The heavenly eye may have searched for alien civilizations, but it will take some time to identify them

"The signals received by fast (China large radio telescope) are also likely to have alien civilization signals, but we don't have time to identify them yet." Peng Bo, director of the fast Key Laboratory of the Chinese Academy of Sciences and researcher of the National Astronomical Observatory, said.

"I really hope to establish contact with aliens one day. I hope this day will come as soon as possible." During the live broadcast of the Chinese Academy of Sciences' New Year speech in 2022, Academician Wu Xiangping said that he believed in the existence of aliens because Australian scientists received a signal on Bilin two months ago, which was ruled out of human interference.

"The signals received by fast (China large radio telescope) are also likely to have alien civilization signals, but we don't have time to identify them yet." Peng Bo, director of the fast Key Laboratory of the Chinese Academy of Sciences and researcher of the National Astronomical Observatory, also said.

To search for signals of alien civilization, radio telescope is a very important tool. It can take images of the universe billions or even billions of years ago, help humans understand the origin of the universe, detect gravitational waves and so on. In December 2020, after the complete collapse of Arecibo radio telescope in the United States, China Tianyan fast, located in Pingtang County, Qiannan, Guizhou Province, has become the largest single antenna radio telescope in the world.

Recently, as a witness for more than 20 years, Peng Bo published the heavenly eye project: real record of fast dream pursuit of large radio telescope, which records the birth process of "China's heavenly eye".

"Tianguo" has 30 football fields

For thousands of years, human beings have mainly observed the universe through the visible light band. In fact, the radiation from cosmic celestial bodies covers the whole electromagnetic spectrum. Among them, the discovery of radio waves with a history of only 90 years is an important way for human beings to "listen" to the universe. In 1932, Carl jansky of Bell Laboratories accidentally discovered radio radiation from the center of the Milky Way galaxy, marking the birth of radio astronomy.

Pember said that the advantages of radio telescopes can be clearly found by observing two photos of the M81 Galaxy Group located in the direction of Ursa Major and 12 million light-years away from the earth. In the photos taken by the optical telescope, these galaxy clusters are three isolated galaxies, while the photos taken by the radio telescope show that there is a certain relationship between the three, "that is, radio observations can 'see' the weak links between optically invisible galaxies and provide 'holograms' of cosmic celestial bodies."

In 1993, at the International Conference of radio scientists held in Kyoto, Japan, participating astronomers including China jointly proposed to see the original shape of the universe before the earth's radio wave environment was completely destroyed, so they decided to build a new generation of large radio telescope array LT (Large Telescope). Before that, the world's largest single aperture telescope was the famous Arecibo radio telescope in the United States. It was built in 1965, with a caliber of 305 meters when it was built, and then expanded to 350 meters. Its figure has appeared in films such as 007's golden eye. It is one of the "top ten projects of the 20th century" and even before the Apollo moon landing program.

In 1994, led by scientists Nan Rendong and Peng Bo, the plan to build China's radio telescope was also on the agenda. After long-term repeated outdoor investigation, scientists found that Guizhou karst depression is very suitable for the construction of spherical reflector telescope array, and finally decided to locate the site in Pingtang County, Qiannan Buyei and Miao Autonomous Prefecture. In September 2016, fast was finally put into operation, covering an area equivalent to 30 football fields. "Assuming it is a big pot that can hold wine, each person on earth can get four bottles of Guizhou Maotai".

"When I first participated in the project, I estimated that it would take 10 years or more, because the large scientific projects of large cooperation are long-term, such as the Hubble telescope and the human lunar landing program, and it is worth being the 'world leader' for a lifetime." Pember said.

509 pulsars have been found

After fast was put into use, dazzling scientific achievements were quickly made. By December 20, 2021, 509 pulsars had been found, more than four times the total number of pulsars found by all other telescopes in the world.

Pulsar is a high-speed rotating neutron star, which is formed after the explosion of huge stars. The earth rotates 24 hours a week, while pulsars can rotate tens of thousands of times per second. Pulsar is one of the "four discoveries" in astronomy in the 1960s, and its research is also the forefront of astronomy. Anthony Hewish, Professor of Cavendish Laboratory of Cambridge University, won the Nobel Prize in physics for the discovery of pulsar in 1974.

Pember said that the pulsar's magnetic field exceeds the earth's magnetic field by 10 trillion times, and this super strong magnetic field cannot be created in the natural laboratory. After observing pulsars through fast, scientists found that major breakthroughs such as gravitational waves and black holes that won the Nobel Prize in physics are directly or indirectly related to pulsars. In the future, gravitational waves are likely to benefit mankind like current electromagnetic waves.

Fast can not only search for interstellar communication, but also find extraterrestrial civilization. So far, more than 4500 extrasolar planets have been discovered, and extraterrestrial water has been found on Europa, Mars and Saturn. In addition, the limit environment of life on earth is constantly rewritten. Located 3800 meters deep in the Cortes sea in Southern California, there are hundreds of hydrothermal vents with the surrounding temperature reaching 287 degrees Celsius, but scientists still found microorganisms in it, and one of the blue microorganisms was discovered by humans for the first time. In 2012, an international team of scientists used the earth deep exploration ship "Earth" to further dig 2466 meters down the seabed with a water depth of 1180 meters in Aomori County, Japan. When conducting stratigraphic analysis, it was found that each cubic centimeter of sediment contained less than 100 tiny microbial cells.

Pember said that these new discoveries on earth and outside the solar system constantly support the possibility of life outside the earth. "The signals received by fast are also likely to have signals of alien civilization, but we don't have time to identify them now. The United States has been doing it since the 1960s".

What if you do find it?

Although radio telescopes only passively receive signals and do not transmit radio signals, exploring extraterrestrial civilization has always been one of their missions. The scientific community also has differences on whether to explore extraterrestrial civilization. The core of the differences is whether to actively launch radio into outer space.

In the book exploration of extraterrestrial civilization: from science to fantasy, written by scholars mu Yunqiu and Jiang Xiaoyuan, it is mentioned that on November 16, 1974, after the first interstellar radio information was sent to M13 globular cluster through Arecibo radio telescope, Martin Ryle, the Nobel laureate and radio astronomer of that year, issued a statement of opposition, He warned that "any creature in outer space may be malicious and hungry", and called for an international ban on any attempt to establish contact with and transmit signals to extraterrestrial life on earth.

Ryle's view has been supported for decades, especially in science fiction films and novels. The alien creatures in the movie alien have brought countless nightmares to mankind after they came to the earth; In the novel trisomy, ye Wenjie continuously sends signals to space regardless of alien warnings, and finally attracts trisomy people. The earth is also hit by the dimensionality reduction of trisomy civilization, which is more powerful. "Exploration of extraterrestrial civilization" also puts forward that in the search for extraterrestrial civilization, the more important question for mankind should be: what if we really find it?

"In fact, the signal sent by Arecibo radio telescope to M13 globular cluster is transmitted more than 25000 light-years away, so discussing whether it will attract aliens is a little 'groundless', which is also the reason why human beings are looking for extraterrestrial civilization in the adjacent universe." Moreover, the probability of events such as asteroids hitting the earth in the adjacent universe is still quite high, so astronomy is more needed to play a role, Pember said.

On October 31, 2021, Wu Xiangping also revealed that China will build another five telescopes at the same level to form a huge array with the current fast. At that time, China's astronomical exploration will lead the world for 50 years.