than 20 years, the French space agency has conducted a non-military but official
investigation into UFO reports. In its first phase, the project was named GEPAN and its
focus was primarily on UFO reports. Subsequently, the project was renamed SEPRA and was
assigned a more general responsibility for studying all atmospheric reentry phenomena. In
the body of the report, we have for convenience referred to the project as
"GEPAN/SEPRA." This appendix gives a brief summary of the history, mission,
operations and achievements of this project.
The French space agency is known as CNES (Centre
National d'Études Spatiales). It was founded in 1962 to conduct French space activities
on a national basis and also in the context of the European Space Agency (ESA) or of other
international collaborations. CNES currently has 2,500 employees. The CNES headquarters
are in Paris but its technical center is in Toulouse.
GEPAN (Groupe d'Études des
Phénomènes Aérospatiaux Non-identifiés - Study Group for Unidentified Aerospace
Phenomena) was established as a department of CNES in Toulouse in 1977. At that time, its
head was Dr. Claude Poher, who had already performed statistical analyses of files
containing several thousand observations worldwide (Poher, 1973). CNES set up a scientific
advisory board comprising astronomers, physicists, legal experts and other eminent
citizens to monitor and guide GEPAN's activities.
The first tasks undertaken
by GEPAN were:
To establish data collection procedures in conjunction with the Air Force,
civil aviation authorities, the Gendarmerie (French internal police), meteorological
offices, the national police, etc.
- To conduct statistical analyses of
- To investigate previously reported cases.
These initial studies led to
the following conclusions:
- Those events that remain unexplained after
careful analysis are neither numerous nor frequent.
- The appearance of some reported phenomena
cannot readily be interpreted in terms of conventional physical, psychological or
- The existence of a physical component of
these phenomena seems highly likely.
Following these initial
steps, GEPAN undertook to develop a more theoretical but rigorous approach to these
studies. It was clear at the outset that it would be necessary to consider both the
physical nature and the psychological nature of the phenomenon. In order to fully
understand a witness's narrative account, it was necessary to consider not only the
account but the psychology and personality of the witness, the physical environment in
which the event occurred, and the witness's psycho-social environment.
GEPAN negotiated agreements
with the Gendarmerie Nationale, the Air Force, the Navy, the meteorological offices,
police, etc. These negotiations led to procedures by which these organizations provided
GEPAN with relevant reports, video tapes, films, etc., which were then processed and
analyzed either by GEPAN or by associated laboratories. However, from 1979 on, GEPAN
worked mainly with reports from the Gendarmerie since these reports proved to be best
suited for GEPAN's purposes.
GEPAN developed a
classification system to reflect the level of difficulty in understanding the reports:
Type A: The phenomenon is fully and
Type B: The nature of the phenomenon has
probably been identified but some doubt remains.
Type C: The report cannot be analyzed since
it lacks precision, so no opinion can be formed.
Type D: The witness testimony is consistent
and accurate but cannot be interpreted in terms of conventional phenomena.
Reports of Type A and Type B
were further subdivided into astronomical, aeronautical, space, miscellaneous, and
identified. GEPAN carried out statistical analyses aimed at classifying cases according to
sets of physical characteristics.
Two types of investigations
were carried out on individual reports:
- Mini-investigations, that were applied to
cases of limited significance; and
- Full investigations, that were applied to
unexplained cases (Type D) in which effort was made to obtain as much information as
possible, including gathering and analyzing physical and biological evidence.
During the GEPAN phase, the
project initiated several lines of research involving other laboratories and consultants.
These were aimed at seeking a possible basis for modeling unexplained aspects of UFO
reports, as well as seeking new techniques for the more active investigation of UFO events
by the development of detection systems. These research topics included:
- Research on possible magnetohydrodynamic
- Study of facilities to collect unexpected
atmospheric phenomena on a worldwide basis, that led to the proposal of the Eurociel
Project to develop a network of ground stations equipped with wide-angle observation
systems and powerful real-time processing algorithms;
- Methodology for image analysis (photographs,
videos, etc.); and
- Study of aeronautical cases, especially
In 1988, GEPAN was replaced
by SEPRA (Service d'Expertise des Phénomènes de Rentrées Atmosphériques - Atmospheric
Re-entry Phenomena Expertise Department). M. J-J. Velasco, who had been a member of GEPAN
since the very beginning, took charge of this new project that was then assigned a wider
mission. This new project was called upon to investigate all re-entry phenomena including
debris from satellites, launches, etc. However, the budget was drastically reduced so that
research into UFO reports could not be maintained at the earlier level. Nevertheless, all
existing official procedures concerning data collection have been maintained to ensure
continuity in receiving reports.
