Can you imagine the size of the universe? She is huge. But where are all the aliens? They have not yet been discovered, but we are almost one hundred percent sure of their existence. So, we are being investigated, infected, invaded, preparing a plan for destruction, isn't it?
Fermi's paradox lies in the absence of visible evidence of the existence of other intelligent civilizations - on all the stars and in all the galaxies of the Universe. Or do you think that if at least one intelligent civilization could let us know about its existence, it would remain “out of reach”? Either we are on the "black" list, or we really are the most advanced life form in the universe (it's scary to think). Even more terrifying may be the fact that we are alone in the universe.
The search for any extraterrestrial life is perhaps one of the most meaningful things we can do as a species. We are ready for contact with aliens. We believe that they will be able to teach us something. But life beyond Earth has yet to be discovered, and experts in the search for extraterrestrial intelligence (SETI) are beginning to despair. In any case, the search continues, as scientists come up with ever more extreme ways to observe the cosmos more deeply, to see glimpses of intelligence on distant stars.
How exactly is the hunt for aliens?
Main candidates
17% of the stars discovered by the Kepler telescope hold Earth-sized exoplanets in orbit. Currently, the list of the most likely candidates for the maintenance of alien life looks like this (despite the fact that there may be many more similar potentially habitable planets):
- Gliese 581g (constellation Libra, 20 light years from Earth)
- Gliese 667c (constellation Scorpio, 22 light years from Earth)
- Kepler-22b (constellation Cygnus, 600 light-years from Earth)
- HD 40307g (constellation of the Artist, 42 light years away)
- HD 85512b (constellation Sail, 35 light-years away)
- Tau Ceti e (Tau Ceti, 11.9 light years away)
- Gliese 163c (constellation Dorado, 50 light-years away)
- Gliese 581d (constellation Libra, 20 light years away)
- Tau Cetif (Tau Ceti, 11.9 light years away).
The basic assumption with which we begin our reflections is this: our hypothetical neighbors in space are developing in a similar way to ours. The lack of visible evidence in space will be a strong argument for this. Although in fact it is unlikely that somewhere outside our solar system, people like us are developing - shopping and fighting among themselves.
However, in the event of such a combination of circumstances, an alien race would have to one day come to the radio waves. We have been "on the air" for almost 120 years (although with the invention of the digital signal, our analog transmitters will soon be silenced), which means that if an extraterrestrial civilization turns the radio receiver within 120 light-years of Earth, it will have a great chance to enjoy our good and bad music. and listen to the news even 120 years ago. That is, they will find us.
Radio leaks are too unreliable. But what if we point the antenna at the stars and “listen” to the ether in the hope of catching a signal specially directed in our direction? Since the 1960s, the SETI program has been hunting for alien radio signals, but only recently, thanks to the Kepler space telescope, have we been able to more accurately target potentially habitable worlds. So everything is just beginning. And although SETI has not yet heard a single signal, great things await us on millions of other worlds.
Interference on the air
A radio signal detected by the 100m telescope in West Virginia while scanning candidate exoplanet KOI 817. This is the type of signal that SETI scientists hope to hear from aliens.
While listening to the air, SETI recorded several false signals. Since we are searching in specific narrow bands (which only certain technologies can produce), ground clutter constantly interferes with SETI searches. Fortunately, astronomers are not stupid and know the difference between alien signals and randomly intercepted chatter.
Possible footprints on the moon
Traces of the Apollo and its equipment are still visible on the lunar surface.
But wait. We seem to be looking for aliens in distant stars, and not on the moon next to us?
Right. Although the main goal of SETI research is focused on finding suspicious radio signals in deep space, it is worth bearing in mind that the Moon will be a very good stop for aliens who accidentally come to visit us. Looking for traces of aliens on the lunar surface will not seem so stupid when you learn that the LRO satellite, which now flies around the moon, found traces of Neil Armstrong in 1969.
Alien artifacts
Mars Phoenix. View from orbit
Why stop at the moon? If an evolved form of aliens resided in our solar system ever in the history of its existence, perhaps they have severely inherited.
