The starry sky has long excited the human imagination. Our distant ancestors tried to understand what kind of strange twinkling dots hang over their heads. How many of them, where did they come from, do they affect earthly events? Since ancient times, man has tried to comprehend how the Universe in which he lives works.

About how ancient people imagined the Universe, today we can only learn from fairy tales and legends that have come down to us. It took centuries and millennia for the emergence and strengthening of the science of the Universe, studying its properties and stages of development - cosmology. The cornerstones of this discipline are astronomy, mathematics and physics.

Today we understand the structure of the Universe much better, but each knowledge gained only gives rise to new questions. The study of atomic particles in a collider, the observation of life in the wild, the landing of an interplanetary probe on an asteroid can also be called the study of the Universe, because these objects are part of it. Man is also a part of our beautiful stellar universe. By studying the solar system or distant galaxies, we learn more about ourselves.

Cosmology and objects of its study

The very concept of the Universe does not have a clear definition in astronomy. in different historical periods and among various peoples it had a number of synonyms, such as "cosmos", "world", "universe", "universe" or "celestial sphere". Often, when speaking about the processes occurring in the depths of the Universe, the term "macrocosm" is used, the opposite of which is the "microcosm" of the world of atoms and elementary particles.

On the difficult path of knowledge, cosmology often intersects with philosophy and even theology, and there is nothing surprising in this. The science of the structure of the Universe is trying to explain when and how the universe arose, to unravel the mystery of the origin of matter, to understand the place of the Earth and humanity in the infinity of space.

Modern cosmology has two biggest problems. First, the object of its study - the Universe - is unique, which makes it impossible to use statistical schemes and methods. In short, we do not know about the existence of other Universes, their properties, structure, so we cannot compare. Secondly, the duration of astronomical processes does not make it possible to conduct direct observations.

Cosmology proceeds from the postulate that the properties and structure of the Universe are the same for any observer, with the exception of rare cosmic phenomena. This means that the matter in the universe is distributed uniformly, and it has the same properties in all directions. It follows that physical laws operating in a part of the Universe can be extrapolated to the entire Metagalaxy.

Theoretical cosmology develops new models, which are then confirmed or refuted by observations. For example, the theory of the origin of the Universe as a result of an explosion was proved.

Age, size and composition

The scale of the universe is amazing: it is much larger than we could have imagined twenty or thirty years ago. Scientists have already discovered about five hundred billion galaxies, and the number is constantly increasing. Each of them rotates around its own axis and moves away from the others at great speed due to the expansion of the Universe.

Quasar 3C 345 is one of the brightest objects in the Universe, located at a distance of five billion light years from us. The human mind cannot even imagine such distances. space ship moving at the speed of light would take a thousand years to circle our Milky Way. It would take him 2.5 thousand years to get to the Andromeda galaxy. And it's the closest neighbor.

Speaking about the size of the Universe, we mean its visible part, also called the Metagalaxy. The more observations we get, the further the boundaries of the universe are pushed apart. Moreover, this happens simultaneously in all directions, which proves its spherical shape.

Our world appeared about 13.8 billion years ago as a result of the Big Bang - an event that gave birth to stars, planets, galaxies and other objects. This figure is the real age of the universe.

Based on the speed of light, it can be assumed that its size is also 13.8 billion light years. However, in fact, they are larger, because since the moment of birth, the Universe has been continuously expanding. Part of it is moving at superluminal speed, due to which a significant number of objects in the Universe will remain invisible forever. This limit is called the Hubble sphere or horizon.

The diameter of the Metagalaxy is 93 billion light years. We do not know what is beyond the known universe. Perhaps there are more distant objects that are inaccessible today for astronomical observations. A significant part of scientists believe in the infinity of the universe.

The age of the universe has been repeatedly verified using various methods and scientific tools. It was last confirmed by the Planck space telescope. The available data are fully consistent with modern models of the expansion of the Universe.

What is the universe made of? Hydrogen is the most common element in the universe (75%), followed by helium (23%), the remaining elements account for a mere 2% of the total amount of matter. The average density is 10-29 g/cm3, a significant part of which falls on the so-called dark energy and matter. The ominous names do not speak of their inferiority, just dark matter, unlike ordinary, does not interact with electromagnetic radiation. Accordingly, we cannot observe it and draw our conclusions only on indirect grounds.

Based on the above density, the mass of the universe is approximately 6*1051 kg. It should be understood that this figure does not include the dark mass.

