Presentation of the system of galaxies and the large-scale structure of the universe. Lesson-presentation "structure and evolution of the universe". Virgo Constellation Galaxy

What do we know about the universe, what is the cosmos like? The Universe is a boundless world that is difficult to comprehend by the human mind, which seems unreal and non-material. In fact, we are surrounded by matter, boundless in space and time, capable of taking various forms. In order to try to understand the true scale of outer space, how the Universe works, the structure of the universe and the processes of evolution, we will need to cross the threshold of our own worldview, look at the world around us from a different angle, from the inside.

A look at the vast expanses of space from Earth

The Formation of the Universe: First Steps

The space that we observe through telescopes is only a part of the stellar Universe, the so-called Megagalaxy. The parameters of the Hubble cosmological horizon are colossal - 15-20 billion light years. These data are approximate, since in the process of evolution the Universe is constantly expanding. The expansion of the universe occurs through the spread of chemical elements and cosmic microwave background radiation. The structure of the universe is constantly changing. In space, clusters of galaxies arise, objects and bodies of the Universe are billions of stars that form elements of the near space - star systems with planets and satellites.

Where is the beginning? How did the universe come into existence? Presumably the age of the Universe is 20 billion years. It is possible that hot and dense protomatter became the source of cosmic matter, the cluster of which exploded at a certain moment. The smallest particles formed as a result of the explosion scattered in all directions, and continue to move away from the epicenter in our time. The Big Bang theory, which now dominates the scientific community, is the most accurate description of the process of formation of the Universe. The substance that arose as a result of a cosmic cataclysm was a heterogeneous mass consisting of the smallest unstable particles that, colliding and scattering, began to interact with each other.

The Big Bang is a theory of the origin of the universe, explaining its formation. According to this theory, initially there was a certain amount of matter, which, as a result of certain processes, exploded with colossal force, scattering a mass of mother into the surrounding space.

Some time later, according to cosmic standards - an instant, according to earthly chronology - millions of years, the stage of materialization of space has come. What is the universe made of? Dispersed matter began to concentrate into clots, large and small, in the place of which the first elements of the Universe subsequently began to appear, huge gas masses - the nursery of future stars. In most cases, the process of formation of material objects in the Universe is explained by the laws of physics and thermodynamics, however, there are a number of points that cannot yet be explained. For example, why in one part of space the expanding substance is concentrated more, while in another part of the universe the matter is very rarefied. Answers to these questions can be obtained only when the mechanism of formation of space objects, large and small, becomes clear.

Now the process of formation of the Universe is explained by the action of the laws of the Universe. Gravitational instability and energy in different areas triggered the formation of protostars, which in turn, under the influence of centrifugal forces and gravity, formed galaxies. In other words, while the matter continued and continues to expand, compression processes began under the influence of gravitational forces. Particles of gas clouds began to concentrate around the imaginary center, eventually forming a new seal. The building material in this gigantic construction site is molecular hydrogen and helium.

The chemical elements of the Universe are the primary building material from which the formation of the objects of the Universe subsequently proceeded.

Further, the law of thermodynamics begins to operate, the processes of decay and ionization are activated. Molecules of hydrogen and helium break up into atoms, from which, under the influence of gravitational forces, the core of a protostar is formed. These processes are the laws of the Universe and have taken the form of a chain reaction, taking place in all distant corners of the Universe, filling the universe with billions, hundreds of billions of stars.

Evolution of the Universe: Highlights

Today, in scientific circles, there is a hypothesis about the cyclicity of the states from which the history of the Universe is woven. Having arisen as a result of an explosion of protomatter, gas accumulations became a nursery for stars, which in turn formed numerous galaxies. However, having reached a certain phase, matter in the Universe begins to strive for its original, concentrated state, i.e. The explosion and the subsequent expansion of matter in space are followed by compression and a return to a superdense state, to the starting point. Subsequently, everything repeats itself, the birth is followed by the final, and so on for many billions of years, ad infinitum.

The beginning and end of the universe in accordance with the cyclical nature of the evolution of the universe

However, having omitted the topic of the formation of the Universe, which remains an open question, we should move on to the structure of the universe. Back in the 30s of the XX century, it became clear that outer space is divided into regions - galaxies, which are huge formations, each with its own stellar population. However, galaxies are not static objects. The speed of expansion of galaxies from the imaginary center of the Universe is constantly changing, as evidenced by the convergence of some and the removal of others from each other.

All of these processes, from the point of view of the duration of earthly life, last very slowly. From the point of view of science and these hypotheses, all evolutionary processes occur rapidly. Conventionally, the evolution of the Universe can be divided into four stages - eras:

• hadron era;
• lepton era;
• photon era;
• stellar era.

Cosmic time scale and the evolution of the Universe, according to which the appearance of space objects can be explained

At the first stage, all matter was concentrated in one large nuclear drop, consisting of particles and antiparticles, combined into groups - hadrons (protons and neutrons). The ratio of particles and antiparticles is approximately 1:1.1. Then comes the process of annihilation of particles and antiparticles. The remaining protons and neutrons are the building material from which the Universe is formed. The duration of the hadron era is negligible, only 0.0001 seconds - the period of the explosive reaction.

Further, after 100 seconds, the process of synthesis of elements begins. At a temperature of a billion degrees, hydrogen and helium molecules are formed in the process of nuclear fusion. All this time, the substance continues to expand in space.

From this moment begins a long, from 300 thousand to 700 thousand years, stage of recombination of nuclei and electrons, forming hydrogen and helium atoms. In this case, a decrease in the temperature of the substance is observed, and the intensity of radiation decreases. The universe becomes transparent. Hydrogen and helium formed in colossal quantities, under the influence of gravitational forces, turns the primary Universe into a giant construction site. After millions of years, the stellar era begins - which is the process of formation of protostars and the first protogalaxies.

This division of evolution into stages fits into the model of the hot Universe, which explains many processes. The true causes of the Big Bang, the mechanism of the expansion of matter remain unexplained.

The structure and structure of the universe

With the formation of hydrogen gas, the stellar era of the evolution of the Universe begins. Hydrogen under the influence of gravity accumulates in huge accumulations, clots. The mass and density of such clusters are colossal, hundreds of thousands of times greater than the mass of the formed galaxy itself. The uneven distribution of hydrogen, observed at the initial stage of the formation of the universe, explains the differences in the sizes of the formed galaxies. Where there should have been a maximum accumulation of hydrogen gas, megagalaxies formed. Where the concentration of hydrogen was negligible, smaller galaxies appeared, like our stellar home, the Milky Way.

The version according to which the Universe is a start-end point around which galaxies revolve at different stages of development

From this moment on, the Universe receives the first formations with clear boundaries and physical parameters. These are no longer nebulae, accumulations of stellar gas and cosmic dust (explosion products), protoclusters of stellar matter. These are star countries, the area of ​​\u200b\u200bwhich is huge in terms of the human mind. The universe becomes full of interesting cosmic phenomena.

From the point of view of scientific justifications and the modern model of the Universe, galaxies were first formed as a result of the action of gravitational forces. Matter was transformed into a colossal universal whirlpool. Centripetal processes ensured the subsequent fragmentation of gas clouds into clusters, which became the birthplace of the first stars. Protogalaxies with a fast rotation period turned into spiral galaxies over time. Where the rotation was slow, and the process of compression of matter was mainly observed, irregular galaxies were formed, more often elliptical. Against this background, more grandiose processes took place in the Universe - the formation of superclusters of galaxies, which closely touch each other with their edges.

Superclusters are numerous groups of galaxies and clusters of galaxies in the large-scale structure of the Universe. Within 1 billion St. years there are about 100 superclusters

From that moment it became clear that the Universe is a huge map, where continents are clusters of galaxies, and countries are megagalaxies and galaxies that formed billions of years ago. Each of the formations consists of a cluster of stars, nebulae, accumulations of interstellar gas and dust. However, all this population is only 1% of the total volume of universal formations. The main mass and volume of galaxies is occupied by dark matter, the nature of which is not possible to find out.

Diversity of the Universe: classes of galaxies

Through the efforts of the American astrophysicist Edwin Hubble, we now have the boundaries of the universe and a clear classification of the galaxies that inhabit it. The classification was based on the structural features of these giant formations. Why do galaxies have different shapes? The answer to this and many other questions is given by the Hubble classification, according to which the Universe consists of galaxies of the following classes:

• spiral;
• elliptical;
• irregular galaxies.

The former include the most common formations that fill the universe. Characteristic features of spiral galaxies are the presence of a clearly defined spiral that rotates around a bright nucleus or tends to a galactic bridge. Spiral galaxies with a core are denoted by the symbols S, while objects with a central bar have the designation already SB. This class also includes our Milky Way galaxy, in the center of which the core is separated by a luminous bar.

A typical spiral galaxy. In the center, a core with a bridge from the ends of which spiral arms emanate is clearly visible.

Similar formations are scattered throughout the universe. The closest spiral galaxy to us, Andromeda, is a giant that is rapidly approaching the Milky Way. The largest representative of this class known to us is the giant galaxy NGC 6872. The diameter of the galactic disk of this monster is approximately 522 thousand light years. This object is located at a distance of 212 million light years from our galaxy.

The next common class of galactic formations are elliptical galaxies. Their designation in accordance with the Hubble classification is the letter E (elliptical). In shape, these formations are ellipsoids. Despite the fact that there are a lot of similar objects in the Universe, elliptical galaxies are not very expressive. They consist mainly of smooth ellipses that are filled with star clusters. Unlike galactic spirals, ellipses do not contain accumulations of interstellar gas and cosmic dust, which are the main optical effects of visualizing such objects.

A typical representative of this class, known today, is an elliptical ring nebula in the constellation Lyra. This object is located at a distance of 2100 light years from Earth.