The search for the "twins" of the Sun
HP 56948 through the eyes of an artist
Forget "habitable exoplanets" for a moment. How about focusing our efforts on finding stars that are identical in temperature, size and chemical composition to our Sun? After all, this object provides our planet with energy, and that's it. chemical substances that formed our planet came from the protoplanetary disk of our newborn Sun 4.5 billion years ago. Let's just look for stars similar to the Sun.
In 2012, astronomers discovered HP 56948, a "clone" of the Sun, located just 200 light-years away. And although no planets have yet been discovered in its orbit, it is very curious whether such stars could be a potentially habitable zone for alien civilizations. We wrote more about these zones in the article about binary systems stars: suns that revolve around each other, providing a large enough field for the development of alien forms.
artificial exoplanets
From the point of view of Kepler, as he observes the "dips" of light flying from the stars, the telescope analyzes the curve of light. Well, since the planets are known to be round, it will be a surprise to get a non-standard light curve. Planets that are not spherical do not exist in nature, so as soon as Kepler discovers, for example, a massive pyramid, this may indicate the intrigues of aliens.
Remarkably, there is a separate search program in this direction - the search for extraterrestrial technologies (SETT), and its main difference from SETI is that we are looking for indirect evidence of high technologies in space.
The disappearance of the stars
Spiral galaxy M51
Could the absence of stars in the galaxy reveal the presence of superintelligent aliens?
In 1964, Soviet astronomer Nikolai Kardashev suggested that some alien civilizations could be so advanced that they would use all the energy coming from the star. These are civilizations of the second type according to the Kardashev scale.
How will they do it? For example, creating a fan-favorite sci-fi Dyson sphere around a star. This shell will collect all the energy from the star, thereby hiding it from any outside observer. From our point of view, if we notice darkness in one of the segments of the galaxy, it is possible that aliens are having fun hiding stars in huge spheres.
Disappearance of asteroids
Asteroids in orbit - alien mining?
Humanity, no joke, is on the verge of turning asteroids into an entire power plant. And although the reality is that most technologies are not yet adapted to the extraction of ore in space, this does not mean that alien civilizations are at the same stage of development.
We know that asteroids are full of valuable materials and that they orbit stars, which means that if there is someone smarter in space than we are, he will come to the same conclusion: we need to take an asteroid, split it and get rich. (Although "getting rich" can be a special distinction of human nature.) Can we detect debris flying in all directions during the operation of such an orbital mining station? Quite.
Black holes as engines of spaceships
If advanced enough, some aliens could even make their own black holes as small as an atom and yet weigh millions of tons. If you turn this black hole into an engine for some unknown reason, it will generate a huge amount of gamma rays, which, in turn, will be converted into energy for the spacecraft. According to experts, such a source of energy could be inexhaustible. And as far as we know, the radiation emitted by these artificial black holes would be easy to fix, which means - hello, earthlings, we come in peace.
Are they alive?
The problems of SETI searches lead to various assumptions. One of them is that aliens use radio transmitters. Another thing is that aliens have always used radio transmitters. The latter is unlikely to be true unless a very advanced civilization has been broadcasting 24 hours a day for billions of years.
As the false SETI results have shown, it is most likely that the signal from outsiders will be intermittent. But how can we catch it if the lifespan of civilization is too short?
Other Mind
Dolphins are intelligent. Perhaps as intelligent as humans. But as far as we know, they don't use the radio. What if extraterrestrial intelligence looked like a dolphin? Will we never be able to find them until we fly to their planet and talk face-to-face? Not only has this assumption sparked a heated debate within SETI, it has forced us to rethink the notion of "intelligence" on a galactic scale.
Introvert Aliens
Since the universe is silent, some astronomers have - prematurely - declared that there is no intelligent life among the stars. From the point of view of science, this is wonderful, even if very short-sighted. But what if an extraterrestrial civilization does not want to make contact? What if she's happily doing her thing, not wanting to talk to us? Moreover, what if they live so efficiently that too little energy escapes into space to be detected?
Preparing for an invasion
Movies like "Battle: Los Angeles" and "Independence Day" have hinted to us that we are not only on the verge of an alien invasion, but also do not really know how to deal with them. Many have wondered: why would they invade at all? The answer, of course, is “why not?”. But the story about the "engine that could" will not surprise anyone.