After 21 years of activity,
the GEPAN/SEPRA files now contain about 3,000 UFO reports supplied by the Gendarmerie.
About 100 of these reports were found to justify specific investigations. Of this number,
only a few cases remain unexplained today.
There have been attempts by
SEPRA to increase the scope of the project at least to a European level, but this has not
yet been successful. One of these attempts was the "Eurociel" project: the basic
concept was to implement two sets of wide-angle optical detection stations, sited some
tens of miles apart following a parallel of latitude, each station to be equipped with
CCD-type cameras, with a minimum of one in the visible and one in the infrared. The output
from these cameras would feed data into a microcomputer that triggers recording of the
data when the computer determines that a change has suddenly occurred. The data from all
these stations would be stored in a central facility to permit the calculation of
trajectories. Such a system could detect lightning, meteors, unknown satellites, and other
known or unknown phenomena.
During the GEPAN phase, the
project produced many reports and investigations and technical documents concerning topics
related to the study of UFO events. These reports were made publicly available. These
reports are no longer being disseminated, but some information can still be requested from
Appendix 2: Procedures for
Analysis of Photographic Evidence
The Panel recommends that,
given a new alleged UFO photograph, the decision to invest effort into its investigation
should be taken only if both of the following conditions are fulfilled:
- the original documentation (negative, slide,
videotape) is available, and
- there is at least one other independent
source of information - either witness testimony or some other physical record.
If, after visual
examination, the displayed object has not been identified (planet, balloon, cloud, etc.),
investigation should be performed in two steps:
Step 1 consists of
establishing or rejecting the authenticity of the photograph (or other record), taking
into account evidence for unintentional false operation of equipment and various spurious
phenomena that may affect the recording equipment. However, this concept of authenticity
is at best relative, since in this area of investigation only negative conclusions may be
considered as final, so that authenticity can never be demonstrated absolutely.
Step 2, if warranted,
consists of extracting as much information as possible from the photograph or other
record, so as to obtain as much information as possible about the object of interest
(size, shape, distance, albedo, emitted energy, spectrum, etc.).
When the original film is
available and analysis seems justified, all technical data concerning the site, viewing
conditions, camera, film, processing, etc., must be collected. If the camera is available
(in an ideal case still loaded with the original film), it must be used to perform the
- Photos of density patterns for relative
- Photos of sources calibrated in intensity, in
various positions in the frame (for absolute photometry);
- Photos of spatial frequency patterns, to
determine the modulation transfer function (MTF); and
- Photos taken at the same site as the
original, eventually with models to simulate the object.
The film should be processed
under rigorously controlled conditions (if it has not already been processed
commercially). If the camera is available but empty, the same operations should be
conducted with a film of the same type as the original.
The investigator should
visit the original site and make measurements concerning the three-dimensional geometry of
the observed landscape or this information should be extracted from detailed maps. If the
photograph has been acquired at nighttime, an astronomical map of the sky at the time of
acquisition will be necessary. The investigator should determine the meteorological
conditions from the official offices or air bases in the neighborhood with particular
attention to the horizontal visibility. The investigator should also take into account all
quantified or quantifiable elements of the witness testimony including the estimated
shape, angular size, velocity, color, etc.
For analysis of the
photograph, it is essential to work from the original negative. This should be carefully
washed and examined under a microscope to look for possible tell-tale artifacts and
scratches, and to check the regularity of the grain structure so as to detect multiple
exposures. The negative should be analyzed by conventional photographic instruments
(enlarger, projector, etc.), and the information on the negative should be digitized by a
Once digitized, the image
may be analyzed by computer analysis, using the classical tools of contrast enhancement,
noise suppression, contour detection, restoration, etc., and more specialized techniques
such as maximum-entropy analysis that may be used to remove the effects of target motion
and/or camera motion. Such analysis will assist in the detection of a possible hoax. For
instance, a suspension thread may be brought into evidence through standard differential
operations. Also, one may estimate the distance (hence the size) of the object through MTF
computations, based on an analysis of atmospheric diffusion and contour blurring. If there
are black areas on the object, it is possible to obtain estimates of the distance by
comparing the luminance of such regions with other identified black parts of the scenery.