The structure of the universe: from atoms to galactic clusters

Space is not just a huge void in which stars, planets and galaxies are evenly scattered. The structure of the Universe is quite complex and has several levels of organization, which we can classify according to the scale of objects:

1. Astronomical bodies in the universe are usually grouped into systems. Stars often form pairs or are part of clusters that contain dozens or even hundreds of stars. In this respect, our Sun is rather atypical, since it does not have a "double";
2. Galaxies are the next level of organization. They can be spiral, elliptical, lenticular, irregular. Scientists do not yet fully understand why galaxies have different shapes. At this level, we discover such wonders of the universe as black holes, dark matter, interstellar gas, binary stars. In addition to stars, they include dust, gas, and electromagnetic radiation. Several hundred billion galaxies have been discovered in the known universe. They often run into each other. It's not like a car accident: the stars just mix and change their orbits. Such processes take millions of years and lead to the formation of new star clusters;
3. Several galaxies form the Local Group. In addition to the Milky Way, ours includes the Triangulum Nebula, the Andromeda Nebula and 31 more systems. Clusters of galaxies are the largest known stable structures in the universe, held together by the gravitational force and some other factor. Scientists have calculated that gravity alone is clearly not enough to maintain the stability of these objects. There is no scientific justification for this phenomenon yet;
4. The next level of the structure of the Universe are superclusters of galaxies, each of which contains dozens or even hundreds of galaxies and clusters. However, gravity no longer holds them, so they follow the expanding universe;
5. The last level of organization of the universe are cells or bubbles, the walls of which form superclusters of galaxies. Between them are empty areas called voids. These structures of the Universe have scales of about 100 Mpc. At this tier, the processes of the expansion of the Universe are most noticeable, and the relic radiation is also associated with it - an echo of the Big Bang.

How did the universe come into being

How did the universe come into existence? What happened before this moment? How did it become that infinite space we know today? Was it an accident or a natural process?

After decades of discussion and furious debate, physicists and astronomers have almost come to a consensus that the universe came into being as a result of an explosion of colossal power. He not only gave rise to all matter in the universe, but also determined the physical laws by which the cosmos known to us exists. This is called the Big Bang theory.

According to this hypothesis, once all matter was in some incomprehensible way collected in one small point with infinite temperature and density. It is called the Singularity. 13.8 billion years ago, the point exploded, forming stars, galaxies, their clusters and other astronomical bodies of the Universe.

Why and how this happened is unclear. Scientists have to bracket out many questions related to the nature of the singularity and its origin: a complete physical theory this stage in the history of the universe does not yet exist. It should be noted that there are other theories of the origin of the Universe, but they have much fewer adherents.

The term "Big Bang" came into use in the late 40s after the publication of the work of the British astronomer Hoyle. Today, this model is thoroughly developed - physicists can confidently describe the processes that took place a fraction of a second after this event. It can also be added that this theory made it possible to determine the exact age of the Universe and describe the main stages of its evolution.

The main evidence for the Big Bang theory is the presence of cosmic microwave background radiation. It was opened in 1965. This phenomenon arose as a result of the recombination of hydrogen atoms. Relic radiation can be called the main source of information about how the Universe was arranged billions of years ago. It is isotropic and uniformly fills the outer space.

Another argument in favor of the objectivity of this model is the very fact of the expansion of the Universe. As a matter of fact, by extrapolating this process into the past, scientists have come to a similar concept.

There are weaknesses in the Big Bang theory. If the universe were formed instantly from one small point, then there should have been a non-uniform distribution of matter, which we do not observe. Also, this model cannot explain where the antimatter got to, the amount of which at the “moment of creation” should not have been inferior to ordinary baryonic matter. However, now the number of antiparticles in the universe is negligible. But the most significant drawback of this theory is its inability to explain the phenomenon of the Big Bang, it is simply perceived as a fait accompli. We don't know what the universe looked like before the singularity.

There are other hypotheses of the origin and further evolution of the universe. The model of a stationary universe has been popular for many years. A number of scientists were of the opinion that, as a result of quantum fluctuations, it arose from a vacuum. Among them was the famous Stephen Hawking. Lee Smolin put forward the theory that ours, like other universes, formed inside black holes.

Attempts have been made to improve the existing Big Bang theory. For example, there is a hypothesis about the cyclic nature of the Universe, according to which the birth from a singularity is nothing more than its transition from one state to another. True, this approach contradicts the second law of thermodynamics.

The evolution of the universe or what happened after the Big Bang

The Big Bang theory allowed scientists to create an accurate model of the evolution of the Universe. And today we know quite well what processes took place in the young Universe. The only exception is the very early stage of creation, which is still the subject of fierce discussion and controversy. Of course, to achieve such a result, one theoretical basis was not enough, it took years of research into the Universe and thousands of experiments on accelerators.

