The question should be similar to that which was used in the previous paragraph. If somewhere in the Universe emerged and began to develop life as much on average, depending on the conditions, will take time to appear intelligent beings was created civilized society? Of course, there is even impossible to answer. Try at least a few to understand the different sides of the issue and the opportunities to make in the future to answer it.

The fact that the Earth was formed intelligent life, and there was a civilization, cannot serve as a proof of the commitment of the emergence of intelligent beings in the evolution of life. As in the question of the inevitability of life, here the main point is the average time required for the emergence of intelligent beings after life has arisen. If the average time is small in comparison with the age of the stars and probably available about them planetary systems, then we can assume that the worlds are inhabited by intelligent beings, almost as many as there are worlds in advanced life. But if this is the average time high in comparison with set deadlines, only a very small part of the inhabited worlds are inhabited and intelligent.

The average time for the emergence of intelligent beings in the evolution of life, of course, must depend primarily on (physical conditions, PA planet. In each spot intelligent beings can appear much earlier or much later than in the mean time. But large deviations from the mean time will be rare. An example of Land in this respect cannot serve as a guide, as the question about multiple civilizations in the Universe could be delivered only in the result of what appeared on Earth is intelligent life.

And still we will try to take into account the experience of the Earth. Our planet was formed approximately 4-5 billion years ago. The first signs of the existence of living organisms relate to the period of the Upper Archean, approximately 1.2 to 1.3 billion years ago. So, for the origin of life it took 3-4 billion years. And intelligent being an evolution of life came at the beginning of the Quaternary period of the Cenozoic era, only about a million years ago. Consequently, it took more than a billion years that have gone the way from the first living organism up to the thinking being. This period is rather substantial even in the measurement set-up measures.

If you monitor the evolution of life on Earth, we can identify a large number of evolutionary lines, razvetvlyayuschikhsya and Abramovicha, which led to the flourishing or extinction of some class, detachment or family of organisms. These evolutionary line led the world of living organisms in our day to a huge number of different types. But only one line led to a sensible creature - human. Can't help wondering - did not part of creating a random person, the best of circumstances? It Could be a special combination of geographic, climatic conditions and circumstances of the relationship between different types of animals that demanded our ancestors elements of labour and social organization to survive, to which they are ready.

You can also ask what would happen if suddenly all the Earth's people disappeared, and flora and the rest of the animal world was saved? How much time would now nature to create new intelligent beings?

We put these questions to them now to answer and to show that the opinion that the evolution of life should inevitably, at some pre-measured term, lead to the emergence of intelligent beings, very simply, and most likely wrong. This problem is much more complicated. It is so difficult that humanity will have to face it empirically studying the worlds around in search of life and intelligent beings.

The idea is to take practical steps to learn something about the extraterrestrial intelligent companies and let them know about the existence of civilization on Earth, Nenova. In the last century Frenchman Charles Cut for almost all his life he made strenuous efforts to persuade your government to the need to allocate funds for the construction of a giant mirror, which could be reflected from the Sun signals to prospective inhabitants of Mars and Venus. The famous German mathematician, and astronomer Carl Gauss was proposed to create with the help of deforestation in Siberia giant rectangular triangle, by the parties has served forest strips in width of 10 miles. The interior of the triangle he offered for contrast to light, sowing wheat in it. Gauss believed that armed telescopes Martians can see this triangle and perceive it as a reference to the inhabitants of the Earth. Austrian astronomer background Littrow offered to dig in the Sahara wide ditches in the shape of circles, squares and triangles, pour water on them, and on top of kerosene and light at night, to make known to the Martians about plowing existence.

Because in the Solar system are inhabited Land only, the search for extraterrestrial life must be made at much greater distances than the distances in the Solar system, I need to look up signs on planets around other stars. Currently, the only possibility of such a search is trying to catch some signals may be sent into space.

However, it should be borne in mind that the notion of ational being" does not mean such beings, which recognized the need to send powerful signals addressed to other inhabited worlds, and capable of such signals to produce and direct.

The history of mankind shows that after the appearance of intelligent beings natural process of creating civilization. They emerged and developed at different times on different continents of our planet. The number of them was great. Some of the once-thriving civilizations became known only recently, after the carried out archaeological work. Have many past civilizations have one thing in common. They come in decline or perished under the blows of external forces, not reaching the stage of technical civilization. Only on our planet civilization reached the stage of technical, this civilization of our time.

What is different technical civilization from non-technical? The author of this book believes that civilization becomes technical when she studied methods of transformation of one type of energy to another. In the most ancient civilizations of China, Egypt, Assyria, Greece, Rome and many others were very advanced art and science, was used mechanisms simple and complex structures. But all these mechanisms, levers, blocks, polispast, catapults, their different combinations; mechanisms of water mills and other devices translated mechanical energy again in mechanical.

