptive terms used by the witnesses in referring to colors tend to fall into five, distinct categories that can be labeled as Metallic, Soft Glow, Spectral Colors, Bright White, and Multi-colored. Typical expressions of the witnesses that illustrate the first four categories are tabulated below.

Metallic Soft Glow Spectral Colors Bright White
aluminum glowing whit orange burning magnesium
silvery luminous red very dazzling
metallic fluorescent orange-red intense bright
chrome - fiery red brilliant
shiny - bluish bright
reflective - yellow intensely luminous
gray - bluish-green blinding white

When more than one color was reported, the witnesses usually indicated whether the colors appeared at the same time or serially, that is, one after another. Therefore, the fifth category naturally divides into two subcategories, Simultaneous and Sequential. From the 477 most recent UFO encounters in the compilation by Vallee, all references to multi-colors are shown below along with the identifying case numbers.

Multi-Colored

Simultaneous Sequential
blue, green, and orange flashes 540 orange to fluorescent green 670
multi~olored 572 varied from white to red 692
yellow-orange with blue-green edges 657 reddish-orange to blinding white 741
very bright with dark underside 736 white to yellow to blue to green 782
blue, red, and green bands 796 white to greenish-blue 821
- red to orange to white together with blue underside 838

The last example appears to be a combination of color changes occurring at the same time that the underside remained blue. Having detected a logical pattern in the colors ascribed to UFOs, one should next examine the various categories individually in considerable detail.

Metallic Surface

Fifty-two witnesses attempted to describe a metallic surface as follows:

Number Using These Terms Alluding To
13 Silver, silvery Silver
6 Aluminum, aluminum-like Aluminum
12 Metallic Unspecified
13 Chrome, shiny, reflective Polished
12 Gray metallic, dark gray Dull
56*
*The total does not add up to fifty-two because compound expressions were tabulated twice.

The witnesses were clearly describing the polished surface of a "white" metal except, perhaps, the twelve who related an impression of dull gray. Eleven of these latter observations, however, occurred under adverse lighting conditions during twilight or at night. Under an overcast sky or through atmospheric haze, a jet airliner that is known to be bright aluminum takes on the appearance of dull gray or even dark gray on the lower half. Therefore, these reports are clearly compatible with the others and there seems to be little doubt about a metallic appearance of UFOs.

Most people encounter only a few white metals in their daily experience, such as aluminum cookware, chrome-plated automobile parts, and stainless steel kitchen utensils. Naturally any white metal would usually be described by reference to these familiar objects. Because quite a few unfamiliar metals are also white, the homey descriptions by witnesses cannot be taken literally. Some hints as to the actual metal of UFOs might be inferred from the properties required by their flight characteristics and mode of propulsion. In view of a need for strength, lightness, and resistance to heat, titanium would be a good candidate. Also, magnesium. Some fragments of a UFO that exploded in South America were subjected to extensive analysis and found to consist of extremely pure magnesium. (2) Some of these samples were later analyzed at the University of Colorado. A high content of strontium was unexpectedly found although strontium is not known to be added to commercial magnesium. Despite this interesting result, the crystal structure suggested that the sample was unlikely to have been part of a manufactured article. It was concluded that it did not have an "unearthly composition" and the reader is left with the implication that it could not have been part of a UFO. (3) A dissenting view that was issued independently, however, judged the metallurgy of the magnesium to be quite unique. (4)

On the whole, science should be considered as an open-ended inquiry, that is, one in which progress and understanding tend to continue indefinitely. Thus, a reliable theory that has served well for decades may be upset by a new discovery. It must then be abandoned in favor of a new concept that is a closer and more comprehensive approximation of nature. Such notions grow to maturity as they elucidate some field of science and prove their resilience in the face of continued progress - One such area that may be considered as a cornerstone of science is the internal structure of atoms and the Periodic Table of the Elements. (5) While this theory is still subject to future revision and refinement, there are no major gaps in the scientific understanding of the natural elements. They are the raw materials from which any object must be fabricated on earth. As the same elements have been measured throughout the universe by analysis of starlight, they are also the raw materials from which an object must be fabricated anywhere. Of this one may be nearly certain, that the metal of a spaceship visiting earth will be composed exclusively of elements that are already known. To be sure, technological superiority may be evidenced by unusual purity or new mixtures and crystal structures, but not necessarily. Modern science is perfectly adequate to support spaceflight by man, hence, advances in metallurgy beyond current knowledge are not required to bring visitors to the earth. In other words, an unearthly composition of UFO fragments should not be expected.

While windows and transparent cupolas on top of disc-shaped UFOs are frequently mentioned, on two occasions in the sample witnesses thought that the entire object was transparent. In one of these, a disc-shaped object flew above a bicyclist for 5 kilometers at a height of 6 meters. It "was luminous and seemed made of glass." (6) In the other instance, witnesses in a stalled vehicle saw occupants inside a "brilliant, transparent, mushroom shaped object." (7) These reports are too rare to justify a separate category of UFOs but they should be kept in mind as possible clues to an advanced material technology, that is, a state of metal that transmits light.

