Original source: China UFO Exploration Network http://bbs.ufots.com
Reports of aliens frequently appear in the media. Many people claim to have seen flying saucers, or even aliens themselves, and they have also taken various photos related to UFOs. Are these claims true or false? Do aliens really exist?
According to those who claim to have seen aliens, most of the aliens they describe are small in stature, with large round heads, narrow mouths like cracks, and wearing tight-fitting clothing, resembling humanoid creatures. However, others claim that the aliens they encountered were tall giants, robot-like monsters, hairy beasts, or even beautiful naked women. Some believe that these aliens come from more than one planet. Others argue that it is impossible for so many different kinds of aliens to visit Earth simultaneously, and this chaotic description proves that the claims about aliens are unreliable. Still, others think that while a considerable portion of these accounts may not be credible, some can indeed be confirmed as true.
Others are enthusiastic about finding traces left by aliens in ancient times. They believe that the circular masks on the characters in the Sahara Desert murals, the giant stone structures on Easter Island and in South America, as well as pyramids and other unexplainable prehistoric wonders are all related to aliens. Some scholars even propose that humans are the descendants of aliens, or that certain ethnic groups (such as the Maya) are the offspring of aliens and Earthlings. However, these can only be considered guesses and hypotheses, and most still lack sufficient evidence.
The renowned astronomer Carl Sagan from Cornell University once pointed out that there are approximately 20 billion stars in the entire Milky Way galaxy, and a significant number of these stars have planets. Among these planets, those with environments similar to Earth's could potentially number up to one million. Since life has been able to arise and evolve on Earth, it is possible that the same could happen on these planets, leading to the development of intelligent beings. And undoubtedly, some of them would be more advanced than human civilization today. Therefore, these astronomers believe that the existence of intelligent life on planets beyond Earth is entirely possible.
However, Sagan dismissed the frequent reports of alien encounters around the world. He believed that these accounts often attribute human technology to so-called aliens, and the described alien appearances are mostly deformations of human forms. On other planets, the evolutionary processes of life differ greatly, and the evolved forms of alien intelligent life might be completely different from humans, as well as the science and technology they possess. Moreover, these potentially habitable planets are thousands or even tens of thousands of light-years away from Earth. Thus, the belief that aliens visit Earth every year, or even every day, is completely unrealistic.
Sagan's view largely represents the opinions of serious scientists. This means that the existence of alien intelligent life is theoretically entirely possible. However, most reports of alien discoveries are not credible. Yet, there are still some events considered reliable that current science cannot explain, and whether some incomprehensible prehistoric wonders are related to alien intelligent life remains a mystery.
Regarding the current state of alien existence, scientists have proposed various possible hypotheses. These hypotheses are quite bold and seem strange now, but who can blame human imagination? Perhaps one day these fantasies will become tangible realities.
**Underground Civilization Theory**
I remember reading a comic story that said the surface of the Earth is a paradise for human evolution, but deep inside the Earth exists another civilization ruled by evolved insects. Eventually, the underground insects waged war with humans for survival rights on the surface. It was reported that after the American satellite "Charlie 7" took pictures near the Arctic Circle, a hole was discovered on the film in the Arctic region. Is this an entrance to the Earth's interior? Additionally, geophysicists generally believe that the weight of the Earth is millions of times greater than six trillion tons. If the Earth's interior were solid, its weight would exceed this estimate, thus giving rise to the "Hollow Earth Theory." Some petroleum exploration teams have discovered large tunnels and enormous underground beings. We can hypothesize that Earth inhabitants are divided into surface dwellers and underground dwellers. The underground kingdom's inhabitants must possess scientific and technological knowledge superior to that of surface dwellers. Therefore, it would be logical for them—our fellow Earthlings—to travel through space in flying saucers that surface dwellers cannot yet manufacture.
**Coexistence Theory**
This theory suggests that aliens live and work among us! In some photographs taken with a new type of radiation camera, some people were found to have a pale green halo around their heads, possibly caused by rays emitted from their brains. However, when attempts were made to investigate these individuals with halos, they were found to have completely disappeared, leaving no trace of their existence. Aliens hide among us, and we do not know what they intend to do, but there is no evidence to suggest that aliens will harm us.
**Human Ancestor Theory**
There is a viewpoint that the ancestors of humans were aliens. Tens of thousands of years ago, a group of highly intelligent and technologically knowledgeable aliens came to Earth. They found the Earth's environment very suitable for living, but because they did not bring enough equipment to deal with Earth's gravity, they changed their plans and decided to create a new species—a hybrid of aliens and Earth apes. Using female apes as subjects, they managed to impregnate them, resulting in today's humans.
**Parallel World Theory**
The universe we see (the total star system) could not have formed within the scope of a four-dimensional universe. That is to say, our surrounding world wasn't formed just within the dimensions of length, width, height, and time. The universe might consist of two worlds stacked on top of each other, with minimal contact but almost transparent to each other. These two material worlds usually influence each other minimally, forming "shadow" worlds. When these two layered worlds were formed, the force that "combined" them was extremely strong, mixing various substances together to form a unified world. Later, the universe expanded, the density of matter decreased, and gravity weakened, forming two practically independent worlds. In other words, it is entirely possible for a hidden parallel world to exist alongside ours in the same space-time. Specifically, it could resemble our world or be completely different. The physical and chemical laws might be the same, but the actual conditions could differ. These two worlds have been separate since 200-150 billion years ago. Therefore, UFOs might originate from that other world. They could accidentally enter our world under special conditions, or they might already have mastered the knowledge of traveling between the two worlds and frequently move back and forth. Their technological level far surpasses ours.
**Fourth Dimension Theory**
Some people believe that UFOs come from the fourth dimension. The disappearance of those ghostly spacecraft happens instantaneously, and the electronic tracking systems of artificial satellites cannot lock onto them when turned on. This suggests that the crew of UFOs manipulate space-time techniques. A technical method can create certain local spatial curvatures, which then expand in the space they touch, allowing people from another space to enter our space. As various eyewitness reports indicate, concrete biological entities suddenly appear on the ground near a UFO without obviously coming through a door. The above explanation offers a plausible account for such occurrences.