View of the elliptical galaxy Centaurus A through the CFHT telescope

The last class of galactic objects that populate the universe are irregular or irregular galaxies. The Hubble classification designation is the Latin character I. The main feature is an irregular shape. In other words, such objects do not have clear symmetrical shapes and a characteristic pattern. In its form, such a galaxy resembles a picture of universal chaos, where star clusters alternate with clouds of gas and cosmic dust. On the scale of the universe, irregular galaxies are a frequent phenomenon.

In turn, irregular galaxies are divided into two subtypes:

• Irregular galaxies of subtype I have a complex irregular structure, a high dense surface, which is distinguished by brightness. Often such a chaotic shape of irregular galaxies is the result of collapsed spirals. A typical example of such a galaxy is the Large and Small Magellanic Clouds;
• Irregular subtype II galaxies have a low surface, a chaotic shape, and are not very bright. Due to the decrease in brightness, such formations are difficult to detect in the vastness of the Universe.

The Large Magellanic Cloud is the closest irregular galaxy to us. Both formations, in turn, are satellites of the Milky Way and may soon (in 1-2 billion years) be absorbed by a larger object.

The irregular galaxy The Large Magellanic Cloud is a satellite of our Milky Way galaxy.

Despite the fact that Edwin Hubble quite accurately placed the galaxies into classes, this classification is not ideal. We could achieve more results if we included Einstein's theory of relativity in the process of knowing the Universe. The universe is represented by a wealth of various forms and structures, each of which has its own characteristic properties and features. Recently, astronomers have been able to detect new galactic formations that are described as intermediate objects between spiral and elliptical galaxies.

The Milky Way is the most known part of the universe to us.

Two spiral arms, symmetrically located around the center, make up the main body of the galaxy. Spirals, in turn, consist of sleeves that smoothly flow into each other. At the junction of the arms of Sagittarius and Cygnus, our Sun is located, located from the center of the Milky Way galaxy at a distance of 2.62 10¹⁷ km. The spirals and arms of spiral galaxies are clusters of stars that increase in density as they approach the galactic center. The rest of the mass and volume of galactic spirals is dark matter, and only a small part is accounted for by interstellar gas and cosmic dust.

The position of the Sun in the arms of the Milky Way, the place of our galaxy in the Universe

The thickness of the spirals is approximately 2 thousand light years. This whole layer cake is in constant motion, rotating at a tremendous speed of 200-300 km / s. The closer to the center of the galaxy, the higher the rotation speed. It will take the sun and our solar system 250 million years to make a complete revolution around the center of the Milky Way.

Our galaxy is made up of a trillion stars, large and small, superheavy and medium-sized. The densest cluster of stars in the Milky Way is the Sagittarius arm. It is in this region that the maximum brightness of our galaxy is observed. The opposite part of the galactic circle, on the contrary, is less bright and poorly distinguishable by visual observation.

The central part of the Milky Way is represented by a core, the dimensions of which are presumably 1000-2000 parsecs. In this brightest region of the galaxy, the maximum number of stars is concentrated, which have different classes, their own paths of development and evolution. Basically, these are old superheavy stars that are at the final stage of the Main Sequence. Confirmation of the presence of the aging center of the Milky Way galaxy is the presence in this region of a large number of neutron stars and black holes. Indeed, the center of the spiral disk of any spiral galaxy is a supermassive black hole, which, like a giant vacuum cleaner, sucks in celestial objects and real matter.

The supermassive black hole in the central part of the Milky Way is the place where all galactic objects die.

As for star clusters, scientists today managed to classify two types of clusters: spherical and open. In addition to star clusters, the spirals and arms of the Milky Way, like any other spiral galaxy, are composed of scattered matter and dark energy. Being a consequence of the Big Bang, matter is in a highly rarefied state, which is represented by rarefied interstellar gas and dust particles. The visible part of matter is represented by nebulae, which in turn are divided into two types: planetary and diffuse nebulae. The visible part of the spectrum of nebulae is explained by the refraction of the light of stars, which radiate light inside the spiral in all directions.

It is in this cosmic soup that our solar system exists. No, we are not the only ones in this vast world. Like the Sun, many stars have their own planetary systems. The whole question is how to detect distant planets, if the distances even within our galaxy exceed the duration of the existence of any intelligent civilization. Time in the Universe is measured by other criteria. Planets with their satellites are the smallest objects in the universe. The number of such objects is incalculable. Each of those stars that are in the visible range may have their own star systems. It is in our power to see only the closest existing planets to us. What happens in the neighborhood, what worlds exist in other arms of the Milky Way, and what planets exist in other galaxies, remains a mystery.

Kepler-16 b is an exoplanet around the double star Kepler-16 in the constellation Cygnus

Conclusion

Having only a superficial idea of ​​how the Universe appeared and how it is evolving, a person has taken only a small step towards comprehending and comprehending the scale of the universe. The grandiose dimensions and scales that scientists have to deal with today indicate that human civilization is only a moment in this bundle of matter, space and time.

Model of the Universe in accordance with the concept of the presence of matter in space, taking into account time

The study of the universe goes from Copernicus to the present day. At first, scientists started from the heliocentric model. In fact, it turned out that the cosmos does not have a real center and all rotation, movement and movement occurs according to the laws of the Universe. Despite the fact that there is a scientific explanation for the ongoing processes, universal objects are divided into classes, types and types, no body in space is similar to another. The sizes of celestial bodies are approximate, as well as their mass. The location of galaxies, stars and planets is conditional. The point is that there is no coordinate system in the Universe. Observing space, we make a projection on the entire visible horizon, considering our Earth as a zero reference point. In fact, we are only a microscopic particle, lost in the infinite expanses of the Universe.

The Universe is a substance in which all objects exist in close relation to space and time

Similarly to binding to dimensions, time in the Universe should be considered as the main component. The origin and age of space objects allows you to make a picture of the birth of the world, to highlight the stages of the evolution of the universe. The system we are dealing with is closely tied to time frames. All processes occurring in space have cycles - the beginning, formation, transformation and final, accompanied by the death of a material object and the transition of matter to another state.

Introduction

Main part

1.Cosmology

2. The structure of the universe:

2.1. Metagalaxy

2.2 Galaxies

2.3.Stars

2.4Planet and solar system

3. Means of observing objects of the Universe

4. The problem of searching for extraterrestrial civilizations

Conclusion

Introduction

The Universe is the most global object of the megaworld, boundless in time and space. According to modern ideas, it is a huge, boundless sphere. There are scientific hypotheses of an "open", that is, a "continuously expanding" Universe, as well as a "closed", that is, a "pulsating" Universe. Both hypotheses exist in several versions. However, very thorough research is required until one or another of them turns into a more or less well-founded scientific theory.

The universe at various levels, from conditionally elementary particles to giant superclusters of galaxies, is characterized by structure. The structure of the Universe is the subject of study of cosmology, one of the important branches of natural science, located at the junction of many natural sciences: astronomy, physics, chemistry, etc. The modern structure of the Universe is the result of cosmic evolution, during which galaxies formed from protogalaxies, stars from protostars, protoplanetary cloud - planets.

Cosmology

Cosmology is an astrophysical theory of the structure and dynamics of the Metagalaxy, which includes a certain understanding of the properties of the entire Universe.

The term "cosmology" itself is derived from two Greek words: cosmos - the universe and logos - law, doctrine. At its core, cosmology is a branch of natural science that uses the achievements and methods of astronomy, physics, mathematics, and philosophy. The natural scientific basis of cosmology is astronomical observations of the Galaxy and other stellar systems, the general theory of relativity, the physics of microprocesses and high energy densities, relativistic thermodynamics, and a number of other latest physical theories.

Many provisions of modern cosmology seem fantastic. The concepts of the Universe, infinity, the Big Bang are not amenable to visual physical perception; such objects and processes cannot be captured directly. Because of this circumstance, one gets the impression that we are talking about something supernatural. But such an impression is deceptive, since the functioning of cosmology is of a very constructive nature, although many of its provisions turn out to be hypothetical.

Modern cosmology is a branch of astronomy that combines the data of physics and mathematics, as well as universal philosophical principles, therefore it is a synthesis of scientific and philosophical knowledge. Such a synthesis in cosmology is necessary, since reflections on the origin and structure of the Universe are empirically difficult to test and most often exist in the form of theoretical hypotheses or mathematical models. Cosmological studies usually develop from theory to practice, from model to experiment, and here the initial philosophical and general scientific attitudes become of great importance. For this reason, cosmological models differ significantly from each other - they are often based on opposite initial philosophical principles. In turn, any cosmological conclusions also affect general philosophical ideas about the structure of the Universe, i.e. change the fundamental ideas of man about the world and himself.

The most important postulate of modern cosmology is that the laws of nature, established on the basis of the study of a very limited part of the Universe, can be extrapolated to much wider regions, and, ultimately, to the entire Universe. Cosmological theories differ depending on what physical principles and laws they are based on. Models built on their basis should allow verification for the observed region of the Universe, and the conclusions of the theory should be confirmed by observations or, in any case, not contradict them.

Structure of the Universe

Metagalaxy

A metagalaxy is a part of the universe accessible to study by astronomical means. It consists of hundreds of billions of galaxies, each of which rotates around its axis and simultaneously scatter from each other at speeds from 200 to 150,000 km. sec(2).

One of the most important properties of the Metagalaxy is its constant expansion, as evidenced by the "expansion" of clusters of galaxies. Evidence that clusters of galaxies are moving away from each other is the "redshift" in the spectra of galaxies and the discovery of cosmic microwave background radiation (background extragalactic radiation corresponding to a temperature of about 2.7 K) (1).

An important consequence follows from the expansion of the Metagalaxy: in the past, the distances between galaxies were smaller. And if we take into account that the galaxies themselves in the past were extended and sparse gas clouds, then it is obvious that billions of years ago the boundaries of these clouds closed and formed a single homogeneous gas cloud that was constantly expanding.

