A message about the study of the universe. What do you think is the significance of the study of the universe by scientists? Professional Management Institute

Professional Management Institute

Faculty of Finance and Credit

Specialty Finance and Credit

Discipline Concept

modern natural science

abstract

on the topic:

Universe

Student Ivanova E.A.

Group UFTZ-51/8-F-Vs-2

Moscow - 2010

Origin of the Universe 3

Expanding Universe Model 5

Evolution and structure of galaxies 10

Astronomy and cosmonautics 12

Literature 14

Origin of the Universe

At all times, people wanted to know where and how the world originated. When mythological ideas dominated in culture, the origin of the world was explained, as, say, in the Vedas, by the disintegration of the first man Purusha. The fact that this was a general mythological scheme is also confirmed by Russian apocrypha, for example, the Pigeon Book. The victory of Christianity confirmed the idea of ​​God's creation of the world out of nothing.

With the advent of science in its modern sense, mythological and religious ideas are being replaced by scientific ideas about the origin of the universe. It is necessary to separate three close terms: being, the universe and the Universe. The first is philosophical and denotes everything that exists, being. The second one is used both in philosophy and in science, without having a specific philosophical load (in terms of opposing being and consciousness), and designates everything as such.

The meaning of the term Universe is narrower and has acquired a specifically scientific sound. The Universe is a place of human settlement, accessible to empirical observation. The gradual narrowing of the scientific meaning of the term Universe is quite understandable, since natural science, unlike philosophy, deals only with what is empirically verifiable by modern scientific methods.

The universe as a whole is studied by a science called cosmology, i.e. space science. The word is also not accidental. Although today everything outside the Earth's atmosphere is called space, this was not the case in ancient Greece. The cosmos was then accepted as "order", "harmony", as opposed to "chaos", "disorder". Thus, cosmology, at its core, as befits a science, reveals the orderliness of our world and is aimed at finding the laws of its functioning. The discovery of these laws is the goal of studying the Universe as a single ordered whole.

This study rests on several premises. First, the universal laws of the functioning of the world formulated by physics are considered to be valid in the entire Universe. Secondly, the observations made by astronomers are also recognized as being extended to the entire Universe. And, thirdly, only those conclusions are recognized as true that do not contradict the possibility of the existence of the observer himself, i.e. man (the so-called anthropic principle).

The conclusions of cosmology are called models of the origin and development of the Universe. Why models? The fact is that one of the basic principles of modern natural science is the idea of ​​the possibility of conducting a controlled and reproducible experiment on the object under study at any time. Only if it is possible to carry out an infinite, in principle, number of experiments, and all of them lead to the same result, on the basis of these experiments, a conclusion is made about the existence of a law to which the functioning of a given object is subject. Only in this case the result is considered quite reliable from a scientific point of view.

This methodological rule remains inapplicable to the Universe. Science formulates universal laws, and the universe is unique. This is a contradiction that requires considering all conclusions about the origin and development of the Universe not as laws, but only as models, i.e. possible explanations. Strictly speaking, all laws and scientific theories are models, since they can be replaced by other concepts in the development of science, but models of the Universe are, as it were, more models than many other scientific statements.

Expanding Universe Model

The most commonly accepted model in cosmology is the model of a homogeneous isotropic non-stationary hot expanding universe, built on the basis of the general theory of relativity and the relativistic theory of gravity created by Albert Einstein in 1916. This model is based on two assumptions: 1) the properties of the Universe are the same at all its points (homogeneity) and direction (isotropy); 2) the best known description of the gravitational field is the Einstein equations. From this follows the so-called curvature of space and the relationship of curvature with the density of mass (energy). Cosmology based on these postulates is relativistic.

An important point of this model is its non-stationarity. This is determined by two postulates of the theory of relativity: 1) the principle of relativity, which states that in all inertial systems all laws are preserved regardless of the speed with which these systems move uniformly and rectilinearly relative to each other; 2) experimentally confirmed constancy of the speed of light.

From the acceptance of the theory of relativity it followed as a consequence (the first to notice this was the Petrograd physicist and mathematician Alexander Alexandrovich Fridman in 1922) that curved space cannot be stationary: it must either expand or contract. This conclusion was ignored until the discovery by the American astronomer Edwin Hubble in 1929 of the so-called "redshift".

Redshift is a decrease in the frequencies of electromagnetic radiation: in the visible part of the spectrum, the lines are shifted towards its red end. The Doppler effect discovered earlier said that when any source of vibrations moves away from us, the frequency of vibrations perceived by us decreases, and the wavelength increases accordingly. When emitted, “reddening” occurs, i.e., the lines of the spectrum shift towards longer red waves.

So, for all distant light sources, the redshift was fixed, and the farther the source was, the more so. The redshift turned out to be proportional to the distance to the source, which confirmed the hypothesis about their removal, i.e. about the expansion of the Metagalaxy - the visible part of the Universe.

The redshift reliably confirms the theoretical conclusion about the non-stationarity of a region of our Universe with linear dimensions of the order of several billion parsecs over at least several billion years. At the same time, the curvature of space cannot be measured, remaining a theoretical hypothesis.

An integral part of the model of the expanding Universe is the idea of ​​the Big Bang, which occurred about 12 -18 billion years ago. “In the beginning there was an explosion. Not the explosion that we are familiar with on Earth, which starts from a certain center and then spreads, capturing more and more space, but an explosion that occurred simultaneously everywhere, filling all space from the very beginning, with each particle of matter rushing away from any other particles ”(Weinberg S. The first three minutes. A modern view on the origin of the Universe.-M., 1981).

The initial state of the universe (the so-called singular point): infinite mass density, infinite curvature of space, and explosive expansion that slows down over time at a high temperature, at which only a mixture of elementary particles (including photons and neutrinos) could exist. The hotness of the initial state was confirmed by the discovery in 1965 of the relic radiation of photons and neutrinos, formed at an early stage of the expansion of the Universe.

An interesting question arises: from what was the Universe formed? What was that from which it arose. The Bible states that God created everything out of nothing. Knowing that the laws of conservation of matter and energy were formulated in classical science, religious philosophers argued about what the biblical “nothing” meant, and some, for the sake of science, believed that nothing meant the initial material chaos ordered by God.

Surprising as it may seem, modern science admits (it admits, but does not assert) that everything could be created from nothing. "Nothing" in scientific terminology is called a vacuum. Vacuum, which physics of the 19th century considered to be emptiness, according to modern scientific concepts, is a peculiar form of matter, capable of “giving birth” to material particles under certain conditions.

Modern quantum mechanics admits (this does not contradict the theory) that the vacuum can come into an "excited state", as a result of which a field can form in it, and from it (which is confirmed by modern physical experiments) - matter.

From the modern scientific point of view, the birth of the Universe “out of nothing” means its spontaneous emergence from vacuum, when a random fluctuation occurs in the absence of particles. If the number of photons is zero, then the field strength does not have a definite value (according to Heisenberg's "uncertainty principle"): the field constantly fluctuates, although the average (observed) value of the strength is zero.

Fluctuation is the appearance of virtual particles that are continuously born and immediately destroyed, but also participate in interactions, like real particles. Due to fluctuations, the vacuum acquires special properties that are manifested in the observed effects.

So, the Universe could be formed from "nothing", i.e. from the excited vacuum. Such a hypothesis, of course, is not a decisive confirmation of the existence of God. After all, all this could happen in accordance with the laws of physics in a natural way without outside interference from any ideal entities. And in this case, scientific hypotheses do not confirm or refute religious dogmas that lie on the other side of empirically confirmed and refuted natural science.

The amazing in modern physics does not end there. Responding to a journalist's request to state the essence of the theory of relativity in one sentence, Einstein said: “It used to be believed that if all matter disappeared from the Universe, then space and time would be preserved; The theory of relativity states that along with matter, space and time would also disappear. Transferring this conclusion to the model of the expanding Universe, we can conclude that before the formation of the Universe there was neither space nor time.

Note that the theory of relativity corresponds to two versions of the model of the expanding Universe. In the first of them, the curvature of space-time is negative or equals zero in the limit; in this variant, all distances increase indefinitely with time. In the second version of the model, the curvature is positive, space is finite, and in this case, expansion is replaced by contraction over time. In both versions, the theory of relativity is consistent with the current empirically confirmed expansion of the universe.

An idle mind inevitably asks questions: what was there when there was nothing, and what is beyond the limits of expansion. The first question is obviously contradictory in itself, the second goes beyond the scope of a particular science. The astronomer may say that, as a scientist, he has no right to answer such questions. But since they nevertheless arise, possible substantiations of the answers are formulated, which are not so much scientific as natural-philosophical.

Thus, a distinction is made between the terms "infinite" and "limitless". An example of infinity, which is not unlimited, is the surface of the Earth: we can walk on it indefinitely, but, nevertheless, it is limited by the atmosphere above and the earth's crust below. The universe can also be infinite, but limited. On the other hand, there is a well-known point of view, according to which there can be nothing infinite in the material world, because it develops in the form of finite systems with feedback loops, by which these systems are created in the process of transforming the environment.

But let us leave these considerations to the realm of natural philosophy, because in natural science, ultimately, the criterion of truth is not abstract considerations, but empirical testing of hypotheses.

What happened after the Big Bang? A clot of plasma was formed - a state in which elementary particles are located - something between a solid and a liquid state, which began to expand more and more under the action of a blast wave. 0.01 sec after the start of the Big Bang, a mixture of light nuclei (2/3 hydrogen and 1/3 helium) appeared in the Universe. How were all the other chemical elements formed?

Evolution and structure of galaxies

The poet asked: “Listen! After all, if the stars are lit, it means that someone needs it? We know that stars are needed to shine, and our Sun provides the energy necessary for our existence. Why are galaxies needed? It turns out that galaxies are also needed, and the Sun not only provides us with energy. Astronomical observations show that a continuous outflow of hydrogen occurs from the nuclei of galaxies. Thus, the nuclei of galaxies are factories for the production of the main building material of the Universe - hydrogen.

Hydrogen, whose atom consists of one proton in the nucleus and one electron in its orbit, is the simplest "brick" from which more complex atoms are formed in the interior of stars in the process of atomic reactions. Moreover, it turns out that it is not by chance that the stars have a different size. The greater the mass of a star, the more complex atoms are synthesized in its interior.

Our Sun, as an ordinary star, produces only helium from hydrogen (which is given by the nuclei of galaxies), very massive stars produce carbon - the main "brick" of living matter. That's what galaxies and stars are for. What is the earth for? It produces all the necessary substances for the existence of human life. Why does man exist? Science cannot answer this question, but it can make us think again about it.

If someone needs the “ignition” of stars, then maybe someone needs a person? Scientific data help us formulate an idea about our purpose, about the meaning of our life. When answering these questions, turning to the evolution of the Universe means thinking cosmically. Natural science teaches us to think cosmically, at the same time, not breaking away from the reality of our existence.

The question of the formation and structure of galaxies is the next important question of the origin of the Universe. It is studied not only by cosmology as the science of the Universe - a single whole, but also by cosmogony (Greek "gonea" means birth) - a field of science that studies the origin and development of cosmic bodies and their systems (distinguish between planetary, stellar, galactic cosmogony) .

The galaxy is a giant cluster of stars and their systems, having its own center (core) and different, not only spherical, but often spiral, elliptical, flattened or even irregular shape. There are billions of galaxies, and in each of them there are billions of stars.

Our galaxy is called the Milky Way and consists of 150 billion stars. It consists of a core and several spiral branches. Its dimensions are 100 thousand light years. Most of the stars in our galaxy are concentrated in a giant "disk" about 1500 light-years thick. The Sun is located at a distance of about 30 thousand light years from the center of the galaxy.

The galaxy closest to ours (to which a light beam runs 2 million years) is the Andromeda Nebula. It is named so because it was in the constellation Andromeda in 1917 that the first extragalactic object was discovered. Its belonging to another galaxy was proved in 1923 by E. Hubble, who found stars in this object by spectral analysis. Later, stars were also discovered in other nebulae.

And in 1963, quasars (quasi-stellar radio sources) were discovered - the most powerful sources of radio emission in the Universe with a luminosity hundreds of times greater than the luminosity of galaxies and sizes ten times smaller than them. It was assumed that quasars are the nuclei of new galaxies and, therefore, the process of galaxy formation continues to this day.

Astronomy and astronautics

Stars are studied by astronomy (from the Greek "astron" - star and "nomos" - law) - the science of the structure and development of cosmic bodies and their systems. This classical science is experiencing its second youth in the 20th century due to the rapid development of observational technology - its main research method: reflecting telescopes, radiation receivers (antennas), etc. In the USSR in 1974, a reflector with a mirror diameter of 6 m came into operation in the Stavropol Territory, which collects light millions of times more than the human eye.

Astronomy studies radio waves, light, infrared, ultraviolet, x-rays and gamma rays. Astronomy is divided into celestial mechanics, radio astronomy, astrophysics and other disciplines.

Astrophysics, a part of astronomy that studies the physical and chemical phenomena occurring in celestial bodies, their systems and in outer space, is gaining particular importance at the present time. Unlike physics, which is based on experiment, astrophysics is based mainly on observations. But in many cases, the conditions in which matter is found in celestial bodies and systems differ from those available to modern laboratories (ultrahigh and ultralow densities, high temperatures, etc.). Thanks to this, astrophysical research leads to the discovery of new physical laws.

The intrinsic value of astrophysics is determined by the fact that at present the main attention in relativistic cosmology is transferred to the physics of the Universe - the state of matter and physical processes occurring at different stages of the expansion of the Universe, including the earliest stages.

One of the main methods of astrophysics is spectral analysis. If you pass a beam of white sunlight through a narrow slit and then through a glass trihedral prism, then it breaks up into its component colors, and an iridescent color strip with a gradual transition from red to violet appears on the screen - a continuous spectrum. The red end of the spectrum is formed by the rays that deviate the least when passing through a prism, the violet - the most deviated. Each chemical element corresponds to well-defined spectral lines, which makes it possible to use this method to study substances.

Unfortunately, short-wave radiation - ultraviolet, x-rays and gamma rays - do not pass through the Earth's atmosphere, and here science comes to the aid of astronomers, which until recently was considered primarily technical - astronautics (from the Greek "nautike" - the art of navigation), providing space exploration for the needs of mankind with the use of aircraft.

Cosmonautics studies problems: theories of space flights - calculations of trajectories, etc.; scientific and technical - the design of space rockets, engines, onboard control systems, launch facilities, automatic stations and manned ships, scientific instruments, ground-based flight control systems, trajectory measurement services, telemetry, organization and supply of orbital stations, etc.; medical and biological - the creation of onboard life support systems, compensation for adverse events in the human body associated with overload, weightlessness, radiation, etc.

The history of astronautics begins with the theoretical calculations of a man's exit into unearthly space, which were given by K.E. Tsiolkovsky in his work "Investigation of world spaces with reactive devices" (1903). Work in the field of rocket technology began in the USSR in 1921. The first launches of liquid fuel rockets were carried out in the USA in 1926.

The main milestones in the history of cosmonautics were the launch of the first artificial Earth satellite on October 4, 1957, the first manned flight into space on April 12, 1961, the lunar expedition in 1969, the creation of orbital manned stations in low Earth orbit, and the launch of a reusable spacecraft.