Today, science identifies the following stages after the Big Bang:

1. The earliest period known to us is called the Planck era, it occupies a segment from 0 to 10-43 seconds. At this time, all the matter and energy of the universe was collected at one point, and the four main interactions were one;
2. The era of the Great Unification (from 10-43 to 10-36 seconds). It is characterized by the appearance of quarks and the separation of the main types of interactions. The main event of this period is the release of gravitational force. In this era, the laws of the universe began to take shape. Today we have the opportunity for a detailed description of the physical processes of this era;
3. The third stage of creation is called the Age of Inflation (from 10-36 to 10-32). At this time, the rapid movement of the Universe began at a speed significantly exceeding the speed of light. It becomes larger than the present visible universe. Cooling starts. In this period, the fundamental forces of the universe are finally separated;
4. In the period from 10−32 to 10−12 seconds, "exotic" particles of the Higgs boson type appear, the space is filled with quark-gluon plasma. The interval from 10−12 to 10−6 seconds is called the era of quarks, from 10−6 to 1 second - hadrons, at 1 second after the Big Bang the era of leptons begins;
5. Phase of nucleosynthesis. It lasted until about the third minute from the start of events. During this period, helium, deuterium, and hydrogen atoms arise from particles in the Universe. Cooling continues, space becomes transparent for photons;
6. Three minutes after the Big Bang, the era of Primary Recombination begins. During this period, the relic radiation appeared, which astronomers are still studying;
7. The period of 380 thousand - 550 million years is called the Dark Ages. The universe at this time is filled with hydrogen, helium, various types radiation. There were no sources of light in the universe;
8. 550 million years after Creation, stars, galaxies and other wonders of the universe appear. The first stars explode, releasing matter to form planetary systems. This period is called the Era of Reionization;
9. At the age of 800 million years, the first star systems with planets. The Age of Substance is coming. During this period, our home planet is also formed.

It is believed that the period of interest for cosmology is from 0.01 seconds after the act of creation to the present day. In this time period, primary elements were formed, from which stars, galaxies, and the solar system arose. For cosmologists, the era of recombination is considered to be a particularly important period, when the cosmic microwave background radiation arose, with the help of which the study of the known Universe continues.

History of cosmology: ancient period

Man has been thinking about the structure of the world around him since time immemorial. The earliest ideas about the structure and laws of the universe can be found in fairy tales and legends. different peoples peace.

It is believed that regular astronomical observations were first practiced in Mesopotamia. Several developed civilizations successively lived on this territory: the Sumerians, Assyrians, Persians. We can learn about how they imagined the Universe from the many cuneiform tablets found on the site of ancient cities. The first records concerning the movement of celestial bodies date back to the 6th millennium BC.

Of the astronomical phenomena, the Sumerians were most interested in cycles - the change of seasons and the phases of the moon. The future harvest and health of domestic animals depended on them, and, consequently, the survival of the human population. From this, a conclusion was drawn about the influence of celestial bodies on the processes occurring on Earth. Therefore, by studying the Universe, you can predict your future - this is how astrology was born.

The Sumerians invented a pole to determine the height of the Sun, created a solar and lunar calendar, described the main constellations, and discovered some laws of celestial mechanics.

Much attention was paid to the movement of space objects in religious practices. ancient egypt. The inhabitants of the Nile Valley used a geocentric model of the universe, in which the Sun revolved around the Earth. Many ancient Egyptian texts containing astronomical information have come down to us.

The science of the sky has reached significant heights in Ancient China. Here in the III millennium BC. e. the post of court astronomer appeared, and in the XII century BC. e. the first observatories were opened. We mainly know about solar eclipses, comet flybys, meteor showers and other interesting cosmic events of antiquity from Chinese annals and chronicles, which were meticulously kept for centuries.

Astronomy was held in high esteem among the Hellenes. They studied this issue in numerous philosophical schools, each of which, as a rule, had its own system of the Universe. The Greeks were the first to suggest the spherical shape of the Earth and the rotation of the planet around its own axis. The astronomer Hipparchus introduced the concepts of apogee and perigee, orbital eccentricity, developed models of the motion of the Sun and Moon, and calculated the periods of rotation of the planets. A great contribution to the development of astronomy was made by Ptolemy, who can be called the creator of the geocentric model of the solar system.

Great heights in the study of the laws of the universe reached the Mayan civilization. This is confirmed by the results of archaeological excavations. The priests knew how to predict solar eclipses, they created a perfect calendar, built numerous observatories. Mayan astronomers observed nearby planets and were able to accurately determine their orbital periods.

Middle Ages and Modern Times

After the collapse of the Roman Empire and the spread of Christianity, Europe plunged into the Dark Ages for almost a millennium - development natural sciences, including astronomy, has practically stopped. Europeans drew information about the structure and laws of the Universe from biblical texts, a few astronomers firmly adhered to the geocentric system of Ptolemy, and astrology enjoyed unprecedented popularity. The real study of the universe by scientists began only in the Renaissance.

At the end of the 15th century, Cardinal Nicholas of Cusa put forward a bold idea about the universality of the universe and the infinity of the depths of the universe. By the 16th century, it became clear that Ptolemy's views were erroneous, and without the adoption of a new paradigm, the further development of science was unthinkable. The Polish mathematician and astronomer Nicolaus Copernicus, who proposed a heliocentric model of the solar system, decided to break the old model.