Soft Glow

The metallic appearance of UFOs in the previous category is a result of light reflecting off their polished surfaces. But witnesses frequently indicate that the UFO itself was luminous. As distinguished from a wide variety of white or colored lights that are reportedly attached to UFOs, light is observed radiating from the entire object or its immediate vicinity. Occasional references to "sparks" immediately suggest that some kind of electrical phenomenon is involved.

An electrical discharge of sufficient strength in the air surrounding a UFO would produce a soft, white glow, known as corona. Such discharge can sometimes be seen at night along a high-voltage transmission line but they are not visible in the daylight. Coronas could be responsible for the typical distinction between metallic discs that are so commonly reported in the daytime and diffuse lights most often seen at night. They would adhere to the UFO surface and gradually dissipate a short distance away, thereby appearing as the "halo" often described by witnesses. Unfortunately, an ordinary corona is not likely to be the correct explanation for the white glow.

The designer of a high-voltage transmission line would seek to use the smallest possible cable to minimize the amount of copper required, the weight suspended between towers, and the number of towers per mile of line. He would select electrical potentials as high as 750,000 volts to reduce the power losses from internal heating of the cable. High voltage, however, would induce power losses through corona discharge unless offset by the use of larger cable sizes. As electrical lines of force converge toward the center of a cable, electrical field strengths at its surface will be smaller for cables of greater diameter. A well-designed transmission line will therefore balance these and other considerations for a minimum construction cost and utilize a cable just large enough to prevent corona under normal operating conditions. Under occasional atmospheric conditions favoring electrical breakdown, corona will occur at field strengths on the order of 3,000,000 volts per meter. (8) The possibility of such extreme electrical fields being developed near a large object, such as a UFO having gently curving surfaces, seems quite remote.

Even so, some technical implications arise in the context of white glow. As some sort of electrical phenomenon is suspected, it can be postulated that a UFO has:

  1. a large, negative potential relative to ground that causes electrons to leak into the atmosphere,
  2. an alternating potential that agitates gas atoms in its vicinity, or
  3. an alternating current within its skin acting as an antenna to radiate energy into the atmosphere.

The following discussions will greatly clarify this aspect of UFO luminosity.

Rainbow Colors

Nearly every color of the rainbow has been ascribed to UFOs. Typical statements by witnesses include most shades of the color spectrum from blue-violet through green, yellow, and orange, to red. Descriptive language of witnesses in the sample cases under study are tabulated in the following chart in accordance with their appropriate positions in the spectrum. Where mixtures of pure colors are implied, the components are inserted in their color zones and connected by vertical lines, such as for "purple" being composed of blue and red.

Before probing for an interpretation of these statements, a digression is required to review the origin and nature of light. Light is produced within atoms of matter. When atoms become sufficiently agitated by collision among themselves or with other elementary particles or by absorption of electromagnetic radiation, one or more electrons are elevated out of their normal energy states (orbits) or removed from the atom completely. As electrons fall back into these vacancies, a certain amount of energy is released. It is radiated away as a photon having that specific energy and a corresponding wave length. X-rays are usually produced from such transitions in the deeper layers of atoms. But radiation in the ultraviolet, visible, and infrared regions of the spectrum are emitted by transitions involving the more loosely bound, outer electrons, that is, those responsible for the chemical behavior of the atom. Within the visible region, a stream of photons having the same wavelength (also frequency) will be perceived as a unique, pure, spectral color ranging from violet to red, with the shorter wavelengths toward the violet end.

The amount of energy involved in these electronic transitions is well known for all the elements in the science of atomic structure and spectroscopy. Therefore, the element responsible for emission of photons of a particular energy and color can be identified in laboratory tests. (9) This knowledge has been put to extremely valuable service in the spectrographic analysis of chemical samples and in identifying the atoms responsible for the emission of light in stars. It may also prove to be advantageous here.

Very common descriptions such as "surrounded with a red glow" (10) and "wrapped in a blue haze" (11) clearly indicate that the source of UFO luminosity is not the object itself but the proximate air. One wonders, therefore, if the specific atoms in the air responsible for the light can be identified. Of course, it would be necessary to know what gases are present in the atmosphere but that is common knowledge. The accompanying table gives the number of cubic feet of each constituent gas in 1,000,000 cubic feet of air. (12) Hydrocarbons are also present in variable amounts depending upon local conditions but these pollutants are disregarded. As most UFO sightings are in remote areas such as mountains, deserts, and farmlands where air is relatively clean, it is assumed that the hydrocarbons are insignificant as a source of light.

Also shown in the table is the number of spectral lines in the visible region that is emitted by each species. With a total of several hundred lines involved, it could become quite troublesome to associate one particular color emitted by a UFO with one specific gas. However, several factors tend to simplify the task. If a large number of the tabulated spectral lines were emitted simultaneously, their mixture would produce white light instead of the individual, pure colors that were reported for UFOs in this category. Furthermore, spectral lines from a given atom are not all the same intensity and the relatively few bright ones will tend to dominate the rest. Different amounts of energy are also required to stimulate the several gases of the atmosphere to emit light. In addition, different amounts of energy are required to excite a single atom depending upon whether it remains electrically neutral or loses one or more electrons. While these facts may appear to be complications, they will be seen to provide the necessary leverage to pry this subject apart.