With this in mind, SETI decided to rethink their strategy and launched the WETI program - waiting for extraterrestrial intelligence. Then all programs of search and communication with extraterrestrial civilizations will have to be curtailed, and then, hiding our heads in the sand, we will sit and hope that no one will find us.
Radio search Modern science does not yet have evidence of the existence of living intelligent beings outside the globe, but she gives convincing reasons in favor of such an assumption. For the first time in the development of science, it became possible to test this hypothesis experimentally.
Observations began in 1960, when Francis Drake attempted to receive signals from the stars t Ceti and e Eridani using an antenna with a diameter of 26 meters. His work was called "project OZMA". Artificial signals were not found, but Drake's work ushered in the era of searching for CC search signals. At first, this activity was given the general name GETI (Communication with ExtraTerrestrial Intelligents - “Communication with extraterrestrial civilizations”). Later it was called more cautiously SETI (Search for ExtraTerrestrial Intelligents - "Search for extraterrestrial civilizations”), meaning that before communication can be established, it is necessary to find at least some traces of the activity of intelligent beings in space. Over the past years in different countries ah, mainly in the USA and the USSR, more than 60 experiments were carried out to search for EC signals, thousands of stars were studied at various frequencies. But so far, the signals of intelligent beings have not been detected.
The search strategy has changed markedly during this time. The first works simply repeated Drake's idea in an expanded form. Then they explored other stars and at other frequencies, but soon realized that they could only hope for success if they could listen to the entire sky at all frequencies. This is possible in the computer age.
In 1992, the US National Aeronautics and Space Administration (NASA) launched the SERENDIP (Search for Extraterrestrial Radio Emission from nearby Developed Intelligent Populations - "Search for extraterrestrial radio emission from neighboring developed civilizations") project. The project is designed for 10 years. Several observatories from different countries participate in it. With the help of a parabolic antenna with a diameter of 34 m in Goldstone (California), a continuous scan of the sky is carried out - strip by strip. When suspicious signals are identified, they are studied in detail by larger telescopes, such as the 64 m antenna in Parkes (Australia) or the 300-meter bowl at Arecibo on the island of Puerto Rico
The work is carried out in parallel with the usual scientific observations. In other words, no matter where the telescope receives signals from, SERENDIP constantly analyzes them for “reasonableness”: suddenly, along the way, it discovers something interesting, just like in a well-known fairy tale
A new search strategy has also been applied. First, a medium-sized radio telescope quickly scans a swath of the sky, repeatedly scanning back and forth. The "look" of the antenna moves quickly, and the computer sorts the received data, selecting a few of the most interesting among the fixed sources. Then, using the same antenna, they are studied in more detail. The telescope fixes the "look" on each of them, thereby increasing its sensitivity. Of course, most sources turn out to be false: radar interference, receiver own noise, etc. But some sources are confirmed and cataloged for detailed study using the largest antennas
The amazing ability of the SERENDIP project is its multi-channel receivers: outer space is monitored not at one frequency, but at once at several million frequencies covering a wide range of radio waves. In previous years, the search for signals was carried out at one fixed frequency, pre-selected by the researchers. Such a strategy was reminiscent of hunting for fish with spears in troubled waters. The hunter tries to guess where the fish should be at the moment, and sticks a spear there. How many chances does he have for success?
The radio receivers of the SERENDIP project in this sense are similar to a fine mesh network that captures widely and does not let a single fish through, and the size of this “net” is constantly growing: a receiver for 4 million channels operates on the antenna in Arecibo! Having created these super receivers, radio astronomers again pointed their antennas at the nearest stars: a thousand stars in the vicinity of the Sun are now listening at millions of different frequencies.
It should be noted that scientific work, which do not have a direct practical application are not very generously financed in any country, and even more so such fantastic ones as the search for an EC. The SERENDIP project was stopped in 1994: the US Senate did not allocate the 12 million dollars necessary for the continuation of work, citing its refusal by saying that "brothers in mind cannot solve our financial problems." But there were enthusiasts who created the Friends of SERENDIP society to support the unique project, headed by the famous science fiction writer Arthur Clark (by the way, he has been living on the island of Sri Lanka for many years, that is, on that very fabulous Serendip).
Now the cosmic search continues; hundreds of unusual signals have already been noticed, which will be studied in more detail
Should we look for extraterrestrial life?