From a modern point of view, his concept was imperfect. In Copernicus, the movement of the planets was provided by the rotation of the celestial spheres to which they were attached. The orbits themselves had a circular shape, and on the border of the world was a sphere with fixed stars. However, by placing the Sun at the center of the system, the Polish scientist undoubtedly made a real revolution. The history of astronomy can be divided into two large parts: the ancient period and the study of the universe from Copernicus to the present day.

In 1608, the Italian scientist Galileo invented the world's first telescope, which gave a huge impetus to the development of observational astronomy. Now scientists could contemplate the depths of the universe. It turned out that the Milky Way consists of billions of stars, the Sun has spots, the Moon has mountains, and satellites revolve around Jupiter. The advent of the telescope caused a real boom in optical observations of the wonders of the universe.

In the middle of the 16th century, the Danish scientist Tycho Brahe was the first to start regular astronomical observations. He proved the cosmic origin of comets, thereby refuting the idea of ​​Copernicus about the celestial spheres. At the beginning of the 17th century, Johannes Kepler unraveled the mysteries of planetary motion by formulating his famous laws. At the same time, the Andromeda and Orion nebulae, the rings of Saturn were discovered, and the first map of the lunar surface was compiled.

In 1687, Isaac Newton formulated the law of universal gravitation, which explains the interaction of all components of the universe. He made it possible to see the hidden meaning of Kepler's laws, which, in fact, were derived empirically. The principles discovered by Newton allowed scientists to take a fresh look at the space of the Universe.

The 18th century was a period of rapid development of astronomy, greatly expanding the boundaries of the known universe. In 1785, Kant came up with the brilliant idea that the Milky Way was a huge collection of stars, pulled together by gravity.

At this time, new celestial bodies appeared on the "map of the Universe", telescopes were improved.

In 1785, the English astronomer Herschel, based on the laws of electromagnetism and Newtonian mechanics, tried to create a model of the universe and determine its shape. However, he failed.

In the 19th century, the instruments of scientists became more precise, and photographic astronomy appeared. Spectral analysis, which appeared in the middle of the century, led to a real revolution in observational astronomy - now the chemical composition of objects has become a topic for research. The asteroid belt was discovered, the speed of light was measured.

Breakthrough era or modern times

The twentieth century was the era of real breakthroughs in astronomy and cosmology. At the beginning of the century, Einstein revealed to the world his theory of relativity, which made a real revolution in our ideas about the universe and allowed us to take a fresh look at the properties of the universe. In 1929, Edwin Hubble discovered that our universe is expanding. In 1931, Georges Lemaitre put forward the idea of ​​its formation from one tiny point. In fact, this was the beginning of the Big Bang theory. In 1965, the relic radiation was discovered, which confirmed this hypothesis.

In 1957, the first artificial satellite and then the space age began. Now astronomers could not only observe celestial bodies through telescopes, but also explore them up close with the help of interplanetary stations and descending probes. We were even able to land on the surface of the moon.

The 1990s can be called "the period dark matter". Her discovery explained the acceleration of the expansion of the universe. At this time, new telescopes were put into operation, allowing us to push the limits of the known universe.

In 2016, gravitational waves were discovered, which is likely to usher in a new branch of astronomy.

Over the past centuries, we have greatly expanded the boundaries of our knowledge of the universe. However, in reality, people just opened the door and looked into a huge and wonderful world full of secrets and amazing wonders.

If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.

The science of celestial bodies

First letter "a"

Second letter "s"

Third letter "t"

The last beech is the letter "I"

Answer for the clue "Science of celestial bodies", 10 letters:
astronomy

Alternative questions in crossword puzzles for the word astronomy

What did the muse Urania patronize?

science of the universe

Caroline Herschel assisted her brother William from 1782 and became one of the first women in this science.

One of the seven free sciences

Word definitions for astronomy in dictionaries

Dictionary Russian language. S.I. Ozhegov, N.Yu. Shvedova. The meaning of the word in the dictionary Explanatory dictionary of the Russian language. S.I. Ozhegov, N.Yu. Shvedova.
-and, well. Science of space bodies ah, the systems they form and about the universe as a whole. adj. astronomical, th, th. Astronomical unit (distance from the Earth to the Sun). Astronomical number (trans.: extremely large).

Encyclopedic Dictionary, 1998 The meaning of the word in the dictionary Encyclopedic Dictionary, 1998
ASTRONOMY (from astro ... and Greek nomos - law) is the science of the structure and development of cosmic bodies, the systems they form and the Universe as a whole. Astronomy includes spherical astronomy, practical astronomy, astrophysics, celestial mechanics, stellar astronomy,...