Work was carried out in parallel in the USSR and the USA, but in recent years there has been a unification of efforts in the field of space exploration. In 1995, the Mir-Shuttle joint project was implemented, in which the American Shuttle ships were used to deliver astronauts to the Russian orbital station Mir.

The ability to study at orbital stations cosmic radiation, which is delayed by the Earth's atmosphere, contributes to significant progress in the field of astrophysics.

Bibliography

1. Einstein A., Infeld L. The evolution of physics. M., 1965.

2. Heisenberg V. Physics and Philosophy. Part and whole. M., 1989.

3. A brief moment of triumph. M., 1989.

The outgoing century will forever remain singled out in the history of astronomy. The universe can only be opened once. Astronomers entered the 20th century with the vision of a single, all-encompassing star system in the Milky Way. We leave this age in an expanding universe filled with myriads of systems like our galaxy, and with the suspicion that there are many universes quite unlike ours. In the 20th century, the nature of the main objects of astronomy, which gave their name to our science, was also unraveled. Descendants will envy the astronomers of the 20th century for the fact that it was we who managed to understand why the stars shine.

Let's try to sketch here, inevitably in broad strokes, an outline of the history of research that led to the discovery of the Universe and the creation of the theory of stars. These great achievements have opened up new horizons and new challenges, which we will also briefly describe.

The main question that worries us when we turn to the past is whether the study of ways of knowing can confirm us in the reliability of our current ideas about the universe. Whoever owns the past can predict the future. It is usually believed that since the end of the 18th century, scientists of every generation have been inclined to think that the foundations of the universe have already been comprehended, that it remains only to clarify the details. The law of universal gravitation perfectly described the motions of planets and binary stars, and until the 20th century it seemed that the laws of Newtonian mechanics were sufficient for the observed picture of the world. This opinion is usually attributed to P. S. Laplace, but in essence he spoke only about the prospect of embracing “in one formula the movement of the greatest bodies of the Universe on a par with the movement of the lightest atoms”, which remains, in a certain sense, the greatest task of modern natural science.

The success of future astronomy, according to Laplace, depended on three conditions: the measurement of time, the measurement of angles, and the perfection of optical instruments, and "the first two at the present time leave almost nothing to be desired." Now, two centuries later, only the first condition has become obsolete - the measurement of time has passed into the jurisdiction of atomic and molecular physics and has reached the limit of accuracy determined by the laws of quantum mechanics. In angle measurements, after almost two centuries of stagnation, the use of interference methods and space exploration have recently led to radical progress, the limits of which are not visible. The improvement of optical instruments, on which Laplace placed special hopes (because the measurements of angles and time, as it seemed to him, had almost reached the limit of the possible ...), is also not limited by anything. At the end of the 20th century, the number of giant ground-based telescopes with mirrors exceeding five meters in diameter exceeded a dozen and will soon reach two dozen; a project of a 100-m telescope is being developed. Laplace was unaware of the possibility of observations in other ranges of the electromagnetic spectrum, in addition to the optical one. Moreover, he could not think of neutrino astronomy, which is now making its first steps, or of gravitational radiation receivers that will work in a couple of years.

How galaxies were discovered

Measurement of the angular distance between celestial objects and the radiation coming from them has been the only weapon of astronomers for all ages. Instruments delivered to the Moon, Venus and Mars take these planets out of astronomy, although the data obtained in this case is still recorded by astronomical methods - radio telescopes.

With what observational means did astronomy enter the 20th century? The largest instruments were the 40-inch refractor at the Yerkes Observatory and the 36-inch Crossley reflector operated at the Lick Observatory. In 1908 the 60-inch telescope at Mount Wilson went into operation. These two reflectors, with the help of photographic plates, actually discovered the world of galaxies, the study of which was the main task of astronomy in the 20th century.

Of course, we have seen them for a long time. The Magellanic Clouds in the southern sky, the Andromeda Nebula in the northern sky are visible to the naked eye. William Herschel at the end of the 18th century compiled a catalog of star clusters and nebulae (most of which were distant galaxies), in which there were about 2500 objects. By the end of the 19th century, 13673 objects were listed in the NGC - New General Catalog of Nebulae and Star Clusters. At the beginning of the 20th century, the Crossley reflector registered about 120,000 "weak nebulae" on photographic plates, but disputes about their nature continued for a long time, which began in the 18th century.

William Herschel himself believed that the faint specks of light visible in his giant reflectors could be distant systems of stars, although some nebulae, in his opinion, could be true and consist of diffuse luminous matter.

However, the final judgment of the 19th century turned out to be different. In a book on the development of astronomy in the 19th century, Agnes Clark wrote: “The question of whether nebulae are outer galaxies is hardly worth discussing now. The progress of research has answered it. It can be said with confidence that no competent thinker in the face of existing facts would argue that at least one nebula could be a star system comparable in size to the Milky Way."

In the first two decades of our century, the belief still prevailed that all the stars and nebulae visible in the sky belonged to the gigantic all-encompassing system of the Milky Way, near the center of which the Sun is located. This was the so-called "Kaptein Universe", a scheme for which the Dutch astronomer J. Kapteyn fought until his death in 1922.

To solve the problem of the nature of "weak nebulae" it was necessary to know the distance to them. Only photometric methods could help here, but for their application it was necessary to know the luminosity (absolute value) of any objects located inside these nebulae and compare it with the visible value. This problem was first solved by the American physicist F. Veri in 1911. First, he estimated the distance to New Perseus in 1901, comparing the angular velocity of the expansion of the nebula that arose after the outburst around the star with the speed of light. He assumed (quite rightly) that the expansion of the nebula is nothing more than the propagation of a wave of illumination of the interstellar medium surrounding the New Star by its flash. Very then compared (determined by him from distance and apparent magnitude) the luminosity of Nova Persei with the apparent magnitude of Nova 1885, which flared up near the center of the Andromeda Nebula, and estimated the distance to the nebula at 500 pc. The fainter "white" (as opposed to greenish gaseous) nebulae, Veery concluded, lie at distances of millions of parsecs. Everything is correct in this reasoning, except that the New 1885 was actually a Supernova, tens of thousands of times brighter than ordinary New ones - which means that the distance to M31 is not 500 ps, ​​but thousands of times more ...

By 1920, three genuine New Stars had become known in the Andromeda Nebula, and all of them were 10-12m fainter than the star of 1885. This difference was one of Shepley's arguments against the extragalactic nature of M31 and faint nebulae in general (supernovae were not yet known at that time).

He used it in the so-called "great dispute" with Lick Observatory astronomer G. Curtis, who was the first to realize that the 1885 outburst in M31 was a special case. This debate was organized by the US National Academy of Sciences in 1920. Shapley's most important argument was that clumps in the spiral arms of galaxies showed, according to A. van Maanen, noticeable proper motions. A comparison of the angular and linear (by radial velocities) rotational velocities of the spiral nebulae gave the distance; for the Triangulum Nebula (TNE), for example, it was found to be 2000 ps. This distance placed the MZZ deep within the Milky Way system, which Shapley had recently estimated at 100,000 ps.

Shapley relied on the period-luminosity relationship for Cepheids discovered by G. Leavitt in 1908 from observations of these stars in the Magellanic Clouds. First, he determined the distances to a number of globular star clusters containing Cepheids, and then, based on them, developed methods for estimating distances for clusters that did not contain Cepheids. He suggested that the concentration of globular clusters in the constellation Sagittarius is explained by the fact that they are condensing towards the center of the Milky Way star system, and found the distance to it at 15,000 ps.

Curtis, on the other hand, believed that this distance was much smaller, and the period-luminosity dependence for Cepheids was unreliable. But he was absolutely right in defending the extragalactic distances of "weak nebulae" and explaining their absence in the Milky Way band by the concentration of light-absorbing matter in it. In such discussions, it always turns out that both sides were partially right.

Thus, in the early 1920s two systems of the universe competed. According to Shapley, in our gigantic Galaxy, the Milky Way system, the Sun was placed on the far outskirts, as were the "faint nebulae." Kapteyn's universe contained the Sun near the center and was much smaller. About what is beyond the Milky Way system, both schemes of the universe were strikingly silent, although some astronomers were convinced (like Herschel in the 18th century!), That numerous faint nebulae were huge star systems comparable to ours, and that spiral The Andromeda and Triangulum nebulae are just the closest of them.

K. Lundmark was completely sure of this, who believed that in the photographs taken by J. Ritchie as early as 1908 with the 60-inch telescope of the Mount Wilson Observatory, individual stars are visible in the MZZ and estimated the distance of the nebula at 300,000 ps. Moreover, back in 1887, I. Roberts obtained photographs on his 20-inch reflector, in which individual stars can be seen in the outer parts of the Andromeda galaxy ... But you can only see what you consider possible to see. When in the early 1920s Humason showed Shapley several variable stars - probable Cepheids, marked by him on the plate with the image of the Andromeda Nebula, Shapley erased his marks - there could not be stars in this gaseous nebula! The erroneousness of this opinion was finally proved in 1924 by E. Hubble, who used the new 100-inch telescope at the Mount Wilson Observatory. He found Cepheids in the MZZ and in M31 and determined distances from them, which turned out to be close to Lundmark's estimates; both systems turned out to be far beyond the limits of the Milky Way system, even with Shapley's overestimated sizes of our Galaxy.

As for the proper motions of the "knots" of the spiral arms, it was only by the mid-1930s that it was proved that they reflect only measurement errors.

Soon, based on the distances to the nearest galaxies, Hubble was able to estimate the distances to more distant systems, and by 1929 provided evidence that the radial velocities of galaxies increase with increasing distances to them. The fact that distant nebulae have large positive radial velocities has been known for a long time, but for the first time Hubble, having reliable distances, was able to confidently determine the coefficient of proportionality between the distances and velocities of galaxies, now known as the Hubble constant.

From the dependence found by Hubble, it followed that the Universe is expanding: all distances between all galaxies increase with time. And this discovery remains the greatest result of astronomy not only in the 20th century. The universe is populated by galaxies and it is expanding! The revolution that took place in the minds of astronomers in just a dozen years is comparable in its significance to the revolution of Copernicus.

Theory of the structure and evolution of stars

The 19th century did not bring an understanding of the nature of the stars, only the old assumption was proved that the stars are distant suns. Gravitational contraction was proposed by Lord Kelvin as a source of energy for stars, but this source was only enough for millions of years, and the evolution of life forms on Earth required hundreds of times more time. We now understand that at a time when even the concept of a quantum of light was unknown, the very formulation of the question of the sources of stellar energy was premature. Who knows what our problems our descendants will say the same about ...

The observational data that the theory of the structure and evolution of stars was supposed to explain also appeared only in our century. E. Hertzsprung in 1908 and G. Ressel in 1910 constructed a diagram relating the surface temperature of a star to its luminosity. It was found that most of the stars are located along the main sequence, stretching from hot bright stars to faint and cold ones, but there is also a group of cold but bright stars - red giants and supergiants.

The explanation of this diagram has become the most important task of the theory of the internal structure of stars, in the creation of which special merit belongs to A. Eddington. By 1924 he had developed a model of a star, the mechanical stability of which is determined by the balance between gravity and radiation plus gas pressure. This pressure keeps the star from unrestrained compression, and it is provided by a very high temperature, growing towards the center of the star. But what creates this temperature, what is the source of stellar energy? J. Jeans believed that this was annihilation, the transformation of matter into energy, and Eddington believed that these were nuclear reactions, the transformation of elements. He said in 1926 that what is possible in Rutherford's laboratory cannot be too difficult for nature, and that "it is reasonable to hope that in the not too distant future we will be able to understand such a simple thing as a star."

In the same years, the origin of lines in the spectra of stars was unraveled, and thus the temperatures and chemical composition of their surface layers were determined. This was done in 1925 by C. Payne, a student of Ressel, on the basis of the theory of excitation and ionization of atoms, which M. Saha had developed shortly before. It turned out that the relative abundance of chemical elements in all stars is approximately the same and close to the solar one: 96-99.9% of the outer layers of stars consist of hydrogen and helium, and the rest is iron, calcium, etc., in approximately the same proportion as the average chemical composition of the Earth and meteorites.

The sharp difference in the spectra of stars was explained by the difference in the temperatures of their surfaces, although the abundance of elements heavier than helium can differ by hundreds of times. The theory faced the second task of fundamental importance - to explain the chemical composition of stars and, in general, the matter of the Universe.

From now on, from the 20s of the 20th century, the development of astronomy began to depend on the successes of physics, which began to return its old debt to astronomy - the foundations of mechanics were created by Galileo, Newton, Lagrange and Laplace on the basis of astronomical data. Advances in nuclear physics enabled H. Bethe (who is now alive!) in 1938 to lay the foundations for the theory of stellar energy sources. The concentration of most stars on the main sequence of the Gerschsprung-Rossl diagram was explained by the fact that this is the longest stage of evolution, in which the energy source of stars is the conversion of hydrogen into helium. This reaction in its explosive version was carried out on Earth in 1952-1953, but the work on the creation of a controlled thermonuclear reactor that began in the same years was still not crowned with success. The understanding of the nature of stars and, in particular, the sources of their energy, achieved in the middle of the 20th century, is the greatest triumph of natural science.

The theory of energy sources and the structure of stars, combined with data on Hertzsprung-Rossle diagrams of star clusters, the stars in each of which were undoubtedly formed simultaneously and almost simultaneously and differ only in masses, made it possible in the middle of the century to understand the basic laws of stellar evolution. It goes the faster, the greater their mass, and the luminosity proportional to the cube of mass determines the rate of consumption of nuclear fuel.

The most populated part of the diagram, the main sequence, is filled with stars in the long stage of hydrogen combustion in the core, after which the core contracts and the star shell swells. The most massive cluster stars are the first to pass into the stage of red supergiants and giants, in which helium is burning in the core. The luminosity of the brightest stars still remaining on the main sequence determines their age and, consequently, the age of the entire cluster. Heavier elements, up to iron, are formed at successive increasingly brief stages of evolution, ending in massive stars with an outburst of a star as a supernova, during which heavier elements are also formed. During supernova explosions and the formation of planetary nebulae (in the late stages of the evolution of less massive stars), elements heavier than helium enter the interstellar medium and then participate in the formation of cosmic dust, comets and planets.

Already in the 1940s it became clear that the most wasteful high-luminosity stars had only enough nuclear fuel for millions of years - they should be formed in our time. The constant proximity of these stars to gas and dust nebulae indicated their genetic connection, and F. Whipple concluded as early as 1942 that interstellar matter is the only obvious source of matter for building stars. The youthfulness of high-luminosity stars was soon confirmed for quite different reasons. In 1947, V. A. Ambartsumyan concluded that in rarefied groupings of these stars, stellar associations, the stars cannot be held together for a long time by mutual gravitation, and, therefore, these groupings were formed recently. The conclusion about the group formation of stars, which continues in our time, has become generally accepted.