The civilization of our time passed the stage of technical in 1769, when James watt built the first steam engine, changing the thermal energy into mechanical energy. Now mankind is widely uses, produces mutual transformations of thermal, mechanical, electrical, chemical, and atomic energy. Thanks to this greatly increased the productive forces. Civilization has become global, it has spread to the entire planet. She was able to explore space. The question of the habitability of other worlds it is already interested in practically.

The most promising nowadays views regarding possible civilizations, which developed PA planets around other stars, is a radio. Calculations show that the two are located on the planets around stars civilization that reached our level of technology, able to engage in radio contact with each other at a distance of up to 50 PS. They must use the wavelength range from 3 to 30 cm, as other ranges or not skipped ionized layers of planetary atmospheres, or a high level of interference caused by radiation of stars around which refers planet atmosphere of the planet, as well as the Galaxy and Metagalaktika. In 1960, Drake and his staff at the us National radio astronomy Observatory in green Bank (state of Western Sergipe) using a radio telescope with the mirror diameter of 27 m started the systematic radioreleinaya directions on two stars - e Eridan and t whale. The program of these observations was named OZMA. The reception was made at a wavelength of 21 see

This wave is of exceptional importance in astronomy. It is the only bright emission line at microwave frequencies emitted by neutral hydrogen and makes it possible to study the distribution and movement of this most plentiful gas in the Universe. As first pointed Kokk?nion and Morrison, the condition make and receive signal in this wavelength should be universal guess radio astronomer of all the worlds. Without such speculation, without such conditions, to establish communication will be much harder makers have to do a search on a large frequency range. But in order to ensure that the received signals artificial, must perform their long reception at the correct frequency.

So, hoping that possible interlocutors of the Universe are not inferior to us in dogadyvalis, Drake and his staff were thorough reception at a wavelength of 21 see the Stars of e Eridan and t whales were chosen because this is the closest star, satisfying the following conditions:

1. Direction to the stars is a significant angle with the plane of the Galaxy. It it is important therefore that direction, lying close to the Galactic plane, gives greater thickness of neutral hydrogen, which fills veto region near the Galactic plane. Neutral hydrogen is studying at a wavelength of 21 cm and if the line of sight many hydrogen atoms, their study in this wavelength will score possible artificial radio signals. The situation is complicated by the fact that due to the movements of various hydrogen mass to and from us is the frequency of received radiation from these masses due affect Doppler is not strictly the same, take line radiation greatly expanded to separate from her, being close to the wavelength of 21 cm, it is impossible. If the direction of the star (PA alleged planet around the star) is a significant angle with the plane of the Galaxy, the beam of view pervades a small layer of hydrogen, coming from him, radiation is not very intensive, and in the background you can expect to distinguish artificial signals.

2. Studied the stars must be single, because the conditions on the planet, located in double or a multiple of the system, less favourable for life because of the irregularity of the motion of the planets in this system.

3. The stars must be spectral class F or later, because there is reason to believe that the stars of early spectral type less likely planetary systems. This last condition, however, satisfy the majority of the nearest stars.

Unfortunately long and careful listening e Eridan and t whale has not given positive results, Any signals that can be recognized artificial, could not be obtained.

This is not surprising. Life, and the more intelligent life, of course, the phenomenon is not so frequent that there was considerable hope to find her on the first two victims of observation of the stars. The negative result of the program OZMA showed the fallacy of excessive optimism on the plurality of inhabited worlds. The roots of this optimism is clear. They caused a huge success in the conquest of space. But you have to understand that the transfer of legal, now quite optimistic about the potential for further conquest of the cosmos to the question about the existence of other inhabited worlds is purely emotional. Logic element in it. The emotional side was so strong, that on the pages of popular science magazines not so long ago it was possible to read about "observational evidence" existence of intelligent life on almost all planets of the Solar system, up to the explosions of atomic bombs on Venus and Jupiter. However, in respect of the conquest of space optimism moved limits. An example is the notorious the Dyson sphere - a proposal to build around the Sun of substances of Jupiter the giant hollow sphere with radius approximately equal to the radius of the earth's orbit. The aim of the field is to serve as a place of life for the excessively increased population. The obvious energy impossibility of this project. In addition, as demonstrated recently by simple calculations C. D. Davydov to the Dyson sphere has not collapsed, its substance must be able to withstand the load of 20 million tons per square centimeter, which is unthinkable.

