UFOs - Unidentified Flying Objects
- A scientific introduction -
This article is an effort to create an extended and more concise version of the Wikipedia: Ufo article. This version also contains information that was deleted or scattered. Aditional sections are recovered from page history sections and other (deleted) pages of Wikipedia and are included here, because I think they contain relevant information and provide a more consistent and broader scope of vision, often entitled "unscientific" or "science-fiction" by wikipedia.
Unidentified flying object (commonly abbreviated as UFO or U.F.O.) is the popular term for any aerial phenomenon whose cause cannot be easily or immediately identified. Both military and civilian research show that a significant majority of UFO sightings have been identified after further investigation, either explicitly or indirectly through the presence of clear and simple explanatory factors (see Occam's Razor).  The United States Air Force, which coined the term in 1952, initially defined UFOs as those objects that remain unidentified after scrutiny by expert investigators, though the term UFO is often used more generally to describe any sighting unidentifiable to the reporting observer(s). Popular culture frequently takes the term UFO as a synonym for alien spacecraft. Cults have become associated with UFOs, and mythology and folklore have evolved around the phenomenon. Some investigators now prefer to use the broader term unidentified aerial phenomenon (or UAP), to avoid the confusion and speculative associations that have become attached to UFO.
Various studies show that after investigation, the majority of UFOs are usually identified, and are relabeled IFOs or Identified Flying Objects. Therefore, some stricter definitions reserve the label "UFO" for only those instances where the objects remain unexplained after a proper investigation.  The percentages of IFOs vs. UFOs varies with the researchers, study, and case sample, ranging from only 5% to 10% being UFOs, according to The J. Allen Hynek Center for UFO Studies , to 20% to 30% being UFOs according to earlier U.S. Air Force statistics or the later Condon Committee .
Studies have also established that only a small percentage of reported UFOs are actual hoaxes, while the majority are observations of some real but conventional object—most commonly aircraft, balloons, or astronomical objects such as meteors or bright planets—that have been misidentified by the observer as anomalies. A small percentage of reported sightings (usually 5%–20%) are classified as unidentified flying objects in the strictest sense (see below for some studies).
Certain scientists have argued that all UFO sightings, in the strictest sense, are misidentifications of prosaic natural phenomena  and historically, there was debate among some scientists about whether scientific investigation was warranted given available empirical data. Very little peer-reviewed literature has been published in which scientists have proposed, studied or supported non-prosaic explanations for UFOs.
UFO reports became frequent after the first widely publicized US sighting – reported by private pilot Kenneth Arnold in 1947 – that gave rise to the popular terms "flying saucer" and "flying disc". Since then, millions of people have reported that they have seen UFOs. 
UFOs have been spotted in many different places around the world. Reports of unusual aerial phenomena date back to ancient times , but modern reports and first official investigations began during World War II with sightings of so-called foo fightersby Allied airplane crews and in 1946 with widespread sightings of European "ghost rockets." UFO reports became even more common after the first widely publicized United States UFO sighting, by private pilot Kenneth Arnold in the summer of 1947. Many tens of thousands of UFO reports have since been made worldwide. 
Physicists and UFOs
Certain physicists, some working for the US Military, others said to be associated with the US Intelligence Community are seriously interested in UFOs as extraterrestrial flying machines. Dr. Jack Sarfatti, in his book "Super Cosmos" (2005), has an extremely detailed "theory" based on the recent discovery of the repulsive anti-gravity field "dark energy" that is accelerating the expansion of the 3D space of our universe. Sarfatti also cites Alcubierre's weightless warp drive without time dilation as essential conditions for "propellantless propulsion" in what Puthoff has called "metric engineering." In his book "The Physics of Star Trek," Lawrence M. Krauss argues that it would be physically impossible to concentrate enough energy in one place to "warp" the fabric of space.
According to other physicists, taking advantage of certain experimentally verified quantum phenomena, such as the Casimir effect, may make the construction of Alcubierre type warp drives theoretically possible.  However, if certain quantum inequalities conjectured by Ford and Roman (1996) hold, then the energy requirements for some warp drives may be absurdly gigantic, e.g. the energy -1067g might be required to transport a small spaceship across the Milky Way galaxy. Counterarguments to these apparent problems have been offered (Krasnikov, 2003), but not all physicists are convinced they can be overcome. (For a detailed discussion, see: Alcubierre drive.)
Besides visual sightings, cases sometimes have an indirect physical evidence, including many cases studied by the military and various government agencies of different countries. Indirect physical evidence would be data obtained from afar, such as radar contact and photographs. More direct physical evidence involves physical interactions with the environment at close range — Hynek's "close encounter" or Vallee's "Type-I" cases—which include "landing traces," electromagnetic interference, and physiological/biological effects.