The structure of galaxies

The discovery of the Universe populated by galaxies was also the discovery of our Galaxy as one of many. We could now compare our stellar system with others and, on the contrary, rely on our knowledge of our Galaxy when studying them. Two difficulties impede the exploration of the Galaxy. One of them is the absorption (more precisely, scattering) of light in gas clouds, which also contain an admixture of solid particles, mainly carbon, due to which the apparent brightness of stars decreases and their photometric distances, which are the only ones determined for distant objects, are distorted. It was only recently that they learned to deal with the absorption of light, making observations in the far infrared range, in which it is small. The development of interference observations from space in the coming decades will make it possible to determine the distances of objects in our Galaxy geometrically, without knowing their luminosity and apparent brightness corrected for absorption. However, the second difficulty is of fundamental nature. We live near the equator of our disk-shaped star system, and we cannot look over it from above. There's nothing you can do about it. The hope that someday we will establish contact with intelligent beings living at least a kiloparsec above (or below) the plane of the Galaxy, and they will share their photographs, is weak ...

In the 40s. It was found that there are two types of stellar population in the Galaxy. The population of type I, which includes the Sun, open clusters, supergiant stars, clouds of gas and dust, is concentrated towards the plane of the Galaxy, and the population of type II (globular clusters, planetary nebulae, some giant stars, etc.) is concentrated towards its center, forming spheroidal halo.

The recognition of two types of stellar population was the result of a series of works that began with the proof of the rotation of the Galaxy by J. Oort in 1927. He showed that the distribution of radial velocities and proper motions of stars in the sky is what should be expected if the stars rotate around the center of the Galaxy. Somewhat earlier, B. Lindblad explained the high radial velocity of globular clusters by the fact that, in fact, the system of these clusters rotates around the center of the Galaxy slowly, while the Sun and other stars of the galactic disk rotate quickly, and their high observed velocities are only a reflection of the motion of the Sun.

The direction perpendicular to the velocity vectors of globular clusters indicated the constellation Sagittarius, where the area of ​​their greatest concentration is also located. It became finally clear that Shapley was right in assuming that the center of the system of globular clusters is also the center of the entire Galaxy.

In the works of Lindblad, Oort, and Bottlinger, a difference was suspected not only in the kinematic characteristics, but also in the physical types of stars in the disk and the Galactic halo. However, only in the work of W. Baade, published in 1944, the concept of two types of stellar population appeared.

Using red-sensitive plates and the low brightness of the night sky associated with wartime blackout, which prevented the lights of Los Angeles from illuminating the sky above Mount Wilson Observatory, Baade took a series of long exposures of the central part of the Andromeda galaxy and was able to resolve it to the stars . Hubble did not succeed, and he even considered it possible that M31 is composed of gas closer to the center. What were these stars? Of course, red giants. However, in open clusters of our Galaxy, they are so weak that if they were the same stars, then in M31 they would be inaccessible for observations. Baade suggested that these are giants, but only of a different type - such as those observed in globular clusters (they are 3 magnitudes brighter). And then everything immediately fell into place. Not only globular clusters, but also field stars typical of them are concentrated towards the center of spiral galaxies. Baade called them the type II population, and the stars of the galactic disk and open clusters the type I population.

Soon it was found that the two types of stellar populations differ not only in kinematics and distribution in space (which was studied in detail in the works of P. P. Parenago and B. V. Kukarkin). The content of heavy elements in objects of population II turned out to be hundreds of times less than that of population I. Creation by the end of the 50s. theory of stellar evolution made it possible to estimate the age of stars. For population II, it is about 10–15 billion years, while for the vast majority of disk objects, the age does not exceed 8 billion years and can be arbitrarily small. In other words, only in the disk are signs of star formation occurring before our eyes in gas and dust clouds, which show the highest concentration towards the plane of the Galaxy.

The abundance of elements heavier than helium in all population I stars is "normal" (close to solar) precisely because they were formed from gas already enriched in these elements during supernova explosions. This enrichment proceeded very rapidly during the first billion years of the life of the Galaxy. The formation of stars and clusters of Population II was a short and violent episode, at the end of which the formation of Population I stars began and continues to this day.

Most edge-on spiral galaxies clearly show a flat disk-like system of blue (young) stars and gas and dust clouds perpendicular to the galaxy's rotation axis, and a spheroidal system of globular clusters concentrating towards the center of the galaxy. Elliptical galaxies are composed almost exclusively of population II objects, while irregular galaxies are dominated by population I.

The nature of the spiral arms of galaxies has long been a mystery. J. Jeans wrote in 1929 that as long as the spiral arms remain unexplained, theories of the structure of galaxies cannot be trusted. He assumed that the arms were swirling with matter ejected from the nuclei of galaxies from other spatial dimensions. More recently, H. Arp defended a close point of view. However, there is no movement of matter along the arm; there is a slowdown in the motion of stars and gas around the center of the galaxy when they enter the arms. This suggests that the regular arms, symmetrical about the center of the galaxy, stretching for tens of kiloparsecs, are spiral waves of increased density of gas and stars that have arisen due to the spiral perturbation of the gravitational field of the galaxy. The reason for it is considered to be the presence of a satellite, as in M51, or the deviations of their central parts from axial symmetry observed in all spiral galaxies with such arms - they have an oval shape.

cosmological problem

Thus, by the middle of the century, the unshakable and now foundation of our ideas about the nature of stars, about the structure of galaxies and their systems, was laid. In 1952, it seemed that the last problem that prevented the general recognition of their correctness was resolved. The rate of expansion of the Universe found by Hubble in 1929 meant that about two billion years ago all matter was at a point and had an infinitely high density.

This also followed from cosmological constructions based on Einstein's general theory of relativity, but the age of the Universe turned out to be unacceptably small, about two billion years - less than the age of the Earth, known from geological data. The reciprocal of the Hubble constant gives the "age of the universe" - the time elapsed since the beginning of its expansion. It is determined by distances to galaxies, which are still based on the luminosities of Cepheids and their apparent magnitudes in nearby galaxies. In 1952, W. Baade, as a result of studies of the Andromeda galaxy on the 5th reflector, on which regular observations began in 1949, came to the conclusion that Cepheids are brighter by about one and a half magnitudes than Hubble thought. Another mistake came to light. Hubble determined the distances of distant galaxies by measuring the brightness of their brightest stars, but many of them turned out to be compact star clusters, the luminosity of which is much greater than that of individual stars. As a result, instead of 500 km / s / Mpc, Hubble's name constant began to be 50-100, and the age of the Universe - about 15-20 billion years. By this time, it was already clear that the age of the oldest population II objects, globular star clusters, was about 10-15 billion years. There were no more contradictions in the picture of the evolution of stars, galaxies and the Universe.

It reached its notable culmination in 1965 with the discovery of microwave background radiation, a relic of the original hot state of the universe. It arose at the moment of separation of matter from radiation, when its temperature was about 4000 degrees, but now, due to the expansion of the Universe, the temperature of the cosmic microwave background radiation is 2.7 K. The cosmological model of the initially hot expanding Universe, confirmed by this discovery, explained why even in the oldest stars Population II has a high content of helium (25-30%) - it was formed mainly in the dostellar gas at an early stage of expansion. At a later stage, the initial density fluctuations developed into protoclusters of galaxies, on the problem of the origin of which Ya. B. Zel'dovich and his school successfully worked. The discovery of the CMB confirmed Friedman's cosmological model and made unnecessary the model of the quasi-stationary Universe by F. Hoyle and G. Bondy, according to which the density of the expanding but eternal Universe always remains constant due to the appearance of new matter.

It seemed that the main problems of astronomy were solved - the initial moments of the expansion of the Universe were already a purely physical problem, the solution of which required the development of the theory of quantum gravity. All the difficulties seem to have been "swept under this rug."

True, there remained a cloud of doubt, the germ of which arose as early as 1933. Now it has grown into a gigantic problem of unobservable, dark matter, common to both physics and astronomy.

In 1933, F. Zwicky discovered that the spread (dispersion) of the velocities of galaxies in the Coma of Veronica cluster is about 1000 km/s. Assuming that this cluster is gravitationally bound, this implies a high mass-to-luminosity ratio for these galaxies, an order of magnitude greater than would be expected based on their stellar composition.

A similar result was then obtained for the cluster of galaxies in Virgo. Zwicky could not find an explanation for this oddity, and the problem was ignored until 1958, when V. A. Ambartsumyan suggested that the high speeds of galaxies in clusters are due to the fact that they decay like stellar associations. For some time this assumption was successful, but it soon became clear that it led to even greater difficulties.

Most elliptical galaxies, whose stars are about 15 billion years old, are located in clusters, however, estimates of the mass of galaxies and their speed in clusters led to the conclusion that the age of the clusters themselves is no more than a billion years - much less than the age of population II stars. Together with the assumption about the formation of stars from superdense matter, about the special role of the nuclei of galaxies that give rise to the surrounding galaxy, these ideas were called the "Byurakan concept"; several Soviet philosophers persistently opposed it to the views of most astronomers. In fact, they argued that the origin of stars and galaxies is still unknown.

However, already from the end of the 1930s, signs began to appear that the unobservable matter was also present in individual galaxies, and not only in the clusters themselves. This primarily followed from the fact that the disks of galaxies retained high rotation speeds at very large distances from the center, where the stars were no longer visible. In 1974, J. Ostryker and J. Peebles and, independently of them, J. Einasto and his colleagues, analyzing the dependences of the rotation rates of galaxies on the distance to their centers and the density of matter in their disks, came to the conclusion that galaxies have extensive crowns of dark , unobservable matter, which may contain about 90% of the mass of the galaxy. The masses of galaxies should be increased by an order of magnitude, and their clusters become gravitationally bound, which also followed from the velocities of hot gas, discovered in the same years when studying clusters of galaxies in the X-ray range.

Since then, the problem of hidden mass has remained unresolved, its carriers are unknown, although almost everyone is sure that this is not ordinary baryonic matter. One cannot, perhaps, say that this problem is in the center of attention of astronomers - the presence of invisible matter is manifested only in the dynamics of galaxies, by its gravitational influence, and in most studies it can be ignored; however, this problem is now becoming the main concern of theoretical physics. There is a growing understanding that telescopes, and not accelerators, will play a decisive role at the forefront of physics not only of the macrocosm, but also of the microcosm, as L. A. Artsimovich prophetically wrote about this back in 1972. In fact, this time has already come.

According to recent estimates, the mass of baryonic matter in the universe is only 4%, of which 3% is hot gas, and 1% is stars and cold gas. Dark matter can make up about 30% of the total mass of the Universe, it is possible that its carriers are still unknown elementary particles. The remaining 66% may be accounted for by "latent energy" or "quintessence", which is considered responsible for the accelerated expansion of the Universe, revealed in recent years by observations of distant la-type supernovae, the luminosity of which can be considered everywhere the same.

This problem is part of the general cosmological problem, which is still far from being solved. We note that at the new stage, which began in the 1980s, cosmology generally removes the problem of the beginning of the world.

Most cosmologists now agree with the assumption that there was a much faster, what is said to be inflationary, expansion of our universe prior to the present expansion. In line with the work on the creation of a unified physical theory, inflationary cosmology appeared, according to which the primary and eternal essence is the so-called. a false physical vacuum in which expanding bubbles of space-time, new universes, with very different parameters and different physical laws are spontaneously born, and one of them is our Universe.

The work on unification of electromagnetically weak and strong (controlling particles in the nuclei of atoms) interactions is successfully progressing, the possibilities of subsequent inclusion in a unified theory of gravitation are also being considered. According to the American physicist R. Feynman, the day will come when we will know everything, and life will become boring. Perhaps, but this day will come only in the infinitely distant future ...

Pessimists like to recall the famous dialogue between an angel and the Almighty:

Lord, they discovered a new elementary particle, how will we react?

Let's add one more nonlinear term to the unified physical field equation!

However, let us hope, together with Einstein, that the Lord, although sophisticated, is not malicious...

New objects of the Universe

A series of discoveries of new astronomical objects followed in the 1960s, made possible by increasing observations outside the optical range of the electromagnetic spectrum. Radio astronomy rose to its feet back in the 1950s, when studies at a wavelength of neutral atomic hydrogen of 21 cm made it possible to detect the concentration of gas clouds in the disk and especially in the spiral arms of our Galaxy. Galaxies were discovered that radiate especially strongly in the radio range, and in 1960 a star-shaped object was found - a powerful radio source. By 1963, there were four of them, and in March of this year, M. Schmidt guessed that the mysterious sequence of emission lines in the spectrum of one of them, 3C 273, is nothing more than a Balmer series of hydrogen lines, but with a redshift of 0.158. The star-shaped object was farther than distant galaxies!

Such objects are called quasars. Their luminosity is much greater than that of ordinary galaxies, and the angular dimensions are much smaller, but all attempts to explain the redshift otherwise than by a large distance have been unsuccessful. The debate continued for ten years, but more and more evidence was accumulating that quasars are distant galaxies with an unusually bright nucleus and powerful radio emission. As early as 1963, IS Shklovsky noted the similarity between their spectra and the spectra of the nuclei of Seyfert galaxies. True, X. Arp still defends the opinion that quasars are objects ejected from the nuclei of galaxies, and their redshift is a property of a newborn in the nuclei of matter ...

The new physics was not needed for the pulsars discovered in 1968 either. Strictly periodic radio pulses repeated every fraction of a second looked so unusual that the British radio astronomers who discovered them classified their discovery for half a year, suspecting that the signals were given by intelligent inhabitants of space. But very soon it became clear that they arise due to the rapid rotation of stars with a strong magnetic field, radio-emitting in a narrow cone. The rotation periods pointed to the monstrous density of pulsars, and this meant that the neutron stars predicted back in the 1930s, the cinders of supernovae, had finally been discovered. It can be said that the discovery of pulsars was almost predicted. In particular, N. S. Kardashev wrote that the object remaining after a supernova explosion should, by virtue of conservation laws, have fast rotation and a strong magnetic field; only collimated radio emission was not predicted.

In the same 1960s, the discovery of X-ray sources began. Most of them turned out to be neutron stars that are part of binary systems. This sort of end product of stellar evolution has been confidently discovered. But stars with masses greater than about three solar masses must end their lives as black holes, collapsing uncontrollably beyond their gravitational radius. The first objects suspicious of black holes were found in the same years. These were the invisible components of eclipsing binary systems, the masses of which exceeded three solar ones. Now there are about a dozen such objects.

Evidence for the presence of black holes in the centers of a number of galaxies is more definite, here we are talking about objects with masses of millions of solar masses. The concentration of a gigantic mass in an insignificant volume has recently been proved for the center of our Galaxy by direct measurements of the motions of stars. Confident signs of the presence of black holes have now been found in the centers of about fifty galaxies. This poses problems no less serious than the existence of matter, seen only by its gravitational influence. The theory of black holes, in any case, their inner region, does not yet exist, and this opens up wide scope for the most daring assumptions. Black holes may turn out to be windows to other universes, to other space-time dimensions...

Neutron stars and black holes, one way or another, are involved in the phenomenon known as a burst of gamma rays. These flares, discovered in 1967, remained mysterious for 30 years - an unbroken record in modern astronomy. For a long 6 years, gamma-ray flashes were the deep secret of the Los Alamos National Observatory (where they were detected using a satellite system designed to detect nuclear explosions), although it was soon established that the flashes come from space.

Finally, the well-known physicist F. Dyson, who visited Los Alamos, told his colleagues that even the Soviets could not launch rockets with hydrogen bombs into space almost every day - they had to publish a report on the phenomenon.

