Two thousand years ago, ancient Greek philosophers put forward the viewpoint of "theory of pangenesis".
/kloc-in 0/600, an Italian thinker named Bruno was burned to death because he thought that there were countless suns in other worlds, countless earths revolved around his own sun, and all kinds of creatures lived in these worlds. Since then, mankind has begun a long and expectant exploration period of alien civilization.
Lovejoy, a famous American philosopher in the 20th century, believed that whatever can exist on the earth must also exist in some other places.
1960, the United States implemented the "Ozma Plan" led by astronomer Drake. Prior to this, Drake put forward the famous "Drake formula" to calculate the technology and civilization of the communication between the Milky Way and human beings. He estimated that there may be 104 planets with communication civilization in our galaxy, while the American philosopher Laro estimated that there may be 100 billion biospheres in our galaxy. In order to verify their conclusion, Drake designed a telegram containing 65,438+0,679 binary symbols, covering mathematics, physiology, astronomy and human profile, and sent it to the galactic globular cluster in June of 65,438+0,964+0,654,38+0, but unfortunately, no reply has been received so far. 1972, astronomers launched the "Ozma II Project" to search for aliens, and received a "wow" signal in 1977. However, this signal never appeared again. In the 1980s, 68 outstanding scientists jointly signed an open letter calling for the use of all radio telescopes to detect radio signals emitted by extraterrestrial civilizations.
However, another group of scientists, represented by Tipra in the United States, opposed this plan, arguing that the Milky Way has no civilization except the Earth, and such an exploration plan will surely end in failure. They have two reasons:
First, wisdom is not an inevitable attribute of biological evolution, natural selection is extremely complicated, and the chances of life like us appearing again are slim;
Second, the age of the Milky Way is 65.438+000 billion years. If there is an extraterrestrial civilization, their detectors should have received it long ago, but there is no such thing, so there is no extraterrestrial civilization.
So far, we haven't received the signal from the alien civilized society. Does it mean that there will be no extraterrestrial civilization? In recent years, Chinese scholars put forward the theory of cosmic holography, which makes people look at this problem from a brand-new angle. They found that holography is a common phenomenon in the universe, that is, when the whole exists, a part of the whole can contain all the information. According to the law of cosmic holography, the existence of aliens and their civilizations is reasonable, because the earth is a cosmic holographic element with high holographic level in the universe, which contains all the information of the solar system, the Milky Way and even the whole universe and is the epitome of the whole universe. From the perspective of holography, there is no essential difference between extraterrestrial civilization and earth civilization, but only a formal difference, so it is entirely possible for them to communicate with each other in the universe.
However, so far, human beings have not really received an official visit from "aliens", nor have they found convincing and conclusive evidence of the existence of alien civilization.
Nowadays, a few astronomers are not afraid of sarcasm and failure, and have been tirelessly exploring alien civilizations for many years.
Paul Holovitz is one of them. In the studio under the Lehman Physics Laboratory of Harvard University, between the tables filled with strange electronic components, stands a tall circuit board bracket, which is a radio receiver that can monitor 240 million different frequencies at the same time, just like there are 240 million radios on the table.
Holovitz became the youngest amateur radio enthusiast in the world at the age of seven. He said that his greatest happiness is that "you can make some toys with vacuum tubes, transformers and other devices, so that you can talk to others." Now, Holovitz is carrying out a beta (65.438+0 billion channel alien experiment) program. He will make cutting-edge electronic products and listen to the voice of civilization from outside the solar system.
Holovitz got some private funds for his BETA project, including the Planetary Society of carl sagan and Steven Allan Spielberg, a great director who is keen on alien civilization. He once made Alien. Money is no longer a problem, the problem is where the radio telescope should point and what frequency to listen to.
Some people use two methods: one is to aim a huge antenna at a star at the same time; The other is to scan the sky with a low-power parabolic antenna, hoping to hit good luck. Holovitz believes that if there is a signal, it must be very strong and occupy a very narrow frequency band, so that it can be separated from noise. He speculates that this signal will be a signal indicating the target and may contain instructions on how to tune it to obtain actual information.
People suspect that someone has received a signal from an alien civilization, but they want to keep it a secret. In fact, the possibility of this happening is very small, because once discovered, this is the greatest discovery in human history. Who will try to keep this secret? And after the discovery, you have to be confirmed by other astronomers to know the result of your discovery.
So far, the exploration of alien civilization has not achieved any results.