If the object is nearer than the minimum depth of field, one should be able to detect
geometrical distortions in the image. If the operator had a slight movement while taking
the picture, analysis of the corresponding blur on the object and on other elements of the
landscape may allow the calculation of a possible range for the distance of the object.
In the case of a color
photograph, one should carry out the above procedures in three steps using three
appropriate color filters for scanning.
If an event is recorded on a
cine camera, each frame may be analyzed as above. However, it is now possible to obtain
additional information by combining and comparing the sequence of images.
In principle, images
recorded by video cameras may be subjected to comparable analyses. However, video records
suffer from one very important weakness: since the basic data is in electronic form, it
could have been modified by the use of suitable electronic equipment, so that the
authenticity of a video record will depend even more critically upon the credibility of
the witness testimony.
Appendix 3: Formation
V. R. ESHLEMAN
A recurrent theme in certain
UFO reports is the concept of an apparition that flies in formation with an aircraft-borne
observer. Without making a judgment on any such reports, we could recommend that UFO
investigators familiarize themselves with natural phenomena that display this
"flying-in-formation" characteristic. Greenler (1980) is a useful resource, from
which the attached list was made. The precise mechanisms for the origin of most of these
phenomena have been determined and are explained in Greenler, but quite a few have still
not been deciphered satisfactorily. Even an experienced observer might be surprised in
seeing a particularly rare example. I have studied certain related phenomena in my
research involving electromagnetic probing of planetary atmospheres, but was quite
astonished a few years ago when I saw a particular example of the following list. A bright
white light flew for minutes in perfect formation between my aircraft and the ground, with
the air below and above apparently being transparently clear.
Formation flying phenomena:
Arcs: Kern, Lowitz, Wegener
anthelic, Hastings anthelic, Tricken anthelic, Parry, alternate Parry, suncave Parry,
sunvex Parry, upper tangent, lower tangent, supralateral, infralateral, circumzenithal,
circumhorizontal, anthelic, subanthelic, contact.
Halos: Hevel, 8 degree, 18
degree, 22 degree, 46 degree, circumscribed.
Bows: fog, cloud, dew,
Rainbows: primary and
secondary; direct and reflected; raindrop and ice crystal; white, red, and red-to-blue.
Pillars: sun, moon,
Rings or Circles: Bishop,
Bottlinger, parhelic, subparhelic, coronal.
Dogs: sun, moon, elongated,
One should also consider:
Nighttime: moon, Venus, Jupiter, bright stars, etc., gegenschein, zodiacal light, comet,
in-cabin light reflected by window.
Other forms: glory (specter
of the Brocken), subsun, wet and dry heiligenschein, seven suns, lenticular and other
distant small clouds, several different kinds of mirages.
The phenomenon which was a
special surprise to me is one in the final grouping, the subsun, due to particularly
stably falling, flat, horizontal, hexagonal, ice crystals which were sufficiently few in
number that the air appeared clear in every direction except the solar specular direction
to the side of and below the airplane, where they efficiently mirrored the sun.
V. R. ESHLEMAN
It is possible that some of
the radar cases presented to the panel have a natural explanation. It seems likely that
some possible natural explanations could be investigated without cooperation or assistance
from the controlling military authorities except for a time record of unidentified traces
that occur during designated test periods.
Some of the observations
suggest that time-variable atmospheric ducting may on occasion result in echoes being
obtained from distant ground locations as a result of refraction. Some of accounts
described (a) groups or swarms of echoes that persist for some time in the same general
location; (b) apparent trajectories of echo sources that exhibit sudden changes in the
vertical and/or horizontal positions; and in particular (c) the tendency of apparent echo
sources to concentrate over mountain tops. These are all characteristics to be expected of
ducting conditions due to weather. These effects can come and go over long periods of time
and they can also lead to scintillation or other changes over short time periods. (See,
for instance, Hall & Barklay 1989.)