Commenting on the negative result of the program OZMA, astronomers reassess the concept of favourable conditions for the development of life and civilizations. So, the American astronomer days even though comes to the conclusion that life can be expected only near stars, mass and, consequently, the luminosity is close to the mass and luminosity of the Sun. In particular, the potential planetary systems around subjected to listen stars St Aridaia and t whale cannot be intelligent life for the reason that these stars luminosity less than the Sun - t China twice, e Eridan 2.5 times. Therefore, the planet where the temperature close to the temperature of the Earth's surface must be at these stars in 1.5-1.6 times closer to the star than Earth is to the Sun, i.e. somewhat closer than Venus to the Sun, But as you know, due to the proximity to the Sun, mercury and Venus rotate around the axis very slowly. Their synodic (i.e. relative to the Sun) periods of rotation is equal for mercury 176 and Venus 117 earth day. This leads to a very large temperature difference on the two sides of the planet - one hemisphere is extremely volatile, another very chilled, and both are so unfavorable for the development of life. It turns out that only stars with luminosity no less than that of the Sun, the planet may be enough to warm rays of the Sun and, in addition, due to the rotation hot relatively evenly, thus favouring the development of life. The days even though believes that in the sphere with a radius of 4 PS, available 27-meter telescope Observatory, green Bank, no stars, near where you would expect the presence of life. However, in his opinion, in the sphere with a radius of 200 PS you can expect several hundred thousand stars with favorable conditions for development of life near them. So the days even though believes that using a larger telescope.

As we have said, we currently estimate the likely number of civilizations are not based on any reliable basis, largely arbitrary, and the author does not consider it possible to get down to some of them. But in any case it is true that the expected number of civilizations in proportion to the number covered by the sphere of the stars, if, of course, the star structure remains about the same. So attempts to catch artificial radio signals from other worlds should of course continue.

However, it should be mentioned that increasing twice as, for example, the number of the listening stars, we are not going twice to increase the number of worlds, from which you can hope to receive signals. This is because the signals can be registered only in the case if radio waves from distant planets are sent to purposefully and it is in our direction. Only in this case, the signal may be of sufficient intensity to be accepted by the radio telescope. Hence, it is necessary not only to we decided to take the radio waves from the stars, but also to creatures, sending a signal, thought it necessary to send it into the Sun. The farther star, the less likely it is that its inhabitants of the planet will decide for the Sun to make a recipient of their radio signals.

We assume that the probability of sending signals in the direction of the Sun from this star is inversely proportional to the square of the distance from the Sun to stars and stellar density in the covered areas will be considered constant. As listening to more distant stars, the number of civilizations that we can hope to reach, will grow. However, when we made assumptions, which can be considered valid, that number will not grow in proportion to the number of the listening stars, but only based on the cube root of this number. This is a very sad fact, dramatically reducing hope of success. However, undoubtedly, the work on radioreleinaya stars it is necessary to organize with possible large scale, as in the case of luck we will be facing the greatest discoveries. In the share, think of the reader, what will it be a wonderful event, if we have definitely know that it is from this point of sky, planets, located about this star, we indicate some sentient being is not created by the imagination of scientists, evaluating only the possibility of intelligent life, and existing clearly and already meddling in our lives. Without exaggeration we can say that the acceptance of artificial signals from another world will become the most important event for the whole time of understanding the world.

This event can be of immense practical value. Beings, signals which will be taken, certainly technically will be far ahead of us. After all, the period of development of the terrestrial civilization radio - nearly half a century, and it is negligible in comparison with set deadlines, with the period of the evolution of life. Because it is incredible that the being, the signals which will be adopted, were exactly on the same stage of technical progress that we are. Behind they can not be, as already send our way radio signals, but there may be arbitrarily far.

Therefore, as noted by American astronomer su Shu-Hu-Ani, the first conversation, apparently, talk geniuses from licit. But we can be comforted by the fact that it is not a conversation. Talking at a distance, for example, 10 PS difficult, as between the moments when asked a question and received the answer, it will be about 70 years, the radio signal will not be able to turn around before. Will be not a conversation and listening to lectures, lectures technically superior beings. First, you will learn to understand the lectures. Reading lectures will have to repeatedly perform the training of their conditional logic signals. As it can be done, has recently shown F. Morrison, who offered examples of initial codes of training. Codes can be built, obviously, only using pulses of different capacity, which should be written by the host device to tape.

The training should be designed carefully, and then they can achieve transmission capabilities pulses any such complicated thoughts. Maybe lecturers distant planet will give us the solution of the most important, is still inaccessible for us, for example, the technical solution use the peaceful uses of energy emitted by hydrogen at turning it into helium - secret nuclear fusion.

