Shklovsky universe life mind read online. For a wide range of readers with secondary education

Shklovsky I S

Universe, life, mind

Shklovsky I. S.

Universe, life, mind

Dedicated to the problem of the possibility of the existence of life, including intelligent life, on other planetary systems. At the same time, the book contains a fairly complete and accessible presentation of the results of modern astrophysics. The book received first prize at the Knowledge Society's competition for the best popular science book. The fifth edition has been revised in accordance with the author's new point of view. The sixth edition, prepared for publication by N. S. Kardashev and V. I. Moroz, is supplemented by three articles by I. S. Shklovsky.

For a wide range of readers with secondary education.

(OCR note: the book contains about 120 figures and many tables. The tables will be given in full in the text; unfortunately, there are no figures, due to the sharp increase in the size of the output file, which is important for the Internet.)

From the editors. I. S. Shklovsky about the Universe, life, mind.

Preface to the fifth edition.

Introduction.

Part one.

ASTRONOMICAL ASPECT OF THE PROBLEM

1. The scale of the Universe and its structure.

2. Basic characteristics of stars.

3. Interstellar medium.

4. Evolution of stars.

5. Supernovae, pulsars and black holes.

6. On the evolution of galaxies.

7. Big Universe.

8. Multiple star systems.

9. On the origin of the solar system.

10. Rotation of stars and planetary cosmogony.

Part two.

LIFE IN THE UNIVERSE

11. Conditions necessary for the emergence and development of life on planets.

12. On the definition of the concept “life”.

13. About the emergence and development of life on Earth.

14. From blue-green algae to humans.

15. "Is there life on Earth?"

16. “Is there life on Mars, is there life on Mars...”

17. Possibility of life on other bodies of the Solar system.

Part three.

INTELLIGENT LIFE IN THE UNIVERSE

18. General notes.

19. Human exploration of the solar system.

20. Radio communications between civilizations located on different planets

systems.

21. Possibility of interstellar communication using optical methods.

22. Communication with alien civilizations using automatic probes.

23. Probability-theoretical analysis of interstellar radio communications. Character

signals.

24. On the possibility of direct contacts between alien civilizations.

25. Remarks on the pace and nature of technological development of mankind.

26. Intelligent life as a cosmic factor.

27. Where are you, brothers in mind?

APPLICATIONS

Appendix I

Searches for extraterrestrial civilizations.

Appendix II.

Is communication with intelligent beings on other planets possible?

Are there other planetary systems?

The collapse of the Jeans hypothesis.

What does the rotation of stars indicate?

Plurality of planetary systems.

Where can life originate?

How many planets can be the cradle of intelligent beings?

Interstellar communication.

What is the nature of this communication channel?

How far will the signal reach?

How to overcome obstacles?

In what direction to search?

Appendix III.

Do extraterrestrial civilizations exist?

FROM THE EDITORS

I. S. Shklovsky about the Universe, life, mind

The author of the book, Joseph Samuilovich Shklovsky, is an outstanding astrophysicist, corresponding member of the USSR Academy of Sciences, member of many foreign academies, who had a significant influence on the development of astrophysics in the second half of the 20th century. He is the creator of a large school of all-wave evolutionary astrophysics, the author of the modern theory of the solar corona, fundamental works on the physics of the interstellar medium based on atomic and molecular radio spectroscopy data, on the connection of cosmic masers with the regions of formation of stars and planetary systems, on the evolution of stars from the main sequence through the red stage giants to planetary nebulae and white dwarfs, about the development of cosmic explosions of supernovae and galactic nuclei, about cosmological relic radiation and, finally, about the problem of life in the Universe.