Gases Volume Approximate Number of Visible Spectral Lines
Nitrogen 780,840 79
Oxygen 209,406 79
Argon 9,340 219
Carbon Dioxide 300 7
Neon 18.18 153
Helium 5.24 9
Krypton 1.14 58
Xenon 0.086 51
Hydrogen 0.5 5
Acetylene 0.02 -

If a gaseous mixture is exposed to a limited amount of energy, either thermal or electrical, only those atoms will begin to emit light for which the energy is sufficient. In other words, some gases are more easily stimulated than others depending upon an inherent sensitivity. The scientific measure of this threshold for each element is known as the ionization potential, that is, the minimum amount of energy required to lift an electron from its ground state to the next higher state. Light of a unique color is emitted when an electron fills the vacancy. Such data for the atmospheric gases are tabulated below. (13) These values pertain to free atoms whereas most gas atoms are bound together in pairs. The corresponding ionization potentials for the diatomic molecules is slightly different than the tabulated value but they will suffice for the present purpose.

Ionization Potential (ev)*
Gases I** II III IV
Nitrogen 14.53 29.59 47.43 77.45
Oxygen 13.61 35.11 54.89 77.39
Argon 15.76 27.62 40.90 59.79
Carbon Dioxide - - - -
Neon 21.56 41.07 63.50 97.02
Helium 54.48 54.56 - -
Krypton 14.00 24.56 36.90 43.50
Xenon 12.13 21.20 31.20 42.00
Hydrogen 13.60 - - -
Acetylene - - - -

* Customarily expressed in electron volts where 1 ev = 1.602 x 10-12 erg.
** Roman numerals indicate: I, neutral atom; II, singly ionized; III, doubly ionized and so on.

As would be expected, the table shows in Column I that the amount of energy required to lift an electron to its next higher state is less than that required to remove it from the atom entirely as given in Column II. Naturally, even greater amounts of energy must be expended to remove a second, or a third, electron as shown in Columns III and IV. The most easily stimulated gas is seen to be xenon, having an ionization potential for the neutral atom of only 12.13 ev. Under normal conditions, the atmosphere is not luminous because less than 12.13 ev is available to the atoms. Suppose that by some unknown means, however, a UFO delivered a gradually increasing amount of energy to the gases surrounding it. At some point, the atmosphere would absorb enough energy to become luminous and the onset would correspond to the excitation of xenon. Further increases in energy transfer would activate the other gases in inverse order of their thresholds and their light would simply be added to that from xenon. Or if some sort of resonance phenomenon excited the various species individually, the atmosphere would take on a series of colors corresponding to each species. Some complex statistical and quantum mechanical aspects apply here but they need not be taken into account to develop the argument.

Well, if xenon is the most easily excited of the atmospheric gases, does it emit one or more colors that can be readily identified and, if so, have such colors been reported by the witnesses? The neutral atom of xenon emits three separate, but closely spaced, spectral lines in the center of the blue band of the spectrum. Thus light from xenon is seen as a pure, intense blue. It is strongly suspected, therefore, that xenon is responsible for the "blue," "brilliant blue," and "luminous blue" that were reported in the sample cases. The identity of xenon as the source seems to be almost assured because no other neutral gases in the atmosphere emit mid-blue photons. Considering the rarity of xenon, it is somewhat surprising that the evidence should point to it. At standard conditions of temperatures and pressure, air contains about 6.06 x 10 (to the 23rd power) molecules and free atoms in 22.4 liters. The proportion of xenon being 0.086 per 1,000,000 means that the density of xenon is about 2.3 x l0 (to the 13th power) atoms per cubic centimeter, certainly an adequate supply.

In the following table, the three blue lines of xenon are plotted in the blue zone of the spectrum between wavelengths of 4240 and 4912 A0. Similar spectral lines from all other neutral gases in the atmosphere are similarly identified. (14) Their colors are indicated by their positions in relation to the standard color zones of the visible spectrum, usually taken as 4000 to 7000 A0 (1 Angstrom = l0-8cm). Some young people can detect ultraviolet in wavelengths as short as 3130 A0, although the faint images are not focused without special glasses.(15)

As the hypothetical UFO increased the transfer of energy to the atmosphere, other color contributions would appear. The "orange-red" or "fiery red" so frequently seen near UFOs can very probably be assigned to the brilliant orange-red of neon, 6402 A0, that is so easily recognized in neon signs. The combination of the green line of neon, 5401 A0 , with the blue of xenon would yield the often reported "bluish green" or it may come from hydrogen, 4861 A0. "Purple" would result from the blue of xenon and the red of argon, 6965 A0. While these identifications are certainly not demonstrated, they tentatively suggest a plausible explanation for the variety of UFO colors.

