Scientists plan to send a second letter to aliens? Hawking once warned: Don't answer

Recently, a piece of news was released that may cause some people to criticize it again, because scientists are preparing to send signals to the target space to indicate our coordinates and relevant information, and to say hello to possible aliens.

The best time to send this message is October 4, 2022, when the night side of the Earth is facing the center of the Milky Way. The target chosen by scientists is the concentric ring 13,000 light-years away from the center of the Milky Way. This will be the second letter sent by humans to aliens, and the first one was sent by the Arecibo radio telescope in 1974.

The information sent this time was based on the first binary information. Scientists re-encoded and improved it. It is more advanced than the past, with more information and more details.

Astronomers hope that sending this crucial letter can be carried out using the world's largest and most advanced radio telescope, the "China Sky Eye" located in Guizhou, and the Allen Telescope Array of the SETI Institute located in northern California, USA.

The late famous scientist Stephen Hawking repeatedly called for "Don't answer!" That is, don't answer messages sent by aliens, so as not to expose the coordinates of the earth and be destroyed by aliens. And now scientists are still actively exposing their goals, isn't this asking for trouble? Many people have been outraged by the act of sending messages to aliens in the past, so how can they not criticize them this time?

Is the danger really coming to humanity? Let us analyze it together.

1. Life and civilization are extremely rare in the universe. For hundreds of years, humans have been trying to find like-minded people in the universe. Unfortunately, modern science has exhausted all means and has not found any aliens. Artificial probes have flown all the planets in the solar system, as well as some dwarf planets, satellites, asteroids, and even comets. Not only have they not found alien civilizations, they have not even found a microorganism like a cell.

The farthest galaxy observed by the Hubble Telescope is 13 billion light-years away from us. More than 4,000 exoplanets have been discovered by various means, many of which are Earth-like habitable planets, that is, planets like the Earth that are not too far or too close to a star and may have liquid water. However, no trace of life has been found.

Of course, human beings’ current means of observation and exploration are still very rudimentary. We cannot even see the nearest star, Proxima Centauri, which is 4 light years away, clearly. Therefore, we cannot be sure whether these observed planets have life or not. But at least it proves one truth, that is, life is very rare in the universe, and civilization is even rarer.

The most optimistic estimate is that there may be 100,000 planets with civilizations in the Milky Way, while the pessimistic estimate is that there is only one civilization in a galaxy. Of course, some people believe that it is very likely that there is only one civilization in the universe, the Earth.

Even if we follow the most optimistic estimate that there are 100,000 civilized planets in the Milky Way, how far away are these civilizations on average? Current observations suggest that the Milky Way is about 200,000 light-years in diameter and is a flat spiral galaxy, a bit like a discus, with a central thickness of about 13,000 light-years and containing 400 billion stars.

The study believes that the thickness of the center of the Milky Way is only the thickness of the galactic bulge. In fact, the Milky Way is very thin, with an average of only about 2,000 light years. Calculated based on the thickness of 2,000 light years, the volume of the entire Milky Way is 628,318,530,717,95 cubic light years. The average volume of each of the 100,000 civilized planets is 628,318,530 light years. On this basis, cubing it, we get the average distance between each civilization is 856 light years.

The distance of 856 light years means that if you send a telegram to your neighbor, he or she will receive it after 856 years. If you want to receive a reply from him or her, it will take at least 1700 years. This is the most optimistic estimate. If there is only one civilization on Earth in the Milky Way, and there may be one civilization in other galaxies, it will take at least hundreds of thousands of years, or even millions of years, to wait for this telegram.

To reach a civilized planet at the most optimistic distance of 856 light years, it would take more than 15 million years, based on the 17 kilometers per second speed of the most distant unmanned probe Voyager 1. This means that even if there is a civilization of the same level as humans in this range, it would take more than 23 million years from receiving the information to sending an expeditionary force to reach Earth.

So, are there civilizations around us that are more advanced than humans? Read on.

Second, decades of searching have made humans too lonely, always dreaming of seeing soulmates from outside the Earth, which has given rise to many fantasies and even hallucinations, such as UFOs flying all over the sky, and many people saying they have seen aliens or alien spacecraft. However, after scientific investigation, there is no clear evidence to prove that aliens have really been to Earth.

People only see science fiction movies, so many people believe in science fiction, even the conspiracy theories contained in it.