I. S. Shklovsky was born on July 1, 1916 in Ukraine, in the city of Glukhov. After graduating from a seven-year school, he worked as a foreman on the construction of the Baikal-Amur Railway, in 1933 he entered the Faculty of Physics and Mathematics of Vladivostok University and two years later transferred to the Faculty of Physics of Moscow State University. In 1938, the young optical physicist was accepted into graduate school at the Department of Astrophysics at the State Astronomical Institute named after. P.K. Sternberg at Moscow State University, with which he was subsequently associated throughout his life. Then the beginning of the war, evacuation to Ashgabat (due to poor eyesight they were not taken to the front), return to Moscow, to the State Police, and many years on the front lines of the revolution in astronomy that began in the post-war years. Continuously, from the time of its founding, he headed the department of astrophysics at the Institute of Space Research of the USSR Academy of Sciences and the department of radio astronomy at the SAI. He died in Moscow on March 3, 1985 from an unexpected stroke. He was always a sincere and kind person with a deep analytical mind, inexhaustible humor, and a lively and sociable character. His great talent as a scientist and philosopher, the originality of his thoughts and the simplicity of their presentation, the speaker’s temperament and benevolence towards those thirsting for knowledge, numerous speeches before specialists and a wide audience earned him wide fame both in scientific circles and among students, students, and graduate students. His most characteristic features were a boundless interest in facts, a search for the main thing, a love of simplicity in understanding natural phenomena, and the desire to always be at the forefront.

His interest in the problem of life in the Universe, apparently, began with joint work with V.I. Krasovsky, linking the catastrophic death of reptiles with an increase in short-wave radiation caused by the explosion of a nearby supernova. The work was reported for the first time in 1957 to the SAI and caused a wide resonance. Then I. S. Shklovsky in 1958 became interested in the hypothesis about the artificiality of the satellites of Mars. The anomalous deceleration of Phobos during its orbital movement led us to assume that it was very dense or even empty inside. To confirm the hypothesis, SAI even launched a special project to measure the diameter of Phobos using the first interplanetary stations sent to Mars. The development of interest in the problem of life in the Universe was greatly influenced by the beginning of space research and the publication in 1959 in the journal Nature of an article by J. Cocconi and F. Morrison, proposing to begin a search for artificial signals at a wavelength of 21 cm. The first article by I.S. Shklovsky in the same area was published in the journal “Nature” No. 7 for 1960. It is given in Appendix II. The first edition of the book “Universe, Life, Mind” was published in 1962. The book had a significant impact on the widest circles of readers in our country and abroad. In Appendix I to this 6th edition we present excerpts from the memoirs of I. S. Shklovsky about how this book was created and about the first years of the formation of the problem of searching for life in the Universe. The reader, of course, will notice that these memoirs are written in the style of literary notes and differ markedly from the general text of the book and two articles. Appendix III contains his last article, published in the journal “Earth and Universe”, when Joseph Samuilovich was no longer alive. It is very interesting to compare Appendix II and Appendix III, reflecting the evolution of Joseph Samuilovich’s views over 25 years. The latest concept of I. S. Shklovsky about the possible uniqueness of life on Earth is widely known. This position is connected, on the one hand, with the contradiction between the boundlessness of humanity’s scientific and technical capabilities and the silence of the cosmos, despite the enormous successes of astrophysical observations in recent years. On the other hand, the author’s position was greatly influenced by the spirit of the first successes of space exploration in the 60s and the significant complication of the international situation, the threat of universal destruction, hanging over the world in recent years.

In general, interest in the problem of searching for life in the Universe has continued to grow in recent years on the part of astronomers and workers in various specialties. In 1982, the General Assembly of the International Astronomical Union (MAC) approved the creation of a permanent commission on Bioastronomy. The 1985 Commission consisted of approximately 250 MAC members. The results of recent research were presented at the first International Symposium of this union, held in 1984 (USA). Some of the most significant works are described in this publication.

The authors of this preface do not share the point of view about the uniqueness of life on Earth. And Joseph Samuilovich himself said many times that he would be the first to rejoice if signs of extraterrestrial civilizations were discovered. In our opinion, the main circumstance that complicates the search is the exceptional difficulty of predicting the appearance and behavior if a civilization is billions, millions, thousands or at least hundreds of years older than us (and the age of the Universe with its modern forms of astronomical objects is 10-20 billion years ). Joseph Samuilovich discussed this problem many times with his colleagues. The search for forms of humanoid communities that are at a technological level close to ours is a naive delusion that does not promise any success. Serious programs, apparently, should be based on the search and study of unusual areas of outer space, which could be associated in the future with intelligent, targeted activities. It is likely that a new class of astronomical objects will be discovered, characterized primarily by an anomalously large amount of matter in solid form. Their discovery can be made using astronomical observations, primarily in the millimeter and infrared ranges, where the maximum thermal radiation of such a substance is located. Particularly interesting here are the results of observations using the first infrared space telescope (IRAS, a project of Great Britain, the Netherlands and the USA). The telescope discovered about 200,000 new astronomical objects, some of which have a spectrum similar to that expected from large astronomical structures. Even in our solar system, about 10,000 new objects have been discovered, apparently asteroids. So, when studying these objects, infrared, submillimeter and millimeter astronomy expect major discoveries, possibly in the field of detecting extraterrestrial life. It is also very likely that special radio signals from other civilizations will be detected. It seems to us now that these should be television broadcasts, and the most promising search for them is in the millimeter wave range.