The short duration of the phenomenon (from fractions to hundreds of seconds) indicated that very compact objects, such as neutron stars, are the source of gamma rays. The complete isotropy of the location in the sky (the absence of concentration either to the plane, or to the center of the Galaxy, or to nearby galaxies) left only two possibilities - they are either very close to us, no farther than the nearest stars, or very far away - and then these are very rare phenomena. monstrous energy in distant galaxies.

The problem plagued astronomers longer than any other in the second half of the 20th century. Unlike quasars or pulsars, Gamma-ray bursts were not detected in any other range of the spectrum, and the reason for this was the short duration of the phenomenon and the absence of any precise coordinates. Only on February 28, 1997, the Italo-Dutch satellite Beppo-SAX registered the gamma-ray burst GRB 970228, at the site of which a fading X-ray source was discovered. This made it possible to determine the exact coordinates by which a faint galaxy was found at the site of the gamma-ray burst. Then, an optical afterglow was discovered near the burst GRB 970508 - and again a faint galaxy was found in its place, the redshift of the lines in the spectrum of which (z=0.835) turned out to be truly gigantic.

Now, similar afterglows in the optical range have already been observed in two dozen gamma-ray bursts, half of them have redshifts measured. With one exception, they are in the range from 0.5 to 4.5, which means monstrously gigantic flare energies, up to 10 53 -10 54 erg, like hundreds and thousands of supernovae that flared up at the same time. There is a growing suspicion that gamma-ray flares are highly focused relativistic jets, which significantly reduces the estimates of the power of flares, but increases the estimates of their frequency in each galaxy.

Gamma-ray bursts are recorded almost every day, and together with their distances, this means that in each galaxy they flare up about once every several million years - in contrast to supernovae, whose flash frequency is once a century. Afterglow images of galaxies seem to show that gamma-ray bursts occur near star-forming regions, and so many astronomers are inclined to assume that they are associated with the collapse of a very massive, rapidly rotating star.

According to another hypothesis, the phenomenon of a gamma-ray burst occurs when the components of a close binary, consisting of neutron stars or black holes, merge, which occurs due to the approach of the components of the system during the emission of gravitational waves. According to the author, in this case, the observed attraction of gamma-ray bursts to star-forming regions can be explained by the fact that they themselves are capable of initiating star formation, and close systems of compact objects arise when stars approach in dense massive clusters, and therefore gamma-ray bursts occur near such clusters .

The problem of gamma-ray bursts remains the most urgent in modern astrophysics. This is where cosmology, the evolution of stars and galaxies, and high-energy physics intersect. Moreover, the influence of gamma-ray flashes on the evolution of life on Earth is not ruled out. Such an outbreak, even at a distance of the order of a kiloparsec, can kill all life on the hemisphere of the Earth facing it (but not under water). It is possible that while such outbreaks were too frequent, terrestrial life could not have evolved far enough.

Summing up

Summing up the results of astronomy of the 20th century, it is necessary to agree with the opinion of I. S. Shklovsky, expressed by him more than 20 years ago. This age was to astronomy what the Age of Discovery was to geography. It might be better to use an archaic term and speak in this context about cosmography, about the description of the Universe.

The universe is inhabited by giant star systems - galaxies, one of which is our system of the Milky Way, and it is expanding. This conclusion, irrefutably proven by 1929, remains the most important outcome of the 20th century to this day.

Cosmography completed in the 20th century, America cannot be rediscovered. However, the understanding of the Universe, as we have already said, will never become exhaustively complete. The problems of the initial stage of its evolution and the nature of the unobservable matter are far from being solved, and being posed by astronomy, they are now the greatest challenge for theoretical physics. Astronomers observe only 5% of the mass of the universe, but the data they obtained was enough to prove the presence of the remaining 95%!

The problem of singularity, the superdense initial stage of the expansion of the Universe, repeatedly arises both during the gravitational collapse of massive stars and in the cores of galaxies, where the presence of black holes has been unconditionally proven. The quantum theory of gravity is still the science of the future, and without it this problem will not be solved.

The activity of galactic nuclei can be associated with the accretion of matter onto supermassive black holes. Narrow jets up to a megaparsec long are knocked out in opposite directions of a number of galaxies, ending in giant gas bubbles. Along these jets, matter is ejected at sublight speeds. Such jets of various scales are observed both in quasars and in binary systems, and apparently everywhere where black holes are involved - and, by the way, in very young stars.

It is possible that similar phenomena are also observed in gamma-ray bursts. The theory of relativistic jets is still in the development stage. This is the area where the accumulation of observational data is especially necessary.

The second most important achievement of astronomy of the 20th century, after the discovery of galaxies and the expansion of the Universe, seems to us to be the construction of a theory of stars, their structure, energy sources and evolution. The combined efforts of observational astronomy and physical theory have led to a result that future ages will only refine in detail. The transformation of main sequence stars into red giants, thermonuclear fusion reactions as a source of energy for stars - these conclusions of the theory rest on the unshakable foundation of many mutually consistent observational and experimental facts. The explanation of the abundance of chemical elements in the Universe is also the most important and indisputable achievement obtained at the intersection of cosmology and the theory of stars.

It can perhaps be said that there were no conceptual achievements of this magnitude in the 19th century. His most important results were more of a methodical nature - high-precision determinations of the position of stars, which led to the determination of the parallaxes of a few stars and the mass determination of their proper motions, and the discovery of spectral analysis, which immediately made it possible to begin determining the radial velocities of stars. It should be noted, however, that only the determination of the distances of stars and the study of their spectra proved in the 19th century the assumption made many centuries ago that our Sun is one of the stars.

In our century, the greatest achievement of methodology is, of course, the transformation of astronomy into all-wave. Already operating neutrino telescopes and emerging gravitational wave receivers mean going beyond the electromagnetic spectrum.

The possibilities of optical astronomy will expand sharply in the coming years, and not only due to the commissioning of a whole armada of large ground-based and space telescopes. There are extensive programs of observations of gravitational lensing of light, which serves as a kind of natural supertelescope; Fantastic perspectives open up ultra-precise astrometric measurements from space. Going into space will make it possible to sharply increase the resolution of radio interferometric methods.

It is impossible not to say about the genuine revolution in optical astronomy that occurred in connection with the massive use, since the 80s, of solid-state radiation receivers - charge-coupled devices (CCD arrays). They register up to 90% of the light falling on them, and the result is immediately given in digital form, convenient for processing. The age of astronomical photography lasted a little longer than a century and is in fact a thing of the past.

Man and the Universe

A feature of astronomy is the unimaginable number of diverse objects with which we have to deal. A proton is indistinguishable from another proton, but each galaxy has its own face. Without the development of electronic means of storing, processing and transmitting information, astronomers would now be helpless. Catalogs, databases and electronic versions of journals posted on the Internet and usually open to the public are not just an invaluable help, in a number of areas work without their use is no longer possible. Equally important is the system of electronic preprints, which instantly makes the results of the work available, as well as a search engine that allows you to find any article and data about any object. The fantasy dream of a world library has been realized for five years already.

We emphasize once again that the spacewalk and the transformation of astronomy into an all-wave astronomy did not bring revolutionary changes in the proper astronomical picture of the world. As I. S. Shklovsky noted, the most important result of astronautics was that direct studies of distant planets confirmed the results of remote astronomical observations, strengthening our faith that our telescopes and theories correctly describe the world - up to well-defined limits, such as the initial singularity and black holes. Here the unknown really awaits us, but the new cosmophysics will include our knowledge of ordinary stars and galaxies as a special case.

This, in our opinion, is a sign of true science - its true results always obey the N. Bohr correspondence principle - the old knowledge is not canceled, but turns out to be the limiting case of the new. From this point of view, there are no revolutions in science. Thus, Ptolemy's planetary theory was an element of pra-science, and not the first approximation to the truth, and the activities of Copernicus, Galileo and Newton marked not a revolution in astronomy, but the birth of modern science. As V. Heisenberg emphasized, the ability to predict a phenomenon does not yet mean its understanding, which was demonstrated by the Ptolemy's system of the world. And true science begins with understanding, which becomes more and more complete with time.

The scientific revolution of the early 20th century, associated with the advent of the theory of relativity and quantum mechanics, meant a revolution not in science, but in the psychology of researchers, and was in essence a new triumph of the human mind. It turned out that we are able to operate with objects and phenomena for which we have neither model representations nor corresponding concepts. The theories, initially developed as purely mathematical formulations, formed a picture that was mutually consistent and confirmed by numerous experiments and observations; it is remarkable that mathematical constructions (like matrix calculus) were used, which were created a hundred years ago and seemed absolutely abstract.

Since the 1980s, ideas have been developed about the multiplicity of universes with very different physical laws in each of them, about their spontaneous birth from the eternal fluctuating physical vacuum. These ideas are closely connected with the work on the creation of a unified theory of physical interactions. We have entered the stage of a new ideological revolution. The question of the origin of our Universe, of what was before its birth is removed - but at the cost of abandoning the uniqueness of the laws of physics!

The amazing "adjustment" of all the parameters of our world to the possibility of our existence in it, the need for an explanation of which is indicated by the anthropic principle (wouldn't it be better to talk about a paradox!), In this case, it is not surprising, the number of diverse universes, according to some estimates, is 10 50, and one of these, our universe could have come into being with a combination of parameters that would allow our very existence, or even necessarily lead to it.

The multiplicity of universes spontaneously emerging from the physical vacuum follows from the new "inflationary" cosmology developed by AD Linde and others. The description of the evolution of our Universe, based on the Einstein-Friedmann cosmology, is not denied, only the area of ​​its applicability is limited in accordance with the correspondence principle.

The fundamental breakthrough in the development of cosmology was, to a certain extent, stimulated by the recognition of the fact that the existence of stars, planets and ourselves is possible only in a narrow range of macro and micro parameters of the physical world. Our conformity to our world has been known for a long time, but for many and many it seemed a completely trivial circumstance, not worthy of reflection; the depth of the problem and its heuristic value were not noticed. Meanwhile, the most economical solution to the anthropic paradox is precisely the assumption of a plurality of universes, and we have the right to draw a logical conclusion that Man is able to cognize the Universe that gave birth to him.

It is possible that a similar situation is observed now - no less profound and potentially fruitful is the problem of the silence of the Universe. The problem of the existence of extraterrestrial intelligence can find a solution on the paths of further development of cosmology, as A. D. Linde writes about this and V. A. Lefevre wrote even earlier. Such serious scientists as F. Hoyle, I. S. Shklovsky, N. S. Kardashev, on whose account brilliantly confirmed ideas, have paid and continue to pay much attention to this problem, but for many specialists it remains science fiction, which should not be dealt with by a serious scientist. Meanwhile, this is the greatest mystery of the universe, because at the same rate of development as our technological civilization, the entire Galaxy must be mastered in a few million years. Our uniqueness or the inevitability of closing each civilization in its cocoon must be explained.

It is possible, however, that the kinds of activity or signaling that we expect to encounter, based on our knowledge and technological experience, are only taking place at a brief stage of development that other civilizations have gone through before us or will go through after us by thousands - or billions - of years. Many phenomena and objects observed by astronomers can be associated with the activity of space subjects far ahead of us, while the probability of finding a civilization close enough to us at a short-term - about 100 years - stage of technological development close to ours is negligible. This requires the coincidence in time of short stages of development, which began with a spread of billions of years. And only a civilization that is at a stage of development close to ours, we are able to identify as such.

Abstract on the topic: "The structure and evolution of the universe"

1. The structure of the universe
2. Models of the universe
3. Our Galaxy
4. Other Galaxies
5. Yesterday of the Metagalaxy
6. Metagalaxy
7. The history of the development of views on the structure of the Universe
8. The evolution of the universe
9. Models of the structure and development of the universe
10. Theories on the basis of which modern ideas about the evolution of the universe are created
11. age of the universe
12. Universe and life
13. living conditions
14. Belt of Life
15. Mysterious Mars
16. Exploring the universe

World, Earth, Space, Universe…

For thousands of years, inquisitive humanity has turned its eyes to the world around it, sought to comprehend it, to break out of the microcosm into the macrocosm.

The majestic picture of the heavenly dome, dotted with myriads of stars, from time immemorial excited the mind and imagination of scientists, poets, everyone living on Earth and enchanted admiring the solemn and wonderful picture, in the words of Lermontov.

What is the Earth, Moon, Sun, stars? Where is the beginning and where is the end of the Universe, how long does it exist, what does it consist of and where are the boundaries of its knowledge?

In my abstract, I outlined everything that is known today to science about the structure and evolution of the Universe.

The study of the Universe, even only part of it known to us, is a daunting task. To obtain the information that modern scientists have, it took the work of many generations.

The universe is infinite in time and space. Each particle of the universe has its beginning and end, both in time and space, but the entire universe is infinite and eternal as it is eternally self-propelled matter.

The universe is everything that exists. From the smallest dust particles and atoms to huge accumulations of stellar worlds and stellar systems. Therefore, it will not be a mistake to say that any science in one way or another studies the Universe, more precisely, in one way or another its aspects. Chemistry studies the world of molecules, physics - the world of atoms and elementary particles, biology - the phenomena of living nature. But there is a scientific discipline whose object of study is the universe itself, or "the universe as a whole." This is a special branch of astronomy, the so-called cosmology. Cosmology is the doctrine of the Universe as a whole, which includes the theory of the entire area covered by astronomical observations as part of the Universe, by the way, the concepts of the Universe as a whole and the “observed” (visible) Universe should not be confused. In the second case, we are talking only about that limited area of ​​space that is accessible to modern methods of scientific research. With the development of cybernetics in various fields of scientific research, modeling techniques have become very popular. The essence of this method lies in the fact that instead of one or another real object, its model is studied, which more or less exactly repeats the original or its most important and essential features. The model is not necessarily a real copy of the object. The construction of approximate models of various phenomena helps us to understand the world around us more and more deeply. So, for example, for a long time, astronomers have been studying a homogeneous and isotropic (imaginary) Universe, in which all physical phenomena proceed in the same way and all laws remain unchanged for any area and in any direction. Models were also studied in which a third condition was added to these two conditions - the immutability of the picture of the world. This means that in whatever era we contemplate the world, it should always look the same in general terms. These largely conditional and schematic models helped to illuminate some important aspects of the world around us. But! No matter how complex this or that theoretical model is, no matter how diverse facts it takes into account, any model is not the phenomenon itself, but only a more or less exact copy of it, so to speak, an image of the real world. Therefore, all results obtained using models of the Universe must be checked by comparison with reality. It is impossible to identify the phenomenon itself with the model. It is impossible, without careful verification, to attribute to nature those properties that the model has. None of the models can claim to be an exact "cast" of the Universe. This indicates the need for in-depth development of models of the inhomogeneous and nonisotron Universe.

The stars in the universe are grouped into giant star systems called galaxies. Star system. In which, as an ordinary star, our Sun is located, is called the Galaxy.

