The vast universe always makes people have an endless desire to explore
After recognizing the vastness of the universe, one of the topics we are most concerned about is: Are human beings lonely in the universe?
In recent years, although there have often been some vague images of UFOs that make people think about it. But there is no conclusive evidence of alien existence.
However, not long ago, Wu Xiangping, an academician of the Chinese Academy of Sciences and an astrophysicist, said in the live broadcast of the 2022 New Year's Eve speech: "I believe that aliens exist. ”
Scientists with rigorous truth-seeking as the standard can firmly believe in the existence of aliens in public, which is a rare phenomenon, because the topic of aliens in the past has always belonged to air-to-air science fiction, and Academician Wu Xiangping's words this time are actually derived from the mysterious signal received by the Australian astronomical community two months ago, which is sent from the nearest star system to Earth, that is, Proxima Centauri 4.22 light-years away.
Most importantly, this electromagnetic wave signal is different from the general clutter, and it has certain characteristics of intelligent civilization, and this feature is not the result of human civilization interference.
At present, the scientific community is deciphering the strange signal received this time, and it is believed that all its information will be obtained in the near future, and the truth about the alien civilization will also come out.
But throughout the history of radio astronomy
The scientific community has actually received a lot of strange signals from outer space, since 1959, when large radio telescopes became one of the main forces of detection, the electromagnetic waves emitted by stars in the universe, the electromagnetic waves emitted by Jupiter, and later the electromagnetic waves emitted by neutron stars and black holes have been studied.
The first signal in history that was highly suspected of belonging to the information of intelligent civilization was first detected in 1977, and on August 15 of that year, Dr. Ehman received a very strong narrowband wireless signal at Ohio State University, although this signal lasted only 72 seconds, but because of its obvious intelligent characteristics, Dr. Ehman wrote a large "WOW" on paper in excitement, which was later famous as a space letter.
Unfortunately, since the WOW signal never appeared again, the astronomical community could not study it, and could only use it as a special signal.
In terms of the current level of technology
The three ways to find an alien civilization, long-range detection, launching probes, and receiving signals, of which only passive reception signals are truly feasible and promising.
Because long-range detection technology can not see the surface image of stars or planets, whether in the eyes of hubble telescope or in the eyes of The Weber telescope, any star in the universe except the sun is a bright spot without details, and no matter how the astronomical community deals with them, it can only increase their brightness, and there is no way to see their disc-like outlines, and it is even more impossible to see the surface details.
The current long-range detection technology can only analyze the mass and volume of the target star or planet, as well as their spectral data, and analyze whether the planet has an atmosphere, whether there is liquid water, and whether it is suitable for human habitation at a distance of several light years, which is the upper limit of the remote detection technology.
As for the launch of probes to find alien civilizations, it is even less hopeless, because the fastest speed of the probes that have been launched is only 17 km/s, and it will take at least 30,000 years to leave the solar system with a radius of one light-year at this speed, and it is difficult to say whether human civilization will exist in 30,000 years.
The most hopeful is the receiving signal method
Because our universe is at least 13.8 billion years old, and human civilization is only 10,000 years old, so in theory, as long as a civilization is born 100,000 or 50,000 years earlier than humans, then their scientific and technological level is unimaginable, and the intensity and characteristics of their electromagnetic waves in the universe will be clearly distinguished from the electromagnetic waves emitted by celestial bodies.
In the case that the narrowest wavelength that celestial bodies can emit in the universe is 500 hertz, as long as the radio telescope of human civilization receives a narrow-band signal of less than 500 hertz, it means that traces of the existence of extraterrestrial civilizations have been found, such as a narrow-band signal received by Australia two months ago.
Although the final results have not yet come out, we have reason to believe that this will definitely not be the last suspected intelligent civilization signal received by human civilization, and in the foreseeable future, as the performance of radio telescopes becomes stronger and stronger, the relevant signals will only increase, and alien civilizations will appear sooner or later.
Ultimately
The Sun is just an ordinary star in the universe, the usual one of the 100 billion to 400 billion stars in the Milky Way, and there is nothing special about it, and so is The Earth.
Since human civilization can be born on Earth, then other civilizations must also be born on other Earth-like planets in the universe, and even if the existence of non-carbon-based life is taken into account, the high temperature and high pressure hell like Venus is also possible to give birth to silicon-based intelligent civilization.