FROM THE EDITORS

I. S. Shklovsky about the Universe, life, mind

The authors of this preface do not share the point of view about the uniqueness of life on Earth. And Joseph Samuilovich himself said many times that he would be the first to rejoice if signs of extraterrestrial civilizations were discovered. In our opinion, the main circumstance complicating the search is the exceptional difficulty of predicting the appearance and behavior if a civilization is billions, millions, thousands or at least hundreds of years older than us (and the age of the Universe with its modern forms of astronomical objects is 10–20 billion years ). Joseph Samuilovich discussed this problem many times with his colleagues. The search for forms of humanoid communities that are at a technological level close to ours is a naive delusion that does not promise any success. Serious programs, apparently, should be based on the search and study of unusual areas of outer space, which could be associated in the future with intelligent, targeted activities. It is likely that a new class of astronomical objects will be discovered, characterized primarily by an anomalously large amount of matter in solid form. Their discovery can be made using astronomical observations, primarily in the millimeter and infrared ranges, where the maximum thermal radiation of such a substance is located. Particularly interesting here are the results of observations using the first infrared space telescope (IRAS, a project of Great Britain, the Netherlands and the USA). The telescope discovered about 200,000 new astronomical objects, some of which have a spectrum similar to that expected from large astronomical structures. Even in our solar system, about 10,000 new objects have been discovered, apparently asteroids. So, when studying these objects, infrared, submillimeter and millimeter astronomy expect major discoveries, possibly in the field of detecting extraterrestrial life. It is also very likely that special radio signals from other civilizations will be detected. It seems to us now that these should be television broadcasts, and the most promising search for them is in the millimeter wave range.

The other side of the research is probably related to the emergence of a new science - the science of the laws and forms of development of civilizations at astronomical time intervals. One of the proposed names for this science is cosmosophy. It is obvious that such a science should be based on the laws of our civilization, generalize them taking into account the diversity of conditions in the Universe, take into account the prospects for the creation of artificial intelligence, immortality, space exploration... In all these issues, I. S. Shklovsky’s book opens up exciting prospects for the reader.

The editors sought to preserve the original text of I. S. Shklovsky as much as possible. Additions made by editors are highlighted with diamonds (#).

N. S. Kardashev, V. I. Moroz

PREFACE TO THE FIFTH EDITION

The first edition of this book was written in the summer of 1962. The publication of the book was timed to coincide with the glorious anniversary - the fifth anniversary of the launch of the first Soviet artificial Earth satellite - an event that, at the proposal of the then President of the USSR Academy of Sciences M. V. Keldysh, should have been widely noted in our scientific press. I will never forget that high intensity of passions and the wonderful excitement constantly experienced at that time by us - witnesses and participants of the Great Enterprise - the first, then still timid, steps on the long path of mankind’s mastery of the Cosmos. Events unfolded with fantastic speed. The first Soviet “Lunniks”, the fantastic feeling of the first, very imperfect photographs of the far side of the Moon, Gagarin’s enchanting flight and Leonov’s first exit into open space. And even then - the first working studies of long-distance space flights to Mars and Venus. Alas, in our age we quickly get used to everything; The generation of people born at the beginning of the space age has already grown up. They will witness even more grandiose and daring achievements. But there is no doubt that mankind’s first breakthrough into space will forever remain the largest milestone in its history.