Another important property of the Metagalaxy is the uniform distribution of matter in it (the bulk of which is concentrated in the stars). In its current state, the Metagalaxy is homogeneous on a scale of about 200 Mpc. It is unlikely that she was like this in the past. At the very beginning of the expansion of the Metagalaxy, the heterogeneity of matter could well exist. The search for traces of the heterogeneity of the past states of the Metagalaxy is one of the most important problems of extragalactic astronomy (2).

The homogeneity of the Metagalaxy (and the Universe) must also be understood in the sense that the structural elements of distant stars and galaxies, the physical laws to which they obey, and physical constants, apparently, are the same everywhere with a high degree of accuracy, i.e. the same as in our region of the Metagalaxy, including the Earth. A typical galaxy a hundred million light-years away looks basically the same as ours. The spectra of atoms, therefore, the laws of chemistry and atomic physics there are identical to those adopted on Earth. This circumstance makes it possible to confidently extend the laws of physics discovered in the terrestrial laboratory to wider regions of the Universe.

The idea of ​​the homogeneity of the Metagalaxy once again proves that the Earth does not occupy any privileged position in the Universe. Of course, the Earth, the Sun and the Galaxy seem important and exceptional to us humans, but they are not so for the Universe as a whole.

According to modern ideas, the Metagalaxy is characterized by a cellular (network, porous) structure. These representations are based on the data of astronomical observations, which showed that galaxies are not evenly distributed, but are concentrated near the boundaries of cells, inside which there are almost no galaxies. In addition, huge volumes of space have been found in which no galaxies have yet been found.

If we take not separate sections of the Metagalaxy, but its large-scale structure as a whole, then it is obvious that in this structure there are no special places or directions that stand out in some way, and the substance is distributed relatively evenly.

The age of the Metagalaxy is close to the age of the Universe, since the formation of its structure falls on the period following the separation of matter and radiation. According to modern data, the age of the Metagalaxy is estimated at 15 billion years. Scientists believe that, apparently, the age of the galaxies that formed at one of the initial stages of the expansion of the Metagalaxy is also close to this.

galaxies

A galaxy is a collection of stars in a lens-shaped volume. Most of the stars are concentrated in the plane of symmetry of this volume (galactic plane), a smaller part is concentrated in a spherical volume (galactic core).

In addition to stars, galaxies include interstellar matter (gases, dust, asteroids, comets), electromagnetic, gravitational fields, and cosmic radiation. The solar system is located near the galactic plane of our galaxy. For a terrestrial observer, the stars concentrating in the galactic plane merge into the visible picture of the Milky Way.

The systematic study of galaxies began at the beginning of the last century, when instruments were installed on telescopes for the spectral analysis of the light emissions of stars.

The American astronomer E. Hubble developed a method for classifying the galaxies known to him at that time, taking into account their observed shape. In his classification, several types (classes) of galaxies are distinguished, each of which has subtypes or subclasses. He also determined the approximate percentage distribution of observed galaxies: elliptical in shape (approximately 25%), spiral (approximately 50%), lenticular (approximately 20%) and peculiar (irregularly shaped) galaxies (approximately 5%) (2).

Elliptical galaxies have a spatial shape of an ellipsoid with varying degrees of compression. They are the simplest in structure: the distribution of stars decreases uniformly from the center.

Irregular galaxies do not have a pronounced shape; they lack a central core.

Spiral galaxies are presented in the form of a spiral, including spiral arms. This is the most numerous type of galaxies, to which our Galaxy belongs - the Milky Way.

The Milky Way is clearly visible on a moonless night. It appears to be a collection of luminous nebulous masses stretching from one side of the horizon to the other, and is composed of about 150 billion stars. In shape, it resembles a flattened ball. In its center is the core, from which several spiral stellar branches extend. Our Galaxy is extremely large: from one edge to the other, a light beam travels about 100,000 Earth years. Most of its stars are concentrated in a giant disk about 1500 light-years thick. At a distance of about 2 million light years from us is the nearest galaxy to us - the Andromeda Nebula, which in its structure resembles the Milky Way, but significantly exceeds it in size.  Our Galaxy, the Andromeda Nebula, together with other neighboring star systems, form the Local Group of galaxies. The Sun is located at a distance of about 30 thousand light years from the center of the Galaxy.

Today it is known that galaxies combine into stable structures (clusters and superclusters of galaxies). Astronomers know a cloud of galaxies with a density of 220,032 galaxies per square degree. Our Galaxy is part of a cluster of galaxies called the Local System.

The Local System includes our Galaxy, the Andromeda Galaxy, the spiral galaxy from the constellation Triangulum, and 31 other star systems. The diameter of this system is 7 million light years. This association of galaxies includes the Andromeda Nebula, which is much larger than our Galaxy: its diameter is more than 300 thousand sv. years. It is located at a distance of 2.3 million sv. years from our galaxy and consists of several billion stars. Along with such a huge galaxy as the Andromeda Nebula, astronomers know dwarf galaxies (3).

In the constellations of Leo and Sculptor, almost spherical galaxies 3000 light years in size were discovered. years across. There are data on the linear dimensions of the following large-scale structures in the Universe: stellar systems - 108 km, galaxies containing about 1013 stars - 3 104 sv. years, a cluster of galaxies (out of 50 bright galaxies) - 107sv. years, superclusters of galaxies - 109 sv. years. The distance between clusters of galaxies is approximately 20 107 sv. years.(1).

The designation of galaxies is usually given relative to the corresponding catalog: catalog designation plus galaxy number (NGC2658, where NGC is the new general Dreyer catalog, 2658 is the galaxy number in this catalog). In the first stellar catalogs, galaxies were erroneously recorded as nebulae of a certain luminosity. In the second half of the twentieth century. it was found that the classification of Hubble galaxies is not accurate: there are a large number of varieties of galaxies that are peculiar in shape. The Local System (cluster of galaxies) is part of a giant supercluster of galaxies, the diameter of which is 100 million years, our Local System is located at a distance of more than 30 million light years from the center of this supercluster. years(1). Modern astronomy uses a wide range of methods for studying objects located at great distances from the observer. A large place in astronomical research is occupied by the method of radiological measurements, developed at the beginning of the last century.

Stars

The world of stars is unusually diverse. And although all stars are hot balls, similar to the Sun, their physical characteristics differ quite significantly. (1) There are, for example, stars - giants and supergiants. They are larger than the Sun in size.

In addition to giant stars, there are also dwarf stars, much smaller than the Sun in size. Some dwarfs are smaller than the Earth and even the Moon. In white dwarfs, thermonuclear reactions practically do not occur; they are possible only in the atmosphere of these stars, where hydrogen from the interstellar medium enters. Basically, these stars shine due to the huge reserves of thermal energy. Their cooling time is hundreds of millions of years. Gradually, the white dwarf cools down, its color changes from white to yellow, and then to red. Finally, it turns into a black dwarf - a dead cold small star the size of the Earth, which cannot be seen from another planetary system (3).

There are also neutron stars - these are huge atomic nuclei.

Stars have different surface temperatures - from several thousand to tens of thousands of degrees. Accordingly, the color of the stars is also distinguished. Relatively "cold" stars with a temperature of 3-4 thousand degrees are red. Our Sun with a surface "heated" up to 6 thousand degrees, has a yellowish color. The hottest stars - those with temperatures above 12,000 degrees - are white and bluish.

Stars do not exist in isolation, but form systems. The simplest star systems - consist of 2 or more stars. Stars are also combined into even larger groups - star clusters.

The age of stars varies over a fairly wide range of values: from 15 billion years, corresponding to the age of the Universe, to hundreds of thousands of the youngest. There are stars that are currently being formed and are in the protostellar stage, that is, they have not yet become real stars.

The birth of stars occurs in gas-dust nebulae under the action of gravitational, magnetic and other forces, due to which unstable uniformities are formed and diffuse matter breaks up into a number of condensations. If such clumps persist long enough, they turn into stars over time. It is important to note that the process of birth is not a separate isolated star, but stellar associations.

The star is a plasma ball. The main mass (98-99%) of visible matter in the part of the Universe known to us is concentrated in stars. Stars are powerful sources of energy. In particular, life on Earth owes its existence to the radiation energy of the Sun.

A star is a dynamic, directionally changing plasma system. During the life of a star, its chemical composition and distribution of chemical elements change significantly. At the later stages of development, stellar matter passes into a state of degenerate gas (in which the quantum mechanical influence of particles on each other significantly affects its physical properties - pressure, heat capacity, etc.), and sometimes neutron matter (pulsars - neutron stars, bursters - X-ray sources, etc.).

Stars are born from cosmic matter as a result of its condensation under the influence of gravitational, magnetic and other forces. Under the influence of the forces of universal gravitation, a dense ball is formed from a gas cloud - a protostar, the evolution of which goes through three stages.

The first stage of evolution is associated with the separation and compaction of cosmic matter. The second is the rapid contraction of the protostar. At some point, the gas pressure inside the protostar increases, which slows down the process of its compression, but the temperature in the inner regions is still insufficient to start a thermonuclear reaction. At the third stage, the protostar continues to shrink, and its temperature rises, which leads to the onset of a thermonuclear reaction. The pressure of the gas flowing out of the star is balanced by the force of attraction, and the gas ball ceases to shrink. An equilibrium object is formed - a star. Such a star is a self-regulating system. If the temperature inside does not rise, then the star swells. In turn, the cooling of the star leads to its subsequent compression and heating, and nuclear reactions in it are accelerated. Thus, the temperature balance is restored. The process of transforming a protostar into a star takes millions of years, which is relatively short on a cosmic scale.