Explanatory dictionary of the Russian language. D.N. Ushakov The meaning of the word in the dictionary Explanatory dictionary of the Russian language. D.N. Ushakov
astronomy, pl. no, w. (from the Greek astron - star and nomos - law). The science of celestial bodies.

New explanatory and derivational dictionary of the Russian language, T. F. Efremova. The meaning of the word in the dictionary New explanatory and derivational dictionary of the Russian language, T. F. Efremova.
and. A complex scientific discipline that studies the structure and development of cosmic bodies, their systems and the Universe as a whole. Academic subject, containing the theoretical foundations of this scientific discipline. unfold A textbook that outlines the content of a given subject.

Big Soviet Encyclopedia The meaning of the word in the dictionary Great Soviet Encyclopedia
"Astronomy", abstract journal of the All-Union Institute of Scientific and Technical Information of the USSR Academy of Sciences. It has been published in Moscow since 1963 (the abstract journal Astronomy and Geodesy was published in 1953–62); 12 issues per year. Publishes abstracts, annotations or bibliographical...

Examples of the use of the word astronomy in the literature.

Ancient sailing directions Sea of ​​Azov side by side with textbooks astronomy and navigation.

Just as these concrete problems, solved by algebraic methods, cannot be considered part of the abstract science of algebra, so, in my opinion, the concrete problems astronomy cannot in any way be included in that branch of abstract-concrete science that develops the theory of action and reaction of free bodies that attract each other.

So it was with the discovery that the refraction and scattering of light do not follow the same law of change: this discovery had an impact both on astronomy, and on physiology, giving us achromatic telescopes and microscopes.

Soon Biruni begins to seriously deal with issues astronomy, already at the age of 21, having achieved important results.

Matthew Vlastar is absolutely correct from the point of view astronomy explains this, which has arisen over time, violation.

in natural science

Topic: Modern science of the origin of the Universe.

Completed student

course

_______________________

Teacher:

_______________________

_______________________

PLAN A:

Introduction 3

Pre-scientific consideration of the origin of the universe. 5

20th century theories about the origin of the universe. 8

Modern science of the origin of the universe. 12

Used literature: 18

Throughout its existence, Man studies the world around him. Being a thinking being, Man, both in the distant past and now, could not and cannot be limited by what is directly given to him at the level of his everyday life. practical activities, and has always striven and will strive to go beyond it.

It is characteristic that the knowledge of the surrounding world by man began with cosmogonic reflections. It was then, at the dawn of mental activity, that the idea of ​​"the beginning of all beginnings" arose. History does not know a single people who, sooner or later, in one form or another, did not ask this question and would not try to answer it. The answers, of course, were different, depending on the level of spiritual development of a given people. The development of human thought, scientific and technological progress made it possible to advance in resolving the issue of the origin of the Universe from mythological thinking to the construction of scientific theories.

The problem of the "beginning of the world" is one of those few ideological problems that run through the entire intellectual history of mankind. Appearing once on White light, the idea of ​​the "beginning of the world" has always occupied the thoughts of scientists since then, and from time to time in one form or another resurfaces again and again. Thus, seemingly buried forever in the Middle Ages, it unexpectedly appeared on the horizon of scientific thought in the second half of the 20th century and began to be seriously discussed on the pages of special journals and at meetings of problematic symposiums.

Over the past century, the science of the universe has reached the highest floors structural organization matter - galaxies, their clusters and superclusters. Modern cosmology has actively taken up the problem of the origin (formation) of these cosmic formations.

How did our distant ancestors imagine the formation of the Universe? Explains the origin of the universe modern science? Consideration of these and other questions related to the emergence of the Universe is devoted to this.

Where did it all start? How did everything cosmic become the way it appears before humanity? What were the initial conditions that laid the foundation for the observable universe?

The answer to these questions has changed with the development of human thought. Among the ancient peoples, the origin of the Universe was endowed with a mythological form, the essence of which boils down to one thing - a certain deity created the entire world surrounding Man. In accordance with the ancient Iranian mythopoetic cosmogony, the Universe is the result of the activity of two equivalent and interconnected creative principles - the god of Good - Ahuramazda and the god of Evil - Ahriman. According to one of her texts, the primordial being, the division of which led to the formation of parts of the visible Universe, was the primordially existing Cosmos. The mythological form of the origin of the Universe is inherent in all existing religions.

Many outstanding thinkers of distant historical epochs tried to explain the origin, structure and existence of the Universe. They deserve special respect for their attempts, in the absence of modern technical means, to comprehend the essence of the Universe using only their mind and the simplest devices. If you make a short digression into the past, you will find that the idea of ​​an evolving universe, adopted by modern scientific thought, was put forward by the ancient thinker Anaxagoras (500-428 BC). Noteworthy is the cosmology of Aristotle (384-332 BC), and the works of the outstanding thinker of the East Ibn Sina (Avicenna) (980-1037), who tried to logically refute the divine creation of the world, and other names that have come down to our time.