It's great that Funlab has a place for books like this. The monograph of the famous Soviet astrophysicist is, in my opinion, unique. Its uniqueness lies, first of all, in its “format”. This is not a popular science, but a strictly SCIENTIFIC publication, submitted for publication by a very conservative main editorial board of physical and mathematical literature. It is the strict scientific approach (albeit “popular” in the sense of accessibility of presentation) that is used to consider such fundamental questions of natural science as the evolution of the Universe, planetary cosmogony, the origin and development of life. This approach distinguishes this monograph both from the works of, say, S. Lem, who was fond of purely philosophical terminology, and from notes in non-specialized journals that oversimplify the essence of the matter. Summarizing a huge amount of factual scientific material, talking about “fantastic” hypotheses and forecasts, the author, to a certain extent, makes the reader feel the power of the scientific method, scientific formulation of questions and tasks of the most daring scale. And this is extremely important, perhaps just for SF readers. After all, truly valuable, talented works of science fiction must necessarily take into account not so much the modern level of knowledge (which is constantly increasing, and especially in astronomy), but rather the modern level (style) of scientific THINKING, which changes much more slowly and characterizes entire eras. Of course, we are talking about those works in which the connection between fantastic fiction and the psychological (social) line is immanent, epistemological in nature, and not a conventional literary device. It is probably no coincidence that the author of the monograph mentions the names of I. Efremov, A. Clark, K. Chapek, G. Wells, S. Lem. It is significant that Shklovsky calls (without specifying) the descriptions of interstellar flights in many science fiction works naive and simply ridiculous. By the way, the hypothesis of the Soviet astrophysicist N.S. Kardashev’s story about traveling inside a black hole, in a transformed form, is found in S. Lem’s novel “Fiasco” (a striking example of a “real” SF). In the same novel, Lem used the idea of the interstellar medium as thermonuclear fuel and the working substance of a rocket (“direct thrust”). Shklovsky also talks about this idea. Yes, the difficulties of transgalactic travel are extremely great. However, with a high degree of probability it can be assumed that one way or another they can be overcome, as the author himself says.

At the beginning of the second part (“Life in the Universe”) of his monograph (4th edition), Shklovsky writes ONLY about the arguments in favor of the hypothesis of the multiplicity of planetary systems. And relatively recently (1995), in connection with the development of observational astronomy methods, the very sought-after STRONG EVIDENCE of this most important statement was obtained - planets were discovered around other stars of the Galaxy, the so-called “exoplanets”. This is one of the most visual evidence of the limitless possibilities of knowledge. On the other hand, it is, of course, sad to realize that the landing of man on Mars, which the author envisioned once in the 80s of the twentieth century, has not yet taken place.

Book by I.S. Shklovsky, in my opinion, stimulates the creative imagination, shows the incredible complexity and beauty of the cosmos, more broadly speaking, the objective world. In fact, are there more exciting questions than the mystery of the origin of life and encounters with other stellar civilizations? In general, we can talk about the aesthetics of knowledge. And in this there is a certain similarity of this monograph with good SF literature. (Isn’t this the principle of the synthesis of science and art?) Shklovsky’s monograph can be recommended both as a good “introduction to the subject” and simply as a means of expanding one’s horizons literally into the vast expanses of the Universe.

Current page: 1 (book has 33 pages total) [available reading passage: 19 pages]

FROM THE EDITORS
I. S. Shklovsky about the Universe, life, mind

The authors of this preface do not share the point of view about the uniqueness of life on Earth. And Joseph Samuilovich himself said many times that he would be the first to rejoice if signs of extraterrestrial civilizations were discovered. In our opinion, the main circumstance complicating the search is the exceptional difficulty of predicting the appearance and behavior if a civilization is billions, millions, thousands or at least hundreds of years older than us (and the age of the Universe with its modern forms of astronomical objects is 10–20 billion years ). Joseph Samuilovich discussed this problem many times with his colleagues. The search for forms of humanoid communities that are at a technological level close to us is a naive delusion that does not promise any success. Serious programs, apparently, should be based on the search and study of unusual areas of outer space, which could be associated in the future with intelligent, targeted activities. It is likely that a new class of astronomical objects will be discovered, characterized primarily by an anomalously large amount of matter in solid form. Their discovery can be made using astronomical observations, primarily in the millimeter and infrared ranges, where the maximum thermal radiation of such a substance is located. Particularly interesting here are the results of observations using the first infrared space telescope (IRAS, a project of Great Britain, the Netherlands and the USA). The telescope discovered about 200,000 new astronomical objects, some of which have a spectrum similar to that expected from large astronomical structures. Even in our solar system, about 10,000 new objects have been discovered, apparently asteroids. So, when studying these objects, infrared, submillimeter and millimeter astronomy expect major discoveries, possibly in the field of detecting extraterrestrial life. It is also very likely that special radio signals from other civilizations will be detected. It seems to us now that these should be television broadcasts, and the most promising search for them is in the millimeter wave range.