Thus, the establishment of direct contact with an extraterrestrial civilization from our side is still impossible. But maybe we should just wait? Here it is impossible not to mention the very topical issue UFO on Earth. So many different cases of "observation" of aliens and their activity have already been noticed that in no case can one unambiguously refute all these data. One can only say that many of them, as it turned out over time, were fiction or the result of an error. But this is a topic for other research.
If some form of life or civilization is discovered somewhere in space, then we absolutely, even approximately, cannot imagine what its representatives will look like and how they will react to contact with us. And suddenly this reaction will be, from our point of view, negative. Then it is good if the level of development of extraterrestrial beings is lower than ours. But it can also be immeasurably higher. Such contact, given the normal attitude towards us from another civilization, is of the greatest interest. But one can only guess about the level of development of aliens, and nothing at all can be said about their structure.
Many scientists are of the opinion that a civilization cannot develop beyond a certain limit, and then it either dies or no longer develops. For example, the German astronomer von Horner named six reasons that, in his opinion, could limit the duration of the existence of a technically advanced civilization:
1) the complete destruction of all life on the planet;
2) destruction of only highly organized beings;
3) physical or spiritual degeneration and extinction;
4) loss of interest in science and technology;
5) lack of energy for the development of a very highly developed civilization;
6) the lifetime is infinitely large;
Von Horner considers the latter possibility to be absolutely incredible. Further, he believes that in the second and third cases, another civilization can develop on the same planet based on (or on the ruins of) the old one, and the time of such “renewal” is relatively short.
Section 7 NSA RAS: "Life and mind in the Universe"
Russian SETI
SETI = Search for Extra T errestrial Intelligence
Search for Extraterrestrial Intelligence
This page contains materials related to SETI activities in the USSR and Russia. Materials are given mainly in Russian in KOI8-r encoding. Some of the materials are given in English.
Materials prepared by the Scientific and Cultural Center SETI at the Academy of Cosmonautics named after K.E. Tsiolkovsky and the section "Search for space signals of artificial origin (SETI)" at the Council for Radio Astronomy Russian Academy Sciences (now - the section "Life and Mind in the Universe" of the Scientific Council for Astronomy of the Russian Academy of Sciences).
The first sections provide information on the history of SETI in the USSR and Russia, a list of major publications, information about SETI organizations and groups.
In the "Current Materials" section, along with news, articles on SETI that have come to us are placed. This section is updated periodically, and previous articles and information about past conferences are transferred to the "Archive" section. Materials from the "News" section are also transferred to the "Archive".
The search for extraterrestrial civilizations does not stop for a minute. On the contrary, about four million computers around the world are processing the data obtained by the Arecibo telescope. The search range, meanwhile, begins to narrow.
We have already written about the project [email protected], in particular, and about distributed computing in general.
Let us briefly recall what it is.
[email protected] is a logical continuation of the SETI program, which was sensational at the time - Search for Extra-Terrestrial Intelligence (search for extraterrestrial intelligence). The project was grandiose, but for now we will limit ourselves to the story of how the program appeared [email protected]
So, the essence of the program is that the underlying data received by the Arecibo radio telescope are distributed all over the world - millions of computers perform individual computational operations, after which the results are “merged” back and subjected to further analysis.
Obtaining results is the most resource-intensive process that requires huge computing power, so distributed computing turns out to be just the salvation here.
Saving for the whole SETI extraterrestrial intelligence program, the idea of creating a distributed computing network came to the smart minds of David Gedye and Craig Kasnoff. They developed scientific plan, and presented it on the fifth international conference in Bioastronomy in July 1996.
The project was accepted with a bang. The following year, a program code was developed that, in fact, does the main job: it analyzes the noise from the Arecibo telescope in search of what could be a signal from other civilizations.
The development of server and client software continued until 1999, when the official launch of the project took place.
Client [email protected] designed as a screensaver.
The PR-calculation turned out to be extremely successful, even more successful than the creators of the program expected. Everyone is invited to help science, while everyone has a small chance to become the very person who caught the signals of an alien civilization.
And all this without leaving home. Or from work. Moreover, calculations do not require a lot of resources, even if the client is graphical and designed for a screensaver (in fact, the screensaver displays the work of the main program that performs calculations).