An atmosphere is said to be
"superrefractive" when a horizontal light or radio ray curves downward with a
radius of curvature that is less than the distance to the center of the planet. The
atmosphere of the planet Venus is at all times globally superrefractive below an altitude
of about 30 kilometers. In principle, echoes could be obtained from every area of the
spherical surface of Venus from a radar system located at any position on the surface. If
the air of Venus were perfectly clear, an observer would see all areas of the surface, all
areas repeating in range to indefinite distances. In the four giant planets also, the
large gradients of refractivity (or density) in their atmospheres produce superrefractive
The Earth's atmosphere is
normally not superrefractive. However, common weather effects (in particular thermal
inversions, where the air temperature increases with altitude, and/or the water-vapor
content decreases with altitude) can and do produce regions of superrefraction that are
localized geographically and in height. As a result, atmospheric ducts (channels that trap
and conduct radar waves) can form that carry the signals far beyond the normal horizon.
Such ducts can bend rays down to a distant surface area or, more easily, to a distant
mountain top. Backscattering of the radar energy from the ground or from discrete objects
on the ground then results in echoes that appear to the radar to be due to a target that
is far away and (if the angle of elevation of the returning energy is measured) high in
the atmosphere. A similar transient ducting of sound can produce the experience of hearing
the whistle of only one particular train out of the many that originate at difference
times from a busy track in the next valley.
As is well known,
atmospheric ducting is the explanation for certain optical mirages, and in particular the
arctic illusion called "fata morgana" where distant ocean or surface ice, which
is essentially flat, appears to the viewer in the form of vertical columns and spires, or
"castles in the air."
People often assume that
mirages occur only rarely. This may be true of optical mirages, but conditions for radar
mirages are more common, due to the role played by water vapor which strongly affects the
atmospheric refractivity in relation to radio waves. Since clouds are closely associated
with high levels of water vapor, optical mirages due to water vapor are often rendered
undetectable by the accompanying opaque cloud. On the other hand, radar propagation is
essentially unaffected by the water droplets of the cloud so that changes in water vapor
content with altitude are very effective in producing atmospheric ducting and radar
With regard to
"impossible" flight paths that may appear to be indicated by some of the echoes
obtained by military radars, it is important to note that the records presented to the
panel are based on measured time delays and measured elevation and azimuth
angles-of-arrival of the reflected energy from the echoing object. As presented, certain
target positions were plotted as height versus time. But height is computed from two
parameters: (1) the measured time delay, which is a very good indication of range; and (2)
the measured vertical angle of arrival, which may not be a valid representation of the
vertical direction to the target. In particular, when ducting occurs, reflections from
distant and distinct surface targets (buildings, bridges, trucks, etc.) may be received at
elevation angles of several degrees, so that a ground target at a range of 100 kilometers,
for example, would appear to represent an object at a height of several kilometers.
Atmospheric turbulence would distort the duct and could cause sudden changes in angle of
perhaps a few tenths of a degree, which would be interpreted as a sudden change in
altitude of the order of half a kilometer. The horizontal angle of arrival would also be
affected by turbulence, adding to the chaotic character of the apparent flight path.
Ducting to and from distant
mountain tops requires less refractive bending than echoes to and from lower surface
areas, and should therefore be more common. This may explain the concentration of apparent
targets over mountains. A test of this hypothesis would be to place a radio receiver,
tuned to the radar frequency, on or near the top of a mountain associated with
unidentified targets. It should be connected to an antenna that has its unobstructed
receiving lobe centered in the azimuthal direction of the radar and its vertical pattern
extending from zero to at least several degrees in elevation. If ducting does in fact
occur, the occurrence of unidentified radar echoes would be found to be correlated with
major increases in the strengths of the radar signals measured by this receiver.
Appendix 5: Sprites
V. R. ESHLEMAN
One of the optical displays
reported by E. Strand may be of special significance as a tentative bridge across the wide
gulf that exists between the UFO and scientific communities.
Two women reported an
unusual, colored, intermittent light display that slowly moved over two hours of
observation made from a remote cabin in Norway in the post-midnight hours of August 3,
1991. The sky was clear until the end of the observation period, when a few clouds moved
in. The key point about this display is that while there was no local thunderstorm
activity, there was an electrical storm in the direction of the display, but the storm was
120 kilometers away. For decades, it has been conventional scientific wisdom that all of
the visible electrical activity of such storms is within and below the clouds, that in
this case would have been below the observers' horizon.