We will present one more hope, utterly fantastic, but we can not say that is absolutely impossible. Let's say that about the star, at a distance of 26.1 PS, there is a very advanced civilization, having devices that are able to review in detail the weight of what is happening on Earth and send into space television image just considered. Assume that intelligent beings this advanced civilization, ensuring the progress of our civilization, and anticipating the development of us funds radio, send images only observed on the Earth again in the Earth. Then we could on the TV to see the true events 169 years ago. Electromagnetic wave length in 26,1 not return pass for 169 years. Could witness an all events invasion of Napoleon in Russia. All disputes historians of the great events of those years would have been permitted. And civilization, at a distance of 400-800 not, could make us witnesses of the age of the Egyptian pharaohs.

Systematic listening to a large number of stars cannot of course be conducted in a relatively short period of time by a single Observatory. This task is beyond the power of even a single state. Already developed a cooperative program of listening of all meet the basic requirements of the stars of the first PA distances of up to 20 PS, and then more distant, all radioobservatory the globe, by the way, anyone can man take his part.

The astronomers already has a large experience of cooperative work. The first of them is the work of a large scale was undertaken after proposed in 1906, Dutch astronomer Kapteina ambitious plan to study regulations and the physical characteristics of stars, including weak stars, 252 selected sites distributed all over the sky. It was necessary, and these sites to determine the position of the stars, their apparent size, color, spectra, of its own motion, radial velocity, and other characteristics. The stars are studied only in selected areas, but not the whole sky to reduce the amount of work. Because the site is distributed but the whole sky, and the resulting material should characterize the stars of heaven. However, even after such reduction the amount of work was very great and the international astronomical Union has distributed it but agreement between different observatories of the globe.

For 70 years already made a huge and very important work. It actively participate in various Observatory. Pulkovo Observatory has long published a catalogue of proper motions of stars in selected areas. Abastumani Observatory issued a catalogue of indicators colors of the stars. Published their works on the definition of the apparent magnitudes of stars in selected areas of the American Observatory mount Wilson, by definition spectra of the stars of German Observatory in Bergedorf, etc. the Collection of all these data on a large number of stars can successfully study the structure of the Galaxy and the properties of its all-star cast.

It is necessary that the cooperative efforts of different countries and observatories around the world continued to turn around and search of extraterrestrial civilizations. Many steps have already been made. Russia has already held "listening" stars t whale, e Eridan, 47 and 380 URSA major, b venatici, p Hair Veronica, h Hercules, p URSA major, h the Driver, y Perseus, h, Bootes. "Auditioned" the Andromeda nebula.

In the United States studied: star Barnard, wolf 359, Latin 726-8, Lalande 21185, Ross 248, e Eridan, 61 Cygni, t whale, 70 Ophiuchus. In addition, already underway "listening" stars from a list of more than 200 names.

While signals, which could be attributed to the intelligent beings on other worlds, was not registered. Nevertheless, the search continues. There is an opinion that the probability of getting a positive result will be more 1/2 only after will be carefully listened 10 thousand stars. In September 1971 in Byurakan astrophysical Observatory hosted an international conference on the problem of "Communication with extraterrestrial civilizations", which was attended by experts of the USSR, the USA, England, Canada, Hungary, Czechoslovakia. At the conference were discussed in detail every aspect of the problem of extraterrestrial civilizations and adopted a resolution, which with small reductions below.

1. Outstanding discoveries of recent years in astronomy, biology, Cybernetics and Radiophysics turned some of the problems of extraterrestrial civilizations and their discovery of a purely speculative to in experimental observation. For the first time in the history of mankind was able to conduct a deep and detailed experimental investigations on this fundamental issue.

2. This problem can be extremely important for the further development of all mankind. If ever extraterrestrial civilizations will be opened, it will have a huge impact PA scientific and technical potential of mankind, and it can also have a positive impact on the future of humanity. Successful communication with extraterrestrial civilization will have a practical and philosophical significance for all humanity, that the attempts of establishing such a link deserve considerable effort. The consequences of opening can contribute to a significant expansion of human knowledge.

3. Technological and scientific potential of our planet appears to be sufficient for the beginning of the case studies in the direction of search of extraterrestrial civilizations. These studies are currently can effectively be carried out by scientific organizations of individual countries. However, already at this stage it seems appropriate joint discussion and coordination of specific programmes of work and exchange of scientific information. 4. At the conference were discussed in detail during various projects of search of extraterrestrial civilizations. Implementation of the most complicated of them will require significant time and effort, as well as the cost of funds commensurate with the cost of space and nuclear research. However, useful search can be started in a more modest scale.