USA military investigation and debunkery
On July 9, Army Air Forces Intelligence began a secret study of the best saucer reports, including Arnold’s. A follow-up study by the Air Materiel Command intelligence and engineering departments at Wright Field Ohio led to the formation the U.S. Air Force’s Project Sign at the end of 1947, the first official U.S. military UFO study.
In 1948, Project Sign wrote their Estimate of the Situation, which concluded that the remaining unidentified sightings were best explained by the ETH. The report ultimately was rejected by the USAF Chief of Staff, General Hoyt Vandenberg, citing a lack of physical evidence, and its existence was not publicly disclosed until 1956 by later Project Blue Book director Edward J. Ruppelt. Ruppelt also indicated that Vandenberg dismantled Project Sign after they wrote their ETH conclusion. With this official policy in place, all subsequent public Air Force reports concluded that there was either insufficient evidence to link UFOs and ETH, or that UFOs did not warrant investigation.
Immediately following the great UFO wave of 1952 and military debunking of the radar and visual sightings plus jet interceptions over Washington, D.C. in August, the CIA’s Office of Scientific Investigation took particular interest in UFOs. Though the ETH was mentioned, it was generally given little credence. However, others within the CIA, such as the Psychological Strategy Board, were more concerned about how an unfriendly power such as the Soviet Union might use UFOs for psychological warfare purposes, exploit the gullibility of the public for the sensational, and clog intelligence channels. Under a directive from the National Security Council to review the problem, in January 1953, the CIA organized the Robertson Panel, a group of scientists who quickly reviewed the Blue Book’s best evidence, including motion pictures and an engineering report that concluded that the performance characteristics were beyond that of earthly craft. After two days’ review, all cases were claimed to have conventional explanations. An official policy of public debunkery was recommended using the mass media and authority figures in order to influence public opinion and reduce the number of UFO reports.
Evolution of public opinion
The early 1950s also saw a number of movies depicting flying saucers and aliens, including The Day the Earth Stood Still (1951), The War of the Worlds, Earth vs. the Flying Saucers (1956), and Forbidden Planet (1956). Despite this, public belief in ETH seems to have remained low during the early 1950s, even among those reporting UFOs. A poll published in Popular Science magazine, in August 1951, showed that 52% of UFO witnesses questioned believed that they had seen a man-made aircraft, while only 4% believed that they had seen an alien craft. However, an additional 28% were uncertain, with more than half of these stating they believed they were either man-made aircraft or “visitors from afar”. Thus the total number of UFO witnesses who considered the ETH viable was approximately 20%. Within a few years, belief in ETH had increased due to the activities of people such as retired U.S. Marine Corps officer Maj. Donald E. Keyhoe, who campaigned to raise public awareness of the UFO phenomenon. By 1957, 25% of Americans responded that they either believed, or were willing to believe, in ETH, while 53% responded that they were not (though a majority of these respondents indicated they thought UFOs to be real but of earthly origin). 22% said that they were uncertain.
During this time, the ETH proponents fragmented into distinct camps, each believing slightly different variations of the hypothesis. The “contactees” of the early 1950s said that the “space brothers” they met were peaceful and benevolent, but by the mid-1960s, a number of alleged alien abductions; including that of Betty and Barney Hill, and of the apparent mutilation of cattle cast the ETH in more sinister terms.
Opinion polls indicate that public belief in the ETH has continued to rise since then. For example, a 1997 Gallup poll of the U.S. public indicated that 87% knew about UFOs, 48% believed them to be real (vs. 33% who thought them to be imaginary), and 45% believed UFOs had visited Earth. Similarly a Roper poll from 2002 found 56% thought UFOs to be real and 48% thought UFOs had visited Earth.
Polls also indicate that the public believe even more strongly that the government is suppressing evidence about UFOs. For example, in both the cited Gallup and Roper polls, the figure was about 80%.
Fewer sightings despite camera phone technology
Support for the extraterrestrial hypothesis in the last decade has seen a decline as the proliferation of smartphone camera technology across the population has not led to a significant increase in recorded UFO sightings. This goes counter to the predictions of supporters of the extraterrestrial hypothesis, even causing a crisis of confidence among some within the informal UFO research community.