Recent developments in the
observations and theory of electrical activity in the high atmosphere (mesosphere and low
ionosphere) demonstrate that this conventional wisdom is in error (see, for instance,
Pasko et al., 1996; Sentman & Wescott, 1995). Some of the reports of
observations in the Hessdalen area could be related to phenomena that occur above storms,
up to an altitude of nearly 100 kilometers, well above the observers' horizon. This
electrical activity goes by the names of "blue jets," " red sprites,"
and "short-lived elves." There have in fact been sporadic reports of these
phenomena decades ago, but these reports were dismissed by the "experts." Now
these events have been captured on film and video.
This example can serve to
remind us of the continual development and change that occurs in all fields of scientific
knowledge, and of the potential advantages of open communication between the purported
experts and interested amateur observers.
Appendix 6: SETI and UFO
V. R. ESHLEMAN
My perception is that the
SETI (Search for Extraterrestrial Intelligence) and UFO studies of a decade ago shared
positions beyond the pale of "respectable" science. They no doubt still do in
the view of many scientists. However there have been several fundamental advances during
the past few years that indirectly provide some increase in plausibility for both areas,
and the SETI community seems to be responding with renewed vigor. It may be useful for our
panel to consider some UFO-SETI comparisons, and the different cultures of their
respective participants. These are my personal and incomplete thoughts on this subject.
There have been recent
advances concerning the question of the possible existence and state of extraterrestrial
life (ETL). Knowledge that there is such life would increase the presumptive probability
of extraterrestrial intelligent life (ETIL). SETI investigators search for the latter
mainly by examining the radio spectrum for telltale electromagnetic signals that may be
purposely sent or inadvertently leaked from a technological society. UFO investigators may
invoke visitation by ETIL as a fallback or default explanation of an apparition or event
which they believe cannot be explained any other way. There are huge gaps in our knowledge
that must be filled in before we can pretend to understand either of these subjects.
With regard to the first
question, the existence and possible abode of ETL, three major recent developments are of
- It is only in the last few years that we have
finally obtained direct evidence of the existence a planetary-sized body orbiting a star
other than our Sun. We now have evidence for several (of order of 10), and more are being
discovered as the Doppler observational technique is being improved. There are billions of
stars in our galaxy alone, and these results suggest that stars may quite generally be
accompanied by planets. One may expect that conditions on these planets would vary over a
wide range, at least as wide as the range covered by the planets of our solar system.
(See, for instance, Cosmovici et al., 1997.)
- Life that is fundamentally different from
nearly all near-surface life on Earth has been found deep in terrestrial rock and in the
deep ocean, where it exists under conditions long assumed to be so hostile as to be
sterile. It would appear that near-surface and subterranean life forms are essentially
independent and that either could exist without the other. It is also possible that life
started several different times on Earth after epochs of total extinction caused by
asteroidal and cometary impacts. These new findings suggest that life might have started
independently at two levels on Earth, or that life can adapt to extraordinarily different
environments. The development of life, under conditions that are thought to be favorable
and under conditions that we previously thought to be unfavorable, may be the rule rather
than the exception for the innumerable planets that probably exist in our galaxy. (See,
for instance, Cosmovici et al., 1997.)
- A meteorite found in Antarctica and known to
have come from Mars (from isotopic "fingerprinting" of its elements) has several
detailed internal characteristics (structural, chemical, and elemental) that may, it is
claimed, be attributed to effects of ancient microscopic life indigenous to Mars. (McKay
et al.,1996). This interpretation is controversial and research on this and other
meteorites is continuing.
These subjects are currently
being investigated widely and were featured among the many areas discussed at an
international meeting in July 1996 held in Capri, Italy, on the subject of Astronomical
and Biochemical Origins and the Search for Life in the Universe (Cosmovici et al.,1997).
About 200 astronomers, biologists, chemists, physicists, and other scientists from 27
countries met for this Fifth International Conference on Bioastronomy and Colloquium No.
161 of the International Astronomical Union. This meeting was supported by international
and national scientific organizations including the International Astronomical Union, the
International Scientific Radio Union, the National Aeronautical and Space Administration,
the European Space Agency, the Consiglio Nazionale delle Richerche, and other Italian
organizations; clearly, this was a mainstream scientific meeting. The SETI community was
very visibly represented in all aspects of the conference, but the problem posed by UFO
reports was never mentioned.
However, the UFO and SETI
communities share defining attributes including a surfeit of putative evidence that
remains unidentified, and the lack of a single example that can be unequivocally verified,
repeated, understood, or captured. That is, both are subject areas of investigation that
totally lack identified objects. Then why is one moving into the mainstream of acceptable
science while the other is not?