Human thought does not stand still. Along with the change in the idea of ​​the structure of the Universe, the idea of ​​its origin also changed, although in the conditions of the existing strong ideological power of religion, this was associated with a certain danger. Maybe this explains the fact that the natural science of the modern European time avoided discussing the issue of the origin of the Universe and focused on studying the structure of the Near Cosmos. This scientific tradition determined for a long time the general direction and the very methodology of astronomical and then astrophysical research. As a result, the foundations of scientific cosmogony were laid not by natural scientists, but by philosophers.

Descartes was the first to take this path, who tried to theoretically reproduce "the origin of the luminaries, the Earth and all the other visible world as if from some seeds" and give a unified mechanical explanation of the totality of astronomical, physical and biological phenomena known to him. However, Descartes' ideas were far from contemporary science.

Therefore, it would be more fair to start the history of scientific cosmogony not with Descartes, but with Kant, who painted a picture of the "mechanical origin of the entire universe." It is Kant who belongs to the first in the scientific-cosmogonic hypothesis about the natural mechanism of the emergence of the material world. In the boundless space of the Universe, recreated by the creative imagination of Kant, the existence of countless other solar systems and other milky way as natural as continuing education new worlds and the death of old ones. It is with Kant that the conscious and practical combination of the principle of universal connection and unity of the material world begins. The universe has ceased to be a collection of divine bodies, perfect and eternal. Now, before the astonished human mind, a world harmony of a completely different kind appeared - the natural harmony of systems of interacting and evolving astronomical bodies, interconnected as links in one chain of nature. However, two characteristics further development scientific cosmology. The first of these is that post-Kantian cosmogony limited itself to the solar system and until the middle of the twentieth century it was only about the origin of the planets, while the stars and their systems remained beyond the horizon. theoretical analysis. The second feature is that the limited observational data, the uncertainty of available astronomical information, the impossibility of experimental substantiation of cosmogonic hypotheses ultimately led to the transformation of scientific cosmogony into a system of abstract ideas, cut off not only from other branches of natural science, but also from related branches of astronomy.

The next stage in the development of cosmology dates back to the 20th century, when the Soviet scientist A.A. Fridman (1888-1925) mathematically proved the idea of ​​a self-developing Universe. The work of A.A. Fridman radically changed the foundations of the former scientific worldview. According to him, the cosmological initial conditions for the formation of the Universe were singular. Explaining the nature of the evolution of the Universe, expanding starting from a singular state, Friedman singled out two cases in particular:

a) the radius of curvature of the Universe is constantly increasing over time, starting from zero;

b) the radius of curvature changes periodically: the Universe shrinks to a point (to nothing, a singular state), then again from a point, brings its radius to a certain value, then again, reducing the radius of its curvature, turns into a point, etc.

In a purely mathematical sense, the singular state appears as nothing - a geometric entity of zero size. In physical terms, the singularity appears as a very peculiar state in which the density of matter and the curvature of space-time are infinite. All superhot, supercurved and superdense cosmic matter is literally drawn into a point and can, according to the figurative expression of the American physicist J. Wheeler, "squeeze through the eye of a needle."

Turning to the assessment of the modern view of the singular beginning of the Universe, it is necessary to pay attention to the following important features of the problem under consideration as a whole.

First, the concept of the initial singularity has a rather specific physical content, which, as science develops, is more and more detailed and refined. In this regard, it should be considered not as a conceptual fixation of the absolute beginning of "all things and events", but as the beginning of the evolution of that fragment of cosmic matter, which at the present level of development of natural science has become an object of scientific knowledge.

Secondly, if, according to modern cosmological data, the evolution of the Universe began 15-20 billion years ago, this does not mean at all that the Universe did not exist before that or was in a state of eternal stagnation.

Achievements of science expanded the possibilities in cognition of the world around Man. New attempts were made to explain how it all began. Georges Lemaitre was the first to raise the question of the origin of the observed large-scale structure of the universe. He put forward the concept of the "Big Bang" of the so-called "primitive atom" and the subsequent transformation of its fragments into stars and galaxies. Of course, from the height of modern astrophysical knowledge, this concept is only of historical interest, but the very idea of ​​the initial explosive movement of cosmic matter and its subsequent evolutionary development has become an integral part of the modern scientific picture of the world.

A fundamentally new stage in the development of modern evolutionary cosmology is associated with the name of the American physicist G.A. Gamow (1904-1968), thanks to whom the concept of a hot Universe entered science. According to his model of the "beginning" of the evolving Universe, Lemaitre's "primal atom" consisted of highly compressed neutrons, the density of which reached a monstrous value - one cubic centimeter of the primary substance weighed a billion tons. As a result of the explosion of this "primary atom", according to G.A. Gamov, a kind of cosmological cauldron was formed with a temperature of about three billion degrees, where natural synthesis took place chemical elements. Fragments of the primary egg - individual neutrons then decayed into electrons and protons, which, in turn, combined with undecayed neutrons, formed the nuclei of future atoms. All this happened in the first 30 minutes after the Big Bang.