The editors sought to preserve the original text of I. S. Shklovsky as much as possible. Additions made by editors are highlighted with diamonds (#).

N. S. Kardashev, V. I. Moroz

PREFACE TO THE FIFTH EDITION

I am writing this so that readers understand the atmosphere in which this book was created. To some extent, it demonstrates the long-known phenomenon that a person’s thought always outstrips his real capabilities and thereby serves as a guiding star, pointing to new goals and problems. From the first “children’s” steps of humanity in Space, which we witnessed, to the upcoming restructuring of the Solar system by humanity, there is a huge distance. But this is how a person is designed that he needs to have a perspective.

The subject of this book is as old as human culture. But only in our time has the possibility of a truly scientific analysis of the problem of the multiplicity of inhabited worlds opened up for the first time. It is now obvious that this problem is complex, requiring the most serious attention of the widest range of scientific professions - cybernetics, astronomers, radiophysicists, biologists, sociologists and even economists. Alas, we previously thought this problem was much simpler than it turned out to be. From the era of “teenage optimism”, which recently had a total character (“let’s build a big, big radio telescope and establish contact with aliens”), researchers are beginning a more mature analysis of this most difficult problem. And the more we delve into its understanding, the clearer it becomes that intelligent life in the Universe is an unusually rare phenomenon, and perhaps even unique. The greater the responsibility falls on humanity so that this spark of consciousness, thanks to its unreasonable actions, does not go out, but flares up into a bright fire, observed even from the distant outskirts of our Galaxy.

INTRODUCTION

The idea that intelligent life exists not only on our planet Earth, but is also widespread on many other worlds, arose in ancient times, when astronomy was still in its infancy. Apparently, the roots of these ideas go back to the times of primitive cults, “reviving” the objects and phenomena that surrounded people. Vague ideas about the plurality of inhabited worlds are contained in the Buddhist religion, where they are associated with the idealistic idea of the transmigration of souls. According to this religious teaching, the Sun, Moon and fixed stars are the places where the souls of deceased people move before they reach the state of Nirvana...

As astronomy developed, ideas about the plurality of habitable worlds became more concrete and scientific. Most Greek philosophers, both materialists and idealists, believed that our Earth was by no means the only habitat of intelligent life.

One can only be surprised at the genius of the guesses of the Greek philosophers, given the level of development of science of those times. So, for example, the founder of the Ionian philosophical school Thales taught. that stars are made of the same substance as the Earth. Anaximander argued that worlds come into being and are destroyed. Anaxagoras, one of the first adherents of the heliocentric system, believed that the Moon was inhabited. According to Anaxagoras, invisible “germs of life” are scattered everywhere, which are the cause of the emergence of all living things. Over the following centuries, up to the present day, similar ideas of “panspermia” (the eternity of life) have been repeatedly expressed by various scientists and philosophers. The ideas of the “germs of life” were adopted by the Christian religion soon after its inception.

The materialist philosophical school of Epicurus taught about the plurality of inhabited worlds, and considered these worlds to be quite similar to our Earth. For example, the Epicurean Mitrodorus argued that “...to consider the Earth the only inhabited world in infinite space would be the same blatant absurdity as to say that only one ear of wheat could grow in a huge sown field.” It is interesting that the supporters of this doctrine by “worlds” meant not only planets, but also many other celestial bodies scattered in the boundless expanses of the Universe.

The remarkable Roman materialist philosopher Lucretius Carus was an ardent supporter of the idea of the plurality of inhabited worlds and the limitlessness of their number. In his famous poem “On the Nature of Things,” he wrote: “This whole visible world is not at all the only one in nature, and we must believe that in other regions of space there are other lands with other people and other animals.” It is interesting to note that Lucretius Carus did not understand the nature of stars at all - he considered them to be luminous earthly vapors... Therefore, he placed his worlds inhabited by intelligent beings outside the visible Universe...

Over the next one and a half thousand years, the dominant Christian religion, based on the teachings of Ptolemy, considered the Earth to be the center of the Universe. Under such conditions, there could be no talk of any development of ideas about the plurality of inhabited worlds. The collapse of the Ptolemaic system, associated with the name of the brilliant Polish astronomer Nicolaus Copernicus, for the first time showed humanity its true place in the Universe. Once the Earth was “relegated” to one of the ordinary planets revolving around the Sun, the idea that life was also possible on other planets received serious scientific justification.

