The best time for this group of information transmission is June 4, 2022, when the night of the earth is just in the direction of the silver heart, and the goal chosen by scientists is the concentric ring which is 0/0.3 million light years away from the silver heart. This will be the second letter sent by human beings to aliens. The first letter was sent by arecibo radio telescope at 1974.
The information sent this time is based on the first binary information, and scientists have re-coded and improved it, which is more advanced and detailed than in the past.
Astronomers hope that sending this crucial letter can be completed by the world's largest and most advanced radio telescopes, namely the 500-meter spherical radio telescope (FAST) in Guizhou and the Allen telescope array in SETI Institute in Northern California.
The late famous scientist Stephen Hawking repeatedly called for: Don't answer! In other words, don't answer the information sent by aliens, so as not to expose the coordinates of the earth and be destroyed by aliens. Now scientists have repeatedly exposed their goals. Isn't this a slap in the face? In the past, many people were angry about sending messages to aliens. How can you not spray this time?
Is the danger of mankind really coming? Let's analyze it together.
For hundreds of years, human beings have been trying to find bosom friends in the universe. Unfortunately, up to now, modern science has exhausted all means and failed to find a hair on the alien. Man-made detectors have flown all over the planets in the solar system, as well as some dwarf planets, satellites, asteroids and even comets. Not only have no alien civilizations been discovered, but even a cell and a microorganism have not been discovered.
Hubble telescope observed that the farthest galaxy is 65.438+0.3 billion light years away from us, and there are more than 4,000 extraterrestrial planets discovered in various ways, many of which are terrestrial livable planets, that is, planets that are not far from the stars like the earth, and may have liquid water, but even the hairs of life have not been found.
Of course, the current means of observation and exploration are still very simple, even the nearest star, proxima centauri Centauri, can't be seen clearly, so it is uncertain whether these observed planets have life. But at least it proves that life is very rare in the universe, and civilization is even rarer.
The most optimistic estimate is that there may be 654.38 million civilized planets in the Milky Way, while the pessimistic estimate is that there is only one civilization in a galaxy. Of course, some people think that there is only one civilization in the universe.
Even according to the most optimistic estimate, there are 65438+ million civilized planets in the Milky Way. How far are these civilizations on average? According to the current observation, the Milky Way is a oblate spiral galaxy with a diameter of about 200,000 light years, which is a bit like a discus. The center thickness is about 654.38+0.3 million light years, including 400 billion stars.
It is considered that the thickness of the galactic center is only the thickness of the galactic bulge. In fact, the Milky Way is very thin, with an average of only about 2000 light years. According to the thickness of 2000 light years, the volume of the whole galaxy is 6283 185307 1795 cubic light years, and each of the 65438+ million civilized planets occupies an average volume of 6283 18530 light years. On this basis, the average distance between civilizations is 856 light years.
A distance of 856 light years means that it will take 856 years to send a telegram to a neighbor's house, and at least 1700 years to receive a reply from others. This is the most optimistic estimate. If there is only one civilization in the Milky Way and there may be one in other galaxies, it will take at least hundreds of thousands or even millions of years to wait for this telegram.
It takes more than 1 50,000 years to reach the civilized planet with the most optimistic distance of 856 light years, according to the speed of unmanned navigator 17 km per second, which is the farthest flight of human beings. In other words, even if there is a human civilization in this area, it will take more than 23 million years from receiving the information to sending an expeditionary force to the earth.
So, is there a more advanced civilization around us than human beings? Keep watching.
Humans are so lonely that they always want to meet their intimate friends outside the earth, which gives birth to many fantasies and even hallucinations. What flying saucers are flying everywhere? Many people say that they have seen aliens or alien flying machines. But after scientific investigation, there is no clear evidence that aliens have really been to the earth.
People only watch science fiction movies, and many people believe in science fiction, even conspiracy theories contained in it.
Scientists have long abandoned all kinds of legends and turned to the most modern means to detect alien signals. The most common method is to scan space with the best optical or radio telescope, and observe and monitor any abnormal signals in space.