The birth of stars in galaxies occurs continuously. This process also compensates for the ongoing death of stars. Therefore, galaxies are made up of old and young stars. The oldest stars are concentrated in globular clusters, their age is comparable to the age of the galaxy. These stars formed as the protogalactic cloud broke up into smaller and smaller clumps. Young stars (about 100 thousand years old) exist due to the energy of gravitational contraction, which heats the central region of the star to a temperature of 10-15 million K and "starts" the thermonuclear reaction of converting hydrogen into helium. It is the thermonuclear reaction that is the source of the own glow of stars.

From the moment the thermonuclear reaction begins, turning hydrogen into helium, a star like our Sun enters the so-called main sequence, according to which the characteristics of the star will change over time: its luminosity, temperature, radius, chemical composition and mass. After hydrogen burns out in the central zone, a helium core is formed near the star. Hydrogen thermonuclear reactions continue to proceed, but only in a thin layer near the surface of this nucleus. Nuclear reactions move to the periphery of the star. The burnt-out core begins to shrink, and the outer shell expands. The shell swells to a colossal size, the external temperature becomes low, and the star passes into the stage of a red giant. From that moment on, the star enters the final stage of its life. Our Sun is waiting for this in about 8 billion years. At the same time, its dimensions will increase to the orbit of Mercury, and perhaps even to the orbit of the Earth, so that nothing will remain of the terrestrial planets (or melted stones will remain).

A red giant is characterized by a low external but very high internal temperature. At the same time, increasingly heavier nuclei are included in thermonuclear processes, which leads to the synthesis of chemical elements and the continuous loss of matter by the red giant, which is ejected into interstellar space. So, in just one year, the Sun, being in the stage of a red giant, can lose one millionth of its weight. In just ten to one hundred thousand years, only the central helium core remains from the red giant, and the star becomes a white dwarf. Thus, the white dwarf, as it were, matures inside the red giant, and then sheds the remnants of the shell, the surface layers, which form a planetary nebula surrounding the star.

White dwarfs are small in size - their diameter is even smaller than the diameter of the Earth, although their mass is comparable to that of the sun. The density of such a star is billions of times greater than the density of water. A cubic centimeter of its substance weighs more than a ton. However, this substance is a gas, albeit of monstrous density. The substance that makes up a white dwarf is a very dense ionized gas, consisting of atomic nuclei and individual electrons.

In white dwarfs, thermonuclear reactions practically do not occur; they are possible only in the atmosphere of these stars, where hydrogen from the interstellar medium enters. Basically, these stars shine due to the huge reserves of thermal energy. Their cooling time is hundreds of millions of years. Gradually, the white dwarf cools down, its color changes from white to yellow, and then to red. Finally, it turns into a black dwarf - a dead, cold, small, globe-sized star that cannot be seen from another planetary system.

More massive stars develop somewhat differently. They live only a few tens of millions of years. Hydrogen burns out in them very quickly, and they turn into red giants in just 2.5 million years. At the same time, in their helium core, the temperature rises to several hundred million degrees. This temperature makes it possible for the reactions of the carbon cycle to proceed (the fusion of helium nuclei, leading to the formation of carbon). The carbon nucleus, in turn, can attach another helium nucleus and form the nucleus of oxygen, neon, etc. down to silicon. The burning core of the star is compressed, and the temperature in it rises to 3-10 billion degrees. Under such conditions, the combination reactions continue until the formation of iron nuclei - the most stable chemical element in the entire sequence. Heavier chemical elements - from iron to bismuth are also formed in the depths of red giants, in the process of slow neutron capture. In this case, energy is not released, as in thermonuclear reactions, but, on the contrary, is absorbed. As a result, the compression of the star is accelerating (4).

The formation of the heaviest nuclei, closing the periodic table, presumably occurs in the shells of exploding stars, during their transformation into new or supernova stars, which become some red giants. In a slagged star, the equilibrium is disturbed, the electron gas is no longer able to withstand the pressure of the nuclear gas. A collapse occurs - a catastrophic compression of the star, it "explodes inside". But if the repulsion of particles or any other reasons still stop this collapse, a powerful explosion occurs - a supernova explosion. At the same time, not only the shell of the star, but also up to 90% of its mass is thrown into the surrounding space, which leads to the formation of gaseous nebulae. In this case, the luminosity of the star increases billions of times. Thus, a supernova explosion was recorded in 1054. In the Chinese chronicles, it was recorded that it was visible during the day, like Venus, for 23 days. In our time, astronomers have found that this supernova left behind the Crab Nebula, which is a powerful source of radio emission (5).

The explosion of a supernova is accompanied by the release of a monstrous amount of energy. In this case, cosmic rays are born, which greatly increase the natural radiation background and normal doses of cosmic radiation. So, astrophysicists have calculated that about once every 10 million years, supernovae flare up in the immediate vicinity of the Sun, increasing the natural background by 7,000 times. This is fraught with the most serious mutations of living organisms on Earth. In addition, during a supernova explosion, the entire outer shell of the star is dumped along with the “slags” accumulated in it - chemical elements, the results of nucleosynthesis. Therefore, the interstellar medium relatively quickly acquires all currently known chemical elements heavier than helium. The stars of the next generations, including the Sun, from the very beginning contain in their composition and in the composition of the gas and dust cloud surrounding them an admixture of heavy elements (5).

Planets and solar system

The solar system is a star-planet system. There are approximately 200 billion stars in our Galaxy, among which, according to experts, some stars have planets. The solar system includes the central body, the Sun, and nine planets with their satellites (more than 60 satellites are known). The diameter of the solar system is more than 11.7 billion km. (2).

At the beginning of the 21st century an object was discovered in the solar system, which astronomers called Sedna (the name of the Eskimo goddess of the ocean). Sedna has a diameter of 2000 km. One revolution around the Sun is 10,500 Earth years (7).

Some astronomers call this object a planet in the solar system. Other astronomers call planets only space objects that have a central core with a relatively high temperature. For example, the temperature in the center of Jupiter, according to calculations, reaches 20,000 K. Since Sedna is currently located at a distance of about 13 billion km from the center of the solar system, information about this object is rather scarce. At the farthest point of the orbit, the distance from Sedna to the Sun reaches a huge value - 130 billion km.

Our star system includes two belts of minor planets (asteroids). The first is located between Mars and Jupiter (contains more than 1 million asteroids), the second is beyond the orbit of the planet Neptune. Some asteroids are over 1000 km in diameter. The outer boundaries of the solar system are surrounded by the so-called Oort cloud, named after the Dutch astronomer who hypothesized the existence of this cloud in the last century. As astronomers believe, the edge of this cloud closest to the solar system consists of ice floes of water and methane (comet nuclei), which, like the smallest planets, revolve around the Sun under the influence of its gravitational force at a distance of over 12 billion km. The number of such miniature planets is in the billions (2).

The solar system is a group of celestial bodies, very different in size and physical structure. This group includes: the Sun, nine large planets, dozens of satellites of planets, thousands of small planets (asteroids), hundreds of comets, countless meteorite bodies. All these bodies are united into one system due to the force of attraction of the central body - the Sun. The solar system is an ordered system that has its own patterns of structure. The unified character of the solar system is manifested in the fact that all the planets revolve around the sun in the same direction and almost in the same plane. The sun, planets, satellites of planets rotate around their axes in the same direction in which they move along their trajectories. The structure of the solar system is also natural: each next planet is approximately twice as far from the Sun as the previous one (2).

The solar system was formed about 5 billion years ago, and the Sun is a second-generation star. Modern concepts of the origin of the planets of the solar system are based on the fact that it is necessary to take into account not only mechanical forces, but also others, in particular electromagnetic ones. It is believed that it was electromagnetic forces that played a decisive role in the origin of the solar system (2).

In accordance with modern concepts, the original gas cloud from which both the Sun and the planets were formed consisted of ionized gas, subject to the influence of electromagnetic forces. After the Sun was formed from a huge gas cloud by means of concentration, small parts of this cloud remained at a very large distance from it. The gravitational force began to attract the remaining gas to the formed star - the Sun, but its magnetic field stopped the falling gas at a distance - just where the planets are. The gravitational constant and magnetic forces influenced the concentration and thickening of the falling gas, and as a result, the planets were formed. When the largest planets arose, the same process was repeated on a smaller scale, thus creating systems of satellites.

There are several mysteries in the study of the solar system.

1. Harmony in the movement of the planets. All planets in the solar system revolve around the sun in elliptical orbits. The movement of all the planets of the solar system occurs in the same plane, the center of which is located in the central part of the equatorial plane of the Sun. The plane formed by the orbits of the planets is called the plane of the ecliptic.

2. All planets and the Sun rotate around their own axis. The axes of rotation of the Sun and the planets, with the exception of the planet Uranus, are directed, roughly speaking, perpendicular to the plane of the ecliptic. The axis of Uranus is directed to the plane of the ecliptic almost parallel, i.e., it rotates lying on its side. Another feature of it is that it rotates around its axis in a different direction, like Venus, unlike the Sun and other planets. All other planets and the Sun rotate against the direction of the clock. Uranus has 15 moons.

3. Between the orbits of Mars and Jupiter there is a belt of minor planets. This is the so-called asteroid belt. Small planets have a diameter of 1 to 1000 km. Their total mass is less than 1/700 of the mass of the Earth.

4. All planets are divided into two groups (terrestrial and extraterrestrial). The first are planets with a high density; heavy chemical elements occupy the main place in their chemical composition. They are small in size and slowly rotate around their axis. This group includes Mercury, Venus, Earth and Mars. There are currently suggestions that Venus is the past of the Earth, and Mars is its future.