It is noted with minor exceptions that the most likely candidates for color emission are helium, neon, argon, krypton, and xenon. It is precisely these noble gases that are favored for use in gaseous lasers. Almost all radiation from un-ionized noble gases in lasers, however, lies in the infrared or far-infrared. Only neon has a group of transitions emitting visible light. This group consists of seven lines with wavelengths between 5939 and 6401 A0, all within the orange zone. On the other hand, many spectral lines in the visible region are produced by ionized atoms of the noble gases, about 340 being known. (16)

An entirely different type of stimulated light emission that does not involve ionization occurs upon dissociation of atoms and molecules leaving the atom in an excited state. (17) As laser operation is critically dependent upon the geometry of apparatus and the pressure of the gases, usually very low, it is virtually impossible that any laser effect, per se, is involved in the luminosity of UFOs. The maser principle, however, may well prove to be the mechanism by which UFOs transfer energy to the atmosphere, namely, by electromagnetic energy of radio frequency or higher. Many clues along this line will be discovered in subsequent sections.

Dazzling Brightness

Sometimes the light emitted by a UFO is so intense that its surface is entirely obscured from view. Everything from "welding torch" to "burning magnesium" has been used to convey this idea. Direct and specific association with a metallic-appearing object has occurred when the source of light came down to the ground, dimmed, and revealed the material body of the UFO itself. Conversely, metallic constructions initially observed on the ground have become dazzling just before zooming out of sight.

The reference to "welding torch" justifies an examination of welding and related phenomena in the search for understanding the bright, white, UFO. The common welding torch burns a mixture of acetylene gas and oxygen at temperatures up to 6,0000F. Thermal agitation at such temperatures ionizes the gas molecules that, upon returning to the ground state, emit light copiously. The intensity may be so great that eyes must be shielded to avoid serious damage. Somewhat lower temperatures are achieved in electrical welding where a continuous arc is maintained between a welding rod and the work piece. The brilliant beam of a carbon-arc spotlight arises from the same process. More than 300 spectral lines in the visible region have been identified from such electrical sparks in air. Nearly all of them are emitted by the predominant gases, nitrogen, oxygen, and to a lesser extent, argon. (18) Collisions by electrons and thermal agitation of the gas molecules produce the requisite ionization. In summary, it is clear that these examples of gaseous luminosity depend upon high temperature, photon emission by the more abundant gases, and the mixture of numerous spectral lines to produce white light.

In addition to man-made sources, one can look to natural phenomena for further clues. In an ordinary bolt of lightning, the gas temperature is raised in a split second to about 25,0000C causing ionization of most of the gas atoms in its path. (19) Sudden expansion of the extremely hot gases sends the crashing sounds of thunder rolling across the countryside. The spectral composition of lightning flashes is typical of any electrical spark in air. The production of thunder is especially germane to this inquiry because UFOs are nearly always reported to be silent, or to make only a soft, hissing noise. A loud explosion is rarely heard from a UFO but not accompanying the standard flyby of an intensely luminous object. (See the chapter on Sounds.) It would appear that the blinding light emitted by UFOs is not associated with extremely high temperatures. Otherwise, thermal expansion of the gases would produce a horrendous racket, like continuous lightning. As no such sounds are reported, it may be concluded that the bright luminosity associated with UFOs is produced at very modest temperatures, compared to lightning.

Another natural phenomenon is also of interest, namely, balls of fire in the air that are known as ball lightning. They consist of brightly shining globules of gas whose sizes normally range between that of a grape and a grapefruit. They lazily drift a few meters off the ground for 1 to 5 seconds but some may last for a minute or so. The globe, or spheroid, typically emits a hissing sound, is not known to radiate heat although it may set fire to objects it touches, and it disappears either silently or with a loud report. This phenomenon has been observed since ancient times and it is thought to be fairly common. (20)

Nevertheless, most people would be very puzzled by a display of ball lightning. In the first place, it would remain unidentified, that is, obviously not a plane, bird, or balloon. Secondly, its drifting through the atmosphere would be properly denoted as "flying." Finally, it would be considered an object of some kind, in contrast to an hallucination, because it may have set fire to a henhouse when it entered through a crack in the door. In a very valid sense, therefore, ball lightning may be considered as an unidentified flying object. However, such an appraisal would have little direct bearing upon the study of UFOs as that term is being used here. Considering the similarities between ball lightning and UFOs as they are sometimes manifest, it is not surprising that the two should be occasionally confused or that reports of the former would show up in the UFO literature. These extraneous reports should obviously be sorted out and disregarded as some instances in the sample of sightings. (21) An attempt to explain the entire subject of UFOs as misinterpreted observations of ball lightning produced much valuable information on plasmas but was not very convincing.(22) However, an unsuspected and ironic relationship between these two subjects becomes apparent upon considering some details.

Numerous theories of ball lightning have been proposed but none thus far is capable of explaining all aspects of the subject. The most promising concept is that a plasma is initiated by the high-frequency, electromagnetic fields associated with ordinary lightning. Frequencies in the range of 100 to 4,000 MHz (million cycles per second) have been observed. While considerable ionization is present, some luminosity in the spheres may result from excited electronic levels not requiring ionization of the gases. (23)

It appears that absorption of energy elevates oxygen atoms to two, well-known, metastable states having decay times of 45 minutes and 8 seconds, respectively. Immediate decay is forbidden as the electrons are trapped in the excited state with the wrong spin. An intermolecular collision is required to deactivate the state through transfer of angular momentum thereby permitting release of the stored energy. It is then apparently transferred to carbon dioxide which immediately radiates it away in a continuous spectrum. Based upon collision rates at 2,000°F it has been estimated that these metastable states would be dissipated in one second, not inconsistent with the lifetime of ball lightning.