Galileo's first telescopic observations, which opened a new era in astronomy, amazed the imagination of his contemporaries. It became clear that planets are celestial bodies similar to Earth in many respects. The question naturally arose: if there are mountains and valleys on the Moon, why not assume that there are also cities inhabited by intelligent beings? And why not consider that our Sun is not the only luminary surrounded by a host of planets? These bold ideas were expressed in a clear and unambiguous form by the great Italian thinker of the sixteenth century, Giordano Bruno. He wrote: “...There are countless suns, countless earths that revolve around their suns, just as our seven planets revolve around our sun... Living beings live on these worlds.”

The Catholic Church brutally dealt with Giordano Bruno. By the court of the Holy Inquisition he was recognized as an incorrigible heretic and burned alive in Rome on the Square of Flowers on February 17, 1600. This crime of the church against science was far from the last. Until the end of the 17th century. The Catholic (as well as Protestant) church fiercely resisted the new, heliocentric system of the world. Gradually, however, the hopelessness of the church's open struggle against the new worldview became clear even to the churchmen themselves. They began to adapt to new conditions. And now theologians already recognize the possibility of the existence of thinking beings on other planets, believing that this does not contradict the basic dogmas of religion...

In the second half of the 17th and 18th centuries. A number of scientists, philosophers and writers have written many books devoted to the problem of the multiplicity of inhabited worlds. Let's name the names of Cyrano de Bergerac, Fontenelle, Huygens, Voltaire. These works, sometimes brilliant in form and containing deep thoughts (especially Voltaire), were completely speculative.

The brilliant Russian scientist M.V. Lomonosov was a staunch supporter of the idea of a plurality of inhabited worlds. The same views were held by such great philosophers and scientists as Kant, Laplace, Herschel. It can be said that this idea became widespread, and there were almost no scientists or thinkers who opposed it. Only a few voices warned against the idea that life, including intelligent life, is common on all planets.

Let us point, for example, to the book of the English scientist Wavell, published in 1853. Wavell, quite boldly for that time (how times change!) stated that not all planets can serve as a refuge for life. For example, he points out that the large planets of the solar system are composed of “water, gases and vapors” and are therefore uninhabitable. Equally uninhabitable are planets that are too close to the Sun, “because due to the large amount of heat, water cannot remain on their surface.” He proves that there can be no life on the Moon - an idea that was very slow to enter the consciousness of people.

Even at the end of the 19th century. the famous astronomer W. Pickering convincingly argued that mass migrations of insects are observed on the surface of the Moon, explaining the observed variability of individual details of the lunar landscape... Note that in relatively recent times this hypothesis in relation to Mars has been revived again...

To what extent were they generally accepted in the 18th century; and the first half of the 19th century. ideas about the widespread distribution of intelligent life can be seen in the following example. The famous English astronomer W. Herschel believed that the Sun is inhabited, and sunspots are gaps in the dazzlingly bright clouds enveloping the dark surface of our star. Through these “gaps” the imaginary inhabitants of the Sun can admire the starry sky... By the way, let us point out that the great Newton also considered the Sun to be inhabited.

In the second half of the 19th century. Flammarion’s book “On the Plurality of Inhabited Worlds” gained great popularity. Suffice it to say that in 20 years it went through 30 editions in France! This book has been translated into a number of foreign languages. In this work, as well as in his other works, Flammarion takes an idealistic position, believing that life is the goal of the formation of planets. Flammarion's books, written in a very temperamental, lively, somewhat pretentious language, made a great impression on his contemporaries. A very strange feeling arises when you read them now, in our days. The discrepancy between the meager amount of knowledge about the nature of the celestial bodies (which was determined by the level of astrophysics that was just beginning to develop at that time) and the categorical judgments about the plurality of inhabited worlds is striking... Flammarion appeals more to the emotions of readers than to their logical thinking.

At the end of the 19th century. and in the 20th century. Various modifications of the old panspermia hypothesis have become widespread. According to this concept, life in the Universe has existed from eternity. Living substance does not arise in any natural way from non-living substance, but is transferred in one way or another from one planet to another.