The number of stars in the galaxy is about 1012 (trillion). The Milky Way, a bright silvery band of stars, encircles the entire sky, making up the bulk of our Galaxy. The Milky Way is brightest in the constellation Sagittarius, where the most powerful clouds of stars are found. It is least bright in the opposite part of the sky. From this it is not difficult to conclude that the solar system is not located in the center of the Galaxy, which is visible from us in the direction of the constellation Sagittarius. The farther from the plane of the Milky Way, the fewer faint stars there are and the less far the star system stretches in these directions. In general, our Galaxy occupies a space resembling a lens or lentil when viewed from the side. The dimensions of the Galaxy were outlined by the arrangement of stars that are visible at great distances. These are Cephids and hot giants. The diameter of the Galaxy is approximately equal to 3000 pc (Parsec (pc) - the distance at which the semi-major axis of the Earth's orbit, perpendicular to the line of sight, is visible at an angle of 1. 1 Parsec \u003d 3.26 light years \u003d 206265 AU \u003d 3 * 1013 km.) or 100,000 light years (a light year is the distance traveled by light during the year), but it does not have a clear boundary, because the stellar density is gradually fading away.

In the center of the galaxy there is a core with a diameter of 1000-2000 pc - a giant dense cluster of stars. It is located at a distance of almost 10,000 pc (30,000 light years) from us in the direction of the constellation Sagittarius, but is almost completely hidden by a dense curtain of clouds, which prevents visual and photographic ordinary observations of this most interesting object of the Galaxy. The core contains many red giants and short-period Cefids.

Upper main sequence stars, and especially supergiants and classical Cephids, make up the younger population. It is located further from the center and forms a relatively thin layer or disk. Among the stars of this disk is dusty matter and clouds of gas. Subdwarfs and giants form a spherical system around the nucleus and disk of the Galaxy.

The mass of our galaxy is now estimated in various ways, equal to 2 * 1011 solar masses (the mass of the Sun is 2 * 1030 kg.), And 1/1000 of it is contained in interstellar gas and dust. The mass of the Galaxy in Andromeda is almost the same, while the mass of the Galaxy in Triangulum is estimated to be 20 times less. Our galaxy is 100,000 light years across. Through painstaking work, the Moscow astronomer V.V. Kukarin in 1944 found indications of the spiral structure of the galaxy, and it turned out that we live between two spiral branches, poor in stars.

In some places in the sky through a telescope, and in some places even with the naked eye, one can distinguish close groups of stars connected by mutual gravity, or star clusters.

There are two types of star clusters: open (fig.) and globular (fig.).

Open clusters usually consist of tens or hundreds of main sequence stars and supergiants with a weak concentration towards the center.

Globular clusters usually consist of tens or hundreds of main sequence stars and red giants. Sometimes they contain short period Cepheids. Open clusters are several parsecs in size. An example of their cluster Glada and Pleiades in the constellation Taurus. The size of globular clusters with a strong concentration of stars towards the center is a dozen parsecs. More than 100 globular and hundreds of open clusters are known, but there should be tens of thousands in the Galaxy of the latter.

In addition to stars, the Galaxy also includes scattered matter, extremely scattered matter, consisting of interstellar gas and dust. It forms nebulae. Nebulae are diffuse (ragged shape (fig.)) and planetary (fig.). They are bright because they are illuminated by nearby stars. Examples: the gas and dust nebula in the constellation Orion and the dark dusty Horsehead Nebula.

The distance to the nebula in the constellation Orion is 500 pc, the diameter of the central part of the nebula is 6 pc, and the mass is approximately 100 times that of the Sun.

There is nothing unique and unique in the Universe in the sense that there is no such body, such a phenomenon in it, the basic and general properties of which would not be repeated in another body, by other phenomena.

The appearance of galaxies is extremely diverse, and some of them are very picturesque. Edwin Powell Hubble (1889-1953), an eminent American astronomer-observer, chose the simplest method of classifying galaxies by their appearance, and it must be said that although reasonable assumptions were subsequently made by other eminent researchers on the classification, the original system derived by Hubble, according to still remains the basis for the classification of galaxies.

Hubble proposed to divide all galaxies into 3 types:

Elliptical - denoted by E (elliptical);

Spiral (Spiral);

Irregular - denoted (irregular).

Elliptical galaxies (Fig.) Outwardly inexpressive. They look like smooth ellipses or circles with a gradual circular decrease in brightness from the center to the periphery. They do not have any additional parts, because elliptical galaxies consist of the second type of stellar population. They are built from red and yellow giant stars, red and yellow dwarfs, and some white stars of not very high brightness. There are no blue-white supergiants and giants, the groups of which can be observed in the form of bright clumps that give structure to the system, there is no dusty matter, which, in those galaxies where it is present, creates dark stripes that shade the shape of the star system.

Externally, elliptical galaxies differ from each other mainly in one feature - greater or lesser compression (NGG and 636, NGC 4406, NGC 3115, etc.)

With somewhat monotonous elliptical galaxies, spiral galaxies (Fig.) Contrast, which may even be the most picturesque objects in the Universe. In elliptical galaxies, the appearance indicates static, stationarity. Spiral galaxies, on the contrary, are an example of shape dynamics. Their beautiful branches, emerging from the central core and, as it were, losing their outlines outside the galaxy, indicate a powerful rapid movement. The variety of shapes and patterns of branches is also striking. As a rule, a galaxy has two spiral branches, originating in opposite points of the core, developing in a similar symmetrical manner and losing in opposite regions of the periphery, the galaxy. However, examples of more than two spiral arms in a galaxy are known. In other cases, there are two spirals, but they are unequal - one is much more developed than the second. Examples of spiral galaxies: M31, NGC 3898, NGC 1302, NGC 6384, NGC 1232, etc.

The types of galaxies I have listed so far have been characterized by symmetry of form and a certain pattern. But there are a large number of irregularly shaped galaxies (Fig.). Without any pattern of structural structure. Hubble gave them a designation from the English word irregular - incorrect.

The irregular shape of the galaxy may be due to the fact that it did not have time to take the correct shape due to the low density of matter in it or because of its young age. There is another possibility: the galaxy may become irregular due to shape distortion as a result of interaction with another galaxy. Apparently, both of these cases occur among irregular galaxies, and this may be related to the division of irregular galaxies into 2 subtypes.

Subtype II is characterized by a relatively high surface, brightness, and irregular structure complexity (NGM 25744, NGC 5204). The French astronomer Vakuler found signs of a spiral structure in some galaxies of this subtype, such as the Magellanic Clouds.

Irregular galaxies of another subtype, designated III, are distinguished by a very low surface and brightness. This feature distinguishes them from the environment of galaxies of all other types. At the same time, it prevents the detection of these galaxies, as a result of which it was possible to identify only a few subtype III galaxies located relatively close (a galaxy in the constellation Leo.).

Only 3 galaxies can be seen with the naked eye, the Large Magellanic Cloud, the Small Magellanic Cloud and the Andromeda Nebula. The tables show data on the ten brightest galaxies in the sky. (LMC, MMO - Large Magellanic Cloud and Small Magellanic Cloud.).

A non-rotating star system, after a certain period of time, should take the form of a ball. This conclusion follows from theoretical studies. It is confirmed by the example of globular clusters, which rotate and have a spherical shape.

If the star system is flattened, then this means that it rotates. Therefore, elliptical galaxies must also rotate, with the exception of those that are spherical and do not have compression. Rotation occurs around an axis that is perpendicular to the main plane of symmetry. The galaxy is compressed along its axis of rotation. The rotation of galaxies was first discovered in 1914 by the American astronomer Slifer.

Of particular interest are galaxies with a sharply increased luminosity. They are called radio galaxies. The most prominent Cygnus galaxy. This is a faint binary galaxy with components extremely closely spaced to each other, which are the most powerful discrete source. Objects like the Cygnus galaxy are certainly very rare in the metagalaxy, but Cygnus is not the only object of its kind in the Universe. They must be at a huge distance from each other (more than 200 Mps).

The flux of radio emission passing from them, due to the large distance, is weaker than from the Cygnus source.

Several bright galaxies included in the NGC catalog are also classified as radio galaxies, because their radio emission is similarly strong, although it is much inferior in energy to light. Of these galaxies, NGC 1273, NGC 5128, NGC 4782, and NGC 6186 are binaries. Single NGC 2623 and NGC 4486.

When British and Australian astronomers, using the interference method in 1963, determined with great accuracy the positions of a significant number of discrete sources of radio emission, they simultaneously determined other angular dimensions of a certain number of radio sources. The diameters of most of them were calculated in minutes or tens of seconds of arc, but for 5 sources, namely 3S48, 3S147, 3S196, 3S273 and 3S286, the dimensions turned out to be less than an arc second.

But the flux of their radio emission was not inferior to the fluxes of radio emission of other firms of discrete sources, exceeding them in terms of radiation area by tens of thousands of times. These star-like sources of radio emission were called quadras. Now more than 1000 of them have been discovered. The brilliance of the quadra does not remain constant. Quadra masses reach a million solar masses. The source of the energy of quadras is still not clear. There are suggestions that quadras are exclusively active nuclei of very distant galaxies.

Theoretical modeling is also important for elucidating the past and future of the observable universe. In 1922 A.A. Friedman began to develop an original theoretical model of the universe. He suggested that the average density is not constant, but changes over time. Friedman came to the conclusion that any sufficiently large part of the Universe, uniformly filled with matter, cannot be in a state of equilibrium: it must either expand or contract. Back in 1917, V.M. Slider discovered a "redshift" of spectral lines in the spectra of distant galaxies. A similar shift is observed when the light source moves away from the observer. In 1929, E. Hubble explained this phenomenon by the mutual recession of these stellar systems. The phenomenon of "redshift" is observed in the spectra of almost all galaxies, except for the nearest (several). And the farther the galaxy is from us, the greater the shift of lines in its spectrum, i.e. all star systems are moving away from us at tremendous speeds of hundreds, thousands, tens of thousands of kilometers per second, more distant galaxies also have greater speeds. And after the “redshift” effect was also discovered in the radio range, there was no doubt left that the observable Universe is expanding. Currently known galaxies are moving away from us at a speed of 0.46 the speed of light. And superstars and quadras - 0.85 of the speed of light. But why do they move, expand? Some kind of force is constantly acting on the galaxies. In the distant past, matter in our region of the universe was in a superdense state. Then there was an "explosion", as a result of which the expansion began. To find out the further fate of the metagalaxy, it is necessary to estimate the average density of the interstellar gas. If it is higher than 10 protons per 1 m3, then the total gravitational field of the metagalaxy is large enough to gradually stop the expansion. And it is displaced by compression.

Two opinions arose about the state of the Metagalaxy before the start of the expansion. According to one of them, the initial substance of the metagalaxy consisted of a "cold" mixture of protons, i.e. nuclei of hydrogen atoms, electrons and neutrons. According to the second, the temperature was very high, and the radiation density even exceeded the density of matter. But after the discovery in 1965 of relic radiation by A. Titsnas and R. Wilson, preference was given to the second theory. After that, an attempt was made to present the course of events at the first stages of the expansion of the Metagalaxy: 1s after the beginning of the expansion of the superdense initial plasma, the density of matter decreased to 500 kg/cm3, and t=1013 Co. Over the next 100s, the density dropped to 50 g/cm2 and the temperature dropped. Protons and neutrons united => helium nuclei. At t=4000o, this went on for several hundred thousand years. Then, after the formation of hydrogen atoms, the gradual formation of hot hydrogen clouds began, from which galaxies and stars were formed. However, in the process of expansion, clumps of superdense to stellar matter could be preserved, and in the process of their decay, stars and galaxies were formed. It is possible that both mechanisms were at work. The concept of Metagalaxy is not quite clear. It was formed on the basis of an analogy with the stars. Observations show that galaxies, like stars, grouped into open and globular clusters, also unite into groups and clusters of different numbers. The entire part of the Universe covered by modern methods of astronomical observations is called the Metagalaxy (or our Universe). In the Metagalaxy, the space between the galaxies is filled with extremely rarefied intergalactic gas, penetrated by cosmic rays, it contains magnetic and gravitational fields, and possibly invisible masses of substances.

From the most distant metagalactic objects, light travels to us for many millions of years. But still there is no reason to assert that the metagalaxy is the whole universe. Perhaps there are others, yet unknown to us metagalaxies.

In 1929, Hubble discovered a remarkable pattern that was called "Hubble's law" or "the law of redshift": the lines of galaxies are shifted to the red end, and the shift is greater, the farther away the galaxy is.

Explaining redshifts by the Doppler effect. Scientists have come to the conclusion that the distance between our own and other galaxies is continuously increasing. Although, of course, galaxies do not scatter in all directions from our galaxy, which does not occupy any special position in the metagalaxy, but there is a mutual removal of all galaxies. Consequently, the Metagalaxy is not stationary.

The discovery of the expansion of the metagalaxy indicates that in the past the metagalaxy was not the same as it is now and will be different in the future, i.e. the metagalaxy is evolving.

The receding velocities of galaxies are determined from the redshift. In many galaxies they are very large, commensurate with the speed of light. The highest speeds (more than 250,000 km/s) are possessed by some quadras, which are considered the most distant objects of the Metagalaxy from us.

We live in an expanding Metagalaxy; the expansion of the metagalaxy manifests itself only at the level of clusters and superclusters of galaxies. A metagalaxy has one feature: there is no center from which galaxies scatter. It was possible to calculate the time interval from the beginning of the expansion of the metagalaxy.

The expansion interval is 20-13 billion years. The expansion of the metagalaxy is the most grandiose of the currently known natural phenomena. This discovery produced a fundamental change in the views of philosophers and scientists. After all, some philosophers put an equal sign between the metagalaxy and the universe, and tried to prove that the expansion of the metagalaxy confirms the religious idea of ​​the divinity of the origin of the universe. But the Universe is aware of natural processes, in all probability these are explosions. There is an assumption that the expansion of the metagalaxy also began with a resembling phenomenon. A colossal explosion of matter with enormous temperature and density.

Calculations performed by astrophysicists indicate that after the expansion began, the substance of the metagalaxy had a high temperature and consisted of elementary particles (nucleons) and their antiparticles. With the expansion, not only the temperature and density of the substance changed, but also the composition of the particles included in it, i.e. many particles and antiparticles were manipulated, generating electromagnetic quanta, the radiation of which in our modern metagalaxy turned out to be more than the atoms that make up stars, planets, diffuse matter.

This theory is called the “hot universe” theory, so that superdense matter turns into a substance with a density close to that of water. A few hours later, the density almost equaled the density of our air, and now, after billions of years, the estimate of the average density of matter in the metagalaxy leads to a value of the order of 10-28 kg/m3.

But all this data was obtained only with the help of unique sophisticated equipment that allows expanding the boundaries of the universe. Until now, mankind has been improving it, more and more ingenious devices have been invented, but even at the dawn of civilization, when the inquisitive human mind turned to sky-high heights, great philosophers thought of their idea of ​​the Universe as something infinite. The ancient Greek philosopher Anaximander (6th century BC) introduced the idea of ​​a certain unified infinity that did not have any habitual observations, qualities, the fundamental principle of everything - apeiron.

The elements were thought at first as semi-material, semi-divine, spiritualized substances. The idea of ​​a purely material basis of all that exists in the ancient Greek basis reached its peak in the teachings of the atomists Leucippus and Democritus (V-IV centuries BC) about the Universe, consisting of qualityless atoms and emptiness.