Various attempts have been made to estimate the temperature of the luminous gases. While a Russian investigator estimated 14,0000K for a yellow ball, other estimates are much lower. One observer concluded that the temperature was somewhat greater than 4,0000K based upon the concentrations of ozone and nitrogen dioxide measured in a trail left by a ball. The range of 4,000 to 5,0000Cwas inferred from Wein's law and the red and red-yellow colors commonly reported. Temperatures as low as 2000C have been considered. Because the witnesses have failed to report any sensation of heat near ball lightning, much preference should be given to the lower estimates. Ball lightning clearly involves a natural mechanism for producing bright luminosity of atmospheric gases at moderate temperatures and this mechanism may well account for the similar luminosity of UFOs.

As mentioned previously, ball lightning appears to be created and sustained by a supply of radiant energy in the frequency range of at least 100 to 4,000 MHz. This range is in the lower end of a zone of the electromagnetic spectrum from about 300 MHz to 300,000 MHz that is known as the microwave region. Lying between the bands used for radio broadcasting and the visible zone, it encompasses the frequencies used for microwave ovens, point-to-point telecommunications, radar, and special bands allocated by the Federal Communications Commission for industrial, scientific, and medical purposes. Most important among the latter are the frequencies of 915 and 2,450 MHz because available tubes, converting direct current to microwave energy at these frequencies, allow high powered applications. For example, a klystron having an average power rating of 500 kW is manufactured.(24) It has been predicted that some similar devices operating in the frequency range of 1,000 to 3,000 MHz will ultimately be feasible at power levels approaching 10 MW. (25) At very low gas pressures, plasmas are easily created by the application of microwave energy. It has been observed in such a plasma that the sensible gas temperature was 7000K whereas the electron temperature exceeded l0,0000K. (26) It seems quite likely that some such compound state exists within ball lightning and on the surface of UFOs when they are extremely bright. Ionization levels and luminosity would be very high while the gas temperature would remain relatively low. A plasma of this type could be sustained on the surface of a UFO only by a continuing absorption of microwave energy emitted by the UFO.

Fortunately, ball lightning can be studied in the laboratory. It was first created artificially by the Radio Frequency Company, Incorporated of Medfield, Massachusetts. Electromagnetic energy from a radio transmitter was injected into a large, aluminum box at resonant frequency. A ball of luminous gases about one foot in diameter suddenly formed and floated around inside the box until the power was turned off. In subsequent research at Brookhaven National Laboratory, similar plasmas have lived several seconds without power. It was suggested by the researchers that the radio-frequency energy was absorbed by nitrogen and oxygen and temporarily held in metastable states. (27)

Metastable states are thus seen to play a leading role in the existence and longevity of ball lightning. If the bright luminosity of UFOs depends upon the same physical processes, then some clues should be hidden in the UFO reports and photographs. A case in point may be the experience of a Brazilian woman, Mrs. de Mendonca, and her companions. At the end of a two-hour car chase, a Saturn-shaped UFO hovered close to the ground for about 15 minutes. An unspecified time later, the witnesses found an "odd luminous haze floating in the air above where the object had hovered" and they watched it slowly dissolve. (28) A similar detail was noted in a sighting of six UFOs in Argentina that, upon departing, left clouds of white smoke. (29) These observations suggest that the UFO charged the metastable states of atmospheric oxygen while hovering and, upon flying away, left them to decay gradually with the production of light.

In numerous photographs, UFOs are depicted with luminous tails that, heretofore, have been inexplicable. (30) By transferring energy to the atmosphere while traversing the sky, a UFO should leave a luminous wake where metastable states are decaying and transferring the stored energy to instantaneous, light emitters. Motion pictures of such tails should yield some quantitative data as the rate of energy transfer to the atmosphere, the speed of the UFO, and the length of the tail can be related with mathematical precision. It should be emphasized that intermolecular collisions are the controlling factor in releasing the stored energy and the rate of collisions is dependent upon the temperature and pressure. Because molecular agitation is diminished at low temperature, a cold day should retard the release of the states and increase the persistence of a UFO tail. Collision rates are also less frequent at low pressures, hence the tails should be especially persistent at high altitudes, having the compound advantage of frigidity and rarefaction. These considerations may suggest an interpretation of the prominent tail attached to a glowing, egg-shaped object that was photographed from earth orbit by the American astronaut, McDivitt. (31)

There exists yet another set of facts closely tying UFOs to ball lightning. Electrical discharges in the atmosphere initiate some important chemical changes. Energy states of atoms are modified and numerous chemical compounds are formed from the constituent gases. In a high-voltage spark, nitrogen is elevated to a metastable state having several interesting properties. It produces a soft, white glow that continues for some time after the electric discharge has been stopped. Such excited nitrogen is known chemically as "activated" because it will readily combine with many other elements whereas ordinary nitrogen will not. (32) It combines with hydrogen to form ammonia (NH3 ) and with oxygen to form nitric oxide (NO). This oxide is quite stable at high temperatures but below 1500C it reacts with oxygen to form nitrogen dioxide (N02). The dioxide can react with still other atmospheric gases to form nitrobenzene, an oily substance that is highly poisonous and has a strong odor like oil of bitter almonds. Also produced by electrical discharges is a highly reactive form of oxygen known as ozone whose odor one learns to recognize in association with sparking, electrical apparatus.