So, for example, according to Svante Arrhenius, particles of living matter - spores or bacteria, settled on small specks of dust, are transferred from one planet to another by the force of light pressure, maintaining their viability. If conditions on a planet are suitable, the spores that land there germinate and give rise to the evolution of life on it.

Although the possibility of transfer of viable spores from one planet to another cannot in principle be considered excluded, it is now difficult to seriously talk about such a mechanism for the transfer of life from one star system to another (see Chapter 16). Arrhenius believed, for example, that under the influence of light pressure dust grains can move at enormous speed. However, our current knowledge of the nature of the interstellar medium most likely excludes such a possibility. Finally, the very conclusion about the eternity of life in the Universe decisively contradicts the currently existing ideas about the evolution of stars and galaxies. According to these ideas, quite reliably substantiated by a large number of observations, in the past the Universe was purely hydrogen or hydrogen-helium plasma. As the Universe evolves, it is continuously “enriched” with heavy elements (see Chapter 7), which are absolutely necessary for all conceivable forms of living matter.

Further, from the observed “relict” radiation of the Universe it follows that in the past (15–20 billion years ago) conditions in the Universe were such that the existence of life was impossible (see Chapter 6). All this means that life could appear in certain regions of the Universe favorable for its development only at a certain stage of the latter’s evolution. Thus, the main assumption of the panspermia hypothesis turns out to be incorrect.

An ardent supporter of the idea of a plurality of worlds inhabited by intelligent beings was the remarkable Russian scientist, founder of astronautics K. E. Tsiolkovsky. Let us cite just a few of his statements on this issue: “Is it likely that Europe is inhabited, but the other part of the world is not? Can there be one island with inhabitants, and others without them...?” And further: “...All phases of the development of living beings can be seen on different planets. What humanity was several thousand years ago and what it will be after several million years - everything can be found in the planetary world...” If the first quote from Tsiolkovsky essentially repeats the statements of ancient philosophers, then the second contains a new important idea, which was subsequently developed . Thinkers and writers of past centuries imagined civilizations on other planets in social, scientific and technical respects to be quite similar to the modern earthly civilization. Tsiolkovsky rightly pointed out the huge difference in the levels of civilization on different worlds. Nevertheless, it should be noted that the statements of our wonderful scientist on this issue could not then (and even now...) be supported by the conclusions of science.

The development of ideas about the plurality of inhabited worlds is inextricably linked with the development of cosmogonic hypotheses. For example, in the first third of the 20th century, when Jeans’s cosmogonic hypothesis dominated, according to which the planetary system of the Sun was formed as a result of an unlikely cosmic catastrophe (“almost collision” of two stars), most scientists believed that life in the Universe was a rare phenomenon. It seemed extremely unlikely that in our star system - the Galaxy, numbering over 150 billion stars, at least one (besides our Sun) would have a family of planets. The collapse of Jeans' cosmogonic hypothesis in the thirties of this century and the rapid development of astrophysics brought us close to the conclusion that there are a huge number of planetary systems in the Galaxy, and our Solar system may be not so much the exception as the rule in the world of stars. However, this very probable assumption has not yet been rigorously proven (see Chapter 10).

The development of stellar cosmogony also had and is of decisive importance for the problem of the emergence and development of life in the Universe. Already now we know which stars are young, which are old, and for how long the stars emit at that almost constant level that is necessary to support life on the planets orbiting around them. Finally, stellar cosmogony gives a distant forecast of the future of our Sun, which is, of course, decisive for the fate of life on Earth. Thus, the achievements of astrophysics over the past 20–30 years have made possible a scientific approach to the problem of the multiplicity of habitable worlds.

Another major “direction of attack” for this problem is biological and biochemical research. The problem of life is largely a chemical problem. In what way and under what external conditions could the synthesis of complex organic compounds occur, the result of which was the appearance of the first “grains” of living matter on the planet? Over the past decades, biochemists have made significant progress on this problem. Here they primarily rely on the results of laboratory experiments. Nevertheless, as it seems to the author of this book, only in recent years has it become possible to approach the question of the origin of life on Earth, and, consequently, on other planets. Only now is the curtain beginning to lift over the “holy of holies” of living substance – heredity.