The second group includes: Jupiter, Saturn, Uranus, Neptune and Pluto. They consist of light chemical elements, rotate rapidly around their axis, slowly revolve around the Sun and receive less radiant energy from the Sun. Below (in the table) data are given on the average surface temperature of the planets on the Celsius scale, the length of the day and night, the length of the year, the diameter of the planets of the solar system and the mass of the planet in relation to the mass of the Earth (taken as 1).

The distance between the orbits of the planets approximately doubles when moving from each of them to the next - the "Rule of Titius - Bode", observed in the arrangement of the planets.

When considering the true distances of the planets to the Sun, it turns out that Pluto in some periods is closer to the Sun than Neptune, and, therefore, it changes its serial number according to the Titius-Bode rule.

Mystery of the planet Venus. In the ancient astronomical sources of China, Babylon, India, 3.5 thousand years old, there is no mention of Venus. American scientist I. Velikovsky in the book "Colliding Worlds", which appeared in the 50s. XX century., He hypothesized that the planet Venus took its place only recently, during the formation of ancient civilizations. Approximately once every 52 years, Venus comes close to Earth, at a distance of 39 million km. During the period of great confrontation, every 175 years, when all the planets line up one after another in the same direction, Mars approaches the Earth at a distance of 55 million km.

Means of observation of objects of the Universe

Modern astronomical instruments are used to measure the exact positions of the luminaries on the celestial sphere (systematic observations of this kind make it possible to study the movements of celestial bodies); to determine the speed of movement of celestial bodies along the line of sight (radial velocities): to calculate the geometric and physical characteristics of celestial bodies; to study the physical processes occurring in various celestial bodies; to determine their chemical composition and for many other studies of celestial objects in which astronomy is engaged. All information about celestial bodies and other space objects is obtained by studying various radiations coming from space, the properties of which are directly dependent on the properties of celestial bodies and on the physical processes taking place in world space. In this regard, the main means of astronomical observations are receivers of cosmic radiation, and primarily telescopes that collect the light of celestial bodies.

Three main types of optical telescopes are currently in use: lens telescopes, or refractors, mirror telescopes, or reflectors, and mixed, mirror-lens systems. The power of a telescope directly depends on the geometric dimensions of its lens or mirror that collects light. Therefore, in recent years, reflecting telescopes have been increasingly used, since, according to technical conditions, it is possible to manufacture mirrors with significantly larger diameters than optical lenses.

Modern telescopes are very complex and sophisticated units, the creation of which uses the latest achievements of electronics and automation. Modern technology has made it possible to create a number of devices and devices that have greatly expanded the possibilities of astronomical observations: television telescopes make it possible to obtain clear images of the planets on the screen, electron-optical converters allow observations to be made in invisible infrared rays, and automatic correction telescopes compensate for the influence of atmospheric interference. In recent years, new receivers of cosmic radiation - radio telescopes - have become more and more widespread, allowing you to look into the bowels of the Universe much further than the most powerful optical systems.

Radio astronomy, which originated in the early 1930s, significantly enriched our understanding of the Universe. our century. In 1943, Soviet scientists L.I., Mandelstam and N.D. Papaleksi theoretically substantiated the possibility of radar of the Moon (10).

Radio waves sent by man reached the Moon and, reflected from it, returned to Earth. - a period of unusually rapid development of radio astronomy. Every year, radio waves brought from space new amazing information about the nature of celestial bodies. Today, radio astronomy uses the most sensitive receivers and the largest antennas. Radio telescopes have penetrated into such depths of space that so far remain inaccessible to conventional optical telescopes. The radio space opened up before man - a picture of the Universe in radio waves (10).

There are also a number of astronomical instruments that have a specific purpose and are used for certain studies. Such instruments include, for example, the solar tower telescope built by Soviet scientists and installed at the Crimean Astrophysical Observatory.

Various sensitive devices are being used more and more widely in astronomical observations, which make it possible to capture the thermal and ultraviolet radiation of celestial bodies, to fix objects invisible to the eye on a photographic plate.

The next stage of transatmospheric observations was the creation of orbital astronomical observatories (OAO) on artificial earth satellites. Such observatories, in particular, are the Soviet Salyut orbital stations. Orbital astronomical observatories of various types and purposes have become firmly established in practice (9).

In the course of astronomical observations, series of numbers, astrophotographs, spectrograms and other materials are obtained, which must be subjected to laboratory processing for final results. This processing is carried out using laboratory measuring instruments. When processing the results of astronomical observations, electronic computers are used.

Coordinate measuring machines are used to measure the positions of images of stars on astrophotographs and images of artificial satellites relative to stars on satellitegrams. Microphotometers are used to measure blackening in photographs of celestial bodies and spectrograms. An important instrument needed for observations is the astronomical clock(9).

The problem of finding extraterrestrial civilizations

The development of natural science in the second half of the 20th century, outstanding discoveries in the field of astronomy, cybernetics, biology, radiophysics made it possible to transfer the problem of extraterrestrial civilizations from a purely speculative and abstract-theoretical into a practical plane. For the first time in the history of mankind, it became possible to conduct deep and detailed experimental research on this important fundamental problem. The need for this kind of research is determined by the fact that the discovery of extraterrestrial civilizations and establishing contact with them can have a huge impact on the scientific and technological potential of society, have a positive impact on the future of mankind.

From the standpoint of modern science, the assumption of the possibility of the existence of extraterrestrial civilizations has objective grounds: the idea of ​​the material unity of the world; about the development, evolution of matter as its general property; natural science data on the regular, natural nature of the origin and evolution of life, as well as the origin and evolution of man on Earth; astronomical data that the Sun is a typical, ordinary star in our Galaxy and there are no grounds for distinguishing it from many other similar stars; At the same time, astronomy proceeds from the fact that in the Cosmos there is a wide variety of physical conditions, which can lead in principle to the emergence of the most diverse forms of highly organized matter.

The assessment of the possible prevalence of extraterrestrial (cosmic) civilizations in our Galaxy is carried out according to the Drake formula:

The current document contains no sources. N=R x f x n x k x d x q x L

where N is the number of extraterrestrial civilizations in the Galaxy; R is the rate of star formation in the Galaxy, averaged over the entire time of its existence (number of stars per year); f is the proportion of stars with planetary systems; n is the average number of planets included in planetary systems and ecologically suitable for life; k is the proportion of planets on which life actually arose; d is the proportion of planets on which, after the emergence of life, its intelligent forms developed, q is the proportion of planets on which intelligent life reached a phase that provides the possibility of communication with other worlds, civilizations: L is the average duration of the existence of such extraterrestrial (cosmic, technical) civilizations ( 3).

With the exception of the first value (R), which refers to astrophysics and can be calculated more or less accurately (about 10 stars per year), all other quantities are very, very uncertain, so they are determined by competent scientists on the basis of expert judgment, which, of course, , are subjective.

The topic of contact with extraterrestrial civilizations is perhaps one of the most popular in science fiction literature and cinematography. It causes, as a rule, the most ardent interest among fans of this genre, all those interested in the problems of the Universe. But the artistic imagination here must be subject to the rigid logic of rational analysis. Such an analysis shows that the following types of contacts are possible: direct contacts, i.e. mutual (or unilateral) visits; contacts through communication channels; mixed type contacts - sending automatic probes to an extraterrestrial civilization that transmit the received information via communication channels.

At present, contacts via communication channels are really possible contacts with extraterrestrial civilizations. If the signal propagation time in both directions t is longer than the lifetime of a civilization (t > L), then we can talk about one-way contact. If t<< L, то возможен двусторонний обмен информацией. Современный уровень естественнонаучных знаний позволяет серьезно говорить лишь о канале связи с помощью электромагнитных волн, а сегодняшняя радиотехника может реально обеспечить установление такой связи

The study of extraterrestrial civilizations should be preceded by the establishment of one form or another of communication with them. Currently, there are several directions to search for traces of the activity of extraterrestrial civilizations (6).

First, the search for traces of astrological engineering activities of extraterrestrial civilizations. This direction is based on the assumption that, sooner or later, technologically advanced civilizations must move to the transformation of the surrounding outer space (creation of artificial satellites, artificial biosphere, etc.), in particular, to intercept a significant part of the star's energy. As calculations show, the radiation of the main part of such astrological engineering structures should be concentrated in the infrared region of the spectrum. Therefore, the task of detecting such extraterrestrial civilizations should begin with a search for local sources of infrared radiation or stars with an anomalous excess of infrared radiation. Such research is currently underway. As a result, several dozen infrared sources were discovered, but so far there is no reason to associate any of them with an extraterrestrial civilization.

Secondly, the search for traces of visiting extraterrestrial civilizations on Earth. This direction is based on the assumption that the activity of extraterrestrial civilizations could manifest itself in the historical past in the form of visiting the Earth, and such a visit could not but leave traces in the monuments of the material or spiritual culture of various peoples. On this path, there are many opportunities for various kinds of sensations - stunning "discoveries", quasi-scientific myths about the cosmic origins of individual cultures (or their elements); thus, legends about the ascension of saints to heaven are called the story of astronauts. The construction of large stone structures, which are still inexplicable, also does not prove their cosmic origin. For example, speculations of this kind around giant stone idols on Easter Island were dispelled by T. Heyerdahl: the descendants of the ancient population of this island showed him how this was done not only without the intervention of astronauts, but also without any technology. In the same row is the hypothesis that the Tunguska meteorite was not a meteorite or a comet, but an alien spacecraft. Such hypotheses and assumptions need to be investigated in the most thorough way (6)

Thirdly, the search for signals from extraterrestrial civilizations. This problem is currently formulated, first of all, as the problem of searching for artificial signals in the radio and optical (for example, by a highly directed laser beam) ranges. The most likely is radio communication. Therefore, the most important task is to choose the optimal range of waves for such a connection. The analysis shows that artificial signals are most likely at waves = 21 cm (hydrogen radio line), = 18 cm (OH radio line), = 1.35 cm (water vapor radio line) or on waves combined from the fundamental frequency with some mathematical constant, etc.).