Some important plans for scientific search for aliens
In 1970s, astronomers made an all-day infrared survey of 250,000 celestial bodies and found 17 celestial bodies with dyson sphere characteristics, but after further observation and screening, they were all excluded. NASA's Kepler mission scanned more than 65,438+million stars and found that a star named KIC 8462852 had a strange brightness change. It was once suspected to be Dyson spherical structure, but it was later ruled out.
The wide-area array radio telescope located in murchison, Australia, is an array system composed of cobweb antennas. It has searched more than 654.38+003 million galaxies, and so far there is no trace of alien civilization.
Hawking personally launched the Breakthrough Listening Program during his lifetime, which was fully funded by Russian billionaire yuri milner. It took 10 years to search the Milky Way and its nearby 100 galaxies by radio and optical technology, looking for traces of aliens. This project will cost US$ 6,543.8+billion, and use world-famous telescopes such as Green Shore in the United States and Parks in Australia to capture and receive radio waves, lasers and other signals from stars in these galaxies. So far, nothing.
Aircraft launched by human beings have reached every planet, some dwarf planets, asteroids and comets, and also retrieved materials from the moon and some asteroids.
All exploration and search have not found any extraterrestrial life so far, let alone extraterrestrial civilization.
Of course, we cannot deny the existence of extraterrestrial life and civilization from now on. In fact, so far, these searches have continued. But at least, the probability of life is extremely small. There are very few living planets in the universe, and civilization is even scarcer.
Since we have not seen and heard the call of extraterrestrial civilization, why can't human beings take the initiative to call for extraterrestrial civilization? In fact, human beings have been calling for aliens for a long time, but they have not got any answer.
The only way of communication between stars is radio communication, because the propagation speed of electric waves is the fastest in the universe, just like the speed of light. It's only been 100 years since man invented radio. 1895, Italian Marconi and Russian popov invented radio almost at the same time, but Marconi was the first to obtain an international patent.
Subsequently, radio developed like wildfire, and in the following decades, radio telescopes were gradually developed. 1974, scientists used the arecibo radio telescope, which was the largest in the world at that time, to send a set of signals to M 13, a globular cluster of Hercules, which was 22,200 light years away, for 3 minutes.
This is the first greeting letter sent by human beings to the possible extraterrestrial civilization in space. The signal includes 65,438+0,679 binary digits, forming an array of 73 rows and 23 columns. The number of rows and columns are prime numbers to remind aliens that this is not a natural signal, but a man-made signal.
If aliens who receive this set of signals are close to humans in technology, they can decode such a set of information:
The position of the sun in the Milky Way, the position of the earth in the solar system, the human being is the intelligent agent of the earth, the relationship between human beings and the surrounding environment, the decimal calculation of 10 in human mathematics, the chemical elements that constitute human beings, the shape and basic structure of human genetic DNA, what the telescope that sends out this group of signals looks like, and so on.
Radio signals travel at the speed of light. It took 48 light years to reach the destination 48 years ago, and it will take more than 22,000 years to reach the destination. If civilized intelligence really exists there and this set of signals is successfully decoded, it will take more than 44,000 years to send a set of answers for us to receive.
In 1970s, four unmanned detectors were launched, namely Pioneer/KOOC-0/0, Pioneer/KOOC-0//KOOC-0/and Voyager/KOOC-0/,and Voyager 2. After completing the solar system investigation mission, these four probes flew out of the solar system from four directions, and the farthest traveler 1 was 23.3 billion kilometers away from us, at the speed of 1 per second. It takes more than 1 7000 years to fly out of the solar gravity circle with a radius of1light-year, and more than 70000 years to fly to the nearest star proxima centauri.
What do scientists send them outside the solar system for? The best hope is to meet aliens and arrest them so that we can know where they came from and who launched them. Because on them, there is a group of cards or CDs engraved with the solar system, the earth and its creatures, including human information, which contains rich information of human civilization such as earth coordinates.