Opinions among scientists
The scientific community has shown very little support for the ETH, and has largely accepted the explanation that reports of UFOs are the result of people misinterpreting common objects or phenomena, or are the work of hoaxers. Professor Stephen Hawking has expressed skepticism about the ETH. In a 1969 lecture, U.S. astrophysicist Carl Sagan said:
“The idea of benign or hostile space aliens from other planets visiting the Earth [is clearly] an emotional idea. There are two sorts of self-deception here: either accepting the idea of extraterrestrial visitation by space aliens in the face of very meager evidence because we want it to be true; or rejecting such an idea out of hand, in the absence of sufficient evidence, because we don’t want it to be true. Each of these extremes is a serious impediment to the study of UFOs.”
Similarly, British astrophysicist Peter A. Sturrock wrote
“for many years, discussions of the UFO issue have remained narrowly polarized between advocates and adversaries of a single theory, namely the extraterrestrial hypothesis … this fixation on the ETH has narrowed and impoverished the debate, precluding an examination of other possible theories for the phenomenon.”
An informal poll done by Sturrock in 1973 of American Institute of Aeronautics and Astronautics members found that about 10% of them believed that UFOs were vehicles from outer space. In another informal poll conducted in 1977 by astrophysicist Peter A. Sturrock, he surveyed members of the American Astronomical Society. Sturrock asked polled scientists to assign probabilities to eight possible explanations for UFOs. The results were:
23% – An unfamiliar natural phenomenon
22% – A familiar phenomenon or device
21% – An unfamiliar terrestrial device
12% – Hoax
9% – An unknown natural phenomenon
7% – Some specifiable other cause
3% – An alien device
3% – Some unspecified other cause
The primary scientific arguments against ETH were summarized by astronomer and UFO researcher J. Allen Hynek during a presentation at the 1983 MUFON Symposium, where he outlined seven key reasons why he could not accept the ETH.
1. Failure of sophisticated surveillance systems to detect incoming or outgoing UFOs
2. Gravitational and atmospheric considerations
3. Statistical considerations
4. Elusive, evasive and absurd behavior of UFOs and their occupants
5. Isolation of the UFO phenomenon in time and space: the Cheshire Cat effect
6. The space unworthiness of UFOs
7. The problem of astronomical distances
Hynek argued that:
1. Despite worldwide radar systems and Earth-orbiting satellites, UFOs are alleged to flit in and out of the atmosphere, leaving little to no evidence.
2. Space aliens are alleged to be overwhelmingly humanoid, and are allegedly able to exist on Earth without much difficulty often lacking “space suits”, even though extra-solar planets would likely have different atmospheres, biospheres, gravity and other factors, and extraterrestrial life would likely be very different from Earthly life.
3. The number of reported UFOs and of purported encounters with UFO-inhabitants outstrips the number of expeditions that an alien civilization (or civilizations) could statistically be expected to mount.
4. The behavior of extraterrestrials reported during alleged abductions is often inconsistent and irrational.
5. UFOs are isolated in time and space: like the Cheshire Cat, they seem to appear and disappear at will, leaving only vague, ambiguous and mocking evidence of their presence
6. Reported UFOs are often far too small to support a crew traveling through space, and their reported flight behavior is often not representative of a craft under intelligent control (erratic flight patterns, sudden course changes).
7. The distance between planets makes interstellar travel impractical, particularly because of the amount of energy that would be required for interstellar travel using conventional means, (According to a NASA estimate, it would take 7×1019 joules of energy to send the current space shuttle on a one-way, 50 year, journey to the nearest star, an enormous amount of energy) and because of the level of technology that would be required to circumvent conventional energy/fuel/speed limitations using exotic means such as Einstein-Rosen Bridges as ways to shorten distances from point A to point B.
According to Hynek, points 1 through 6 could be argued, but point 7 represented an insurmountable barrier to the validity of the ETH.