A serious approach to the search for signals from extraterrestrial civilizations requires the creation of a permanent service covering the entire celestial sphere. Moreover, such a service should be quite universal - designed to receive signals of various types (pulse, narrowband and broadband). The first work on the search for signals of extraterrestrial civilizations was carried out in the USA in 1950. The radio emission of the nearest stars (Cetus and Eridanus) at a wavelength of 21 cm was studied. Subsequently (70–80s), such studies were also carried out in the USSR. In the course of the research, encouraging results were obtained. For example, in 1977 in the United States (the Ohio University Observatory), while surveying the sky at a wavelength of 21 cm, a narrow-band signal was recorded, the characteristics of which indicated its extraterrestrial and, probably, artificial origin (8). However, this signal could not be recorded again, and the question of its nature remained open. Since 1972, searches in the optical range have been carried out at orbital stations. Projects for the construction of multimirror telescopes on the Earth and on the Moon, giant space radio telescopes, etc. were discussed.

The search for signals from extraterrestrial civilizations is one side of contact with them. But there is another side - a message to such civilizations about our earthly civilization. Therefore, along with the search for signals from space civilizations, attempts were made to send a message to extraterrestrial civilizations. In 1974, a radio message was sent from the radio astronomy observatory in Arecibo (Puerto Rico) to the globular cluster M-31, located at a distance of 24 thousand light years from the Earth, containing a coded text about life and civilization on Earth (8) . Information messages were also repeatedly placed on spacecraft, the trajectories of which provided them with an exit beyond the solar system. Of course, there is very little chance that these messages will ever reach their goal, but you have to start somewhere. It is important that humanity not only seriously thinks about contacts with intelligent beings from other worlds, but is already able to establish such contacts, albeit in the simplest form.

Cosmic natural sources of radiation conduct a constant intense "radio transmission" on the waves of the meter range. So that it does not create annoying interference, radio communication between the inhabited worlds must be carried out at wavelengths not exceeding 50 cm (11).

Shorter radio waves (a few centimeters) are not suitable, since the thermal radio emission of the planets occurs precisely at such waves, and it will “jam” artificial radio communications. In the United States, a project is being discussed to create a complex for receiving extraterrestrial radio signals, consisting of a thousand synchronous radio telescopes installed at a distance of 15 km from each other. In essence, such a complex is similar to one gigantic parabolic radio telescope with a mirror area of ​​20 km. The project is expected to be implemented within the next 10-20 years. The cost of the planned construction is truly astronomical - at least 10 billion dollars. The projected complex of radio telescopes will make it possible to receive artificial radio signals within a radius of 1000 light years (12).

In the last decade, among scientists and philosophers, the opinion that Mankind is alone, if not in the entire Universe, then at least in our Galaxy, has been increasingly prevailing. Such an opinion entails the most important ideological conclusions about the meaning and value of earthly civilization, its achievements.

Conclusion

The Universe is the entire existing material world, unlimited in time and space and infinitely diverse in the forms that matter takes in the process of its development.

The universe in the broadest sense is our environment. The importance of human practical activity is the fact that irreversible physical processes dominate in the Universe, that it changes over time, is in constant development. Man began to explore outer space, went into open space. Our accomplishments are gaining ever greater scope, global and even cosmic scales. And in order to take into account their immediate and long-term consequences, the changes that they can bring to the state of our habitat, including space, we must study not only terrestrial phenomena and processes, but also patterns on a cosmic scale.

The impressive progress of the science of the Universe, initiated by the great Copernican revolution, has repeatedly led to very deep, sometimes radical changes in the research activities of astronomers and, as a result, in the system of knowledge about the structure and evolution of space objects. In our time, astronomy is developing at a particularly rapid pace, growing every decade. The flow of outstanding discoveries and achievements irresistibly fills it with new content.

At the beginning of the 21st century, scientists are facing new questions about the structure of the Universe, the answers to which they hope to get with the help of an accelerator - the Large Hadron Collider

The modern scientific picture of the world is dynamic and contradictory. It contains more questions than answers. It amazes, frightens, confounds, shocks. The quest for the knowing mind knows no bounds, and in the coming years we may be overwhelmed by new discoveries and new ideas.

Bibliography

1. Naidysh V.M. Concepts of modern natural science: textbook \ ed. 2nd, revised. and additional - M .: Alfa-M; INFRA-M, 2004. - 622 p.

2. Lavrinenko V.N. Concepts of modern natural science: textbook\V.N. Lavrinenko, V.P. Ratnikova - M.: 2006. - 317 p.

3. News of astronomy, Universe, astronomy, philosophy: ed. Moscow State University 1988. - 192 p.

4. Danilova V.S., Kozhevnikov N.I. Basic concepts of modern natural science: textbook \ M .: Aspect-press, 2000 - 256 p.

5. Karpenkov S.Kh. Modern natural science: textbook \ M. Academic project 2003. - 560 p.

6. News of astronomy, astronautics, Universe. - URL: universe-news.ru

7. Likhin A. F. Concepts of modern natural science: textbook \ TK Welby, Prospekt Publishing House, 2006. - 264 p.

8. Tursunov A. Philosophy and modern cosmology M. \ INFRA-M, 2001, - 458 p.

Astronomy. Lesson 1.

Astronomy is the science of celestial bodies (from the ancient Greek words aston - star and nomos - law)

It studies visible and actual movements and laws,
determining these movements, shape, size, mass and relief
Surfaces, nature and physical condition of celestial bodies,
interaction and their evolution.

Exploring the universe

The number of stars in the galaxy is in the trillions. The most numerous
Stars are dwarfs with masses about 10 times smaller than the Sun. Except
single stars and their satellites (planets), the Galaxy includes
double and multiple stars, as well as groups of stars connected by gravity
and moving in space as a whole, called stellar
clusters. Some of them can be found in the sky through a telescope, and
sometimes with the naked eye. Such clusters do not have the correct
forms; more than a thousand of them are now known. star clusters
divided into scattered and spherical. Unlike scattering stellar
clusters consisting mainly of stars that belong to the main
sequences, globular clusters contain red and yellow
giants and supergiants. Sky surveys made by x-ray
telescopes mounted on special artificial satellites
Earth, led to the discovery of X-ray radiation of many spherical
clusters.

The structure of the galaxy

The vast majority of stars and diffuse matter in the Galaxy is
lenticular volume. The Sun is at a distance of about 10,000 pc from
the center of the Galaxy, hidden from us by clouds of interstellar dust. In the center
The galaxy has a nucleus, which has recently been carefully
investigated in the infrared, radio and x-ray wavelengths.
Opaque clouds of dust obscure the core from us, obstructing visual
and ordinary photographic observations of this most interesting object
Galaxies. If we could look at the galactic disk "from above", then
would find huge spiral branches,
mostly containing the hottest and brightest stars, as well as
massive gas clouds. A disc with spiral arms forms the base
flat subsystem of the Galaxy. And objects concentrating towards the nucleus
Galaxies and only partially penetrating the disk are spherical.
subsystem. This is the simplified form of the structure of the Galaxy.

Types of galaxies

1 Spiral. This is 30% of galaxies. They are of two kinds. Normal and
crossed.
2 Elliptical. It is believed that most galaxies are shaped
flattened sphere. Among them there are spherical and almost flat. The most
the largest known elliptical galaxy is M87 in the constellation Virgo.
3 Not correct. Many galaxies have a ragged shape without bright
pronounced contour. These include the Magellanic Cloud of Our
local group.

Sun

The sun is the center of our planetary system, its main element, without which
there would be no Earth, no life on it. Stargazing people do with
ancient times. Since then, our knowledge of the luminary has expanded significantly,
enriched with numerous information about the movement, internal structure and
the nature of this space object. Moreover, the study of the Sun contributes a huge
contribution to the understanding of the structure of the Universe as a whole, especially those of its elements,
which are similar in essence and principles of "work".

Sun

The sun is an object that exists
by human standards, a very long time ago.
Its formation began around 5
billion years ago. Then in place
The solar system was a vast
molecular cloud.
Under the influence of gravitational forces, it began
turbulences appear, similar to the earth
tornadoes. In the center of one of them, the substance (in
it was mostly hydrogen) began to condense,
and 4.5 billion years ago a young
star, which after a long time
period of time was named the Sun.
Around him gradually began to form
planets - our corner of the universe began
acquire familiar to modern
human kind. -

yellow dwarf

The sun is not a unique object. It belongs to the class of yellow dwarfs,
relatively small main sequence stars. Term
"service" allocated to such bodies is approximately 10 billion
years. By the standards of space, this is quite a bit. Now our luminary, you can
say, in the prime of life: not yet old, no longer young - ahead
half a lifetime more.

The structure of the sun

Light year

A light year is the distance that light travels in one year. International Astronomical
the union gave its explanation for the light year - this is the distance that light travels in a vacuum, without
participation of gravity, for the Julian year. The Julian year is equal to 365 days. It is this decryption
used in scientific literature. If we take professional literature, then there is a distance
calculated in parsecs or kilo- and megaparsecs.
Until 1984, a light year was the distance traveled by light in one tropical year.
The new definition differs from the old one by only 0.002%. Special difference between definitions
no.
There are specific figures that determined the distance of light hours, minutes, days, etc.
A light year is 9,460,800,000,000 km,
month - 788 333 million km.,
week - 197,083 million km.,
day - 26,277 million km,
hour - 1,094 million km.,
minute - about 18 million km.,
second - about 300 thousand km.