Scientists have long abandoned all kinds of legends and turned to the most modern means to tirelessly detect alien signals. The most commonly used method is to use the best optical or radio telescopes to scan the space and observe and listen for any abnormal signals in space.

Some important plans for the scientific search for aliens

In the 1970s, astronomers conducted an infrared survey of 250,000 celestial bodies in the sky and discovered 17 celestial bodies with Dyson sphere-like characteristics, but after further observation and identification, they were all ruled out one by one; NASA's Kepler mission scanned more than 100,000 stars and found a star called KIC 8462852 with strange brightness changes. It was also suspected to be a Dyson sphere structure, but was later ruled out.

The Murchison Wide Field Array radio telescope in Australia is an array system composed of spider-web-like antennas. It has searched more than 10.3 million star systems and has found no traces of alien civilization so far.

The Breakthrough Listen Project, which was initiated by Hawking himself and fully funded by Russian billionaire Yuri Milner, is a project that uses radio and optical technology to search the Milky Way and 100 nearby galaxies for traces of aliens over a 10-year period. The project will cost $100 million and use world-renowned telescopes such as Green Bank in the United States and Parkes in Australia to capture and receive radio waves, lasers and other signals from stars in these galaxies, but no results have been achieved so far.

Spacecraft launched by humans have reached every planet, as well as some dwarf planets, asteroids, and comets, and have also brought back material from the moon and some asteroids.

All the exploration and searches have so far not found any extraterrestrial life, let alone extraterrestrial civilization.

This certainly does not deny the existence of extraterrestrial life and civilization. In fact, the search is still ongoing. But at least it can be said that the probability of life appearing is extremely small. Planets with life in the universe are extremely rare, and civilization is even rarer.

Since we haven't seen or heard the calls from extraterrestrial civilizations, why can't humans take the initiative to call them? In fact, humans have already called aliens, but they haven't received any response.

The only way to communicate between the stars is through radio communication, because the propagation speed of radio waves is the same as the speed of light, which is the fastest speed in the universe. It has only been more than 100 years since humans invented radio. In 1895, Marconi of Italy and Popov of Russia invented radio almost at the same time, but Marconi was the first to obtain an international patent.

Subsequently, radio developed rapidly like wildfire, and in the following decades, radio telescopes were gradually developed. In 1974, scientists used the Arecibo radio telescope in the United States, the largest in the world at that time, to send a set of signals for 3 minutes to the Hercules globular cluster M13, 22,200 light-years away from us.

This is the first greeting letter sent by humans to possible extraterrestrial civilizations in space. The signal includes 1679 binary digits, forming an array of 73 rows and 23 columns. The number of rows and columns are both prime numbers. This is to remind aliens that this is not a natural signal, but an artificial signal.

If the aliens who received this signal had a similar technological level to humans, they would be able to decode the following information:

The position of the sun in the Milky Way, the position of the earth in the solar system, humans are intelligent entities on Earth, the relationship between humans and the surrounding environment, human mathematics uses decimal calculations, the chemical elements that make up humans, the shape and basic structure of human gene DNA, what the telescope that sends this set of signals looks like, etc.

Radio signals travel at the speed of light. If it was sent 48 years ago, it would have traveled 48 light years and would have taken more than 22,000 years to reach its destination. If there really is an intelligent civilization out there and it receives this signal and decodes it successfully, it will send a reply and it will take more than 44,000 years for us to receive it.

In the 1970s, four unmanned probes were launched, namely Pioneer 10, 11, Voyager 1 and 2. After completing their solar system exploration missions, these four probes flew out of the solar system in four directions. Voyager 1, the farthest-flying probe, is now 23.3 billion kilometers away from us. At a speed of 17 kilometers per second, it will take more than 17,000 years to fly out of the solar gravitational circle with a radius of one light year. It will take more than 70,000 years to fly to the nearest star, Proxima Centauri.

Why do scientists send them out of the solar system? The biggest hope is to encounter aliens. If they are captured, they will know where they come from and who sent them. Because they carry a set of cards or discs with information about the solar system, the earth, and the creatures on the earth, including human beings, which contain rich information about human civilization, such as the coordinates of the earth.