In fact, your computer is engaged in "straining", filtering individual fragments of the noise received by Arecibo, and searching for "golden grains" in it.
At the moment, more than four million people have already turned out to want to “commune”. The more participants, the higher the overall performance.
At some point, the organizers of the program were even afraid that the data would begin to arrive slower than they could be processed.
So far, the data has not run out, but no accurate results have been obtained either.
However, something like a shortlist of signal sources has been formed, on which from now on the Arecibo radio observatory will focus its attention.
On March 18, 2003, the Arecibo telescope will operate for 24 hours exclusively on [email protected], that is, to study only the most "suspicious" radio signals - from only 150 sources.
I must say that the mood of the leading specialists of the program is not too combative. “The chances are 1 in 10,000 that one of these signals actually turns out to be hello from alien civilizations,” said Dan Werthimer, one of the leaders [email protected]
But if they manage to detect something that looks like a signal from aliens, then they "will jump around and cut off the phones of observatories in England and Germany." They'll need independent confirmation to make sure it's not a glitch in software and not student jokes.
Arecibo telescope close-up. This is a whole crater, lined with metal sheets, and thus turned into a giant "dish" antenna.
The sources of radio waves that scientists intend to explore were chosen according to one principle: the clarity and repeatability of the signal emanating from the same point. Usually such signals, due to the movement of the antennas of the telescope, last for 12 seconds and are shaped like a bell.
This was stated by David Messerschmitt of the University of California at Berkeley. He revealed this statement in his work, which should change the approach to the search for extraterrestrial civilizations.
The most common claim that radio is the best and final form of communication is not the ultimate truth, and this is not surprising, since we ourselves use this technology quite recently (even by earthly standards). However, having no more convenient alternative for searching for other civilizations, this process needs to be optimized and improved as much as possible, Messerschmitt believes.
According to the researcher, the first step is to get rid of the problem of excessive load in the case of listening and sending a signal not to any specific area, but in all directions. In his opinion, the best optimization strategy should adhere to the principle that transmission power should be strictly limited. Since the transfer itself takes a huge amount of time, there is no point in chasing a high transfer rate.
There are other options, but each of them has its drawbacks. For example, for economical signal transmission, polarization can be used electromagnetic waves and different kinds multiplexing, however, despite the fact that this will save energy, another problem arises - orientation towards contact with civilizations that have already mastered this technology (so, if, the level of technology of an extraterrestrial civilization will be the same as we had in the 1960s years, they will not be able to receive the signal). On the other hand, this minus cannot be called big, but unpleasant - calmly. Therefore, optimization in this vector is rather doubtful.
The researcher suggests using methods that are not popular for SETI. Messerschmitt notes that by using the widest possible range, the average power consumption should be much more economical than the fixed frequency approach (as SETI does). That is, if CCs think the same way, then it is necessary to search for more broadband signals with less power and information transfer rate.
In addition, the author of the paper believes that the SETI approach to search strategy is fundamentally wrong. The main problem lies in the fact that the so-called "truth check" takes a lot of energy for a long repeating signal - they try to distinguish a real signal from a false one by long "listening" to a specific sector. At one time, a similar problem was encountered in 1977, when the so-called “Wow!” signal was registered. This signal was received by the Big Ear radio telescope, but it was the “truth check” method that was used to verify its origin, and the signal was not confirmed and intercepted again. It would seem that listening should go on an ongoing basis, but neither then nor now, such a strategy is not used.
If we follow the thought of David Messerschmitt and assume that the computer transmitting the signal saved energy, then register the signal “Wow!” researchers would not have been able to for a very simple reason - there was no need to repeat the signal more often than, for example, once every few years.
According to the researcher, it is quite simple to avoid such failures - for this you need to systematically and for a long time examine each sector of the sky, moving away from the strategy of not systematically “listening” to different parts and maintaining a database of all signals, presumably of artificial origin.
Note that SETI (Search for Extraterrestrial Intelligence) is the common name for projects and activities to search for extraterrestrial civilizations and possibly make contact with them. The beginning of the project dates back to 1959. There is an opinion that the SETI project can carry a serious danger. It is assumed that a highly developed alien civilization can use radio signals as an information weapon or a means of its own distribution.