The unmanned New Horizon probe launched in 2006, after touring the asteroids in Pluto and Kuiper Belt, also completed the solar system patrol mission and flew out of the solar system, carrying a CD engraved with rich information, 434,000 human names, a little ashes of clyde tombaugh, the discoverer of Pluto, a quarter coin and a small number of spacecraft-1 aircraft.
These practices have long caused panic among some people. They believe Hawking's warning and the story of the dark forest, and think that those who do these things are traitors to mankind and put mankind at risk. Therefore, some people call for the immediate recall of Voyager 1 and other detectors, or let them self-destruct and stop all future signals sent into space.
But more scientists just treat these as jokes. They don't believe that there really is a dark forest. As can be seen from the above introduction, there are so few civilizations in the universe that it is very likely that every civilization will be destroyed and it is difficult to meet another civilization. So if aliens know the coordinates of the earth, they will plunder and slaughter humans?
1, the chance of civilization meeting is too small, which has been said a lot before, so I won't repeat it.
Even if there is an extraterrestrial civilization in our nearest distance, that is, about 856 light years, the information we sent only took 48 years, and it will take more than 800 years to reach them. If they find the coordinates of the earth and really have the intention of occupation and slaughter, it depends on how high the level of civilization is.
If it is similar to or only a little higher than human civilization, can they have the ability to invade the earth? At present, our fastest unmanned detector is the Parker solar detector, which will reach about 200 kilometers per second when it is closest to the sun. Assuming that this civilized manned spacecraft can reach 200 kilometers per second, it will take 6.5438+0.28 million years to come to the earth.
Therefore, even if they have a wicked heart, they don't have the ability to be thieves. If they came to the earth in 1.28 million years, what would human beings look like? Is it extinct or become a god? Afraid of them?
3. What did aliens come to plunder and slaughter the earth for? For resources? What resources does the earth have? Water, atmosphere? There are many planets with these resources, which can be said to be countless in the universe. In the solar system, there are as many as seven or eight planets with more water resources than the earth, and there are many planets with atmospheres, just a few. Several gaseous planets are giant planets, much bigger than the earth.
The environment of different planets in the universe is very different, and the conditions of life and civilization are also very different, so it is impossible to need the earth as a resource. For example, scientists think that Titan may have life. If there is, it is alkyl life. It depends on methane and other compounds as food, and needs to survive in the environment of-0/79. This kind of life came to earth. All water, atmosphere and the temperature of the earth are toxic to them. They will die as soon as they meet. What are they doing here?
And advanced civilization, the demand for resources is becoming more and more single. For example, the future of mankind is likely to require only pure energy, that is, stellar energy. With energy and elements, anything needed can be made. The human body itself may eventually disappear and exist in the form of consciousness.
So what are these advanced civilizations doing on earth?
4. If there is advanced civilization around us, do we still need to expose ourselves? People have long known that there is such a low-level civilization. If they come, how should we hide and deal with them? Isn't this alarmist?
Hawking's "don't answer" and the dark forest conjecture are both an ideology of human beings in this low-level civilization at this stage. With the progress of civilization, the spiritual consciousness of any civilization can't stay in the current state of human consciousness, so I think Hawking's Don't Answer and Dark Forest are meaningless.
Although Hawking is a respected scientist, I can't agree with him in this respect. In fact, the vast majority of people who are crazy about exposing targets believe that UFOs really haunt the earth and that aliens have long been hiding on the earth, the moon and the 5 1 area in the United States. Since there are aliens everywhere, aliens have already been to the earth, why are they afraid of exposing their targets? Isn't this a self-deceiving joke? Why should a cold joke be filled with indignation?
Therefore, I am very much in favor of using the "500-meter spherical radio telescope (FAST)" to send greetings to the universe, hoping that aliens can hear it. I hope that mankind can find a bosom friend as soon as possible and get rid of loneliness. what do you think? Welcome to the discussion and thank you for reading.