While the sense of smell is not thoroughly understood, it is known to depend upon the molecular structure and chemical groups as a series of benzene derivatives have a similar odor. The nose is extremely sensitive, ethyl mercaptan being detectable down to concentrations as low as 4 X 10-8 milligrams per liter of air. (33) The above gases should be manufactured in an electrical discharge within ball lightning and they would not have to be present in large amounts to be noticed, that is, smelled by the witnesses. The odor of ball lightning is "usually described as sharp and repugnant, resembling ozone, burning sulphur or nitric oxide." (34) The reference to sulphur is readily understood as that element is a notorious air pollutant arising from automobile exhausts and smoke from industrial plants. Even in rural areas, the sulphur content of air may be quite high due to its production by bacteria in the mud of swamps and lake- and stream-bottoms. (35) While it may seem farfetched to inquire whether UFOs have any odor, it would be particularly significant if witnesses have detected those very gases that are produced in electrical discharges in direct association with them. One need only examine the record, as in the following tabulation, to see that such is the case.

Descriptions implying sulphur dioxide are the most numerous, however, benzene and its derivatives are mentioned. The term "pungent" and the reference to an electrical circuit almost assuredly implies ozone. At any rate, this evidence is an independent source of information that points to an electrical disturbance on the surface of UFOs that is undoubtedly associated with the luminosity.

Case No. Description Of Odor
51 Strange, cloying smell
72 Pungent
73 Burning benzene
94 Burning sulphur
101 Unpleasant
102 Ether mixed with sulphurous smoke, nauseous
199 Nitrobenzene
584 Sulphurous
615 Powerful, embalming fluid
616 Strong, unpleasant
684 Burned gasoline
721 Sulphur or rotten eggs
768 Sulphur
832 Sulphur, camphorated oil
844 Burning electrical circuit
875 Sulphur
879 Strong, melted iron
909 Strange, powerful

of this process and microwave energy is strongly implied by experimental data. Irradiation of various gases with microwaves produces a wide variety of gas atoms and free radicals, the required forms for chemical recombination's. In air, nitric oxide is produced. The efficiency of this reaction is greatly increased when the microwave energy is pulsed. Ethane and methane are decomposed into carbon and hydrogen but benzene is stable. In other words, a pulsed discharge of microwaves in air would suffice to generate nitric oxide and, in a subsequent reaction, the benzene that has been noted in the vicinity of UFOs. (36) As the benzene is not decomposed in the microwave field, any that were formed would accumulate then linger until detected. Oxidation of sulphur has also been accomplished in the laboratory with microwave irradiation, namely, conversion of sulphur dioxide to sulphur trioxide. Similar oxidation of atmospheric sulphur to sulphur dioxide could well be responsible for the commonly reported sulphurous odors. (37)

Sequential Multi-Colors

From the foregoing discussion it appears that energy originating in the UFOs is responsible for atmospheric luminosity in their immediate vicinity. Furthermore, various colors seem to be associated with different rates of energy transfer from UFOs to the atmosphere. Thus it might be possible to identify several energy states of UFOs that are distinguished by the character of the induced light. While certainly incomplete, energy states are tentatively assigned as follows:

State Appearance Physical Basis
0 Metallic Energy inadequate to excite perceptible light
1 Blue glow Excitation of xenon only
2 Orange-red Selective exitation of neon
3 White glow Decay of metastable nitrogen
4 Brilliant white Limited ionization of all gases augmented by the "ball lightning mechanism"

If such categories are real, one would expect to find some correlation between the color of a UFO and its pattern of flight, a relationship that was observed at least as early as 1956.

"The colors mentioned seem associated in some way with the speed, or more probably with the rate of acceleration. The silvery grey with an aureole of dark red is seen when the object is stationary or traveling very slowly. Then comes the vivid red. At high acceleration the white, green, blue and purple appear." (38)

Very little progress in understanding this relationship has been made, however, the present model may be helpful.

When two people got out of their car to watch an object hovering at ground level, "its color changed from orange to fluorescent green before it took off." (39) Apparently State 2 prevailed while the object was stationary and the change preceded the acceleration. The original orange color must have been produced by photons having wave lengths between 5850 A and 6470 A. Similarly, the green color necessarily arose from wave lengths between 4912 A and 5750 A. Photons producing a green sensation, being of shorter wave lengths, are more energetic than their yellow cousins. Thus the change from orange to green implies an increase in the energy emitted by the atoms. From the above definitions of the color bands, one can easily calculate the minimum and maximum energy changes that might occur, assuming constant intensity. The color changes would be accomplished by an increase of about 5 to 24 percent. It is suspected that the orange color derived from neon at 6402 A. But neon also has a prominent line in the green at 5401 A. If these wave lengths were involved, the energy increase would amount to about 16 percent. That the UFO began pumping more energy into the atmosphere as it accelerated is clear. But further analysis is frustrated by complications such as the absorption efficiency of the atoms for an unknown mechanism, transition probabilities within the emitting atoms, and the variable sensitivity of the human eye to different colors. Although green is frequently observed, it has not been possible to assign a meaningful UFO state number to it.