It may not be generally
realized that the several different groups of SETI observers have received and tabulated
an appreciable number of URS, or unidentified radio signals, in the course of listening to
billions of radio channels for hundreds of thousands of hours, looking in tens of
thousands of directions. They measure signals that are noise and signals that range up to
many times stronger than can be explained in terms of natural noise. They identify nearly
all of the strong signals as coming from radio and TV stations, from military radars and
various kinds of communications systems, from satellites and deep space probes launched by
various national and international organizations, and from many kinds of equipment that
leak electromagnetic energy over broad spectral bands. After very thoughtful and vigorous
winnowing, there has been a residual number of strong signals received by every group that
are, and will no doubt remain, unidentified. But these are not described and released to
the media as something unusual or mysterious. This is because they could not be verified
by other observers or by repeat observations at the same frequency and in the same
direction in the sky. Improved techniques and protocols are being developed to markedly
reduce the frequency of URS (even to the point where there may be concern that a real ETI
signal could be discarded). Nevertheless, it is to be expected that continuing URS will
persist in the SETI endeavor, and will remain unidentified and undiscussed.
The SETI participants
include a large fraction of scientifically trained radio astronomers, and they employ
complex and expensive equipment that includes the largest antennas and most sensitive
electronic and digital systems in the world. The UFO community is much broader and
diverse, and cannot bring to bear the instrumental firepower that is routine in SETI
research. In fact, no equipment is involved in most UFO case studies. The nature of UFO
phenomena is such that it would be unreasonable to demand repeat observations of the same
kind of incident and independent confirmation of events by different observers.
However, the status of UFO
studies may be improved if we can find a way to move in a direction where independent
confirmation and repeatability could be realized and become routine. Where some level of
repeatability exists but explanations are incomplete (e.g., in the Hessdalen
project), more investigative resources are clearly required. Open channels of
communication between UFO investigators and a broader scientific group may lead to natural
explanations of many observations and thereby winnow the numerous reports to a few notable
examples to which intense cooperative efforts could be applied.
Appendix 7: Further
Thoughts on SETI and UFO Investigations
The SETI and UFO problems
may or may not be related to each other. As there does not so far exist any proof
concerning this question, it seems wise to keep those two problems apart and not to
confuse them. The questions raised by the UFO and SETI problems are not at all comparable,
and the strategies for their research are drastically different. The SETI problem
corresponds to a one-bit theoretical question: does there exist, elsewhere in the
universe, any form of intelligence that has reached the technological level of
transmitting intelligent electromagnetic signals that humans could detect and identify?
Although this question is undoubtedly exciting and justified by existing probabilistic
computations about the existence of planets, the appearance of life, the duration of a
civilization, etc., the final answer is theoretically Yes or No. However, only a Yes
answer will be final, since a No answer may be revised in view of technical improvements
of detection techniques.
The UFO problem arises from
the verified existence of a very large and coherent set of testimonies worldwide. Its
approach is bound to be in three steps:
Step 1. Try by all means to identify the
stimulus that has led to the report: the report may be due to inadequate information,
misinterpretation of a familiar phenomenon or device, an unusual astronomical or
atmospheric phenomenon, an unusual technological device, or a hoax (perpetrated by the
reporter or on the reporter).
Step 2. If Step 1 has not yielded an
explanation of the report, try to characterize the event that led to the report and
compare it with other case descriptions.
Step 3. For any case that is strong in
testimony and rich in detail, one should try to define a model. In this activity, we are
clearly not dealing with a simple question with a Yes /No (one-bit) answer. Different
cases require analyses with different levels of complexity.
The SETI and UFO problems
also involve different approaches. Scientists may pursue the SETI project and remain in a
very familiar environment: the relevant technological area is clearly identified and one
may follow a predefined strategy by specifying the frequency search band, the required
receiver sensitivity, the intrinsic properties of an intelligent signal, etc. On the other
hand, research on the UFO problem is necessarily complex, multidisciplinary, unpredictable
and must be expected to evolve as research progresses. The basic detection is usually
carried out by unprepared human beings, and analysis may call upon a wide range of
disciplines including human perception, psychology, astronomy, image processing, physics,
chemistry, etc. Moreover, effective research in this field must be conducted with an open
Although in public opinion
the UFO and SETI projects are closely associated, they should be kept clearly separated as
far as serious research is concerned. The questions being addressed are quite different in
nature: the SETI project aims at a simple Yes/No answer to the question of the existence
of extraterrestrial intelligence, whereas research into the UFO project must be pursued
with a completely open mind as to the questions that need to be posed and answered.