- Radar contact and tracking, sometimes from multiple sites. These are often considered among the best cases since they usually involve trained military personnel and control tower operators, simultaneous visual sightings, and aircraft intercepts. One such recent example were the mass sightings of large, silent, low-flying black triangles in 1989 and 1990 over Belgium, tracked by multiple NATO radar and jet interceptors, and investigated by Belgium's military (included photographic evidence). Another famous case from 1986 was the JAL 1628 case over Alaska investigated by the FAA. 
- Photographic evidence, including still photos, movie film, and video, including some in the infrared spectrum (rare).
- Recorded visual spectrograms (extremely rare) — (see Spectrometer)
- Recorded gravimetric and magnetic disturbances (extremely rare)
- Landing physical trace evidence, including ground impressions, burned and/or desiccated soil, burned and broken foliage, magnetic anomalies, increased radiation levels, and metallic traces. See, e.g. Height 611 UFO Incident or the 1964 Lonnie Zamora's Socorro, New Mexico encounter, considered one of the most inexplicable of the USAF Project Blue Book cases). A well-known example from December 1980 was the USAF Rendlesham Forest Incident in England. Another less than 2 weeks later, in January 1981, occurred in Trans-en-Provence and was investigated by GEPAN, then France's official government UFO-investigation agency. Project Blue Book head Edward J. Ruppelt described a classic 1952 CE2 case involving a patch of charred grass roots. Catalogs of several thousand such cases have been compiled, particularly by researcher Ted Phillips.
- Physiological effects on people and animals including temporary paralysis, skin burns and rashes, corneal burns, and symptoms superficially resembling radiation poisoning, such as the Cash-Landrum incident in 1980. One such case dates back to 1886, a Venezuelan incident reported in Scientific American magazine.
- So-called animal/cattle mutilation cases, that some feel are also part of the UFO phenomenon. Such cases can and have been analyzed using forensic science techniques.
- Biological effects on plants such as increased or decreased growth, germination effects on seeds, and blown-out stem nodes (usually associated with physical trace cases or crop circles)
- Electromagnetic interference (EM) effects, including stalled cars, power black-outs, radio/TV interference, magnetic compass deflections, and aircraft navigation, communication, and engine disruption. A list of over 30 such aircraft EM incidents was compiled by NASA scientist Dr. Richard F. Haines.  A famous 1976 military case over Tehran, recorded in CIA and DIA classified documents, resulted in communication losses in multiple aircraft and weapons system failure in an F-4 Phantom II jet interceptor as it was about to fire a missile on one of the UFOs. This was also a radar/visual case. (Fawcett & Greenwood, 81-89; Good, 318-322, 497-502)
- Remote radiation detection, some noted in FBI and CIA documents occurring over government nuclear installations at Los Alamos National Laboratory and Oak Ridge National Laboratory in 1950, also reported by Project Blue Book director Ed Ruppelt in his book.
- Actual hard physical evidence cases, such as 1957, Ubatuba, Brazil, magnesium fragments analyzed by the Brazilian government and in the Condon Report and by others. The 1964 Socorro/Lonnie Zamora incident also left metal traces, analyzed by NASA.
- Misc: Recorded electromagnetic emissions, such as microwaves detected in the well-known 1957 RB-47 surveillance aircraft case, which was also a visual and radar case; polarization rings observed around a UFO by a scientist, explained by Dr. James Harder as intense magnetic fields from the UFO causing the Faraday effect. 
These various reported physical evidence cases have been studied by various scientist and engineers, both privately and in official governmental studies (such as Project Blue Book, the Condon Committee, and the French GEPAN/SEPRA). A comprehensive scientific review of physical evidence cases was carried out by the 1998 Sturrock UFO panel. 
Attempts have been made to reverse engineer the possible physics behind UFOs through analysis of both eyewitness reports and the physical evidence. Examples are former NASA and nuclear engineer James McCampbell in his book Ufology » online, NACA/NASA engineer Paul R. Hill in his book Unconventional Flying Objects, and German rocketry pioneer Hermann Oberth. Among subjects tackled by McCampbell, Hill, and Oberth was the question of how UFOs can fly at supersonic speeds without creating a sonic boom. McCampbell's proposed solution of a microwave plasma parting the air in front of the craft is currently being researched by Dr. Leik Myrabo, Professor of Engineering Physics at the Rensselaer Polytechnic Institute as a possible advance in hypersonic flight. » 1995 Aviation Week article
The study of UFO claims over the years has led to valuable discoveries about atmospheric phenomena and psychology. In psychology, the study of UFO sightings has revealed information on misinterpretation, perceptual illusions, hallucination and fantasy-prone personality. Many have questioned the reliability of hypnosis in UFO abduction cases.