Ancient Greek philosophers owned a number of brilliant conjectures about the structure of the universe. Anaxander expressed the idea of ​​the isolation of the Earth, in space. Eilalai was the first to describe the Pythagorean system of the world, where the Earth, like the Sun, revolved around a kind of “giant fire”. The sphericity of the Earth was claimed by another Pythagorean Parmenides (VI-V centuries BC) Heraclides of Pontus (V-IV centuries BC) also claimed its rotation around its axis and conveyed to the Greeks an even more ancient idea of ​​the Egyptians that the sun itself can serve as the center of rotation of some planets (Venus, Mercury).

The French philosopher and scientist, physicist, mathematician, physiologist Rene Descartes (1596-1650) created a theory about the evolutionary vortex model of the Universe based on heliocentralism. In his model, he considered celestial bodies and their systems in their development. For the XVII century. his idea was extraordinarily bold. According to Descartes, all celestial bodies were formed as a result of vortex movements that occurred in the homogeneous at the beginning, world matter. Absolutely identical material particles, being in continuous motion and interaction, changed their shape and size, which led to the rich diversity of nature that we observe.

The solar system, according to Descartes, is one of such whirlwinds of world matter. The planets do not have their own movement - they move, carried away by the world whirlwind. Descartes also introduced a new idea to explain gravity: he believed that in the vortices that arise around the planets, particles press on each other and thereby cause the phenomenon of gravity (for example, on Earth). Thus, Descartes was the first to consider heaviness not as an innate, but as a derivative quality of bodies.

The great German scientist, philosopher Immanuel Kant (1724-1804) created the first universal concept of the evolving Universe, enriching the picture of its even structure and representing the Universe as infinite in a special sense. He substantiated the possibilities and significant probability of the emergence of such a Universe solely under the action of mechanical forces of attraction and repulsion and tried to find out the further fate of this Universe at all its scale levels - from the planetary system to the world of the nebula.

Einstein made a radical scientific revolution by introducing his theory of relativity. It was relatively simple, like all ingenious things. He did not have to first discover new phenomena, establish quantitative patterns. He just gave a fundamentally new explanation.

Einstein revealed a deeper meaning of established dependencies, effects already connected into a certain physical and mathematical system (in the form of Poincaré's postulates). Replacing in this case the theory of the absoluteness of space and time of the ideas of their relativity "Poincaré", which is now no longer associated with the idea of ​​the absolute in space, the absolute frame of reference. Such a revolution eliminated the main contradiction that created the crisis situation in the theoretical understanding of the action. Moreover, the way was opened for further penetration into the properties and laws of the surrounding world, so deeply that Einstein himself did not immediately realize the degree of revolutionaryness of his idea.

In an article dated 06/30/1905, which laid the foundations of the special theory of relativity, Einstein, generalizing the principles of Galileo's relativity, proclaimed the equality of all inertial frames of reference not only in mechanical, but also in electromagnetic phenomena.

Einstein's special or particular theory of relativity was the result of a generalization of Galileo's mechanics and Maxwell Lorentz's electrodynamics. It describes the laws of all physical processes at speeds close to the speed of light.

For the first time, fundamentally new cosmological consequences of the general theory of relativity were revealed by the outstanding Soviet mathematician and theoretical physicist Alexander Fridman (1888-1925). Speaking in 1922-24. he criticized Einstein's findings that the universe is finite and shaped like a four-dimensional cylinder. Einstein made his conclusion based on the assumption of the stationarity of the Universe, but Friedman showed the groundlessness of his original postulate.

Friedman gave two models of the universe. Soon these models found surprisingly accurate confirmation in direct observations of the movements of distant galaxies in the effect of "redshift" in their spectra.

By this, Friedman proved that the matter in the Universe cannot be at rest. With his conclusions, Friedman theoretically contributed to the discovery of the need for the global evolution of the Universe.

There are several theories of evolution: The theory of the pulsating Universe states that our world came into existence as a result of a gigantic explosion. But the expansion of the universe will not continue forever, because. gravity will stop it.

According to this theory, our Universe has been expanding for 18 billion years since the explosion. In the future, the expansion will completely slow down and stop, and then it will begin to contract until the substance contracts again and a new explosion occurs.

Stationary explosion theory: according to it, the Universe has no beginning, no end. She always arrives in the same state. A new whirlpool is constantly being formed to replace matter with receding galaxies. For this reason, the Universe is always the same, but if the Universe, the beginning of which was laid by the explosion, expands to infinity, then it will gradually cool down and completely die out.

But so far, none of these theories has been proven, because. at the moment there is no exact evidence of at least one of them.

The discovery of diverse evolutionary processes in various systems and bodies that make up the Universe made it possible to study the patterns of cosmic evolution on the basis of observational data and theoretical calculations.

One of the most important tasks is to determine the age of space objects and their systems. Since in most cases it is difficult to decide what should be considered and understood as the “moment of birth” of a body or system, when setting the age of the characteristics, two estimates are meant:

The time during which the system is already in the observable state.

The total lifetime of this system from the moment of its appearance. Obviously, the second characteristic can be obtained only on the basis of theoretical calculations.

Usually the first of these quantities is called age, and the second - lifetime.

The fact of the mutual removal of the galaxies that make up the metagalaxy indicates that some time ago it was in a qualitatively different state and was denser.

The most probable value of the Hubble constant (the coefficient of proportionality relating the removal rates of extragalactic objects and the distance to them, which is 60 km/sec - megaparsec), leads to the value of the expansion time of the metagalaxy to the current state of 17 billion years.

From all the above and those proofs that were not included in my abstract due to their cumbersomeness and mathematical and physical complexity, we can confidently conclude: the Universe is evolving, violent processes have occurred in the past, are occurring now and will occur in the future.

The problem of life in space is one of the most fascinating and popular problems in the science of the Universe, which has long been of concern not only to scientists, but to all people. Even J. Bruno and M. Lomonosov suggested a plurality of inhabited worlds. The study of life in the universe is one of the most difficult tasks that mankind has ever faced. This is a phenomenon that humanity has experienced. We are talking about a phenomenon with which people in essence have not yet had to face directly. All data about life outside the Earth are purely hypothetical. Therefore, the scientific discipline “exobnalogy” is engaged in deep research of biological patterns and cosmic phenomena.

So the study of extraterrestrial, cosmic life forms would help a person, firstly, to understand the essence of life, i.e. what distinguishes all living organisms from inorganic nature, secondly, to find out the ways of the emergence and development of life and, thirdly, to determine the place and role of man in the universe. Now it can be considered fairly firmly established that life on our own planet arose in the distant past from inanimate, inorganic matter under certain external conditions. Of these conditions, three main ones can be distinguished. First of all, it is the presence of water, which is part of the living substance, the living cell. Secondly, the presence of a gaseous atmosphere necessary for the gas exchange of the organism with the external environment. True, one can imagine any other environment. The third condition is the presence of a suitable temperature range on the surface of a given celestial body. Also, external energy is needed for the synthesis of a molecule of living matter from the original organic molecules, the energy of cosmic rays, or ultraviolet radiation, or the energy of electronic discharges. External energy is also needed for the subsequent life of living organisms. The conditions necessary for the emergence of life, at one time developed naturally, during the evolution of the Earth, there are no such grounds for believing that they cannot be formed in the process of development of other celestial bodies. Many hypotheses have been put forward in this regard. Academician A.I. Oparin believes that life should have appeared when the surface of our planet was a continuous ocean. As a result of the combination of C2CH 2 and N2, the simplest organic compounds arose. Then, in the waters of the primary ocean, the molecules of these compounds united and strengthened, forming a complex solution of organic substances. At the third stage, complexes of molecules separated from this environment, which gave rise to primary living organisms. Oro and Fesenkov noticed that comets and meteorites can be a kind of carriers, if not of life itself, then at least of its initial elements. However, if we do not enter into an area close to fantasy, and remain on the basis of only fairly firmly established scientific facts, then when looking for living organisms on other celestial bodies, we must first of all proceed from what we know about earthly life.

As for our solar system, its various planets move at different distances from the Sun and receive unequal amounts of solar energy. Concerning. In the solar system, a peculiar thermal belt of life can be distinguished, which includes the Earth, Mars and Venus, as well as the Moon at first glance, the physical conditions on the Moon do not completely exclude the possibility of the existence of living organisms: there is no atmospheric shell on the Moon, no water, the temperature varies from –1500С to +1300С, the surface of the Moon is constantly bombarded by meteorites, cosmic rays, ultraviolet radiation of the Sun, etc. And while one can guess whether there are highly organized life forms in nature that can develop under such conditions. An exception can only be microbes and bacteria, which, as you know, are able to adapt to the most unfavorable conditions: heating and deep cooling; ultraviolet and radioactive radiation: intense radiation, etc. At present, a number of scientists believe that there are organic substances on the Moon. They could have formed here at the dawn of the existence of the Moon or be brought by meteorites. There are suggestions that a whole thick layer of complex organic compounds is located above the layer of lunar soil (10 m). Similarly, Venus, if the temperature on its surface is high, then despite the presence of an atmosphere, the conditions for life on this planet are of little use. Mars is much more promising in this respect.

Nowadays, astronomers are primarily interested in the question of the physical conditions on Mars. Living organisms living on a celestial body continuously interact with the environment. So, for example, on the surface of Mars there are dark spots of the "sea". They change their color according to the seasons. This phenomenon is reminiscent of seasonal changes in the color of green vegetation. The atmosphere of Mars is much thinner than Earth's. Free oxygen has not yet been found in the air envelope of the seas. In this regard, it can be assumed that Martian plants release oxygen not into the atmosphere but into the soil, or retain it in their roots, or plants are so small that they release a small amount of oxygen so that it can be detected from Earth. Water. It is known that there are no open water surfaces on Mars. But researchers believe that there is water on the surface of the planet: this was evidenced by the decrease in the spring-summer periods of white spots, polar caps. Under those physical conditions that exist on Mars, water in a liquid state cannot exist there. It should immediately evaporate and freeze, settling in the form of a thin layer of frost. The soil is a layer of ice or permafrost. Liquid water can exist at considerable depths. It has been noted that Martian plants lack chlorophyll and are replaced by carotenoids, a red pigment. Of particular interest are the Martian channels. The American astronomer Lovell believes that this is an irrigation system built by intelligent inhabitants of Mars. They look like dark irregular veins and chains of individual spots. A number of hypotheses have been put forward over the decades:

vegetation zones

Formations of a tectonic nature

Cracks in the permafrost

The results of meteorite impacts.

But it is too early to draw conclusions on the basis of hypotheses alone. But it is undeniable that the very curious conclusions that graph theory leads to: a thorough statistical analysis of various formations such as networks found in terrestrial conditions led scientists to the conclusion that artificial networks differ from natural ones at nodes. Of artificial origin, nodes with four converging lines predominate, and the network of channels of Mars has predominantly nodes of the 4th order, the network also has a significant percentage of these nodes; make figuring out the nature of the mysterious Martian transformations even more fascinating.

Treatises and articles of scientists whose names were mentioned in the abstract:

1. G. Descartes. "Treatise on the System of the World" 1633, "Discourse on Method" 1637, "Geometry", "Dioptics", "Meteors" 1638, "Principles of Philosophy" 1644, "Treatise on Light" 1664.
2. I. Kant. "The General Natural History and Theory of the Heavens" 1755
3. A. Friedman. "On the curvature of the space of the world" 1922, "On the possibility of a world with a constant negative curvature of space" 1924

Literature used in writing the abstract:

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10. V.V. Kazyutinsky "Universe Astronomy, Philosophy", M., "Knowledge" 1972

Modern science has significantly expanded the possibilities of cognition of the Universe, and the technical equipment has also increased significantly, which makes it possible to comprehensively study outer space.

The study of meteorites. Meteorites are an excellent material for studying the universe, since their composition can be used to judge its substance. The study of meteorites has shown that they are composed of the same elements as the Earth. This fact serves as a vivid confirmation of the unity of matter in the Universe.

The study of meteorites pushes the boundaries of our knowledge of the internal structure of the Earth, since they are fragments of different parts of cosmic bodies. Meteorites carry very valuable "information about the history of the origin of the planets of the solar system. According to nuclear chronology, their age, equal to approximately 4.5-4.6 billion years, almost coincides with the age of the Earth.

The study of outer space with the help of telescopes and radio telescopes. Powerful telescopes make it possible to photograph space

cosmic bodies and individual sections of the sky, in combination with various instruments, make it possible to determine the luminosity, temperature, relief of cosmic bodies, etc. Using telescopes, they study the spectra of luminaries, their change, and, by the nature of the spectrum, draw conclusions about the movement of cosmic bodies, their chemical composition substances, the type of reactions occurring on them. The use of radio telescopes has significantly expanded the possibilities of knowing the Universe.

The study of outer space with the help of artificial satellites, space stations and ships. The beginning of this type of space exploration was laid on October 4, 1957, when in the Soviet Union, for the first time in the world, an artificial Earth satellite was launched into near-Earth orbit. On April 12, 1961, Yu. Gagarin, a citizen of the Soviet Union, was the first to make a space flight around the Earth on a manned Vostok spacecraft. A few years later, Soviet cosmonaut A. Leonov first went into outer space.

In the Soviet Union, for the first time in world practice, the Luna-16 automatic spacecraft was successfully flown to another celestial body and returned to Earth. For a long time, the Lunokhod-1 automatic apparatus worked on the Moon, which made it possible to establish the general type of rocks that make up the surface of the lunar sea, to study the nature of the distribution of small craters and stones. As a result of the successful operation of the Luna-20 automatic station, the problem of taking soil from the hard-to-reach continental region of the Moon was solved.

Valuable information about the atmosphere of Venus has been obtained with the help of Soviet automatic stations. For the first time, a soft landing of a spacecraft on the surface of Mars was carried out, and the Mars-2 and Mars-3 stations became artificial satellites of Mars. During the flight in orbits, they transmitted a large amount of information about the physical features of the planet and the outer space surrounding it.

Particularly valuable information was provided by the lunar soil brought to Earth by Soviet automatic stations and American cosmonauts. The material of the Moon's surface bears the imprints of both the primary processes that led to the formation of parent rocks and subsequent influences, many of which are absent on the Earth's surface. However, due to its features, the Moon was in many respects "preserved" for a long geological time, so it can be expected that the Moon will reflect processes similar to the processes that took place in the early stages of the formation of the Earth.

A new page in the study of the Cosmos and the Earth was the unparalleled research of Soviet cosmonauts on space stations of the Salyut type. Photographing various regions of our country with the help of multi-focus devices made it possible

make adjustments to tectonic zoning, identify promising areas for prospecting for minerals, study with the help of photographs the nature of grain ripening, the preservation of forest plantations, etc. Our astronauts carried out research on growing crystals characterized by unique properties; conducted experiments on the soldering of materials that are not amenable to this process under terrestrial conditions; conducted observations of the vital activity of organisms in conditions of weightlessness; carried out astronomical observations with the help of special apparatuses, etc. Docking with Salyut-6 of transport ships, refueling of its engines and timely correction of the orbit made it possible to create a prototype space station for space exploration in orbit.