Virgo Constellation Galaxy

Virgo can best be seen in
early spring, namely in March -
April, when it passes into the southern
part of the horizon. Thanks to
constellation
It has
imposing
dimensions, the Sun is in it
more than a month - starting from 16
September through October 30th. On the
ancient star atlases Virgo
represented as a girl with a spikelet
wheat in the right hand. However, not
each
able
make out
in
a chaotic scattering of stars
such an image. However, find
constellation Virgo in the sky is not so
difficult. It contains a star
first magnitude, thanks to the bright
the light of which the Virgin can easily
search among other constellations.

Andromeda's nebula

Largest galaxy closest to the Milky Way.
Contains approximately 1 trillion stars, which is 2.5-5 times more
Milky Way. Located in the constellation Andromeda and distant
from the Earth at a distance of 2.52 million sv. years. The plane of the galaxy is tilted
to the line of sight at an angle of 15°, its apparent size is 3.2 × 1.0°, visible
magnitude - +3.4m.

Milky Way

The Milky Way is a spiral galaxy
type. At the same time, it has a jumper in the form of a huge
star system interconnected
gravitational forces. It is believed that the Milky
The path has been in existence for more than thirteen billion
years. This is the period during which the
The galaxy formed about 400 billion constellations
and stars, over a thousand huge in size
gaseous nebulae, clusters and clouds. The form
The Milky Way is clearly visible on the map of the universe. At
looking at it, it becomes clear that
a cluster of stars is a disk, diameter
which is equal to 100 thousand light years (one such
a light year is ten trillion
kilometers). The thickness of the star cluster is 15 thousand,
and the depth is about 8 thousand light years. How much does it weigh
Milky Way? This (the definition of its mass is very
difficult task) it is not possible to calculate
possible. The difficulty lies in defining
masses of dark matter that do not enter into
interaction with electromagnetic radiation. Here
why astronomers can't definitively answer
this question. But there are rough estimates
according to which the weight of the Galaxy is within
500 to 3000 billion solar masses

Milky Way core

This part of the Milky Way is located in the constellation Sagittarius. The core contains a source of non-thermal
radiation, having a temperature of about ten million degrees. In the center of this section
The Milky Way contains a seal called the "bulge". It's a whole string of old stars
which moves in an elongated orbit. For most of these celestial bodies, the life cycle is already
comes to the end. At the center of the Milky Way's core is a supermassive black
hole. This piece of outer space, whose weight is equal to the mass of three million suns,
has strong gravity. Another black hole revolves around it, only smaller
size. Such a system creates such a strong gravitational field that the
nearby, constellations and stars move along very unusual trajectories. near the center
The Milky Way has other features. So, it is characterized by a large cluster of stars.
Moreover, the distance between them is hundreds of times less than that observed on the periphery.
education.
Milky Way core

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Lesson type: lesson of studying and primary consolidation of new knowledge.

Target: Formation of ideas about the structure of the Universe and the place of the planet Earth in the Universe.

Tasks: Educational: introduce students to cosmology, introduce non-systemic units of measurement used in cosmology, introduce the age and size of the Universe, introduce the concept of a galaxy, introduce the types of galaxies, form an idea of ​​galaxy clusters, types of star clusters, the formation of nebulae in the Universe, introduce using spectral analysis in cosmology, to form knowledge about the phenomenon of redshift of spectral lines in the spectra of galaxies, about the Doppler effect, about the Hubble law, to introduce the Big Bang Theory, to introduce the concept of the critical density of matter.

Educational: to promote the education of moral qualities, a tolerant attitude towards all the inhabitants of our planet and responsibility for the safety of life on planet Earth.

Educational: to promote an increase in interest in the study of the discipline "Physics", to promote the development of logical thinking (analysis, generalization of the knowledge gained).

During the classes

I. Organizational moment.

Slides 1-2

Before the students, the objectives of the lesson are determined, the course of the lesson and the final results of its implementation are highlighted.

II. Motivation of educational activity.

Knowledge of the structure and evolution of the Universe helps to realize the place of each of us in this world and the responsibility that lies with us for the safety of life and our unique planet for future generations of people.

III. Knowledge update.

Frontal survey

1. What is the name of the closest star to planet Earth? (Sun)
2. How many planets are in the solar system? (Eight)
3. What are the names of the planets in the solar system? (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune)
4. What is the position of the planet Earth in the solar system in terms of distance from the Sun? (Planet Earth is the third planet from the Sun)

IV. Presentation of new material.

Slides 3-5. Cosmology. Non-system units of measure. Age and size of the universe.

“The universe is a concept that does not have a strict definition in astronomy and philosophy. It is divided into two fundamentally different entities: speculative (philosophical) and material, accessible to observation at the present time or in the foreseeable future. Following tradition, the first is called the Universe, and the second - the astronomical Universe, or Metagalaxy. Today we will get acquainted with the structure of the astronomical Universe. And we will determine the place of our planet Earth in the Universe. "The Universe is the subject of study of cosmology."

The distances and masses of objects in the universe are very large. Cosmology uses non-systemic units of measurement. 1 light year(1 St. G.) - the distance that light travels in 1 year in vacuum - 9.5 * 10 15 m; 1 astronomical unit(1 AU) - the average distance from the Earth to the Sun (the average radius of the earth's orbit) - 1.5 * 10 11 m; 1 parsec(1 pc) - the distance from which the average radius of the earth's orbit (equal to 1 AU), perpendicular to the line of sight, is visible at an angle of one arc second (1") - 3 * 10 16 m; 1 solar mass(1 M o) - 2 * 10 30 kg.

Scientists have determined the age and size of the universe. Age of the Universe t=1.3 * 10 10 years. Radius of the Universe R=1.3 * 10 10 sv.l.

Slides 6-19. Galaxies. Types of galaxies. clusters of galaxies.

At the beginning of the 20th century, it became obvious that almost all of the visible matter in the Universe is concentrated in giant stellar-gas islands with a characteristic size of several kpc. These "islands" became known as galaxies.

galaxies are large star systems in which stars are connected to each other by gravitational forces. There are galaxies containing trillions of stars. “This group of galaxies is called Stephan's Quintet. However, only four galaxies from this group, located 300 million light-years away from us, participate in the cosmic dance, now approaching, then moving away from each other. It's pretty easy to find one. The four interacting galaxies are yellowish in color and have twisted loops and tails shaped by destructive tidal gravitational forces. The bluish galaxy at the top left of the picture is much closer than the others, only 40 million light-years away.”

There are different types of galaxies: elliptical, spiral and irregular.

Elliptical galaxies make up about 25% of the total number of high luminosity galaxies.

Elliptical galaxies have the form of circles or ellipses, the brightness gradually decreases from the center to the periphery, they do not rotate, they have little gas and dust, M 10 13 M o . Before you is the elliptical galaxy M87 in the constellation Virgo.

Spiral galaxies in appearance resemble two plates stacked together or a biconvex lens. They have both a halo and a massive stellar disk. The central part of the disk, which is visible as a swelling, is called the bulge. The dark band running along the disk is an opaque layer of the interstellar medium, interstellar dust. The flat disc shape is due to rotation. There is a hypothesis that during the formation of a galaxy, centrifugal forces prevent the protogalactic cloud from collapsing in a direction perpendicular to the rotation axis. The gas is concentrated in a certain plane - this is how the disks of galaxies were formed.

Spiral galaxies consist of a nucleus and several spiral arms or branches, branches extending directly from the nucleus. Spiral galaxies rotate, they have a lot of gas and dust, M 10 12 M?

“The American aerospace agency NASA has launched its own account on the Instagram network, where photos are posted with views of the Earth and other corners of the Universe. Stunning photographs from the Hubble Telescope, NASA's most famous Grand Observatory, allow you to see things that have never been seen by the human eye. Previously unseen distant galaxies and nebulae, dying and reborn stars amaze the imagination with their diversity, pushing the dream of distant travels. Fabulous landscapes of stardust and gas clouds reveal mysterious phenomena of stunning beauty in front of us.” Before you is one of the most beautiful spiral galaxies in the constellation Coma Berenices.

In the 20s. In the 20th century, it became clear that spiral nebulae are huge star systems similar to our Galaxy and millions of light years away from it. In 1924, Hubble and Ritchie decomposed the spiral arms of the nebulae in Andromeda and Triangulum into stars. These "extragalactic nebulae" have been found to be several times farther from us than the diameter of the Milky Way system. These systems began to be called galaxies by analogy with ours. “The medium-sized galaxy M33 is also called the Triangulum galaxy after the constellation in which it is located. It is about 4 times smaller in radius than our Milky Way galaxy and the Andromeda galaxy. M33 is not far from the Milky Way and is perfectly visible with good binoculars.”

“The Andromeda Galaxy is the closest of the giant galaxies to our Milky Way. Most likely, our galaxy looks about the same as this one. The hundreds of billions of stars that make up the Andromeda galaxy together give a visible diffuse glow. The individual stars in the image are actually stars in our galaxy, much closer than the distant object.”

“When observing the starry sky far from large cities, on a moonless night, a wide luminous band is clearly visible on it - the Milky Way. The Milky Way stretches like a silvery strip across both hemispheres, locking into a star ring. Observations have established that all the stars form a huge star system (galaxy).” The galaxy contains two main subsystems nested one inside the other: a halo (its stars are concentrated towards the center of the galaxy) and a stellar disk (“two plates folded at the edges”). “The solar system is part of the Milky Way galaxy. We are inside a galaxy, so it is difficult for us to imagine its appearance, but there are many other similar galaxies in the Universe and we can judge our Milky Way from them.” The Milky Way galaxy consists of a nucleus at the center of the galaxy and three spiral arms.

“Studies of the distribution of stars, gas and dust have shown that our Milky Way galaxy is a flat system with a spiral structure.” Our galaxy is huge. The disk diameter of the galaxy is about 30 pc (100,000 ly); thickness - about 1,000 St. l.