The New Horizons unmanned probe, launched in 2006, completed its solar system exploration mission after exploring Pluto and the asteroids in the Kuiper Belt and flew out of the solar system. It also carried a CD with rich information, 434,000 human names, some ashes of Clyde Tombaugh, the discoverer of Pluto, a quarter and a small piece of the SpaceShipOne spacecraft.

These practices have long caused panic among some people, who firmly believe in Hawking's warnings and the Dark Forest theory, and believe that those who do these things are traitors to humanity and put humanity in danger. So some people have called for the rapid recall of probes such as Voyager 1, or for them to self-destruct, and for all signals sent to space to be blocked in the future.

But more scientists just treat these as jokes, they don't believe that there is really a dark forest. From the above introduction, we can see that the universe civilization is too rare, so rare that it is very likely that each civilization will be destroyed and it will be difficult to encounter another civilization. So if aliens know the coordinates of the earth, will they come to plunder and slaughter humans?

It can be said with certainty that no, based on the following common sense: 1. The probability of civilizations encountering each other is too small. This has been mentioned a lot before and I will not repeat it here.

2. Even if there is an extraterrestrial civilization at the closest distance to us, which is about 856 light years away, the information we sent has only traveled for 48 years, and it will take more than 800 years to reach them. If they discover the coordinates of the earth, they really have the intention to occupy and slaughter us. It depends on how advanced this civilization is.

If they are similar to human civilization or only slightly higher, will they be able to invade the Earth? Currently, the fastest unmanned probe we have is the Parker Solar Probe. When it reaches the closest distance to the Sun, it will reach about 200 kilometers per second under the influence of the Sun's gravity. Assuming that the manned spacecraft of this civilization can reach 200 kilometers per second, it will take more than 1.28 million years to reach the Earth.

Therefore, even if they have the intention to steal, they do not have the ability to do so. If they come to Earth 1.28 million years later, what will happen to humans? Will they be extinct or have they become gods? Will we be afraid of them?

3. Why do aliens come to plunder and slaughter the earth? For resources? What resources does the earth have? Water, atmosphere? There are many planets with these resources. It can be said that there are countless planets in the universe. In the solar system, there are seven or eight planets with more water resources than the earth. There are also many planets with atmosphere, but the number varies. Several gas planets are giant planets, much larger than the earth.

The environments of different planets in the universe vary greatly, and the conditions for the survival of life and civilization also vary greatly. It is impossible that they all need resources like the Earth. For example, scientists believe that there may be life on Titan. If there is, it is an alkyl life that feeds on compounds such as methane and needs to survive in an environment of minus 179 degrees Celsius. If this kind of life comes to Earth, all the water, atmosphere, and Earth's temperature are highly toxic to them. Once they encounter them, they will die. What are they doing here?

The demand for resources of advanced civilizations is becoming increasingly simple. For example, in the future of human beings, it is very likely that only simple energy, that is, stellar energy, will be needed. With energy and elements, everything needed can be manufactured. The human body itself may eventually disappear, and only consciousness can survive.

So what are these advanced civilizations doing on Earth?

4. If there is a high-level civilization around us, do we need to expose ourselves? People have long known that there is such a low-level civilization. If they want to come, what ability do we have to hide and deal with it? Isn't this just worrying about nothing?

Therefore, Hawking's "Don't answer" and the Dark Forest conjecture are both ideologies of the low-level civilization of human beings at this stage. As the level of civilization improves, the spiritual consciousness of any civilization cannot remain at the current state of consciousness of human beings. Therefore, I think Hawking's "Don't answer" and the Dark Forest conjecture are meaningless.

Although Hawking is a scientist I respect, I don't agree with his views on this aspect. In fact, most of those who are madly criticizing and opposing the exposure of the target are people who believe that UFOs really often appear on the earth, and that aliens have long been hiding on the earth, the moon, and Area 51 in the United States. Since there are aliens everywhere and aliens have been to the earth long ago, why are they afraid of exposing the target? Isn't this a joke that deceives oneself? Why be indignant about a cold joke?

Therefore, I strongly agree to use the "China Sky Eye" to send greetings to the universe, hoping that aliens can hear it. I hope that humans can find soulmates as soon as possible and get rid of loneliness. What do you think? Welcome to discuss, thank you for reading.

The copyright of Space-Time Communication is original. Infringement and plagiarism are unethical behavior. Please understand and cooperate.