The hypothesis of the formation of the planets of the solar system

For a long time, the problem of the formation of the Earth and the solar system as a whole has attracted the attention of prominent scientists. I. Kant, P. Laplace, D. Gine, Soviet scientists - academicians O. Yu. Schmidt, V. G. Fesenkov, A. P. Vinogradov and others were engaged in its solution. However, no final solution to this problem has yet been obtained. In the light of modern scientific achievements, the hypothesis of the formation of the solar system is reduced to the following.

Within our Galaxy, near its equatorial plane, there was an inhomogeneous gas-dust disk consisting of slowly rotating gas-dust clouds. The composition of the clouds consisted mainly of hydrogen atoms, due to the increase in the density of which their formation could occur. The density of hydrogen atoms in such a cloud reaches 1000 atoms/cm 3 , which is 10,000 times higher than their density in the normal interstellar space of the Galaxy. Along with hydrogen, the composition of the cloud could include carbon, nitrogen, oxygen, micron dust particles. Inside the clouds there is a chaotic, turbulent movement of matter.

With an increase in size and density, the cloud begins to contract under the influence of gravitational forces. Gravitational contraction of almost the entire mass of the initially cold cloud (-220 °C) leads to its compaction to the state of the Protosun. In the center of the latter, thermonuclear reactions become possible, accompanied by the release of a huge amount of energy and matter in the form of an explosion. According to acad. A.P. Vinogradov, a hot plasma cloud (protoplanetary cloud) was formed around the Proto-Sun from matter ejected about 5.5 billion years ago by explosions. At the first stage of planet formation, the protoplanetary cloud cooled, gases were lost into outer space, and part of its matter condensed into solid particles. The most refractory chemical elements condensed first: 10

tungsten, titanium, molybdenum, platinum, etc., as well as their oxides. Thus, the hot gaseous substance again turned into a cold gas-dust cloud. The protoplanetary cloud lost energy over time as a result of the collision of “dust particles”. Its flattening took place, the motion of matter in it was ordered, became close to circular. Gradually around the young Sun, as a result of the condensation of dusty matter, a wide annular disk formed, which disintegrated into separate cold clusters of matter - swarms of solid gas particles. They interacted with each other, mixed, collided, merged, being exposed to cosmic radiation. Separate phases of matter were formed, mainly silicates, an iron-nickel metal alloy, sulfides, etc. As a result of the agglomeration of these phases, stone and other meteorites arose. The same process of contraction of the cold matter of the protoplanetary cloud led to the formation of the protoplanets of the solar system about 5 billion years ago. Having formed as a geological body, the Proto-Earth has not yet become a planet. It was a cold accumulation of cosmic matter, but it was from that time that its pre-geological evolution began.

Under the influence of such factors as impacts of meteorite bodies, gravitational compaction and heat release by radioactive elements, the heating of the upper parts of the Proto-Earth began. Iron melted first, then silicates. This led to the formation of a belt of liquid iron here. Due to the differentiation of matter, the lighter silicate material should have floated to the top, while the heavy metal should have concentrated in the center of the planet. Viscous, predominantly silicate masses formed the primary mantle of the Earth, and metallic masses formed its core. So, apparently, about 4.6 billion years ago, the planet Earth was formed.

The inner planets, located closer to the Sun, were formed by the condensation of a high-temperature iron-rich fraction. The farther from the Sun, the less the content of metallic material in the planets. Thus, 2/3 of Mercury consists of metallic iron, and Mars - of "/ 4. In the asteroidal ring, mainly chondrite asteroids were formed, in which the content of the low-temperature fraction increased. And, finally, the main component of the outer planets are gases, almost entirely composed of from undivided solar matter.

INTRODUCTION

The study of the Universe, even only part of it known to us, is a daunting task. To obtain the information that modern scientists have, it took the work of many generations. We know the structure of the universe in a vast volume of space, which light takes billions of years to cross. But the inquisitive thought of man strives to penetrate further. What lies beyond the observable region of the world? Is the universe infinite in volume? And its expansion - why did it start and will it always continue in the future? And what is the origin of the "hidden" mass? And finally, how did intelligent life originate in the universe?

Does it exist anywhere else besides our planet? There are no definitive and complete answers to these questions yet.

The universe is inexhaustible. The thirst for knowledge is also tireless, forcing people to ask more and more new questions about the world and persistently seek answers to them.

Perhaps that is why I chose this topic for the essay. The unknown has always attracted the attention of man. The universe, stars and planets are a perfect example of this.

This branch is quite well covered both by the achievements of science and the works of literature. However, in some matters, opinions are different, so it is worth reflecting on some topic of interest to you and drawing your own conclusions.

FOREWORD

The stars in the universe are grouped into giant star systems called galaxies. The number of stars in the Galaxy is about 1012 (trillion). Our galaxy is called the Milky Way. It includes the Sun, 9 large planets with their 34 satellites, more than 100 thousand small planets (asteroids), about 1011 comets, as well as countless small, so-called meteoroids (diameter from 100 meters to negligible dust particles).

The Milky Way, a bright silver band of stars, encircles the entire sky, making up the bulk of our Galaxy. In general, our Galaxy occupies a space resembling a lens or lentil when viewed from the side. The dimensions of the Galaxy were outlined by the arrangement of stars that are visible at great distances. The mass of our Galaxy is now estimated in various ways, it is approximately 2 * 1011 masses of the Sun (the mass of the Sun is 2 * 1030 kg), and 1/1000 of it is contained in interstellar gas and dust. The mass of the galaxy in Andromeda is almost the same, while the mass of the galaxy in Triangulum is estimated to be 20 times less. Our galaxy is 100,000 light years across. Through painstaking work, the Moscow astronomer V.V. Kukarin in 1944 found indications of the spiral structure of the Galaxy, and it turned out that we live in a space between two spiral branches, poor in stars. In some places in the sky with a telescope, and in some places even with the naked eye, one can distinguish close groups of stars connected by mutual gravity, or star clusters.

According to the currently accepted hypothesis, the formation of the solar system began about 4.6 billion years ago with the gravitational collapse of a small part of a giant interstellar gas and dust cloud. In general terms, this process can be described as follows:

• The trigger mechanism for the gravitational collapse was a small (spontaneous) compaction of the matter of the gas and dust cloud (possible reasons for which could be both the natural dynamics of the cloud, and the passage of a shock wave from a supernova explosion through the matter of the cloud, etc.), which became the center of gravitational attraction for the surrounding matter - center of gravitational collapse. The cloud already contained not only primary hydrogen and helium, but also numerous heavy elements (metals) left over from the stars of previous generations. In addition, the collapsing cloud had some initial angular momentum.
• In the process of gravitational compression, the size of the gas and dust cloud decreased and, due to the law of conservation of angular momentum, the speed of rotation of the cloud increased. Due to the rotation, the compression rates of the clouds parallel and perpendicular to the axis of rotation differed, which led to the flattening of the cloud and the formation of a characteristic disk.
• As a consequence of compression, the density and intensity of collisions of matter particles with each other increased, as a result of which the temperature of the matter continuously increased as it was compressed. The central regions of the disk were heated most strongly.
• Upon reaching a temperature of several thousand kelvins, the central region of the disk began to glow - a protostar was formed. The cloud matter continued to fall onto the protostar, increasing the pressure and temperature at the center. The outer regions of the disk remained relatively cold. Due to hydrodynamic instabilities, separate seals began to develop in them, which became local gravitational centers for the formation of planets from the substance of the protoplanetary disk.
• When the temperature in the center of the protostar reached millions of kelvins, a thermonuclear hydrogen burning reaction began in the central region. The protostar has evolved into an ordinary main sequence star. In the outer region of the disk, large clusters formed planets revolving around the central star in approximately the same plane and in the same direction.

Subsequent evolution

After the initial formation, the solar system has evolved significantly. Many satellites of the planets were formed from gas and dust disks orbiting the planets, while other satellites were presumably captured by the planets, or were the result of collisions between the bodies of the solar system (according to one hypothesis, this is how the Moon was formed). Collisions of the bodies of the solar system have always occurred, up to the present moment, which, along with gravitational interaction, was the main driving force of the evolution of the solar system. In the course of evolution, the orbits of the planets changed significantly, up to a change in their order - planetary migration took place. It is currently assumed that planetary migration explains much of the early evolution of the solar system.

Future

In about 5 billion years, the surface of the Sun will cool down, and the Sun itself will increase many times in size (its diameter will reach the diameter of the modern orbit of the Earth), turning into a red giant. Subsequently, the outer layers of the Sun will be ejected by a powerful explosion into the surrounding space, forming a planetary nebula, in the center of which only a small stellar core will remain - a white dwarf. At this stage, nuclear reactions will stop and in the future there will be a slow steady cooling of the Sun.

In the very distant future, the gravity of nearby stars will gradually destroy the planetary system. Some of the planets will be destroyed, others will be thrown into interstellar space. Ultimately, after trillions of years, the cooled Sun will most likely lose all of its planets, and alone will continue its orbit around the center of our Milky Way galaxy among many other stars.

Admiring the stars on a clear autumn night, we immediately notice a wide foggy strip passing through the whole sky - Milky Way is the name of our galaxy. We involuntarily think about other worlds that inhabit the cosmos, and admire the grandeur and grandiose beauty of the universe around us. How did planets, stars, galaxies originate?

At the beginning of the world, after the Big Bang, a myriad of formed particles scattered at great speeds and gradually turned into atoms of primary matter, which formed a huge cloud, billions of times greater than the mass of the Sun. This cloud began to thicken, the first atoms of hydrogen and helium appeared in it. As in any gas, turbulent flows arose in it, generating eddies. In these whirlwinds, hydrogen clusters appeared rotating at different speeds, which became more and more dense, shrinking around their center - the axis of rotation. The rotation speed increased with decreasing volume in accordance with the law of conservation of momentum. In this case, the centrifugal force acting along the equatorial plane increases, and the cloud is flattened, turning from a spherical shape into a lenticular or disk-shaped one. This is how galaxies are born.

The first stars appeared at the spherical stage of galaxy formation. They consisted only of hydrogen and helium. A thermonuclear reaction took place in them - the combination of two protons. Having used up their supply of hydrogen, these stars exploded and became supernovae. As a result of the explosion, new elements appeared, heavier than helium. This happened everywhere, the interstellar gas was replenished with new elements, from which, as a result of thermonuclear reactions, ever heavier ones were obtained.

The Milky Way is a spiral galaxy.

This is how our galaxy, the Milky Way, was formed. If you look at it "from above" from space, it looks like a disk with a spiral structure - arms, where young stars and regions with an increased density of interstellar gas are located. In the middle of the disk is a spherical bulge - the core of the galaxy. If you look at the map of the starry sky, then the center of our galaxy will be in the constellation Sagittarius. Astronomers were able to identify the closest spiral branches of the galaxy to Earth: the branches of Orion (where the solar system is located), Perseus and Sagittarius. The nearest branch to the core is the Karina (Kiel) branch, and the existence of a distant branch, the Centaur, is assumed. These spiral branches-sleeves got their names from the constellations in which they are located on the map of the starry sky.

If we look at a spiral galaxy through a good telescope, we will see that it looks like a fiery fireworks wheel. But what determines such a structure of galaxies? It would seem that there is nothing surprising in this. The famous scientist astronomer Carl Friedrich von Weizsäcker once said that if at first Milky Way if it looked like a cow, it would still have acquired a spiral structure. Some scientists have seriously begun to develop the "Weizsäcker galactic cow", and, indeed, according to calculations, it should have turned into a galactic spiral in about a hundred million years. And our Milky Way is much older - almost a hundred times. During this time, the beautiful spiral galaxy should have been transformed in such a way that the spirals form long threads that wrap around the center. But, as it turned out, not a single known galaxy has a filamentous structure and does not stretch, although spiral branches-sleeves, consisting of stars and gas, constantly rotate around the center of the galaxy. An irresolvable contradiction? No, if we give up the idea that the interstellar matter is constantly located in one spiral arm and assume that a stream of gas and stars simply moves through these spiral arms. That is, the stars and gas move, rotating around the center, and the arms of the spiral are certain states of the structure of the galaxy, along which flows of cosmic matter and stars move. How can this be? Light a candle or gas burner. You will see flames in which a chemical combustion reaction of a substance takes place. The flame is a region of space that determines the state of the gas flow. Similarly, in spiral arms, the flow of stars and gas has a certain state, which is determined by the gravitational field.

If we imagine a huge number of stars forming a rotating disk, we will see that where the density of stars is greater, they tend to get even closer, but the centrifugal force complicates the process, and the balance in such a rotating disk is very unstable. This situation was simulated on a computer, and it turned out that as a result, spiral regions of increased density of stars are formed. Those. the stars themselves form spiral arms that do not become filamentous and do not stretch. Moreover, the stars flow through these spiral regions. Once in the sleeve, they approach, leaving - they diverge. The same thing happens with interstellar gas. Once in the spiral arm, the gas condenses, and conditions are created for the formation of new stars. Therefore, young stars form in this region. Among them are bright blue stars that cause the cosmic gas and dust to glow, ionizing them. Luminous clouds of ionized gas are created, thanks to which we can admire the beautiful spectacle of spiral galaxies.

The stars in the central part of the galaxy are mostly made up of red giants that formed almost simultaneously with the galaxy. At the very center, the presence of a supermassive black hole (Sagittarius A) is assumed, around which another black hole of average mass is possibly rotating. Their gravitational interaction is the center of gravity of the entire galaxy and controls the movement of stars.

According to the latest scientific data, the diameter milky way- about 100,000 light years (approximately 30,000 parsecs), and the average thickness of our disk is about 1000 light years. According to modern estimates, the number of stars in the galaxy ranges from 200 billion to 400 billion.

In the Universe, in addition to spiral galaxies, there are other types: elliptical, barred galaxies, dwarf, irregular, and others.
Galaxies are combined into clusters, which can include several hundred galaxies. These clusters, in turn, can combine into superclusters. Our Galaxy belongs to the Local (Local) group, which includes the constellation Andromeda. In total, there are about 40 galaxies in the Local Group, and it itself is part of the Virgo supercluster. So our vast galaxy Milky Way with billions of stars is just a small island in the boundless ocean of the universe.

The evolution of even one star cannot be traced over the lifetime of several generations of people. The life of the shortest-lived stars is estimated in millions of years. Mankind does not live that long. Therefore, the ability to trace stellar evolution from the beginning - the birth of a star - to its end lies in comparing the chemical and physical characteristics of stars at different stages of development.

The main indicator of the physical properties of a star is its luminosity and color. According to these characteristics, the stars were grouped into groups called sequences. There are several of them: the main sequence, the sequence of supergiants, bright and weak giants. There are also subgiants, subdwarfs and white dwarfs.

These funny names reflect the different stages of the state of the star, which it goes through in the process of its evolution. The two astronomers Hertzsprung and Ressel have compiled a diagram that relates the surface temperature of a star to its luminosity. The temperature of a star is determined by its color. It turned out that the hottest stars are blue, the coldest are red. When Hertzsprung and Ressel placed stars with known physical characteristics - luminosity-color (temperature) on the diagram, it turned out that they are located in groups. It turned out to be a rather funny picture, where the place of a star on it determined at what stage of evolution this star is.

Most of the stars (almost 90%) were on the main sequence. This means that the star spends the main part of its life in this place of the diagram. The diagram also shows that the smallest stars - dwarfs - are at the bottom, and the largest - supergiants - at the top.