Wow, the sudden arrival of the signal
The last famous call took place at Ohio State University, where the work of detecting extraterrestrial intelligent life has been going on. 1977, they received a signal and an astronomer wrote "Wow!" After typing the data. 1 min later, the signal was interrupted and no new signal was heard. "Wow!" The signal in the event has all the characteristics of intelligent signal, but scientists are not sure whether it comes from our own wisdom or from other planets.
Although astronomers engaged in the exploration of alien civilization know very well that this may be just a kind of waiting they have been waiting for all their lives, they are still willing to wait. Why? Frank Derek said: "What pushes these people forward is that once they succeed, it is a great success." The 65-year-old Drake is the director of a non-profit organization that explores extraterrestrial intelligent life. In his view, the signal from extraterrestrial intelligent life will be "the greatest discovery, which will change our life and future." This is a fascinating goal. "
Extraterrestrial civilization is related to UFOs.
Many people think that the study of exploring extraterrestrial civilization is related to UFOs. Polls show that 60% of Americans believe that UFOs come from other planets and that aliens have landed on the earth. Whenever Frank Derek appears in public, he is always surrounded by fanatical UFO fans. When he tried to deny their views, these UFO fans accused him of "covering up the facts from the government", and some people claimed on the Internet that Drake's job was to collect and dissect alien corpses.
Astronomer Jill Tate is also a staunch participant in the program to explore alien civilizations. She promoted the "Phoenix Project" of the Institute for Exploration of Extraterrestrial Intelligence, which aims to monitor 65,438+0,000 nearby stars within a few years. In Tate's view, knowing that there is an advanced alien civilization society will make human science and technology rejuvenate. However, Tate doubts whether she can live long enough to succeed in an intelligent life beyond exploration. She is 565,438+0 years old. She said, "This may be my granddaughter's successful project." Tate believes that the exploration of foreign civilizations indicates human civilization, and they are willing to do this work, not because they want to "build a monument", but out of curiosity.
1995 65438+ 10 In October, Tate came to Parks Observatory in Australia for the first exploration of the Phoenix Project. This exploration has experienced many difficulties, such as swarms of flies on the pasture, day and night observation and troubleshooting. By July, she had observed about 200 stars. Although there were many false signals, Tate was still very excited, but she still didn't catch the alien signal.
Not only that, but the plan to explore alien civilization also faces financial constraints. Although the public and other scientists think it is worth doing, they are pragmatic on the issue of funds. Some exploration projects are in danger of bankruptcy, and Stu Bao Ye maintains the Serenelip project with the money given by his mother. I once found "Wow!" The telescope of Ohio State University is also in danger of being dismantled, because they have no money to paint the telescope, and no one is willing to pay for it. The landlord of the land where the telescope is located wants to drive them away.
Drake said: "Exploring extraterrestrial intelligent life is a bumpy road." But once on this road, I don't want to leave. "Holovitz agreed with this view. He said: "You are building a huge bridge that spans 4 billion years of evolution. How fascinating it is that the isolation of our earth culture is coming to an end. "
Human exploration
1960, the United States made an "Ozma" plan, that is, using radio observatories to monitor the radio waves of two constellations in the universe, but no results were achieved.
1972, astronomers launched the "Ozma II Project" to search for aliens, and received a "wow" signal in 1977. However, this signal never appeared again. In the same year, the United States launched "Pioneer/KOOC-0/0" and "Pioneer/KOOC-0//KOOC-0/"detectors. These two detectors each carry a "business card" of the earth person.
1974165438+10 In October, the United States used the Arecibo telescope in Puerto Rico to send a telegram to aliens. The telegram was coded in binary, which conveyed the information of human beings on earth, but there was still no "bosom friend".
1 On August 20th and September 5th, 1977, the United States launched the dual-detector Voyager 2 and1. They are carrying a gold-plated copper record.
1985 "Tami" project was implemented, and 840 radio channels were used to scan cosmic celestial bodies, which was equivalent to 1 minute to complete 1 10,000 "Ozma" projects.
1992, the United States implemented the "Phoenix" program to search for intelligent life in outer space, using the largest astronomical telescope and radio telescope at that time to search for radio signals of different wavelengths emitted by various celestial bodies in the universe.
In 2004, Russia installed six aluminum "information disks" on the launched Glonass-M 12L satellite, which contained text and pattern information sent to extraterrestrial civilization.