Psychologists point out that almost all UFO-related claims are based solely on eyewitness and anecdotal evidence, which is extremely unreliable. It has further been shown that memory of an event can be unconsciously altered to suit a desired interpretation of what was remembered. For example, a person who has a supposed UFO sighting may simply be reinterpreting an older memory to fit a desired explanation. Many skeptics believe this to be the case with the Roswell incident and many other UFO claims.
Some researchers recommend that observations be classified according to the features of the phenomenon or object that are reported or recorded. Typical categories include:
- Saucer, toy-top, or disk-shaped “craft” without visible or audible propulsion. (day and night)
- Rapidly-moving lights or lights with apparent ability to rapidly change direction and then suddenly stop, impossible for conventional aircraft.
- Large triangular “craft” or triangular light pattern
- Cigar-shaped “craft” with lighted windows (Meteor fireballs are sometimes reported this way).
- Other: chevrons, equilateral triangles, spheres, domes, diamonds, shapeless black masses, eggs, and cylinders.
J. Allen Hynek developed another commonly used system of description, dividing sightings into six categories. It first separates sightings into distant- and close-encounter categories, arbitrarily setting 500 feet as the cutoff point. It then subdivides these close and distant categories based on appearance or special features. The three distant-encounter categories are:
- Nocturnal Lights (NL): Anomalous lights seen in the night sky.
- Daylight Discs (DD): Any anomalous object, generally but not necessarily “discoidal”, seen in the distant daytime sky.
- Radar/Visual cases (RV). Objects seen simultaneously by eye and on radar.
Subgroups of the distant category of sightings correlate with evidentiary value. RV cases are usually considered to have the highest value because of radar corroboration, whereas NL cases have the lowest because it is so easy to mistake lights seen at night for prosaic phenomena such as meteors, bright stars, or aircraft. RV reports are also fewest in number, while NL are most common.
Hynek also defined three “close encounter” (CE) subcategories:
From the » UFO Casebook :
- CE4+: aliens communicate with the observer, even abduct, experiment on the observers, others. » UFO Casebook lists additional categories, in which the UFO and/or alien is captured/destroyed by military forces and/or civilians.
Like the RV cases, CE cases are considered higher in evidentiary value because they include measurable physical effects, and because objects seen up close are less likely to be the result of misperception. Like the RV cases, these tend to be relatively rare.
Hynek’s CE classification system has since been expanded to include such things as alleged alien abductions and cattle mutilation phenomena.
Jacques Vallée has devised a UFO classification system which is preferred by many UFO investigators over Hynek’s system as it is considerably more descriptive than Hynek’s, especially in terms of the reported behavior of UFOs.
Type - I (a, b,c, d)- Observation of an unusual object, spherical discoidal, or of another geometry, on or situated close to the ground (tree height, or lower), which may be associated with traces - thermal, luminous, or mechanical effects.
- a - On or near ground.
- b - Near or over body of water.
- c - Occupants appear to display interest in witnesses by gestures or luminous signals.
- d - Object appears to be “scouting” a terrestrial vehicle.
Type - II (a, b,c) - Observation of an unusual object with vertical cylindrical formation in the sky, associated with a diffuse cloud. This phenomenon has been given various names such as “cloud-cigar” or “cloud-sphere.”
- a - Moving erratically through the sky
- b - Object is stationary and gives rise to secondary objects (sometimes referred to as “satellite objects”)
- c - Object is surrounded by secondary objects
Type - III (a, b,c, d,e)- Observation of an unusual object of spherical, discoidal or elliptical shape, stationary in the sky.
- a - Hovering between two periods of motion with “falling-leaf” descent, up and down, or pendulum motion
- b - Interruption of continuous flight to hover and then continue motion
- c - Alters appearance while hovering - e.g., change of luminosity, generation of secondary object, etc.
- d - “Dogfights” or swarming among several objects
- e - Trajectory abruptly altered during continuous flight to fly slowly above a certain area, circle, or suddenly change course
Type IV (a, b,c, d) - Observation of an unusual object in continuous flight.
- a - Continuous flight
- b - Trajectory affected by nearby conventional aircraft
- c - Formation flight
- d - Wavy or zig-zag trajectory
Type V (a, b,c)- Observation of an unusual object of indistinct appearance, i.e., appearing to be not fully material or solid in structure.
- a - Extended apparent diameter, non-point source luminous objects (“fuzzy”)
- b - Starlike objects (point source), motionless for extended periods
- c - Starlike objects rapidly crossing the sky, possibly with peculiar trajectories
To be continued...
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