Three paths for the development of stellar evolution

The time allotted for the life of a star is determined primarily by its mass. The mass of a star also determines what it will become when it ceases to be one. The greater the mass, the shorter the life of the star. The most massive - supergiants - live only a few million years, while most stars of medium fatness - about 15 billion years.

All stars, after the source of energy due to which they live, burn with a bright flame, begin to quietly cool down, decrease in size and shrink. They are compressed to the state of a massive compact object with a very high density: a white dwarf, a neutron star and a black hole.

Stars with low mass can withstand compression because gravity is relatively low. They are compressed into a small white dwarf and remain in this stable state until their mass increases to a critical value.

If the star's mass is greater than the critical value, then it continues to shrink until the electrons "stick together" with protons, forming a neutron substance. Thus, a small neutron ball with a radius of several kilometers is obtained - a neutron star.

If the star's mass is so huge that gravity continues to compress even neutron matter, then a gravitational collapse occurs, after which a black hole forms in place of the giant star.

What is a white dwarf? Something that didn't become a neutron star or a black hole.

This is what medium and small stars turn into at the end of their evolution. Thermonuclear reactions have already ended, however, they remain very hot dense balls of gas. The stars slowly cool down, glowing with bright white light. The fate of a white dwarf awaits our Sun, as its mass is below critical. The critical mass is 1.4 solar masses. This value is called the Chandrasekhar limit. Chandrasekhar is an Indian astronomer who calculated this value.

The state of a neutron star ends the evolution of such stars, the masses of which exceed the solar mass by several times. A neutron star is the result of a supernova explosion. With a mass 1.5-2 times greater than the sun, it has a radius of 10-20 km. A neutron star rotates rapidly and periodically emits streams of elementary particles and electromagnetic radiation. Such stars are called pulsars. The state of a neutron star is also determined by its mass. The Oppenheimer-Volkov limit is a value that determines the maximum possible mass of a neutron star. To be stable in this state, it is necessary that its mass does not exceed three solar masses.

If the mass of a neutron star exceeds this value, then the monstrous force of gravity compresses it so in the arms of collapse that it becomes a black hole.

A black hole is what happens when the gravitational contraction of massive bodies is unlimited, i.e. when a star shrinks to such an extent that it becomes completely invisible. Not a single ray of light can leave its surface. And here there is also an indicator that determines the state of a space object as a black hole. This is the gravitational radius, or Schwarzschild radius. It is also called the event horizon, since it is impossible to describe or see what happens inside a sphere with such a radius at the site of a collapsed star.

Maybe inside this sphere there are beautiful bright worlds or an exit to another Universe. But for a simple observer, this is just a gap in space, which twists around itself the light coming from other stars and absorbs cosmic matter. By the way other space objects behave next to it, we can make assumptions about its properties.

For example, it can be assumed that the most massive black holes are located in the place where the brightest glow of star clusters is observed. By attracting stellar matter and other space objects to themselves, black holes make them glow, surrounding themselves with a bright luminous halo - a quasar. Darkness cannot exist without light, and light exists because of darkness. This proves the evolution of stars.

BLACK HOLES.

Black holes amaze the imagination: they stop time, captivate light, form holes in space itself. Even light becomes a prisoner of the gravitational sarcophagus.

There are about a billion black holes in our galaxy alone. Nowadays, astrophysicists use black holes to explain mysterious phenomena quite often. The physics and astrophysics of black holes have received wide recognition from the scientific community.

It is believed that the existence of such space objects as black holes, was first substantiated by A. Einstein. The general theory of relativity predicted the possibility of unlimited gravitational compression of massive cosmic bodies to a state of collapse, after which these bodies can only be detected by their gravity.
In fact, people started talking about black holes long before the advent of the theory of relativity.

And it was in the time of I. Newton, who, as everyone knows, discovered the law of universal gravitation. According to this law, everything is subject to gravity, even a beam of light is deflected in the field of attraction of massive bodies. Actually, the history of black holes in the scientific world begins with the realization of this fact.

It began with the work of the English priest and geologist John Michell, who in his article came to the conclusion about the possibility of the existence of black holes based on reasoning about the behavior of a cannonball depending on its speed. As a result, he came to the conclusion that there could be a very small but very heavy star, and that "the speed of its escape" was greater than the speed of light; then the light from its surface will not reach the observer, and it will be possible to detect it only by the force of its attraction. At first glance, the course of reasoning does not shine with iron logic, but perhaps this is just such a case when they try to clothe intuitive insight in the fabric of logic, which this time was quite full of holes due to lack of scientific knowledge.

The famous Frenchman Pierre Laplace wrote in 1795 in his book Exposition of the System of the World:

“A luminous star with a density equal to the density of the Earth and a diameter 250 times greater than the diameter of the Sun does not allow a single light beam to reach us because of its gravity; therefore it is possible that the brightest celestial bodies in the universe turn out to be invisible for this reason. Laplace did not prove his brilliant statement in any way, he simply knew it. However, the scientific world does not take seriously such fundamental things without calculations, formulas and other evidence. Laplace had to work hard, and a few years later he gave his prediction a scientific justification, made on the same classical Newton's law of universal gravitation. These proofs also cannot be considered rigorous, since we already know that Newton's laws do not quite correspond to reality on the scale of the universe and quantum mechanics. But, in those days, it was Newton's theory that was the most advanced, science could not offer anything better, and therefore scientists had to look for the truth where there was light - under the lantern of the classical laws of mechanics.

Black holes in the mysterious light of mysticism

Those interested in occult knowledge and practicing magicians and wizards know that if an object exists, then information about it exists, regardless of whether its presence in nature has been discovered or not yet. Example: the electromagnetic field took place before scientists wrote about it.

Occult scientists differ from material scientists in that they are not in a hurry to make their knowledge public in the hope of receiving the Nobel Prize and recognition of a grateful humanity. They, for a reason incomprehensible to mere mortals, carefully encrypt what they managed to draw from the cosmic storehouse of information and transmit it secretly to specially selected initiates. However, one way or another, this knowledge seeps into the world in the form of incomprehensible symbols, legends, fairy tales, etc.

The famous occult writer Gustav Meyrink has a short story "The Black Ball", an excerpt from which is given below:

“A velvet-black round body hung motionless in space.

In general, this thing was not at all like a ball, more like a gaping hole. It was nothing but a real hole.

It was absolute, mathematical nothingness!

And so it happened - immediately there was a sharp howling sound, which became louder and louder - the air of the hall began to be sucked into the ball. Scraps of paper, gloves, ladies' veils - everything rushed along with the stream.

And when one of the officers of the civil militia poked a saber into a black hole, the blade disappeared into it, as if dissolved.
.......
The crowd, which did not understand what was happening, and only heard a terrible, ever-growing rumble, rushed out in fear of an inexplicable phenomenon.
Only two Indians remained.

The entire universe, which Brahma created, supported by Vishnu and destroyed by Shiva, will gradually fall into this ball, - solemnly announced Rajendralalamitra. - That's what trouble we brought, brother, going to the West!

Well, what's in that! muttered the Gosain. “Someday we are all destined to go to that world, which is the denial of being.”

What is the exact description of the properties black hole according to modern ideas! And this story was written even before the advent of A. Einstein's theory of relativity ...

I would also like to add that in the story a black ball appears as a material embodiment of the thought-form of one of those present ... Isn't this the hint of an occultist about the causes of black holes?
Modern ideas about the properties of a black hole.

What does modern physics say about the properties of black holes? It turns out that a black hole is determined by only one parameter - mass. And it is practically indestructible. For example, if it occurs to someone to shoot it with nuclear weapons in order to somehow change it or “tear it to shreds”, then its mass will simply increase by the mass of these same bombs and that’s it. The black hole will simply become more massive. But it turned out, not everything is so simple. A black hole is not just a gluttonous monster that consumes everything and everything. It can "evaporate" little by little due to mixed Hawking radiation. That is, a black hole can turn any body that has fallen into it into information and “give it away” in the form of a stream of various radiations and quarks. Such objects are discovered by astronomers, they are called pulsars. Thus, it can be concluded that black holes are characterized not only by their mass, but also by the information they contain.

How do black holes form?

Black holes are born from very large and beautiful stars - red giants, the mass of which exceeds the solar mass by more than ten times. The evolution of such stars is very fast. After a few million years, all hydrogen “burns out”, turning into helium, which, in turn, as a result of combustion, turns into carbon, carbon into other, heavier elements, etc. The rate of transformation also increases. Finally, iron atoms appear.

On this, the stellar nuclear reactor stops its work. Energy is no longer released from iron nuclei. They themselves begin to capture electrons from the surrounding gas. The central region of the star, consisting of gaseous iron, begins to decrease due to the compaction and absorption of electrons by the iron nuclei. Finally, a dense iron core forms in the center of the star. Further, it all depends on how much iron is obtained in this star. If its mass was 1.5 solar masses, then an irreversible process begins, which leads to collapse.

The fact is that iron atoms are so tightly pressed against each other that they simply flatten out. Protons and electrons combine with each other to form neutrons. When protons and electrons combine, an unimaginable amount of energy is released, which sweeps the outer part of the star. Then you can observe the explosion of a supernova, which means the end of the star. After the explosion, a neutron core remains in place of a massive giant. Further development of events inevitably leads to the formation of a black hole.

Chandrasekhar limit and Schwarzschild radius.

This is the classic way black holes form. A neutron star can come from a white dwarf - a star from the class of very dense and hot stars. The number equal to 1.4 solar masses also plays a big role here - the Chandrasekhar limit. As soon as the mass of the white dwarf reaches this value, the process of "collapse" of the star begins, described above. A white dwarf turns into a neutron star in a minute.

Any ray of light emerging from the surface of such a star is bent in space, it travels almost parallel to the surface of the star. Several times, turning around in a spiral around it, the beam can escape into outer space. Now imagine a neutron star with a mass equal to three solar and a radius of 8.85 km. In this case, not a single ray will be able to escape from the surface of the star, it will be so bent in the field of the star that it will return back. That's what they are, black holes!

The radius to which the body must be compressed so that light cannot leave it is called the Schwarzschild radius or event horizon. Do you want to become a black hole? Then you'll have to shrink to 0,000... just 21 centimetres, and no one will see you! But your mass will remain - turn on your imagination and imagine what you could do in such a state. Probably, calmly seep through the earth, to the very center ... But let's return to space.

White and gray holes .

A white hole is an object that is the opposite of a black hole. The matter of the white hole is pushed out and scattered in space. If the matter is not compressed, but expands from under the Schwarzschild sphere, then this object is a white hole. Gray holes combine the properties of black and white holes.

The term "white hole" appears at a symposium on relativistic astrophysics in 1969. The famous English scientist R. Penrose made a presentation at this symposium "Black holes and white holes". Ya. B. Zeldovich and I. D. Novikov in 1971 introduced the concept of “gray hole”.

The nature of the formation of massive black holes is now clear. Massive stars, consuming their nuclear fuel and shrinking, must necessarily reach their gravitational radius and turn into black holes. For a black hole to form in this way, the mass of the star must be at least twice the mass of the Sun. The gravitational force of a less massive body is not enough to form a black hole.

PULSARS.

Pulsars are talking black holes.

In 1967, pulsars were discovered - neutron stars that emit narrowly directed streams of elementary particles. These radiations are periodic pulses of the electromagnetic spectrum. For the first time they were recorded as radio emissions. Their clear periodicity led the astronomers who discovered these impulses to the idea that the signals are sent by "green men" - aliens, in order to enter into long-awaited contact with earthlings. Immediately everyone was classified and began to decipher the message. As a result of research, confirmed by other facts, it was concluded that these signals belong to a rotating neutron star, or black hole. Due to the periodicity of the pulses, these space objects were called pulsars.

How does the radiation visible in the X-ray spectrum escape from the embrace of a black hole? It is believed that neutrons are not so stable on the surface of a pulsar. They can even decay into protons and electrons, which, in turn, give rise to other elementary particles. In a strong magnetic field, electrons accelerate along the lines of force, and at the poles of the pulsar, where gravity is the least, they break out into outer space. This representation explains the periodicity of the sent pulses. But on the other hand, a black hole can gradually evaporate due to the emission of elementary particles. So far, no traces of evaporated black holes have been found in space.

Black holes - eaters of stellar matter

But with the help of an X-ray telescope, it was discovered how the stellar gas broke away from the star in the form of a luminous cloud and flowed into the dark region of outer space, where it became invisible, in other words, disappeared. The conclusion suggests itself.

This star, traveling through the galaxy, approached the black hole and ended up in its gravitational field. The most unstable elements of the trapped star, the surface stellar matter and the circumstellar gas, were the first to crawl towards it. The gaseous substance, warming up, approaches the black hole in a spiral, thus highlighting its location. This region is called the "accretion disk" and is very similar in appearance to a spiral galaxy.

QUASARS.

The light from quasars points to black holes.

In 1963, quasars (quasi-stellar sources) were discovered - the most powerful sources of radio emission in the Universe with a luminosity hundreds of times greater than the luminosity of galaxies and sizes ten times smaller than them. It was assumed that quasars are the nuclei of new galaxies and, therefore, the process of galaxy formation continues to this day.

The brightest discovered objects in the universe, quasars, also owe their origin to black holes. Particularly massive black holes attract nearby space objects so strongly that, approaching it in a crowd, they begin to glow like 10 galaxies combined. The quasar is notable for its variable brightness, which probably corresponds to the periodicity of the rotation of the huge neutron star around which it was formed. Although no one can say exactly what quasars are.

I would like to point out an interesting fact. When the existence of black holes was deduced from Einstein's theory of relativity, many astronomers enthusiastically searched space for confirmation of this assumption. And they found enough facts and objects confirming this theory. At present, when enough facts and observations have accumulated that indicate the presence of black holes in space, their very existence is being questioned by many astronomers. Thus, representatives of homo sapiens, like black holes, are the most mysterious objects in the universe.

CONCLUSION

After the work done, the following conclusions can be drawn:

The degree of knowledge of the universe is extremely small.

Celestial bodies are like living beings: they have their own stages of development, signs that determine the age of a particular celestial body.

The Universe is evolving, turbulent processes took place in the past, are taking place now and will take place in the future.

The significance of this topic in natural science is obvious - it determines everything. The Universe is the beginning, the continuation and the end of everything (although we can say that the Universe has no end, it just reborn from time to time). The exploration of outer space turned the worldview of man, influenced further scientific activity.

BIBLIOGRAPHY

1. Dagaev M.M., Charugin V.M. Book for reading on astronomy. - M .: Education, 1988.

2. Gorelov A.A. KSE.- M.: VLADOS, 2003.

3. Novikov I.D. Evolution of the Universe. - M.: Nauka, 1990.

Laplace Pierre. Statement of the system of the world [transl. O. Borisenko] M.: Enlightenment, 1980.

Meyrink Gustav. Ring of Saturn: a collection [transl. from Austrian I. Steblova.].-M.: ABC Classics, 2004.-832s.

Gorelov A.A. KSE: Proc. A manual for students of higher educational institutions. - M .: Humanitarian Publishing Center VLADOS, 2003. - 512 pp.: ill.