The hot model was a specific astrophysical hypothesis, indicating the ways of experimental verification of its consequences. Gamow predicted the existence at the present time of the remnants of the thermal radiation of the primary hot plasma, and his collaborators Alfer and Herman back in 1948 quite accurately calculated the temperature of this residual radiation of the already modern Universe. However, Gamow and his collaborators failed to give a satisfactory explanation for the natural formation and prevalence of heavy chemical elements in the Universe, which caused skepticism towards his theory on the part of specialists. As it turned out, the proposed mechanism of nuclear fusion could not ensure the occurrence of the now observed amount of these elements.

Scientists began to look for other physical models of the "beginning". In 1961, Academician Ya.B. Zeldovich put forward an alternative cold model, according to which the original plasma consisted of a mixture of cold (with a temperature below absolute zero) degenerate particles - protons, electrons and neutrinos. Three years later, astrophysicists I.D. Novikov and A.G. Doroshkevich made a comparative analysis of two opposite models of cosmological initial conditions - hot and cold - and indicated the way of experimental verification and selection of one of them. It was proposed to try to detect the remnants of primary radiation by studying the spectrum of radiation from stars and cosmic radio sources. The discovery of the remnants of the primary radiation would confirm the correctness of the hot model, and if they do not exist, then this will testify in favor of the cold model.

Almost at the same time, a group of American researchers led by physicist Robert Dicke, not knowing about the published results of the work of Gamow, Alfer and Herman, revived the hot model of the Universe based on other theoretical considerations. By means of astrophysical measurements, R.Dicke and his collaborators found confirmation of the existence of cosmic thermal radiation. This landmark discovery made it possible to obtain important, previously inaccessible information about the initial stages of the evolution of the astronomical Universe. The registered cosmic microwave background radiation is nothing but a direct radio report on the unique universal events that took place shortly after the "Big Bang" - the most grandiose catastrophic process in terms of its scale and consequences in the observable history of the Universe.

Thus, as a result of recent astronomical observations, it was possible to unambiguously resolve the fundamental question of the nature of the physical conditions that prevailed in the early stages of cosmic evolution: the hot model of the "beginning" turned out to be the most adequate. What has been said, however, does not mean that all theoretical statements and conclusions of Gamow's cosmological concept have been confirmed. Of the two initial hypotheses of the theory - about the neutron composition of the "cosmic egg" and the hot state of the young Universe - only the latter has stood the test of time, indicating the quantitative predominance of radiation over matter at the sources of the currently observed cosmological expansion.

At the current stage of development of physical cosmology, the task of creating a thermal history of the Universe, in particular, a scenario for the formation of a large-scale structure of the Universe, has come to the fore.

The latest theoretical research of physicists was carried out in the direction of the following fundamental idea: all known types of physical interactions are based on one universal interaction; electromagnetic, weak, strong and gravitational interactions are different facets of a single interaction, splitting as the energy level of the corresponding physical processes decreases. In other words, at very high temperatures (exceeding certain critical values) various types of physical interactions begin to combine, and at the limit all four types of interaction are reduced to a single single proto-interaction, called the "Great Fusion".

According to quantum theory what remains after the removal of particles of matter (for example, from some closed vessel using a vacuum pump) is not at all empty in the literal sense of the word, as classical physics believed. Although the vacuum does not contain ordinary particles, it is saturated with "half-living ", the so-called virtual bodies. To turn them into real particles of matter, it is enough to excite the vacuum, for example, to act on it with an electromagnetic field created by charged particles introduced into it.

But what was the cause of the Big Bang? According to astronomy data physical quantity the cosmological constant involved in Einstein's equations of gravitation is very small, possibly close to zero. But even being so insignificant, it can cause very large cosmological consequences. The development of quantum field theory led to even more interesting conclusions. It turned out that the cosmological constant is a function of energy, in particular, it depends on temperature. At ultrahigh temperatures, which prevailed in the earliest phases of the development of cosmic matter, the cosmological constant could be very large, and most importantly, positive in sign. In other words, in the distant past, the vacuum could be in an extremely unusual physical state, characterized by the presence of powerful repulsive forces. It was these forces that served as the physical cause of the "Big Bang" and the subsequent rapid expansion of the Universe.

Consideration of the causes and consequences of the cosmological "Big Bang" would not be complete without one more physical concept. We are talking about the so-called phase transition (transformation), i.e. a qualitative transformation of a substance, accompanied by a sharp change from one of its states to another. Soviet physicists D.A. Kirzhnits and A.D. Linde were the first to draw attention to the fact that in the initial phase of the formation of the Universe, when cosmic matter was in a superhot, but already cooling state, similar physical processes (phase transitions) could occur.