Moreover, the respective technical strategies have nothing in common: SETI research is
carried out primarily within the established framework of radio astronomy, whereas UFO
research is necessarily multidisciplinary and innovative.
Appendix 8: Scientific
P. A. STURROCK
In attempting to resolve a
complex problem such as that posed by UFO reports, one is very much in the "gray
area" of scientific research that is not well defined: the facts are to some extent
shaky; some of the hypotheses are speculative; and it is not clear how to evaluate the
hypotheses on the basis of the facts and of other relevant information. Furthermore, one
has the difficulty of relating the analysis of individual reports ("Is this report
due to a hoax?") to the global questions represented by the hypotheses ("Are
some reports due to hoaxes?"). In such a situation, it is essential to have some way
to organize one's analysis of whatever research is being conducted. Scientific inference
is the intellectual basis of science, and the procedures of scientific inference offer a
framework for organizing such analyses. (See, for instance, Good, 1950; Jeffreys, 1973.)
The formalism of scientific
inference involves expressing all judgments in terms of probabilities. Where there are
definite rules for deriving probabilities from the evidence, these rules can be used;
otherwise, the probabilities may be regarded as subjective. If each judgment is made by
several investigators, this can provide both a mean or consensus estimate and a measure of
the degree of uncertainty of that estimate. For a recent exposition of this formalism, see
for instance Sturrock (1994d)
In investigating any
specific case, it is necessary to work with a complete and mutually exclusive set of
hypotheses. The following set of 8 hypotheses was used in Sturrock's survey of the members
of the American Astronomical Society (Sturrock, 1994a; 1994b; 1994c):
An investigator may begin by
assigning "prior probabilities" to these hypotheses, although this is not
essential. If so, each value must be greater than zero and less than unity, and they must
sum to unity. Once these prior probabilities have been assigned, the investigator should
then forget about his prejudices.
b. Some well established phenomenon or device,
c. Some well established but unfamiliar natural phenomenon,
d. Some unfamiliar terrestrial technological device,
e. Some hitherto unknown natural phenomenon,
f. A technological device not of terrestrial origin,
g. Some other cause which [the investigator] can specify, and
h. Some other cause which [the investigator] cannot specify.
Bayes' theorem then provides a mechanism for
updating one's assessment of probabilities on the basis of new evidence. The new evidence
may be a single case or an analysis of a catalog of cases. When measurements are made in
terms of "log-odds" defined by log[(p/(1 - p)] rather than the
probability pitself, it turns out that investigators with very different prejudices
should assign the same weight of evidence, measured by the change in log-odds, to the same
experimental or observational data. Hence, although they may differ in their prejudices,
they should be able to agree in their assessments of the evidence.
It is even more convenient
to work in terms of the quantity 10*log[p/(1-p)], since one may then use the
familiar engineering term "db" or "decibel" to represent an
assessment. For instance, if one begins with the assessment that the probability of an
event being due to an extraterrestrial vehicle is 10-6, one could rephrase that
as saying "my assessment is -60 db." If a certain research program made that
proposition even more unlikely by, say, 10 db, one would then lower that assessment to -70
db. If, on the other hand, the evidence seemed to support that hypothesis with weight 10
db, the resulting assessment would be -50 db. If six separate and completely independent
studies were each to yield evidence of 10 db, the investigator would end up with an
assessment of 0 db, which represents even odds of the proposition being true. That is, the
evidence would have been just sufficient to change the mind of the investigator from being
highly skeptical about the hypothesis to considering it just as likely to be true as not
It is highly unlikely that any research project that
is in operation for only one or two years will solve the UFO problem. However, it could
and should provide useful relevant evidence, and that evidence should lead to a measurable
change in the assessments of an interested scientist. In an area such as that of UFO
research, that is all that can be expected. On the other hand, several research projects,
each lasting a reasonable length of time, should provide sufficient evidence that an
hypothesis may be effectively definitely established or definitely rejected.
If these suggestions are
considered to have merit, they could be developed into a more specific and more useful
form by means of a workshop that brings together UFO investigators, professional
investigators (of accidents, failures, etc.), physical scientists, and statisticians.
Source: F.Louange and J-J.Velasco