to initiate a centralized, United Nations authority on UFOs. UFO origin hypotheses At the MUFON annual symposium in 1973, held in Akron, Ohio, Hynek first expressed his doubts regarding the extraterrestrial (formerly interplanetary or intergalactic) hypothesis, in a speech titled "The Embarrassment of the Riches". He was aware that the number of UFO sightings was much higher than was reflected in the Project Blue Book statistics. "A few good sightings a year, over the world, would bolster the extraterrestrial hypothesis—but many thousands every year? From remote regions of space? And to what purpose? To scare us by stopping cars, and disturbing animals, and puzzling us with their seemingly pointless antics?" In a paper presented to the Joint Symposium of the American Institute of Aeronautics & Astronautics in Los Angeles in 1975, he wrote, "If you object, I ask you to explain—quantitatively, not qualitatively—the reported phenomena of materialization and dematerialization, of shape changes, of the noiseless hovering in the Earth's gravitational field, accelerations that—for an appreciable mass—require energy sources far beyond present capabilities—even theoretical capabilities, the well-known and often reported E-M (electro-magnetic interference) effect, the psychic effects on percipients, including purported telepathic communications." In 1977, at the First International UFO Congress in Chicago, Hynek presented his thoughts in his speech "What I Really Believe About UFOs". "I do believe", he said, "that the UFO phenomenon as a whole is real, but I do not mean necessarily that it's just one thing. We must ask whether the diversity of observed UFOs ... all spring from the same basic source, as do weather phenomena, which all originate in the atmosphere", or whether they differ "as a rain shower differs from a meteor, which in turn differs from a cosmic-ray shower." We must not ask, Hynek said, simply which hypothesis can explain the most facts, but rather which hypothesis can explain the most puzzling facts. Regarding hypotheses of extraterrestrial intelligence (ETI) and extradimensional intelligence (EDI), Hynek continued, "There is sufficient evidence to defend both". As evidence for the ETI hypothesis, he mentioned the cases involving radar as good evidence of something solid, as well as the cases of physical evidence. Then he turned to defending the EDI hypothesis: in addition to the observations of materialization and dematerialization, he cited the "poltergeist" phenomenon experienced by some people after a close encounter; the photographs of UFOs, sometimes in only one frame, and not seen by witnesses;