There were more than 300 complete witness reports before the 20th century. According to eyewitness reports, UFOs are mostly disc-shaped, spherical and cigar-shaped. Since the late 1940s, the number of UFO sightings has increased dramatically, which has caused a debate in the scientific community. Negative scientists believe that many eyewitness reports are not credible, and UFOs do not exist, but people's illusions or eyewitness misinterpretations of natural phenomena. Affirmers believe that UFOs are a real phenomenon and are being confirmed by more and more facts. By the 1980s, there were about 654.38 million+eyewitness reports all over the world. UFO sightings and sighting reports can be divided into four categories: daytime sightings; Witness the incident at night; Radar imaging; Close contacts and related physical evidence. Some sightings were also filmed. People have made various explanations for UFO, including: ① a natural phenomenon that has not been fully understood; ② Misunderstanding of known objects or phenomena; ③ Psychological phenomena and fraud; (4) The product of advanced extraterrestrial civilization. Many countries in the world study UFOs. There are about 350 monographs and nearly 100 periodicals about UFO. A group of experts from all over the world participated in this work. China has also established a folk academic research group-China UFO Research Association, which is mainly composed of scientific and technological workers. The popular science publication UFO Exploration in China was founded in 198 1.
The book "Aerospace" in Encyclopedia of China officially includes the explanation of "UFO". The author is Mr. Sun Shili, the third chairman of the UFO Research Society of China. The full text of the explanation of UFOs in Encyclopedia of China is as follows: UFOs are UFOs in the air. Internationally known as UFO, commonly known as UFO. According to eyewitness reports, most of them are disc-shaped, spherical and cigar-shaped, moving at high speed or slowly in the air.
1947, Kenneth Arnold, a businessman from Idaho, USA, saw nine conventional flying saucers while flying a private jet across the Cascade Mountains in Washington. A few days later, mysterious metal fragments were found in Roswell, New Mexico.
Some people think that the historical records about UFOs first appeared in the Bible. According to the Old Testament, the prophet Ezekiel saw the earliest UFO. (Ezekiel in the Old Testament records: "I looked (to the west) and saw a strong wind blowing from the north. There is a large cloud including flashing fire, surrounded by light. Out of its fire, like shining pure gold. We can see the images of four living creatures. " )