Further study of the cosmological consequences of phase transitions with broken symmetry led to new theoretical discoveries and generalizations. Among them is the discovery of a previously unknown epoch in the self-development of the Universe. It turned out that during the cosmological phase transition, it could reach a state of extremely rapid expansion, in which its dimensions increased many times over, and the density of matter remained practically unchanged. The initial state, which gave rise to the expanding Universe, is considered to be the gravitational vacuum. The sharp changes accompanying the process of cosmological expansion of space are characterized by fantastic figures. So it is assumed that the entire observable universe arose from a single vacuum bubble less than 10 to the minus 33 power of cm! The vacuum bubble from which our universe was formed had a mass equal to only one hundred-thousandth of a gram.

At present, there is still no comprehensively tested and universally recognized theory of the origin of the large-scale structure of the Universe, although scientists have made significant progress in understanding the natural ways of its formation and evolution. Since 1981, the development of a physical theory of an inflating (inflationary) Universe began. To date, physicists have proposed several versions of this theory. It is assumed that the evolution of the Universe, which began with a grandiose general cosmic cataclysm, called the "Big Bang", was subsequently accompanied by a repeated change in the expansion regime.

According to the assumptions of scientists, after 10 to the minus forty-third degree of seconds after the "Big Bang" the density of super-hot cosmic matter was very high (10 to 94 degree grams / cm cubic). The vacuum density was also high, although in order of magnitude it was much less than the density of ordinary matter, and therefore the gravitational effect of the primitive physical "emptiness" was imperceptible. However, during the expansion of the Universe, the density and temperature of matter fell, while the vacuum density remained unchanged. This circumstance led to a sharp change in the physical situation already 10 to minus 35 seconds after the "Big Bang". The density of the vacuum first becomes equal, and then, after a few superinstants of cosmic time, it becomes greater than it. Then the gravitational effect of vacuum makes itself felt - its repulsive forces again take precedence over the gravitational forces of ordinary matter, after which the Universe begins to expand at an extremely fast pace (swells up) and in an infinitesimal fraction of a second reaches enormous sizes. However, this process is limited in time and space. The Universe, like any expanding gas, first cools quickly and already in the region of 10 to minus 33 degrees of a second after the "Big Bang" is strongly supercooled. As a result of this universal "cooling" the Universe passes from one phase to another. We are talking about a phase transition of the first kind - an abrupt change in the internal structure of cosmic matter and all the physical properties and characteristics associated with it. At the final stage of this cosmic phase transition, the entire energy reserve of vacuum is converted into the thermal energy of ordinary matter, and as a result, the universal plasma is again heated to its original temperature, and, accordingly, its expansion mode changes.

No less interesting, and in a global perspective, another result of the latest theoretical research is more important - the fundamental possibility of avoiding the initial singularity in its physical sense. We are talking about a completely new physical view of the problem of the origin of the Universe.

It turned out that, contrary to some recent theoretical predictions (that the initial singularity cannot be avoided even with a quantum generalization general theory relativity) there are certain microphysical factors that can prevent the infinite compression of matter under the action of gravitational forces.

Back in the late thirties, it was theoretically discovered that stars with a mass exceeding the mass of the Sun by more than three times, last step of their evolution are irresistibly compressed to a singulatory state. The latter, in contrast to the singularity of the cosmological type, called Friedmann's, is called Schwarzschild's (after the German astronomer who first considered the astrophysical consequences of Einstein's theory of gravitation). But from a purely physical point of view, both types of singularities are identical. Formally, they differ in that the first singularity is the initial state of the evolution of matter, while the second is the final one.

According to recent theoretical concepts, the gravitational collapse must end with the compression of matter literally "to a point" - to a state of infinite density. According to the latest physical concepts, the collapse can be stopped somewhere in the region of the Planck density value, i.e. at the turn of 10 to the 94th degree of grams / cm cubic. This means that the Universe resumes its expansion not from scratch, but having a geometrically defined (minimum) volume and a physically acceptable, regular state.

Academician M.A.Markov put forward an interesting version of the pulsating Universe. Within the logical framework of this cosmological model, the old theoretical difficulties, if not finally resolved, are at least illuminated from a new perspective perspective. The model is based on the hypothesis that with a sharp decrease in the distance, the constants of all physical interactions tend to zero. This assumption is a consequence of another assumption, according to which the gravitational interaction constant depends on the degree of density of the substance.

According to Markov's theory, whenever the Universe passes from the Friedmann stage (final contraction) to the de Sitter stage (initial expansion), its physical and geometrical characteristics turn out to be the same. Markov believes that this condition is quite sufficient to overcome the classical difficulty in the way of the physical realization of the eternally oscillating Universe.

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