There are about 100 billion stars in our galaxy. The average distance between stars in a galaxy is about 5 sv. years. The center of the galaxy is located in the constellation Sagittarius. “Astronomers are currently carefully studying the center of our galaxy. Observations of the movement of individual stars near the center of the galaxy showed that there, in a small area with dimensions comparable to the size of the solar system, invisible matter is concentrated, the mass of which exceeds the mass of the Sun by 2 million times. This indicates the existence of a massive black hole at the center of the galaxy.” The Milky Way galaxy revolves around the center of the galaxy. The Sun makes one revolution around the center of the galaxy in 200 million years.

Examples of irregular galaxies are the Large Magellanic Cloud and the Small Magellanic Cloud, the closest galaxies to us, visible to the naked eye in the southern hemisphere of the sky, near the Milky Way. These two galaxies are satellites of our galaxy.

Irregular galaxies lack a clearly defined core, no rotational symmetry, and about half of the matter in them is interstellar gas. When examining the sky with telescopes, many irregular, ragged galaxies, similar to the Magellanic Clouds, were discovered.

“In the cores of some galaxies, violent processes take place; such galaxies are called active galaxies. In the galaxy M87 in the constellation Virgo, there is an ejection of matter at a speed of 3000 km / s, the mass of this ejection is This galaxy turned out to be a powerful source of radio emission. An even more powerful source of radio emission are quasars. Quasars are also powerful sources of infrared, X-rays and gamma rays. But the sizes of quasars turned out to be small, about 1 AU. Quasars are not stars; these are bright and highly active galactic nuclei billions of light-years from Earth.” “At the center of the quasar is a supermassive black hole sucking matter into itself - stars, gas and dust. Falling into a black hole, matter forms a huge disk, in which it heats up from friction and the action of tidal forces to gigantic temperatures.” “The Hubble website has published what is probably one of the most detailed photographs of the quasar to date. This is one of the most famous quasars, 3C 273, which is located in the constellation Virgo.” It became the first open object of its kind; in the early 1960s it was discovered by astronomer Alan Sandage. “Qusar 3C 273 is the brightest and one of the closest quasars: it is about 2 billion light-years away and bright enough to be seen in an amateur telescope.”

Galaxies are rarely single. 90% of galaxies are concentrated in clusters, which include from tens to several thousand members. The average diameter of a cluster of galaxies is 5 Mpc, the average number of galaxies in a cluster is 130. “The Local Group of galaxies, whose dimensions are 1.5 Mpc, includes our Galaxy, the Andromeda Galaxy M31, the Triangulum Galaxy M33, the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (MMO) - a total of 35 galaxies connected by mutual gravity. The galaxies of the Local Group are connected by common gravity and move around a common center of mass in the constellation Virgo.”

Slides 21-23. star clusters.

In the galaxy, every third star is a double, there are systems of three or more stars. More complex objects are also known - star clusters.

Open star clusters are found near the galactic plane. In front of you is the Pleiades star cluster. The blue haze that accompanies the Pleiades is scattered dust that reflects starlight.

Globular clusters are the oldest formations in our Galaxy, their age is from 10 to 15 billion years and is comparable to the age of the Universe. The poor chemical composition and elongated orbits along which they move in the Galaxy indicate that globular clusters formed during the era of the formation of the Galaxy itself. Globular clusters stand out strongly against the stellar background due to the significant number of stars and a clear spherical shape. The diameter of globular clusters ranges from 20 to 100 pc. M= 104 106 M?

Slides 24-29. Interstellar matter. Nebulae.

In addition to stars, cosmic rays (protons, electrons, and atomic nuclei of chemical elements), which move at speeds close to the speed of light, galaxies contain gas and dust. Gas and dust in the galaxy are distributed very unevenly. In addition to rarefied dust clouds, dense dark dust clouds are observed. When these dense clouds are illuminated by bright stars, they reflect their light, and then we see nebulae.

“The Hubble team releases a stunning photo every year to celebrate the anniversary of the Space Telescope launch on April 24, 1990. In 2013, they presented the world with a photograph of the famous Horsehead Nebula, which is located in the constellation of Orion, 1500 light years from Earth.

“The bright Lagoon Nebula contains many different astronomical objects. Objects of particular interest include a bright open star cluster and several active star forming regions.”

“The colorful Trifid Nebula allows you to explore cosmic contrasts. Also known as M20, it lies some 5,000 light-years away in the nebula-rich constellation of Sagittarius. The size of the nebula is about 40 sv. l.”

“It is not yet known what illuminates this nebula. Particularly puzzling is the bright, inverted V-shaped arc that marks the top edge of mountain-like interstellar dust clouds near the center of the image. This ghostly nebula contains a small star-forming region filled with dark dust. It was first seen in infrared images taken by the IRAS satellite in 1983. Shown here is a remarkable image taken by the Hubble Space Telescope. Although it shows a lot of new details, the reason for the appearance of a bright, clear arc could not be established. ”

The total mass of dust is only 0.03% of the total mass of the galaxy. Its total luminosity is 30% of the luminosity of stars and completely determines the radiation of the galaxy in the infrared range. Dust temperature 15-25 K.

Slides 30-33. Application of spectral analysis. Redshift. Doppler effect. Hubble law.

The light of galaxies is the total light of billions of stars and gas. To study the physical properties of galaxies, astronomers use spectral analysis methods . Spectral analysis- a physical method for the qualitative and quantitative determination of the atomic and molecular composition of a substance, based on the study of its spectrum. Astronomers use the method of spectral analysis to determine the chemical composition of objects and their speed of movement.

In 1912, Slipher, an American astronomer, discovered a shift of lines towards the red end in the spectra of distant galaxies. “This phenomenon has been called redshift. In this case, the ratio of the shift of the spectral line to the wavelength turned out to be the same for all lines in the spectrum of a given galaxy. Attitude , where is the wavelength of the spectral line observed in the laboratory, characterizes the redshift”.

“The currently accepted interpretation of this phenomenon is related to the Doppler effect. The shift of the spectral lines to the red end of the spectrum is caused by the movement (removal) of the radiating object (galaxy) with a speed v in the direction from the observer. At small redshifts (z), the speed of the galaxy can be found using the Doppler formula: , where c is the speed of light in vacuum”.

In 1929, Hubble found that the entire system of galaxies is expanding. “According to the spectra of galaxies, it has been established that they are “running away” from us at a speed v, proportional to the distance to the galaxy:

v= H r, where H = 2.4 * 10 -18 s -1 is the Hubble constant, r is the distance to the galaxy (m)”.

Slides 34-38. The Big Bang Theory. Critical density of matter.

The theory of the expanding Universe appeared, according to which our Universe arose from a superdense state in the course of a grandiose explosion and its expansion continues in our time. About 13 billion years ago, all the matter of the Metagalaxy was concentrated in a small volume. The density of the substance was very high. This state of matter is called "singular". The expansion as a result of the “explosion” (“pop”) led to a decrease in the density of the substance. Galaxies and stars began to form.

There is a critical value of the density of matter, on which the nature of its motion depends. The critical value of the substance density kr is calculated by the formula:

where H \u003d 2.4 * 10 -18 s -1 is the Hubble constant, G \u003d 6.67 * 10 -11 (N * m 2) / kg 2 is the gravitational constant. Substituting numerical values, we get kr =10 -26 kg/m 3 . At< кр - расширение Вселенной. При >cr - compression of the Universe. The average density of matter in the universe = 3 * 10 -28 kg/m 3 .

Man always seeks to know the world around him. The study of the universe has just begun. Much remains to be known. Humanity is only at the very beginning of the path of studying the Universe and its mysteries. “Representing the Universe as the whole surrounding world, we immediately make it unique and unique. And at the same time, we deprive ourselves of the opportunity to describe it in terms of classical mechanics: because of its uniqueness, the Universe cannot interact with anything, it is a system of systems, and therefore such concepts as mass, shape, size lose their meaning in relation to it. Instead, one has to resort to the language of thermodynamics, using such concepts as density, pressure, temperature, chemical composition.”

For more detailed acquaintance with this information, you can use the following sources:

one). Physics. Grade 11: textbook. for general education Institutions: basic and profile. levels / G.Ya. Myakishev, B.B. Bukhovtsev, V.M. Chagurin; ed. IN AND. Nikolaev, N.A. Parfentiev. - 19th ed. - M .: Education, 2010. - 399 p., L. ill. - (Classic course). – ISBN 978-5-09-022777-3.;

four). http://www.adme.ru

The address of our home in the Universe: the Universe, the Local Group of Galaxies, the Milky Way Galaxy, the Solar System, Planet Earth - the third planet from the Sun.

We love our planet and will always protect it!

V. Primary consolidation of knowledge.

Frontal survey

• What is the name of the science that studies the structure and evolution of the universe? (Cosmology)
• What off-system units of measurement are used in cosmology? (light year, astronomical unit, parsec, solar mass)
• What distance is called a light year? (distance traveled by light in one year)

VI. Independent work.

Students are invited to independently solve the problem: The average density of matter in the universe = 3 * 10 -28 kg/m 3 . Calculate the critical value of matter density and compare it with the average matter density in the Universe. Analyze the result and draw a conclusion about whether the Universe is expanding or contracting.

VII. Reflection.

Students are invited to evaluate the work of the teacher and their own work in the lesson by drawing positive or negative emoticons on the sheets of paper issued by the teacher.

VIII. Homework.

Paragraphs 124, 125, 126 Orally answer the questions on pages 369, 373.

Literature:

1. Physics. Grade 11: textbook. for general education Institutions: basic and profile. levels / G.Ya. Myakishev, B.B. Bukhovtsev, V.M. Chagurin; ed. IN AND. Nikolaev, N.A. Parfentiev. - 19th ed. - M .: Education, 2010. - 399 p., L. ill. - (Classic course). – ISBN 978-5-09-022777-3.
2. http://en.wikipedia.org
3. http://www.adme.ru