The outstanding successes of genetics and, above all, the elucidation of the “cybernetic meaning” of deoxyribonucleic and ribonucleic acids urgently require a new definition of the most basic concept of “life”. It is becoming increasingly clear that the problem of the origin of life is largely a genetic problem. The enormous successes of molecular biology allow us to hope that this most important problem of natural science will be solved in the foreseeable future.

A fundamentally new stage in the development of ideas about the plurality of inhabited worlds began with the launch in our country of the first artificial Earth satellite. In the thirty years that have elapsed since the memorable day of October 4, 1957, amazing successes have been achieved in mastering and studying the areas of outer space closest to our planet. The apotheosis of these successes were the triumphant flights of Soviet and American cosmonauts. People somehow suddenly “weightily, roughly, visibly” felt that they inhabited a very small planet surrounded by limitless outer space. Of course, all of them were taught (most often quite poorly) astronomy in schools, and they “theoretically” knew the place of the Earth in space. However, in their specific activities, people were guided, so to speak, by “practical geocentrism.” Therefore, one cannot even overestimate the revolution in the consciousness of people, which marked the beginning of a new era in the history of mankind - the era of direct study and, in the long term, the conquest of space.

The question of life on other worlds, which until recently was purely abstract, is now acquiring real practical significance. In the coming years, if we talk about the planets of the Solar System, it will be finally solved experimentally. Special instruments - indicators of life - have been and will be sent to the surface of the planets and will give a confident answer: is there life there and, if so, what kind of life. The time is not far off when astronauts will land on Mars, and maybe even on the mysterious, inhospitable Venus, and will be able to study life there (if it exists, of course) using the same methods as biologists on Earth. Most likely, however, they will not find any, even the most primitive forms of life there, as indicated by the results of experiments already performed.

As an expression of the enormous interest of broad sections of the people in the problem of the habitability of other worlds, one should consider the appearance in the last three decades of a number of works by prominent physicists and astronomers, in which the problem of establishing communications with intelligent beings inhabiting other planetary systems is strictly scientifically examined. A number of scientific conferences dedicated to extraterrestrial civilizations have already taken place in the USA and in our country. When developing this fascinating problem, scientists cannot be confined to their specialty. It is necessary to build certain hypotheses about the ways of development of civilizations in the future of thousands and millions of years. And this, really, is not an easy and not entirely defined task... And yet it must be solved, since it has a very specific meaning, and most importantly, the correctness of the solution can, in principle, be verified by the criterion of practice.

The purpose of this book is to acquaint a wide range of readers interested in the fascinating problem of life in the Universe with the current state of this problem. We emphasize “with modern”, since the development of our ideas about the multiplicity of inhabited worlds is now proceeding quite quickly. In addition, in contrast to other books devoted to this problem (for example, A. I. Oparin and V. G. Fesenkov “Life in the Universe” and G. Spencer Jones “Life on Other Worlds”), which mainly discusses the issue of life Only on the planets of the solar system - Mars and Venus - on the basis of hopelessly outdated data, have we paid quite a lot of attention to other planetary systems. Finally, an analysis of the possibilities of intelligent life in the Universe and the problem of establishing communications between civilizations separated by interstellar distances, as far as we know, was not carried out in any book before 1962, when the first edition of this book was written.

This book consists of three parts. The first part contains astronomical information necessary for understanding modern ideas about the evolution of galaxies, stars and planetary systems. The second part examines the conditions for the emergence of life on a planet. In addition, the question of the habitability of Mars, Venus and other planets of the solar system is discussed here. This part concludes with a critical examination of current versions of the panspermia hypothesis. Finally, the third part contains an analysis of the possibility of intelligent life in certain areas of the Universe. Particular attention is paid to the problem of establishing contacts between civilizations of different planetary systems. By its nature, the third part of the book differs from the first two, which set out specific results and results of the development of science in the relevant areas. By necessity, a hypothetical element predominates in this part - after all, we have not yet established contacts with alien civilizations and, in essence, it is not known when we will establish or whether we will establish them at all... But this in no way means that this part is devoid of scientific content and is pure fantasy. On the contrary, it is here that the latest achievements of science and technology, which in the future can lead to success, are analyzed, and as strictly as possible. At the same time, this part of the book allows us to give some real idea of the power of the human mind even at the present stage of its development. After all, humanity has already become a factor of cosmic significance through its active activities. What can we expect in a few centuries?