A man saw a luminous, oval object rising from the flat roof of his house, "varying in color between white and red." (40) Very little detail is available in this report and it cannot be determined whether white to red was the sequence of color change or whether the transition occurred several times in reversing order. At least it shows a color change associated with ascension.

An oval object followed a woman driving her car for 13 kilometers. Its "color suddenly changed from reddish-orange to bluish-white before accelerating out of sight." (41) As a prelude to acceleration, this UFO "stepped on the gas" and moved from State 2 to State 4. The "bluish" component is appropriate to State 4 as a welding arc has such a cast.

An object shaped like two plates glued together with an oval on top hovered at treetop level over a man's car for two minutes. "It took a 45-degree inclination, rose, made a right angle turn, and changed color (white to yellow to blue to green) as it accelerated." (42)

Again, a brilliant color display occurs upon acceleration. The corresponding States, 4-2-1-?, seem to be appropriate to a gradual reduction of power in approaching cruising speed.

Following a chase by a glowing object at 170 km/hr, a witness stopped his car to watch. "The color changed in sequence, orange to red to blue to green, and the object wobbled on its axis" as the object came from 100 meters to within 30 meters. It then suddenly left straight up. (43) The energy states, 3-2-1-?, are seemingly appropriate to deceleration during the close approach. The transition of blue to green is puzzling.

A lighted object in the sky was observed to be going up and down; its color "turning from white to greenish-blue." (44) Again, the description is not explicit enough to determine if the color change was repeated and synchronized with the changes in altitude, or if a gradual change occurred throughout the sighting. In the former interpretation, alternation between States 3 and 1 would make sense.

Four boys observed a cone-shaped object descending with an oscillating motion. It has "a blue underside, and a top that changed from red to orange to white." (45) The last change, corresponding to States 2-3, implies an increase in power for deceleration.

Every instance of sequential color change in the sample cases was associated with accelerations and the energy state model. Rough as it is, this association seems to make this perplexing aspect of UFOs more meaningful. This correlation is critically important as it establishes a relationship between the UFO propulsion system and the stimulation of atmospheric gases to emission of light. A great deal of work in this area is certainly needed and a thorough analysis of the better documented cases by a theoretical spectroscopist should bring it into sharp focus.

Although no source for green light was suggested above, a likely candidate is neon with its spectral line at 5401 A. The logical difficulty of positively identifying neon is the relatively high energy required for excitation, being the same as that for its orange-red line. The latter would be expected to dominate and obscure the green. Obviously, only a partial solution to this problem can be offered now. A similar uncertainty prevails for the often-noted, bluish-green color for which two possible sources are in contention. A commercial laser based upon argon emits a bluish-green light having wave lengths in the range of 4579-5145 A, mid-blue to about mid-green, although spectral lines in that range for argon are not tabulated in the literature. (46) As Argon is fairly abundant in air, these lasing transitions could account for this color. A competing possibility is the bluish-green line of hydrogen at 4861 A whose low threshold makes it easy to stimulate. One problem is that free hydrogen in the atmosphere is very rare, less than one part per million. But each molecule of water vapor in the atmosphere, containing two atoms of hydrogen, assures an adequate supply. The concentration of hydrogen would be greatest on damp, rainy or foggy days, when the relative humidity is 100% and the air is filled with water droplets. If it were found that the bluish-green color were more pronounced during inclement weather, the source might be pinpointed to hydrogen. But no such correlation has been attempted. UFOs frequently take refuge in clouds whose moisture content is substantially greater than the surrounding air. This circumstance affords some opportunity to detect light emission from hydrogen if it is significant. From statements of the witnesses, it is apparent that clouds become luminous when they are entered by a UFO and the color has been called "unusual." (47) At least once it was observed to be "green" (48) and no conflicting reports have been encountered. It seems that hydrogen probably contributes to the colorful display from UFOs but it may share the credit for bluish-green with argon.

Simultaneous Multi-Colors

In addition to UFOs exhibiting several colors one after another during maneuvers, they are sometimes seen to produce several colors at the same time. In one instance the underside remained blue whereas the colors on top changed. (49) Horizontal bands of color on another object were "blue, red and green." (50) These cases are not very instructive but they may point to a highly selective mechanism for stimulating the emission of light, probably from the noble gases. Horizontal disposition of the bands on an axially symmetric object may reflect geometrical features that would alter or distort electromagnetic fields in their vicinity. Perhaps that might be the explanation for a "six story" object from which rainbow colors poured off its edges "like water." (51)

Other Lighting Details

Apart from the diffuse luminosity, UFOs are frequently observed to carry ordinary "navigation" lights. One of the most common features is a prominent light on the top which may be of any color, either steady or flashing. Other lights are sometimes distributed over the surface, typically at the ends of elongated objects or along the periphery and on the bottom of discs. These lights vary greatly in number and color and, in the sample cases, have no discernible significance. Usually, two or more lights of different colors are reported; one object was estimated to have about 30 lights. Nearly all colors are reported, most often red blue, white, yellow, orange and green. Some are steady while others are flashing. This display has been aptly compared to a "Christmas tree."

Another type of illumination less common than surface lights consists of one or more powerful beams resembling search lights. They are used for scanning the countryside, pointing directly downward or upward, or at houses and vehicles. By switching a vertical beam on and off, an object on the ground seemed to signal another one at high altitude which answered in the same manner. (52) Red, white, blue and green beams have been reported.

Finally, about a dozen witnesses reported "windows," "portholes," "openings" or "doors" through which poured bright light, most commonly with a yellow to orange tinge. Individual lights and general illumination have also been observed through transparent domes atop disc-shaped objects.

Footnotes

1. VaIlee, Jacques, Passport to Magonia, "Appendix A, Century of UFO Landings, 1868 to
1968," Regnery, 1969. Individual events in this catalog are hereafter referred to solely by
case number, as in Case 438.
2. Lorenzen, Coral E., Flying Saucers, The Startling Evidence of The Invasion From Outer Space,
Chapter 9, Signet, 1966.
3. Condon, Edward U., Scientific Study of Unidentified Flying Objects, p. 97, Dutton, 1969.
4. Saunders, David R., and Harkins, R. Roger, UFOs? YES! Where The Condon Committee
Went Wrong, p.170, Signet, 1968.
5. Peaslee, D.C. and Mueller, H., Elements of Atomic Physics, Prentice Hall, 1955.
6. Case 486.
7. Case 848.
8. Harnwell, Gaylord P., Principles of Electricity and Electromagnetism, Second Edition, p.85,
McGraw-Hill, 1949.
9. Herzberg, Gerhard, Atomic Spectra and Atomic Structure, Dover, 1944.
10. Case 34l.
11. Case 349.
12. McGraw-Hill Encyclopedia of Science and Technology, 1971.
13. Handbook of Chemistry and Physics, Chemical Rubber Company, 1969.
14. Handbook of Chemistry and Physics, Chemical Rubber Company, 1971.
15. Besancon, Robert M., Editor, The Encyclopedia of Physics, p. 743, Reinhold, 1966.
16. Lengyel, Bela A., Lasers, Wiley-Interscience, 1971.
17. Bennet, W.R., et al, "Dissociation Excitation Transfers and Optical Maser Oscillations in
Ne-Ox and Ar-Ox It Discharges," Phys. Rev. Letters, 8, 470-473, 1962.
18. Handbook of Chemistry and Physics, Chemical Rubber Company, p. 1,631, 1937.
19. Encyclopedia of Science and Technology, Vol.7, p.574, McGraw-Hill, 1971.
20. Uman, Martin A., Lightning, "Appendix C, Ball Lightning," p.243, McGraw-Hill, 1969.
21. Cases 560, 601, 613, 733, 737, and probably 776.
22. Klass, Phillip J., UFOs, Unidentified, Random House, 1968.
23. Singer, Stanley, The Nature of Ball Lightning," Plenum, 1971.
24. Neville, Roy 0., et al, "Microwaves," Kirk-Othmer Encyclopedia of Chemical Technology,
Supplement Volume, 2nd Edition, pp 563589, Wiley, 1971.
25. Goerz, D.J., Industrial Microwaves Today, Bechtel.
26. Baddour, R.F., and Timmins, R.S., eds., The Application of Plasmas to Chemical Processing,
MIT, 1967.
27. Klass, Phillip J., UFOs-Identified, p. 151, Random House, 1968.
28. Lorenzen, Coral E., Flying Saucers, The Startling Evidence of The Invasion From Outer
Space, p.148, Signet, 1966.
29. Case 584.
30. Also see descriptions in Cases 282, 309, 310, 316, 322, 339 and 366.
31. Edwards, Frank, Flying Saucers-Serious Business, Photograph section, Bantam, 1966.
32. Latimer, Wendell M. and Hildebrand, Joel H., Reference Book of inorganic Chemistry,
Revised Edition, p. 181, Macmillan, 1940.
33. Encyclopedia Britannica, Vol.20, p.822, 1965.
34. Uman, Martin A., Lightning, p.245, McGraw-Hill, 1969.
35. Grey, D.C. and Jensen, M.L., "Bacteriogenic Sulphur in Air Pollution," Science, Vol. 177,
p.1099, 22 September 1972.
36. Cases 74 and 199.
37. Neville, Roy 0., et al, 'Microwaves, Kirk-Othmer Encyclopedia of Chemical Technology,
Supplement Volume, 2nd Edition, pp 563589, Wiley, 1971.
38. Michel, Aime, The Truth About Flying Saucers, p. 143, Pyramid, 1967. The relationship
between color change and UFO power was vaguely noted even earlier, see Keyhoe,
Donald E., Flying Saucers From Outer Space, p. 52, Holt, 1953.
39. Case 670.
40. Case 692, quoted from the original source.
41. Case74l.
42. Case 772.
43. Case 682.
44. Case82l.
45. Case 826.
46. Manufactured by Energy Systems, Inc., Palo Alto, California, according to Leinwoll, Stanley,
Understanding Lasers and Masers, Rider, 1965.
47. Cases 675 and 575.
48. Case 684.
49. Case 836.
50. Case 796.
51. Case 789.
52. Case 619.